Documentation/DocBook/media/v4l/controls.xml

   1   <section id="control">
   2     <title>User Controls</title>
   3
   4     <para>Devices typically have a number of user-settable controls
   5 such as brightness, saturation and so on, which would be presented to
   6 the user on a graphical user interface. But, different devices
   7 will have different controls available, and furthermore, the range of
   8 possible values, and the default value will vary from device to
   9 device. The control ioctls provide the information and a mechanism to
  10 create a nice user interface for these controls that will work
  11 correctly with any device.</para>
  12
  13     <para>All controls are accessed using an ID value. V4L2 defines
  14 several IDs for specific purposes. Drivers can also implement their
  15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
  16 and higher values. The pre-defined control IDs have the prefix
  17 <constant>V4L2_CID_</constant>, and are listed in <xref
  18 linkend="control-id" />. The ID is used when querying the attributes of
  19 a control, and when getting or setting the current value.</para>
  20
  21     <para>Generally applications should present controls to the user
  22 without assumptions about their purpose. Each control comes with a
  23 name string the user is supposed to understand. When the purpose is
  24 non-intuitive the driver writer should provide a user manual, a user
  25 interface plug-in or a driver specific panel application. Predefined
  26 IDs were introduced to change a few controls programmatically, for
  27 example to mute a device during a channel switch.</para>
  28
  29     <para>Drivers may enumerate different controls after switching
  30 the current video input or output, tuner or modulator, or audio input
  31 or output. Different in the sense of other bounds, another default and
  32 current value, step size or other menu items. A control with a certain
  33 <emphasis>custom</emphasis> ID can also change name and
  34 type.<footnote>
  35         <para>It will be more convenient for applications if drivers
  36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
  37 that was never required.</para>
  38       </footnote> Control values are stored globally, they do not
  39 change when switching except to stay within the reported bounds. They
  40 also do not change &eg; when the device is opened or closed, when the
  41 tuner radio frequency is changed or generally never without
  42 application request. Since V4L2 specifies no event mechanism, panel
  43 applications intended to cooperate with other panel applications (be
  44 they built into a larger application, as a TV viewer) may need to
  45 regularly poll control values to update their user
  46 interface.<footnote>
  47         <para>Applications could call an ioctl to request events.
  48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
  49 shared properties the &func-select; function would indicate
  50 readability until any ioctl (querying the properties) is
  51 called.</para>
  52       </footnote></para>
  53
  54     <para>
  55       All controls use machine endianness.
  56     </para>
  57
  58     <table pgwide="1" frame="none" id="control-id">
  59       <title>Control IDs</title>
  60       <tgroup cols="3">
  61         &cs-def;
  62         <thead>
  63           <row>
  64             <entry>ID</entry>
  65             <entry>Type</entry>
  66             <entry>Description</entry>
  67           </row>
  68         </thead>
  69         <tbody valign="top">
  70           <row>
  71             <entry><constant>V4L2_CID_BASE</constant></entry>
  72             <entry></entry>
  73             <entry>First predefined ID, equal to
  74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
  75           </row>
  76           <row>
  77             <entry><constant>V4L2_CID_USER_BASE</constant></entry>
  78             <entry></entry>
  79             <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
  80           </row>
  81           <row>
  82             <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
  83             <entry>integer</entry>
  84             <entry>Picture brightness, or more precisely, the black
  85 level.</entry>
  86           </row>
  87           <row>
  88             <entry><constant>V4L2_CID_CONTRAST</constant></entry>
  89             <entry>integer</entry>
  90             <entry>Picture contrast or luma gain.</entry>
  91           </row>
  92           <row>
  93             <entry><constant>V4L2_CID_SATURATION</constant></entry>
  94             <entry>integer</entry>
  95             <entry>Picture color saturation or chroma gain.</entry>
  96           </row>
  97           <row>
  98             <entry><constant>V4L2_CID_HUE</constant></entry>
  99             <entry>integer</entry>
 100             <entry>Hue or color balance.</entry>
 101           </row>
 102           <row>
 103             <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
 104             <entry>integer</entry>
 105             <entry>Overall audio volume. Note some drivers also
 106 provide an OSS or ALSA mixer interface.</entry>
 107           </row>
 108           <row>
 109             <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
 110             <entry>integer</entry>
 111             <entry>Audio stereo balance. Minimum corresponds to all
 112 the way left, maximum to right.</entry>
 113           </row>
 114           <row>
 115             <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
 116             <entry>integer</entry>
 117             <entry>Audio bass adjustment.</entry>
 118           </row>
 119           <row>
 120             <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
 121             <entry>integer</entry>
 122             <entry>Audio treble adjustment.</entry>
 123           </row>
 124           <row>
 125             <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
 126             <entry>boolean</entry>
 127             <entry>Mute audio, &ie; set the volume to zero, however
 128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
 129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
 130 noise. Actually the entire device should be reset to a low power
 131 consumption state.</entry>
 132           </row>
 133           <row>
 134             <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
 135             <entry>boolean</entry>
 136             <entry>Loudness mode (bass boost).</entry>
 137           </row>
 138           <row>
 139             <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
 140             <entry>integer</entry>
 141             <entry>Another name for brightness (not a synonym of
 142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
 143 and should not be used in new drivers and applications.</entry>
 144           </row>
 145           <row>
 146             <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
 147             <entry>boolean</entry>
 148             <entry>Automatic white balance (cameras).</entry>
 149           </row>
 150           <row>
 151             <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
 152             <entry>button</entry>
 153             <entry>This is an action control. When set (the value is
 154 ignored), the device will do a white balance and then hold the current
 155 setting. Contrast this with the boolean
 156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
 157 activated, keeps adjusting the white balance.</entry>
 158           </row>
 159           <row>
 160             <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
 161             <entry>integer</entry>
 162             <entry>Red chroma balance.</entry>
 163           </row>
 164           <row>
 165             <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
 166             <entry>integer</entry>
 167             <entry>Blue chroma balance.</entry>
 168           </row>
 169           <row>
 170             <entry><constant>V4L2_CID_GAMMA</constant></entry>
 171             <entry>integer</entry>
 172             <entry>Gamma adjust.</entry>
 173           </row>
 174           <row>
 175             <entry><constant>V4L2_CID_WHITENESS</constant></entry>
 176             <entry>integer</entry>
 177             <entry>Whiteness for grey-scale devices. This is a synonym
 178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
 179 and should not be used in new drivers and applications.</entry>
 180           </row>
 181           <row>
 182             <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
 183             <entry>integer</entry>
 184             <entry>Exposure (cameras). [Unit?]</entry>
 185           </row>
 186           <row>
 187             <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
 188             <entry>boolean</entry>
 189             <entry>Automatic gain/exposure control.</entry>
 190           </row>
 191           <row>
 192             <entry><constant>V4L2_CID_GAIN</constant></entry>
 193             <entry>integer</entry>
 194             <entry>Gain control.</entry>
 195           </row>
 196           <row>
 197             <entry><constant>V4L2_CID_HFLIP</constant></entry>
 198             <entry>boolean</entry>
 199             <entry>Mirror the picture horizontally.</entry>
 200           </row>
 201           <row>
 202             <entry><constant>V4L2_CID_VFLIP</constant></entry>
 203             <entry>boolean</entry>
 204             <entry>Mirror the picture vertically.</entry>
 205           </row>
 206           <row id="v4l2-power-line-frequency">
 207             <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
 208             <entry>enum</entry>
 209             <entry>Enables a power line frequency filter to avoid
 210 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
 211 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
 212 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
 213 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
 214 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
 215           </row>
 216           <row>
 217             <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
 218             <entry>boolean</entry>
 219             <entry>Enables automatic hue control by the device. The
 220 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
 221 hue control is enabled is undefined, drivers should ignore such
 222 request.</entry>
 223           </row>
 224           <row>
 225             <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
 226             <entry>integer</entry>
 227             <entry>This control specifies the white balance settings
 228 as a color temperature in Kelvin. A driver should have a minimum of
 229 2800 (incandescent) to 6500 (daylight). For more information about
 230 color temperature see <ulink
 231 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
 232           </row>
 233           <row>
 234             <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
 235             <entry>integer</entry>
 236             <entry>Adjusts the sharpness filters in a camera. The
 237 minimum value disables the filters, higher values give a sharper
 238 picture.</entry>
 239           </row>
 240           <row>
 241             <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
 242             <entry>integer</entry>
 243             <entry>Adjusts the backlight compensation in a camera. The
 244 minimum value disables backlight compensation.</entry>
 245           </row>
 246           <row>
 247             <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
 248             <entry>boolean</entry>
 249             <entry>Chroma automatic gain control.</entry>
 250           </row>
 251           <row>
 252             <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
 253             <entry>integer</entry>
 254             <entry>Adjusts the Chroma gain control (for use when chroma AGC
 255             is disabled).</entry>
 256           </row>
 257           <row>
 258             <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
 259             <entry>boolean</entry>
 260             <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>
 261           </row>
 262           <row id="v4l2-colorfx">
 263             <entry><constant>V4L2_CID_COLORFX</constant></entry>
 264             <entry>enum</entry>
 265             <entry>Selects a color effect. The following values are defined:
 266             </entry>
 267           </row><row>
 268           <entry></entry>
 269           <entry></entry>
 270             <entrytbl spanname="descr" cols="2">
 271               <tbody valign="top">
 272                 <row>
 273                   <entry><constant>V4L2_COLORFX_NONE</constant>&nbsp;</entry>
 274                   <entry>Color effect is disabled.</entry>
 275                 </row>
 276                 <row>
 277                   <entry><constant>V4L2_COLORFX_ANTIQUE</constant>&nbsp;</entry>
 278                   <entry>An aging (old photo) effect.</entry>
 279                 </row>
 280                 <row>
 281                   <entry><constant>V4L2_COLORFX_ART_FREEZE</constant>&nbsp;</entry>
 282                   <entry>Frost color effect.</entry>
 283                 </row>
 284                 <row>
 285                   <entry><constant>V4L2_COLORFX_AQUA</constant>&nbsp;</entry>
 286                   <entry>Water color, cool tone.</entry>
 287                 </row>
 288                 <row>
 289                   <entry><constant>V4L2_COLORFX_BW</constant>&nbsp;</entry>
 290                   <entry>Black and white.</entry>
 291                 </row>
 292                 <row>
 293                   <entry><constant>V4L2_COLORFX_EMBOSS</constant>&nbsp;</entry>
 294                   <entry>Emboss, the highlights and shadows replace light/dark boundaries
 295                   and low contrast areas are set to a gray background.</entry>
 296                 </row>
 297                 <row>
 298                   <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant>&nbsp;</entry>
 299                   <entry>Grass green.</entry>
 300                 </row>
 301                 <row>
 302                   <entry><constant>V4L2_COLORFX_NEGATIVE</constant>&nbsp;</entry>
 303                   <entry>Negative.</entry>
 304                 </row>
 305                 <row>
 306                   <entry><constant>V4L2_COLORFX_SEPIA</constant>&nbsp;</entry>
 307                   <entry>Sepia tone.</entry>
 308                 </row>
 309                 <row>
 310                   <entry><constant>V4L2_COLORFX_SKETCH</constant>&nbsp;</entry>
 311                   <entry>Sketch.</entry>
 312                 </row>
 313                 <row>
 314                   <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant>&nbsp;</entry>
 315                   <entry>Skin whiten.</entry>
 316                 </row>
 317                 <row>
 318                   <entry><constant>V4L2_COLORFX_SKY_BLUE</constant>&nbsp;</entry>
 319                   <entry>Sky blue.</entry>
 320                 </row>
 321                 <row>
 322                   <entry><constant>V4L2_COLORFX_SOLARIZATION</constant>&nbsp;</entry>
 323                   <entry>Solarization, the image is partially reversed in tone,
 324                   only color values above or below a certain threshold are inverted.
 325                   </entry>
 326                 </row>
 327                 <row>
 328                   <entry><constant>V4L2_COLORFX_SILHOUETTE</constant>&nbsp;</entry>
 329                   <entry>Silhouette (outline).</entry>
 330                 </row>
 331                 <row>
 332                   <entry><constant>V4L2_COLORFX_VIVID</constant>&nbsp;</entry>
 333                   <entry>Vivid colors.</entry>
 334                 </row>
 335                 <row>
 336                   <entry><constant>V4L2_COLORFX_SET_CBCR</constant>&nbsp;</entry>
 337                   <entry>The Cb and Cr chroma components are replaced by fixed
 338                   coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
 339                   control.</entry>
 340                 </row>
 341               </tbody>
 342             </entrytbl>
 343           </row>
 344           <row>
 345             <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
 346             <entry>integer</entry>
 347             <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
 348             color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
 349             Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
 350           </entry>
 351           </row>
 352           <row>
 353             <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
 354             <entry>boolean</entry>
 355             <entry>Enable Automatic Brightness.</entry>
 356           </row>
 357           <row>
 358             <entry><constant>V4L2_CID_ROTATE</constant></entry>
 359             <entry>integer</entry>
 360             <entry>Rotates the image by specified angle. Common angles are 90,
 361             270 and 180. Rotating the image to 90 and 270 will reverse the height
 362             and width of the display window. It is necessary to set the new height and
 363             width of the picture using the &VIDIOC-S-FMT; ioctl according to
 364             the rotation angle selected.</entry>
 365           </row>
 366           <row>
 367             <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
 368             <entry>integer</entry>
 369             <entry>Sets the background color on the current output device.
 370             Background color needs to be specified in the RGB24 format. The
 371             supplied 32 bit value is interpreted as bits 0-7 Red color information,
 372             bits 8-15 Green color information, bits 16-23 Blue color
 373             information and bits 24-31 must be zero.</entry>
 374           </row>
 375           <row>
 376             <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
 377                 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
 378             <entry>boolean</entry>
 379             <entry>Switch on or off the illuminator 1 or 2 of the device
 380                 (usually a microscope).</entry>
 381           </row>
 382           <row>
 383             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
 384             <entry>integer</entry>
 385             <entry>This is a read-only control that can be read by the application
 386 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
 387 The value is the minimum number of CAPTURE buffers that is necessary for hardware
 388 to work.</entry>
 389           </row>
 390           <row>
 391             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
 392             <entry>integer</entry>
 393             <entry>This is a read-only control that can be read by the application
 394 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
 395 The value is the minimum number of OUTPUT buffers that is necessary for hardware
 396 to work.</entry>
 397           </row>
 398           <row id="v4l2-alpha-component">
 399             <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
 400             <entry>integer</entry>
 401             <entry>Sets the alpha color component. When a capture device (or
 402             capture queue of a mem-to-mem device) produces a frame format that
 403             includes an alpha component
 404             (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
 405             and the alpha value is not defined by the device or the mem-to-mem
 406             input data this control lets you select the alpha component value of
 407             all pixels. When an output device (or output queue of a mem-to-mem
 408             device) consumes a frame format that doesn't include an alpha
 409             component and the device supports alpha channel processing this
 410             control lets you set the alpha component value of all pixels for
 411             further processing in the device.
 412             </entry>
 413           </row>
 414           <row>
 415             <entry><constant>V4L2_CID_LASTP1</constant></entry>
 416             <entry></entry>
 417             <entry>End of the predefined control IDs (currently
 418               <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
 419           </row>
 420           <row>
 421             <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
 422             <entry></entry>
 423             <entry>ID of the first custom (driver specific) control.
 424 Applications depending on particular custom controls should check the
 425 driver name and version, see <xref linkend="querycap" />.</entry>
 426           </row>
 427         </tbody>
 428       </tgroup>
 429     </table>
 430
 431     <para>Applications can enumerate the available controls with the
 432 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
 433 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
 434 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
 435 <constant>VIDIOC_G_CTRL</constant> and
 436 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
 437 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
 438 more menu type controls.</para>
 439
 440     <example>
 441       <title>Enumerating all controls</title>
 442
 443       <programlisting>
 444 &v4l2-queryctrl; queryctrl;
 445 &v4l2-querymenu; querymenu;
 446
 447 static void
 448 enumerate_menu (void)
 449 {
 450         printf ("  Menu items:\n");
 451
 452         memset (&amp;querymenu, 0, sizeof (querymenu));
 453         querymenu.id = queryctrl.id;
 454
 455         for (querymenu.index = queryctrl.minimum;
 456              querymenu.index &lt;= queryctrl.maximum;
 457               querymenu.index++) {
 458                 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
 459                         printf ("  %s\n", querymenu.name);
 460                 }
 461         }
 462 }
 463
 464 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 465
 466 for (queryctrl.id = V4L2_CID_BASE;
 467      queryctrl.id &lt; V4L2_CID_LASTP1;
 468      queryctrl.id++) {
 469         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 470                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 471                         continue;
 472
 473                 printf ("Control %s\n", queryctrl.name);
 474
 475                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 476                         enumerate_menu ();
 477         } else {
 478                 if (errno == EINVAL)
 479                         continue;
 480
 481                 perror ("VIDIOC_QUERYCTRL");
 482                 exit (EXIT_FAILURE);
 483         }
 484 }
 485
 486 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
 487      queryctrl.id++) {
 488         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 489                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 490                         continue;
 491
 492                 printf ("Control %s\n", queryctrl.name);
 493
 494                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 495                         enumerate_menu ();
 496         } else {
 497                 if (errno == EINVAL)
 498                         break;
 499
 500                 perror ("VIDIOC_QUERYCTRL");
 501                 exit (EXIT_FAILURE);
 502         }
 503 }
 504 </programlisting>
 505     </example>
 506
 507     <example>
 508       <title>Changing controls</title>
 509
 510       <programlisting>
 511 &v4l2-queryctrl; queryctrl;
 512 &v4l2-control; control;
 513
 514 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 515 queryctrl.id = V4L2_CID_BRIGHTNESS;
 516
 517 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 518         if (errno != EINVAL) {
 519                 perror ("VIDIOC_QUERYCTRL");
 520                 exit (EXIT_FAILURE);
 521         } else {
 522                 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 523         }
 524 } else if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED) {
 525         printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 526 } else {
 527         memset (&amp;control, 0, sizeof (control));
 528         control.id = V4L2_CID_BRIGHTNESS;
 529         control.value = queryctrl.default_value;
 530
 531         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)) {
 532                 perror ("VIDIOC_S_CTRL");
 533                 exit (EXIT_FAILURE);
 534         }
 535 }
 536
 537 memset (&amp;control, 0, sizeof (control));
 538 control.id = V4L2_CID_CONTRAST;
 539
 540 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &amp;control)) {
 541         control.value += 1;
 542
 543         /* The driver may clamp the value or return ERANGE, ignored here */
 544
 545         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)
 546             &amp;&amp; errno != ERANGE) {
 547                 perror ("VIDIOC_S_CTRL");
 548                 exit (EXIT_FAILURE);
 549         }
 550 /* Ignore if V4L2_CID_CONTRAST is unsupported */
 551 } else if (errno != EINVAL) {
 552         perror ("VIDIOC_G_CTRL");
 553         exit (EXIT_FAILURE);
 554 }
 555
 556 control.id = V4L2_CID_AUDIO_MUTE;
 557 control.value = TRUE; /* silence */
 558
 559 /* Errors ignored */
 560 ioctl (fd, VIDIOC_S_CTRL, &amp;control);
 561 </programlisting>
 562     </example>
 563   </section>
 564
 565   <section id="extended-controls">
 566     <title>Extended Controls</title>
 567
 568     <section>
 569       <title>Introduction</title>
 570
 571       <para>The control mechanism as originally designed was meant
 572 to be used for user settings (brightness, saturation, etc). However,
 573 it turned out to be a very useful model for implementing more
 574 complicated driver APIs where each driver implements only a subset of
 575 a larger API.</para>
 576
 577       <para>The MPEG encoding API was the driving force behind
 578 designing and implementing this extended control mechanism: the MPEG
 579 standard is quite large and the currently supported hardware MPEG
 580 encoders each only implement a subset of this standard. Further more,
 581 many parameters relating to how the video is encoded into an MPEG
 582 stream are specific to the MPEG encoding chip since the MPEG standard
 583 only defines the format of the resulting MPEG stream, not how the
 584 video is actually encoded into that format.</para>
 585
 586       <para>Unfortunately, the original control API lacked some
 587 features needed for these new uses and so it was extended into the
 588 (not terribly originally named) extended control API.</para>
 589
 590       <para>Even though the MPEG encoding API was the first effort
 591 to use the Extended Control API, nowadays there are also other classes
 592 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
 593 The Extended Controls API as well as all Extended Controls classes are
 594 described in the following text.</para>
 595     </section>
 596
 597     <section>
 598       <title>The Extended Control API</title>
 599
 600       <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
 601 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
 602 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
 603 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
 604 since it is often required to atomically change several controls at
 605 once.</para>
 606
 607       <para>Each of the new ioctls expects a pointer to a
 608 &v4l2-ext-controls;. This structure contains a pointer to the control
 609 array, a count of the number of controls in that array and a control
 610 class. Control classes are used to group similar controls into a
 611 single class. For example, control class
 612 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
 613 (&ie; all controls that can also be set using the old
 614 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
 615 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
 616 relating to MPEG encoding, etc.</para>
 617
 618       <para>All controls in the control array must belong to the
 619 specified control class. An error is returned if this is not the
 620 case.</para>
 621
 622       <para>It is also possible to use an empty control array (count
 623 == 0) to check whether the specified control class is
 624 supported.</para>
 625
 626       <para>The control array is a &v4l2-ext-control; array. The
 627 <structname>v4l2_ext_control</structname> structure is very similar to
 628 &v4l2-control;, except for the fact that it also allows for 64-bit
 629 values and pointers to be passed.</para>
 630
 631       <para>It is important to realize that due to the flexibility of
 632 controls it is necessary to check whether the control you want to set
 633 actually is supported in the driver and what the valid range of values
 634 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
 635 check this. Also note that it is possible that some of the menu
 636 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
 637 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
 638 return an error). A good example is the list of supported MPEG audio
 639 bitrates. Some drivers only support one or two bitrates, others
 640 support a wider range.</para>
 641
 642       <para>
 643         All controls use machine endianness.
 644       </para>
 645     </section>
 646
 647     <section>
 648       <title>Enumerating Extended Controls</title>
 649
 650       <para>The recommended way to enumerate over the extended
 651 controls is by using &VIDIOC-QUERYCTRL; in combination with the
 652 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
 653
 654       <informalexample>
 655         <programlisting>
 656 &v4l2-queryctrl; qctrl;
 657
 658 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
 659 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 660         /* ... */
 661         qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 662 }
 663 </programlisting>
 664       </informalexample>
 665
 666       <para>The initial control ID is set to 0 ORed with the
 667 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
 668 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
 669 control with a higher ID than the specified one. When no such controls
 670 are found an error is returned.</para>
 671
 672       <para>If you want to get all controls within a specific control
 673 class, then you can set the initial
 674 <structfield>qctrl.id</structfield> value to the control class and add
 675 an extra check to break out of the loop when a control of another
 676 control class is found:</para>
 677
 678       <informalexample>
 679         <programlisting>
 680 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
 681 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 682         if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
 683                 break;
 684                 /* ... */
 685                 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 686         }
 687 </programlisting>
 688       </informalexample>
 689
 690       <para>The 32-bit <structfield>qctrl.id</structfield> value is
 691 subdivided into three bit ranges: the top 4 bits are reserved for
 692 flags (&eg; <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
 693 actually part of the ID. The remaining 28 bits form the control ID, of
 694 which the most significant 12 bits define the control class and the
 695 least significant 16 bits identify the control within the control
 696 class. It is guaranteed that these last 16 bits are always non-zero
 697 for controls. The range of 0x1000 and up are reserved for
 698 driver-specific controls. The macro
 699 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
 700 ID based on a control ID.</para>
 701
 702       <para>If the driver does not support extended controls, then
 703 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
 704 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
 705 that case the old method of enumerating control should be used (see
 706 1.8). But if it is supported, then it is guaranteed to enumerate over
 707 all controls, including driver-private controls.</para>
 708     </section>
 709
 710     <section>
 711       <title>Creating Control Panels</title>
 712
 713       <para>It is possible to create control panels for a graphical
 714 user interface where the user can select the various controls.
 715 Basically you will have to iterate over all controls using the method
 716 described above. Each control class starts with a control of type
 717 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
 718 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
 719 control class which can be used as the title of a tab page within a
 720 control panel.</para>
 721
 722       <para>The flags field of &v4l2-queryctrl; also contains hints on
 723 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
 724 for more details.</para>
 725     </section>
 726
 727     <section id="mpeg-controls">
 728       <title>Codec Control Reference</title>
 729
 730       <para>Below all controls within the Codec control class are
 731 described. First the generic controls, then controls specific for
 732 certain hardware.</para>
 733
 734       <para>Note: These controls are applicable to all codecs and
 735 not just MPEG. The defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG
 736 as the controls were originally made for MPEG codecs and later
 737 extended to cover all encoding formats.</para>
 738
 739       <section>
 740         <title>Generic Codec Controls</title>
 741
 742         <table pgwide="1" frame="none" id="mpeg-control-id">
 743           <title>Codec Control IDs</title>
 744           <tgroup cols="4">
 745             <colspec colname="c1" colwidth="1*" />
 746             <colspec colname="c2" colwidth="6*" />
 747             <colspec colname="c3" colwidth="2*" />
 748             <colspec colname="c4" colwidth="6*" />
 749             <spanspec namest="c1" nameend="c2" spanname="id" />
 750             <spanspec namest="c2" nameend="c4" spanname="descr" />
 751             <thead>
 752               <row>
 753                 <entry spanname="id" align="left">ID</entry>
 754                 <entry align="left">Type</entry>
 755               </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
 756               </row>
 757             </thead>
 758             <tbody valign="top">
 759               <row><entry></entry></row>
 760               <row>
 761                 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant>&nbsp;</entry>
 762                 <entry>class</entry>
 763               </row><row><entry spanname="descr">The Codec class
 764 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
 765 description of this control class. This description can be used as the
 766 caption of a Tab page in a GUI, for example.</entry>
 767               </row>
 768               <row><entry></entry></row>
 769               <row id="v4l2-mpeg-stream-type">
 770                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant>&nbsp;</entry>
 771                 <entry>enum&nbsp;v4l2_mpeg_stream_type</entry>
 772               </row><row><entry spanname="descr">The MPEG-1, -2 or -4
 773 output stream type. One cannot assume anything here. Each hardware
 774 MPEG encoder tends to support different subsets of the available MPEG
 775 stream types. This control is specific to multiplexed MPEG streams.
 776 The currently defined stream types are:</entry>
 777               </row>
 778               <row>
 779                 <entrytbl spanname="descr" cols="2">
 780                   <tbody valign="top">
 781                     <row>
 782                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant>&nbsp;</entry>
 783                       <entry>MPEG-2 program stream</entry>
 784                     </row>
 785                     <row>
 786                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant>&nbsp;</entry>
 787                       <entry>MPEG-2 transport stream</entry>
 788                     </row>
 789                     <row>
 790                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant>&nbsp;</entry>
 791                       <entry>MPEG-1 system stream</entry>
 792                     </row>
 793                     <row>
 794                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant>&nbsp;</entry>
 795                       <entry>MPEG-2 DVD-compatible stream</entry>
 796                     </row>
 797                     <row>
 798                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant>&nbsp;</entry>
 799                       <entry>MPEG-1 VCD-compatible stream</entry>
 800                     </row>
 801                     <row>
 802                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant>&nbsp;</entry>
 803                       <entry>MPEG-2 SVCD-compatible stream</entry>
 804                     </row>
 805                   </tbody>
 806                 </entrytbl>
 807               </row>
 808               <row><entry></entry></row>
 809               <row>
 810                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant>&nbsp;</entry>
 811                 <entry>integer</entry>
 812               </row><row><entry spanname="descr">Program Map Table
 813 Packet ID for the MPEG transport stream (default 16)</entry>
 814               </row>
 815               <row><entry></entry></row>
 816               <row>
 817                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant>&nbsp;</entry>
 818                 <entry>integer</entry>
 819               </row><row><entry spanname="descr">Audio Packet ID for
 820 the MPEG transport stream (default 256)</entry>
 821               </row>
 822               <row><entry></entry></row>
 823               <row>
 824                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant>&nbsp;</entry>
 825                 <entry>integer</entry>
 826               </row><row><entry spanname="descr">Video Packet ID for
 827 the MPEG transport stream (default 260)</entry>
 828               </row>
 829               <row><entry></entry></row>
 830               <row>
 831                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant>&nbsp;</entry>
 832                 <entry>integer</entry>
 833               </row><row><entry spanname="descr">Packet ID for the
 834 MPEG transport stream carrying PCR fields (default 259)</entry>
 835               </row>
 836               <row><entry></entry></row>
 837               <row>
 838                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant>&nbsp;</entry>
 839                 <entry>integer</entry>
 840               </row><row><entry spanname="descr">Audio ID for MPEG
 841 PES</entry>
 842               </row>
 843               <row><entry></entry></row>
 844               <row>
 845                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant>&nbsp;</entry>
 846                 <entry>integer</entry>
 847               </row><row><entry spanname="descr">Video ID for MPEG
 848 PES</entry>
 849               </row>
 850               <row><entry></entry></row>
 851               <row id="v4l2-mpeg-stream-vbi-fmt">
 852                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant>&nbsp;</entry>
 853                 <entry>enum&nbsp;v4l2_mpeg_stream_vbi_fmt</entry>
 854               </row><row><entry spanname="descr">Some cards can embed
 855 VBI data (&eg; Closed Caption, Teletext) into the MPEG stream. This
 856 control selects whether VBI data should be embedded, and if so, what
 857 embedding method should be used. The list of possible VBI formats
 858 depends on the driver. The currently defined VBI format types
 859 are:</entry>
 860               </row>
 861               <row>
 862                 <entrytbl spanname="descr" cols="2">
 863                   <tbody valign="top">
 864                     <row>
 865                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant>&nbsp;</entry>
 866                       <entry>No VBI in the MPEG stream</entry>
 867                     </row>
 868                     <row>
 869                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant>&nbsp;</entry>
 870                       <entry>VBI in private packets, IVTV format (documented
 871 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
 872                     </row>
 873                   </tbody>
 874                 </entrytbl>
 875               </row>
 876               <row><entry></entry></row>
 877               <row id="v4l2-mpeg-audio-sampling-freq">
 878                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant>&nbsp;</entry>
 879                 <entry>enum&nbsp;v4l2_mpeg_audio_sampling_freq</entry>
 880               </row><row><entry spanname="descr">MPEG Audio sampling
 881 frequency. Possible values are:</entry>
 882               </row>
 883               <row>
 884                 <entrytbl spanname="descr" cols="2">
 885                   <tbody valign="top">
 886                     <row>
 887                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant>&nbsp;</entry>
 888                       <entry>44.1 kHz</entry>
 889                     </row>
 890                     <row>
 891                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant>&nbsp;</entry>
 892                       <entry>48 kHz</entry>
 893                     </row>
 894                     <row>
 895                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant>&nbsp;</entry>
 896                       <entry>32 kHz</entry>
 897                     </row>
 898                   </tbody>
 899                 </entrytbl>
 900               </row>
 901               <row><entry></entry></row>
 902               <row id="v4l2-mpeg-audio-encoding">
 903                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant>&nbsp;</entry>
 904                 <entry>enum&nbsp;v4l2_mpeg_audio_encoding</entry>
 905               </row><row><entry spanname="descr">MPEG Audio encoding.
 906 This control is specific to multiplexed MPEG streams.
 907 Possible values are:</entry>
 908               </row>
 909               <row>
 910                 <entrytbl spanname="descr" cols="2">
 911                   <tbody valign="top">
 912                     <row>
 913                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant>&nbsp;</entry>
 914                       <entry>MPEG-1/2 Layer I encoding</entry>
 915                     </row>
 916                     <row>
 917                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant>&nbsp;</entry>
 918                       <entry>MPEG-1/2 Layer II encoding</entry>
 919                     </row>
 920                     <row>
 921                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant>&nbsp;</entry>
 922                       <entry>MPEG-1/2 Layer III encoding</entry>
 923                     </row>
 924                     <row>
 925                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant>&nbsp;</entry>
 926                       <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
 927                     </row>
 928                     <row>
 929                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant>&nbsp;</entry>
 930                       <entry>AC-3 aka ATSC A/52 encoding</entry>
 931                     </row>
 932                   </tbody>
 933                 </entrytbl>
 934               </row>
 935               <row><entry></entry></row>
 936               <row id="v4l2-mpeg-audio-l1-bitrate">
 937                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant>&nbsp;</entry>
 938                 <entry>enum&nbsp;v4l2_mpeg_audio_l1_bitrate</entry>
 939               </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
 940 Possible values are:</entry>
 941               </row>
 942               <row>
 943                 <entrytbl spanname="descr" cols="2">
 944                   <tbody valign="top">
 945                     <row>
 946                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant>&nbsp;</entry>
 947                       <entry>32 kbit/s</entry></row>
 948                     <row>
 949                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant>&nbsp;</entry>
 950                       <entry>64 kbit/s</entry>
 951                     </row>
 952                     <row>
 953                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant>&nbsp;</entry>
 954                       <entry>96 kbit/s</entry>
 955                     </row>
 956                     <row>
 957                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant>&nbsp;</entry>
 958                       <entry>128 kbit/s</entry>
 959                     </row>
 960                     <row>
 961                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant>&nbsp;</entry>
 962                       <entry>160 kbit/s</entry>
 963                     </row>
 964                     <row>
 965                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant>&nbsp;</entry>
 966                       <entry>192 kbit/s</entry>
 967                     </row>
 968                     <row>
 969                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant>&nbsp;</entry>
 970                       <entry>224 kbit/s</entry>
 971                     </row>
 972                     <row>
 973                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant>&nbsp;</entry>
 974                       <entry>256 kbit/s</entry>
 975                     </row>
 976                     <row>
 977                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant>&nbsp;</entry>
 978                       <entry>288 kbit/s</entry>
 979                     </row>
 980                     <row>
 981                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant>&nbsp;</entry>
 982                       <entry>320 kbit/s</entry>
 983                     </row>
 984                     <row>
 985                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant>&nbsp;</entry>
 986                       <entry>352 kbit/s</entry>
 987                     </row>
 988                     <row>
 989                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant>&nbsp;</entry>
 990                       <entry>384 kbit/s</entry>
 991                     </row>
 992                     <row>
 993                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant>&nbsp;</entry>
 994                       <entry>416 kbit/s</entry>
 995                     </row>
 996                     <row>
 997                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant>&nbsp;</entry>
 998                       <entry>448 kbit/s</entry>
 999                     </row>
1000                   </tbody>
1001                 </entrytbl>
1002               </row>
1003               <row><entry></entry></row>
1004               <row id="v4l2-mpeg-audio-l2-bitrate">
1005                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant>&nbsp;</entry>
1006                 <entry>enum&nbsp;v4l2_mpeg_audio_l2_bitrate</entry>
1007               </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1008 Possible values are:</entry>
1009               </row>
1010               <row>
1011                 <entrytbl spanname="descr" cols="2">
1012                   <tbody valign="top">
1013                     <row>
1014                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant>&nbsp;</entry>
1015                       <entry>32 kbit/s</entry>
1016                     </row>
1017                     <row>
1018                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant>&nbsp;</entry>
1019                       <entry>48 kbit/s</entry>
1020                     </row>
1021                     <row>
1022                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant>&nbsp;</entry>
1023                       <entry>56 kbit/s</entry>
1024                     </row>
1025                     <row>
1026                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant>&nbsp;</entry>
1027                       <entry>64 kbit/s</entry>
1028                     </row>
1029                     <row>
1030                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant>&nbsp;</entry>
1031                       <entry>80 kbit/s</entry>
1032                     </row>
1033                     <row>
1034                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant>&nbsp;</entry>
1035                       <entry>96 kbit/s</entry>
1036                     </row>
1037                     <row>
1038                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant>&nbsp;</entry>
1039                       <entry>112 kbit/s</entry>
1040                     </row>
1041                     <row>
1042                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant>&nbsp;</entry>
1043                       <entry>128 kbit/s</entry>
1044                     </row>
1045                     <row>
1046                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant>&nbsp;</entry>
1047                       <entry>160 kbit/s</entry>
1048                     </row>
1049                     <row>
1050                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant>&nbsp;</entry>
1051                       <entry>192 kbit/s</entry>
1052                     </row>
1053                     <row>
1054                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant>&nbsp;</entry>
1055                       <entry>224 kbit/s</entry>
1056                     </row>
1057                     <row>
1058                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant>&nbsp;</entry>
1059                       <entry>256 kbit/s</entry>
1060                     </row>
1061                     <row>
1062                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant>&nbsp;</entry>
1063                       <entry>320 kbit/s</entry>
1064                     </row>
1065                     <row>
1066                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant>&nbsp;</entry>
1067                       <entry>384 kbit/s</entry>
1068                     </row>
1069                   </tbody>
1070                 </entrytbl>
1071               </row>
1072               <row><entry></entry></row>
1073               <row id="v4l2-mpeg-audio-l3-bitrate">
1074                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant>&nbsp;</entry>
1075                 <entry>enum&nbsp;v4l2_mpeg_audio_l3_bitrate</entry>
1076               </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1077 Possible values are:</entry>
1078               </row>
1079               <row>
1080                 <entrytbl spanname="descr" cols="2">
1081                   <tbody valign="top">
1082                     <row>
1083                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant>&nbsp;</entry>
1084                       <entry>32 kbit/s</entry>
1085                     </row>
1086                     <row>
1087                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant>&nbsp;</entry>
1088                       <entry>40 kbit/s</entry>
1089                     </row>
1090                     <row>
1091                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant>&nbsp;</entry>
1092                       <entry>48 kbit/s</entry>
1093                     </row>
1094                     <row>
1095                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant>&nbsp;</entry>
1096                       <entry>56 kbit/s</entry>
1097                     </row>
1098                     <row>
1099                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant>&nbsp;</entry>
1100                       <entry>64 kbit/s</entry>
1101                     </row>
1102                     <row>
1103                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant>&nbsp;</entry>
1104                       <entry>80 kbit/s</entry>
1105                     </row>
1106                     <row>
1107                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant>&nbsp;</entry>
1108                       <entry>96 kbit/s</entry>
1109                     </row>
1110                     <row>
1111                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant>&nbsp;</entry>
1112                       <entry>112 kbit/s</entry>
1113                     </row>
1114                     <row>
1115                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant>&nbsp;</entry>
1116                       <entry>128 kbit/s</entry>
1117                     </row>
1118                     <row>
1119                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant>&nbsp;</entry>
1120                       <entry>160 kbit/s</entry>
1121                     </row>
1122                     <row>
1123                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant>&nbsp;</entry>
1124                       <entry>192 kbit/s</entry>
1125                     </row>
1126                     <row>
1127                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant>&nbsp;</entry>
1128                       <entry>224 kbit/s</entry>
1129                     </row>
1130                     <row>
1131                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant>&nbsp;</entry>
1132                       <entry>256 kbit/s</entry>
1133                     </row>
1134                     <row>
1135                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant>&nbsp;</entry>
1136                       <entry>320 kbit/s</entry>
1137                     </row>
1138                   </tbody>
1139                 </entrytbl>
1140               </row>
1141               <row><entry></entry></row>
1142               <row>
1143                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant>&nbsp;</entry>
1144                 <entry>integer</entry>
1145               </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1146               </row>
1147               <row><entry></entry></row>
1148               <row id="v4l2-mpeg-audio-ac3-bitrate">
1149                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant>&nbsp;</entry>
1150                 <entry>enum&nbsp;v4l2_mpeg_audio_ac3_bitrate</entry>
1151               </row><row><entry spanname="descr">AC-3 bitrate.
1152 Possible values are:</entry>
1153               </row>
1154               <row>
1155                 <entrytbl spanname="descr" cols="2">
1156                   <tbody valign="top">
1157                     <row>
1158                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant>&nbsp;</entry>
1159                       <entry>32 kbit/s</entry>
1160                     </row>
1161                     <row>
1162                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant>&nbsp;</entry>
1163                       <entry>40 kbit/s</entry>
1164                     </row>
1165                     <row>
1166                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant>&nbsp;</entry>
1167                       <entry>48 kbit/s</entry>
1168                     </row>
1169                     <row>
1170                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant>&nbsp;</entry>
1171                       <entry>56 kbit/s</entry>
1172                     </row>
1173                     <row>
1174                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant>&nbsp;</entry>
1175                       <entry>64 kbit/s</entry>
1176                     </row>
1177                     <row>
1178                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant>&nbsp;</entry>
1179                       <entry>80 kbit/s</entry>
1180                     </row>
1181                     <row>
1182                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant>&nbsp;</entry>
1183                       <entry>96 kbit/s</entry>
1184                     </row>
1185                     <row>
1186                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant>&nbsp;</entry>
1187                       <entry>112 kbit/s</entry>
1188                     </row>
1189                     <row>
1190                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant>&nbsp;</entry>
1191                       <entry>128 kbit/s</entry>
1192                     </row>
1193                     <row>
1194                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant>&nbsp;</entry>
1195                       <entry>160 kbit/s</entry>
1196                     </row>
1197                     <row>
1198                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant>&nbsp;</entry>
1199                       <entry>192 kbit/s</entry>
1200                     </row>
1201                     <row>
1202                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant>&nbsp;</entry>
1203                       <entry>224 kbit/s</entry>
1204                     </row>
1205                     <row>
1206                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant>&nbsp;</entry>
1207                       <entry>256 kbit/s</entry>
1208                     </row>
1209                     <row>
1210                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant>&nbsp;</entry>
1211                       <entry>320 kbit/s</entry>
1212                     </row>
1213                     <row>
1214                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant>&nbsp;</entry>
1215                       <entry>384 kbit/s</entry>
1216                     </row>
1217                     <row>
1218                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant>&nbsp;</entry>
1219                       <entry>448 kbit/s</entry>
1220                     </row>
1221                     <row>
1222                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant>&nbsp;</entry>
1223                       <entry>512 kbit/s</entry>
1224                     </row>
1225                     <row>
1226                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant>&nbsp;</entry>
1227                       <entry>576 kbit/s</entry>
1228                     </row>
1229                     <row>
1230                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant>&nbsp;</entry>
1231                       <entry>640 kbit/s</entry>
1232                     </row>
1233                   </tbody>
1234                 </entrytbl>
1235               </row>
1236               <row><entry></entry></row>
1237               <row id="v4l2-mpeg-audio-mode">
1238                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant>&nbsp;</entry>
1239                 <entry>enum&nbsp;v4l2_mpeg_audio_mode</entry>
1240               </row><row><entry spanname="descr">MPEG Audio mode.
1241 Possible values are:</entry>
1242               </row>
1243               <row>
1244                 <entrytbl spanname="descr" cols="2">
1245                   <tbody valign="top">
1246                     <row>
1247                       <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant>&nbsp;</entry>
1248                       <entry>Stereo</entry>
1249                     </row>
1250                     <row>
1251                       <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant>&nbsp;</entry>
1252                       <entry>Joint Stereo</entry>
1253                     </row>
1254                     <row>
1255                       <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant>&nbsp;</entry>
1256                       <entry>Bilingual</entry>
1257                     </row>
1258                     <row>
1259                       <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant>&nbsp;</entry>
1260                       <entry>Mono</entry>
1261                     </row>
1262                   </tbody>
1263                 </entrytbl>
1264               </row>
1265               <row><entry></entry></row>
1266               <row id="v4l2-mpeg-audio-mode-extension">
1267                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant>&nbsp;</entry>
1268                 <entry>enum&nbsp;v4l2_mpeg_audio_mode_extension</entry>
1269               </row><row><entry spanname="descr">Joint Stereo
1270 audio mode extension. In Layer I and II they indicate which subbands
1271 are in intensity stereo. All other subbands are coded in stereo. Layer
1272 III is not (yet) supported. Possible values
1273 are:</entry>
1274               </row>
1275               <row>
1276                 <entrytbl spanname="descr" cols="2">
1277                   <tbody valign="top">
1278                     <row>
1279                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant>&nbsp;</entry>
1280                       <entry>Subbands 4-31 in intensity stereo</entry>
1281                     </row>
1282                     <row>
1283                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant>&nbsp;</entry>
1284                       <entry>Subbands 8-31 in intensity stereo</entry>
1285                     </row>
1286                     <row>
1287                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant>&nbsp;</entry>
1288                       <entry>Subbands 12-31 in intensity stereo</entry>
1289                     </row>
1290                     <row>
1291                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant>&nbsp;</entry>
1292                       <entry>Subbands 16-31 in intensity stereo</entry>
1293                     </row>
1294                   </tbody>
1295                 </entrytbl>
1296               </row>
1297               <row><entry></entry></row>
1298               <row id="v4l2-mpeg-audio-emphasis">
1299                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant>&nbsp;</entry>
1300                 <entry>enum&nbsp;v4l2_mpeg_audio_emphasis</entry>
1301               </row><row><entry spanname="descr">Audio Emphasis.
1302 Possible values are:</entry>
1303               </row>
1304               <row>
1305                 <entrytbl spanname="descr" cols="2">
1306                   <tbody valign="top">
1307                     <row>
1308                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant>&nbsp;</entry>
1309                       <entry>None</entry>
1310                     </row>
1311                     <row>
1312                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant>&nbsp;</entry>
1313                       <entry>50/15 microsecond emphasis</entry>
1314                     </row>
1315                     <row>
1316                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant>&nbsp;</entry>
1317                       <entry>CCITT J.17</entry>
1318                     </row>
1319                   </tbody>
1320                 </entrytbl>
1321               </row>
1322               <row><entry></entry></row>
1323               <row id="v4l2-mpeg-audio-crc">
1324                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant>&nbsp;</entry>
1325                 <entry>enum&nbsp;v4l2_mpeg_audio_crc</entry>
1326               </row><row><entry spanname="descr">CRC method. Possible
1327 values are:</entry>
1328               </row>
1329               <row>
1330                 <entrytbl spanname="descr" cols="2">
1331                   <tbody valign="top">
1332                     <row>
1333                       <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant>&nbsp;</entry>
1334                       <entry>None</entry>
1335                     </row>
1336                     <row>
1337                       <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant>&nbsp;</entry>
1338                       <entry>16 bit parity check</entry>
1339                     </row>
1340                   </tbody>
1341                 </entrytbl>
1342               </row>
1343               <row><entry></entry></row>
1344               <row>
1345                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant>&nbsp;</entry>
1346                 <entry>boolean</entry>
1347               </row><row><entry spanname="descr">Mutes the audio when
1348 capturing. This is not done by muting audio hardware, which can still
1349 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1350 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1351               </row>
1352               <row><entry></entry></row>
1353               <row id="v4l2-mpeg-audio-dec-playback">
1354                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant>&nbsp;</entry>
1355                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1356               </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1357 Possible values are:</entry>
1358               </row>
1359               <row>
1360                 <entrytbl spanname="descr" cols="2">
1361                   <tbody valign="top">
1362                     <row>
1363                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant>&nbsp;</entry>
1364                       <entry>Automatically determines the best playback mode.</entry>
1365                     </row>
1366                     <row>
1367                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant>&nbsp;</entry>
1368                       <entry>Stereo playback.</entry>
1369                     </row>
1370                     <row>
1371                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant>&nbsp;</entry>
1372                       <entry>Left channel playback.</entry>
1373                     </row>
1374                     <row>
1375                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant>&nbsp;</entry>
1376                       <entry>Right channel playback.</entry>
1377                     </row>
1378                     <row>
1379                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant>&nbsp;</entry>
1380                       <entry>Mono playback.</entry>
1381                     </row>
1382                     <row>
1383                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant>&nbsp;</entry>
1384                       <entry>Stereo playback with swapped left and right channels.</entry>
1385                     </row>
1386                   </tbody>
1387                 </entrytbl>
1388               </row>
1389               <row><entry></entry></row>
1390               <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1391                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant>&nbsp;</entry>
1392                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1393               </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1394               </row>
1395               <row><entry></entry></row>
1396               <row id="v4l2-mpeg-video-encoding">
1397                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant>&nbsp;</entry>
1398                 <entry>enum&nbsp;v4l2_mpeg_video_encoding</entry>
1399               </row><row><entry spanname="descr">MPEG Video encoding
1400 method. This control is specific to multiplexed MPEG streams.
1401 Possible values are:</entry>
1402               </row>
1403               <row>
1404                 <entrytbl spanname="descr" cols="2">
1405                   <tbody valign="top">
1406                     <row>
1407                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant>&nbsp;</entry>
1408                       <entry>MPEG-1 Video encoding</entry>
1409                     </row>
1410                     <row>
1411                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant>&nbsp;</entry>
1412                       <entry>MPEG-2 Video encoding</entry>
1413                     </row>
1414                     <row>
1415                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant>&nbsp;</entry>
1416                       <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1417                     </row>
1418                   </tbody>
1419                 </entrytbl>
1420               </row>
1421               <row><entry></entry></row>
1422               <row id="v4l2-mpeg-video-aspect">
1423                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant>&nbsp;</entry>
1424                 <entry>enum&nbsp;v4l2_mpeg_video_aspect</entry>
1425               </row><row><entry spanname="descr">Video aspect.
1426 Possible values are:</entry>
1427               </row>
1428               <row>
1429                 <entrytbl spanname="descr" cols="2">
1430                   <tbody valign="top">
1431                     <row>
1432                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant>&nbsp;</entry>
1433                     </row>
1434                     <row>
1435                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant>&nbsp;</entry>
1436                     </row>
1437                     <row>
1438                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant>&nbsp;</entry>
1439                     </row>
1440                     <row>
1441                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant>&nbsp;</entry>
1442                     </row>
1443                   </tbody>
1444                 </entrytbl>
1445               </row>
1446               <row><entry></entry></row>
1447               <row>
1448                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant>&nbsp;</entry>
1449                 <entry>integer</entry>
1450               </row><row><entry spanname="descr">Number of B-Frames
1451 (default 2)</entry>
1452               </row>
1453               <row><entry></entry></row>
1454               <row>
1455                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant>&nbsp;</entry>
1456                 <entry>integer</entry>
1457               </row><row><entry spanname="descr">GOP size (default
1458 12)</entry>
1459               </row>
1460               <row><entry></entry></row>
1461               <row>
1462                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant>&nbsp;</entry>
1463                 <entry>boolean</entry>
1464               </row><row><entry spanname="descr">GOP closure (default
1465 1)</entry>
1466               </row>
1467               <row><entry></entry></row>
1468               <row>
1469                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant>&nbsp;</entry>
1470                 <entry>boolean</entry>
1471               </row><row><entry spanname="descr">Enable 3:2 pulldown
1472 (default 0)</entry>
1473               </row>
1474               <row><entry></entry></row>
1475               <row id="v4l2-mpeg-video-bitrate-mode">
1476                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant>&nbsp;</entry>
1477                 <entry>enum&nbsp;v4l2_mpeg_video_bitrate_mode</entry>
1478               </row><row><entry spanname="descr">Video bitrate mode.
1479 Possible values are:</entry>
1480               </row>
1481               <row>
1482                 <entrytbl spanname="descr" cols="2">
1483                   <tbody valign="top">
1484                     <row>
1485                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant>&nbsp;</entry>
1486                       <entry>Variable bitrate</entry>
1487                     </row>
1488                     <row>
1489                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant>&nbsp;</entry>
1490                       <entry>Constant bitrate</entry>
1491                     </row>
1492                   </tbody>
1493                 </entrytbl>
1494               </row>
1495               <row><entry></entry></row>
1496               <row>
1497                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant>&nbsp;</entry>
1498                 <entry>integer</entry>
1499               </row><row><entry spanname="descr">Video bitrate in bits
1500 per second.</entry>
1501               </row>
1502               <row><entry></entry></row>
1503               <row>
1504                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant>&nbsp;</entry>
1505                 <entry>integer</entry>
1506               </row><row><entry spanname="descr">Peak video bitrate in
1507 bits per second. Must be larger or equal to the average video bitrate.
1508 It is ignored if the video bitrate mode is set to constant
1509 bitrate.</entry>
1510               </row>
1511               <row><entry></entry></row>
1512               <row>
1513                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant>&nbsp;</entry>
1514                 <entry>integer</entry>
1515               </row><row><entry spanname="descr">For every captured
1516 frame, skip this many subsequent frames (default 0).</entry>
1517               </row>
1518               <row><entry></entry></row>
1519               <row>
1520                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant>&nbsp;</entry>
1521                 <entry>boolean</entry>
1522               </row>
1523               <row><entry spanname="descr">"Mutes" the video to a
1524 fixed color when capturing. This is useful for testing, to produce a
1525 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1526               </row>
1527               <row><entry></entry></row>
1528               <row>
1529                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant>&nbsp;</entry>
1530                 <entry>integer</entry>
1531               </row><row><entry spanname="descr">Sets the "mute" color
1532 of the video. The supplied 32-bit integer is interpreted as follows (bit
1533 0 = least significant bit):</entry>
1534               </row>
1535               <row>
1536                 <entrytbl spanname="descr" cols="2">
1537                   <tbody valign="top">
1538                     <row>
1539                       <entry>Bit 0:7</entry>
1540                       <entry>V chrominance information</entry>
1541                     </row>
1542                     <row>
1543                       <entry>Bit 8:15</entry>
1544                       <entry>U chrominance information</entry>
1545                     </row>
1546                     <row>
1547                       <entry>Bit 16:23</entry>
1548                       <entry>Y luminance information</entry>
1549                     </row>
1550                     <row>
1551                       <entry>Bit 24:31</entry>
1552                       <entry>Must be zero.</entry>
1553                     </row>
1554                   </tbody>
1555                 </entrytbl>
1556               </row>
1557               <row><entry></entry></row>
1558               <row id="v4l2-mpeg-video-dec-pts">
1559                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant>&nbsp;</entry>
1560                 <entry>integer64</entry>
1561               </row><row><entry spanname="descr">This read-only control returns the
1562 33-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1563 the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1564               </row>
1565               <row><entry></entry></row>
1566               <row id="v4l2-mpeg-video-dec-frame">
1567                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant>&nbsp;</entry>
1568                 <entry>integer64</entry>
1569               </row><row><entry spanname="descr">This read-only control returns the
1570 frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1571 the decoder is started.</entry>
1572               </row>
1573
1574               <row><entry></entry></row>
1575               <row>
1576                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant>&nbsp;</entry>
1577                 <entry>boolean</entry>
1578               </row>
1579               <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1580 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1581 </entry>
1582               </row>
1583
1584               <row><entry></entry></row>
1585               <row>
1586                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant>&nbsp;</entry>
1587                 <entry>boolean</entry>
1588               </row>
1589               <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1590 Applicable to the H264 encoder.</entry>
1591               </row>
1592
1593               <row><entry></entry></row>
1594               <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1595                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant>&nbsp;</entry>
1596                 <entry>enum&nbsp;v4l2_mpeg_video_h264_vui_sar_idc</entry>
1597               </row>
1598               <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1599 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1600               </row>
1601               <row>
1602                 <entrytbl spanname="descr" cols="2">
1603                   <tbody valign="top">
1604
1605                         <row>
1606                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant>&nbsp;</entry>
1607                           <entry>Unspecified</entry>
1608                         </row>
1609                         <row>
1610                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant>&nbsp;</entry>
1611                           <entry>1x1</entry>
1612                         </row>
1613                         <row>
1614                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant>&nbsp;</entry>
1615                           <entry>12x11</entry>
1616                         </row>
1617                         <row>
1618                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant>&nbsp;</entry>
1619                           <entry>10x11</entry>
1620                         </row>
1621                         <row>
1622                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant>&nbsp;</entry>
1623                           <entry>16x11</entry>
1624                         </row>
1625                         <row>
1626                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant>&nbsp;</entry>
1627                           <entry>40x33</entry>
1628                         </row>
1629                         <row>
1630                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant>&nbsp;</entry>
1631                           <entry>24x11</entry>
1632                         </row>
1633                         <row>
1634                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant>&nbsp;</entry>
1635                           <entry>20x11</entry>
1636                         </row>
1637                         <row>
1638                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant>&nbsp;</entry>
1639                           <entry>32x11</entry>
1640                         </row>
1641                         <row>
1642                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant>&nbsp;</entry>
1643                           <entry>80x33</entry>
1644                         </row>
1645                         <row>
1646                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant>&nbsp;</entry>
1647                           <entry>18x11</entry>
1648                         </row>
1649                         <row>
1650                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant>&nbsp;</entry>
1651                           <entry>15x11</entry>
1652                         </row>
1653                         <row>
1654                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant>&nbsp;</entry>
1655                           <entry>64x33</entry>
1656                         </row>
1657                         <row>
1658                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant>&nbsp;</entry>
1659                           <entry>160x99</entry>
1660                         </row>
1661                         <row>
1662                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant>&nbsp;</entry>
1663                           <entry>4x3</entry>
1664                         </row>
1665                         <row>
1666                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant>&nbsp;</entry>
1667                           <entry>3x2</entry>
1668                         </row>
1669                         <row>
1670                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant>&nbsp;</entry>
1671                           <entry>2x1</entry>
1672                         </row>
1673                         <row>
1674                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant>&nbsp;</entry>
1675                           <entry>Extended SAR</entry>
1676                         </row>
1677                   </tbody>
1678                 </entrytbl>
1679               </row>
1680
1681               <row><entry></entry></row>
1682               <row>
1683                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant>&nbsp;</entry>
1684                 <entry>integer</entry>
1685               </row>
1686               <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1687 Applicable to the H264 encoder.</entry>
1688               </row>
1689
1690               <row><entry></entry></row>
1691               <row>
1692                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant>&nbsp;</entry>
1693                 <entry>integer</entry>
1694               </row>
1695               <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1696 Applicable to the H264 encoder.</entry>
1697               </row>
1698
1699               <row><entry></entry></row>
1700               <row id="v4l2-mpeg-video-h264-level">
1701                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant>&nbsp;</entry>
1702                 <entry>enum&nbsp;v4l2_mpeg_video_h264_level</entry>
1703               </row>
1704               <row><entry spanname="descr">The level information for the H264 video elementary stream.
1705 Applicable to the H264 encoder.
1706 Possible values are:</entry>
1707               </row>
1708               <row>
1709                 <entrytbl spanname="descr" cols="2">
1710                   <tbody valign="top">
1711                     <row>
1712                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant>&nbsp;</entry>
1713                       <entry>Level 1.0</entry>
1714                     </row>
1715                     <row>
1716                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant>&nbsp;</entry>
1717                       <entry>Level 1B</entry>
1718                     </row>
1719                     <row>
1720                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant>&nbsp;</entry>
1721                       <entry>Level 1.1</entry>
1722                     </row>
1723                     <row>
1724                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant>&nbsp;</entry>
1725                       <entry>Level 1.2</entry>
1726                     </row>
1727                     <row>
1728                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant>&nbsp;</entry>
1729                       <entry>Level 1.3</entry>
1730                     </row>
1731                     <row>
1732                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant>&nbsp;</entry>
1733                       <entry>Level 2.0</entry>
1734                     </row>
1735                     <row>
1736                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant>&nbsp;</entry>
1737                       <entry>Level 2.1</entry>
1738                     </row>
1739                     <row>
1740                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant>&nbsp;</entry>
1741                       <entry>Level 2.2</entry>
1742                     </row>
1743                     <row>
1744                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant>&nbsp;</entry>
1745                       <entry>Level 3.0</entry>
1746                     </row>
1747                     <row>
1748                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant>&nbsp;</entry>
1749                       <entry>Level 3.1</entry>
1750                     </row>
1751                     <row>
1752                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant>&nbsp;</entry>
1753                       <entry>Level 3.2</entry>
1754                     </row>
1755                     <row>
1756                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant>&nbsp;</entry>
1757                       <entry>Level 4.0</entry>
1758                     </row>
1759                     <row>
1760                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant>&nbsp;</entry>
1761                       <entry>Level 4.1</entry>
1762                     </row>
1763                     <row>
1764                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant>&nbsp;</entry>
1765                       <entry>Level 4.2</entry>
1766                     </row>
1767                     <row>
1768                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant>&nbsp;</entry>
1769                       <entry>Level 5.0</entry>
1770                     </row>
1771                     <row>
1772                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant>&nbsp;</entry>
1773                       <entry>Level 5.1</entry>
1774                     </row>
1775                   </tbody>
1776                 </entrytbl>
1777               </row>
1778
1779               <row><entry></entry></row>
1780               <row id="v4l2-mpeg-video-mpeg4-level">
1781                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant>&nbsp;</entry>
1782                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_level</entry>
1783               </row>
1784               <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1785 Applicable to the MPEG4 encoder.
1786 Possible values are:</entry>
1787               </row>
1788               <row>
1789                 <entrytbl spanname="descr" cols="2">
1790                   <tbody valign="top">
1791                     <row>
1792                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant>&nbsp;</entry>
1793                       <entry>Level 0</entry>
1794                     </row>
1795                     <row>
1796                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant>&nbsp;</entry>
1797                       <entry>Level 0b</entry>
1798                     </row>
1799                     <row>
1800                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant>&nbsp;</entry>
1801                       <entry>Level 1</entry>
1802                     </row>
1803                     <row>
1804                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant>&nbsp;</entry>
1805                       <entry>Level 2</entry>
1806                     </row>
1807                     <row>
1808                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant>&nbsp;</entry>
1809                       <entry>Level 3</entry>
1810                     </row>
1811                     <row>
1812                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant>&nbsp;</entry>
1813                       <entry>Level 3b</entry>
1814                     </row>
1815                     <row>
1816                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant>&nbsp;</entry>
1817                       <entry>Level 4</entry>
1818                     </row>
1819                     <row>
1820                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant>&nbsp;</entry>
1821                       <entry>Level 5</entry>
1822                     </row>
1823                   </tbody>
1824                 </entrytbl>
1825               </row>
1826
1827               <row><entry></entry></row>
1828               <row id="v4l2-mpeg-video-h264-profile">
1829                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant>&nbsp;</entry>
1830                 <entry>enum&nbsp;v4l2_mpeg_video_h264_profile</entry>
1831               </row>
1832               <row><entry spanname="descr">The profile information for H264.
1833 Applicable to the H264 encoder.
1834 Possible values are:</entry>
1835               </row>
1836               <row>
1837                 <entrytbl spanname="descr" cols="2">
1838                   <tbody valign="top">
1839                     <row>
1840                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant>&nbsp;</entry>
1841                       <entry>Baseline profile</entry>
1842                     </row>
1843                     <row>
1844                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant>&nbsp;</entry>
1845                       <entry>Constrained Baseline profile</entry>
1846                     </row>
1847                     <row>
1848                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant>&nbsp;</entry>
1849                       <entry>Main profile</entry>
1850                     </row>
1851                     <row>
1852                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant>&nbsp;</entry>
1853                       <entry>Extended profile</entry>
1854                     </row>
1855                     <row>
1856                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant>&nbsp;</entry>
1857                       <entry>High profile</entry>
1858                     </row>
1859                     <row>
1860                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant>&nbsp;</entry>
1861                       <entry>High 10 profile</entry>
1862                     </row>
1863                     <row>
1864                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant>&nbsp;</entry>
1865                       <entry>High 422 profile</entry>
1866                     </row>
1867                     <row>
1868                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant>&nbsp;</entry>
1869                       <entry>High 444 Predictive profile</entry>
1870                     </row>
1871                     <row>
1872                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant>&nbsp;</entry>
1873                       <entry>High 10 Intra profile</entry>
1874                     </row>
1875                     <row>
1876                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant>&nbsp;</entry>
1877                       <entry>High 422 Intra profile</entry>
1878                     </row>
1879                     <row>
1880                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant>&nbsp;</entry>
1881                       <entry>High 444 Intra profile</entry>
1882                     </row>
1883                     <row>
1884                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant>&nbsp;</entry>
1885                       <entry>CAVLC 444 Intra profile</entry>
1886                     </row>
1887                     <row>
1888                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant>&nbsp;</entry>
1889                       <entry>Scalable Baseline profile</entry>
1890                     </row>
1891                     <row>
1892                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant>&nbsp;</entry>
1893                       <entry>Scalable High profile</entry>
1894                     </row>
1895                     <row>
1896                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant>&nbsp;</entry>
1897                       <entry>Scalable High Intra profile</entry>
1898                     </row>
1899                     <row>
1900                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant>&nbsp;</entry>
1901                       <entry>Stereo High profile</entry>
1902                     </row>
1903                     <row>
1904                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant>&nbsp;</entry>
1905                       <entry>Multiview High profile</entry>
1906                     </row>
1907
1908                   </tbody>
1909                 </entrytbl>
1910               </row>
1911
1912               <row><entry></entry></row>
1913               <row id="v4l2-mpeg-video-mpeg4-profile">
1914                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant>&nbsp;</entry>
1915                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_profile</entry>
1916               </row>
1917               <row><entry spanname="descr">The profile information for MPEG4.
1918 Applicable to the MPEG4 encoder.
1919 Possible values are:</entry>
1920               </row>
1921               <row>
1922                 <entrytbl spanname="descr" cols="2">
1923                   <tbody valign="top">
1924                     <row>
1925                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant>&nbsp;</entry>
1926                       <entry>Simple profile</entry>
1927                     </row>
1928                     <row>
1929                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant>&nbsp;</entry>
1930                       <entry>Advanced Simple profile</entry>
1931                     </row>
1932                     <row>
1933                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant>&nbsp;</entry>
1934                       <entry>Core profile</entry>
1935                     </row>
1936                     <row>
1937                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant>&nbsp;</entry>
1938                       <entry>Simple Scalable profile</entry>
1939                     </row>
1940                     <row>
1941                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant>&nbsp;</entry>
1942                       <entry></entry>
1943                     </row>
1944                   </tbody>
1945                 </entrytbl>
1946               </row>
1947
1948               <row><entry></entry></row>
1949               <row>
1950                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant>&nbsp;</entry>
1951                 <entry>integer</entry>
1952               </row>
1953               <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1954 Applicable to the encoder.
1955 </entry>
1956               </row>
1957
1958               <row><entry></entry></row>
1959               <row id="v4l2-mpeg-video-multi-slice-mode">
1960                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant>&nbsp;</entry>
1961                 <entry>enum&nbsp;v4l2_mpeg_video_multi_slice_mode</entry>
1962               </row>
1963               <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1964 Applicable to the encoder.
1965 Possible values are:</entry>
1966               </row>
1967               <row>
1968                 <entrytbl spanname="descr" cols="2">
1969                   <tbody valign="top">
1970                     <row>
1971                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant>&nbsp;</entry>
1972                       <entry>Single slice per frame.</entry>
1973                     </row>
1974                     <row>
1975                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>&nbsp;</entry>
1976                       <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1977                     </row>
1978                     <row>
1979                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>&nbsp;</entry>
1980                       <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1981                     </row>
1982                   </tbody>
1983                 </entrytbl>
1984               </row>
1985
1986               <row><entry></entry></row>
1987               <row>
1988                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant>&nbsp;</entry>
1989                 <entry>integer</entry>
1990               </row>
1991               <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
1992 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
1993 Applicable to the encoder.</entry>
1994               </row>
1995
1996               <row><entry></entry></row>
1997               <row>
1998                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant>&nbsp;</entry>
1999                 <entry>integer</entry>
2000               </row>
2001               <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
2002 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
2003 Applicable to the encoder.</entry>
2004               </row>
2005
2006               <row><entry></entry></row>
2007               <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2008                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant>&nbsp;</entry>
2009                 <entry>enum&nbsp;v4l2_mpeg_video_h264_loop_filter_mode</entry>
2010               </row>
2011               <row><entry spanname="descr">Loop filter mode for H264 encoder.
2012 Possible values are:</entry>
2013               </row>
2014               <row>
2015                 <entrytbl spanname="descr" cols="2">
2016                   <tbody valign="top">
2017                     <row>
2018                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant>&nbsp;</entry>
2019                       <entry>Loop filter is enabled.</entry>
2020                     </row>
2021                     <row>
2022                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant>&nbsp;</entry>
2023                       <entry>Loop filter is disabled.</entry>
2024                     </row>
2025                     <row>
2026                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant>&nbsp;</entry>
2027                       <entry>Loop filter is disabled at the slice boundary.</entry>
2028                     </row>
2029                   </tbody>
2030                 </entrytbl>
2031               </row>
2032
2033               <row><entry></entry></row>
2034               <row>
2035                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant>&nbsp;</entry>
2036                 <entry>integer</entry>
2037               </row>
2038               <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2039 Applicable to the H264 encoder.</entry>
2040               </row>
2041
2042               <row><entry></entry></row>
2043               <row>
2044                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant>&nbsp;</entry>
2045                 <entry>integer</entry>
2046               </row>
2047               <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2048 Applicable to the H264 encoder.</entry>
2049               </row>
2050
2051               <row><entry></entry></row>
2052               <row id="v4l2-mpeg-video-h264-entropy-mode">
2053                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant>&nbsp;</entry>
2054                 <entry>enum&nbsp;v4l2_mpeg_video_h264_entropy_mode</entry>
2055               </row>
2056               <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2057 Applicable to the H264 encoder.
2058 Possible values are:</entry>
2059               </row>
2060               <row>
2061                 <entrytbl spanname="descr" cols="2">
2062                   <tbody valign="top">
2063                     <row>
2064                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant>&nbsp;</entry>
2065                       <entry>Use CAVLC entropy coding.</entry>
2066                     </row>
2067                     <row>
2068                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant>&nbsp;</entry>
2069                       <entry>Use CABAC entropy coding.</entry>
2070                     </row>
2071                   </tbody>
2072                 </entrytbl>
2073               </row>
2074
2075               <row><entry></entry></row>
2076               <row>
2077                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant>&nbsp;</entry>
2078                 <entry>boolean</entry>
2079               </row>
2080               <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2081               </row>
2082
2083               <row><entry></entry></row>
2084               <row>
2085                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant>&nbsp;</entry>
2086                 <entry>integer</entry>
2087               </row>
2088               <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2089 refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2090 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2091               </row>
2092
2093               <row><entry></entry></row>
2094               <row>
2095                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant>&nbsp;</entry>
2096                 <entry>boolean</entry>
2097               </row>
2098               <row><entry spanname="descr">Frame level rate control enable.
2099 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2100 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2101 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2102 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2103 Applicable to encoders.</entry>
2104               </row>
2105
2106               <row><entry></entry></row>
2107               <row>
2108                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>&nbsp;</entry>
2109                 <entry>boolean</entry>
2110               </row>
2111               <row><entry spanname="descr">Macroblock level rate control enable.
2112 Applicable to the MPEG4 and H264 encoders.</entry>
2113               </row>
2114
2115               <row><entry></entry></row>
2116               <row>
2117                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant>&nbsp;</entry>
2118                 <entry>boolean</entry>
2119               </row>
2120               <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2121               </row>
2122
2123               <row><entry></entry></row>
2124               <row>
2125                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>&nbsp;</entry>
2126                 <entry>integer</entry>
2127               </row>
2128               <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2129               </row>
2130
2131               <row><entry></entry></row>
2132               <row>
2133                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>&nbsp;</entry>
2134                 <entry>integer</entry>
2135               </row>
2136               <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2137               </row>
2138
2139               <row><entry></entry></row>
2140               <row>
2141                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant>&nbsp;</entry>
2142                 <entry>integer</entry>
2143               </row>
2144               <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2145               </row>
2146
2147               <row><entry></entry></row>
2148               <row>
2149                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant>&nbsp;</entry>
2150                 <entry>integer</entry>
2151               </row>
2152               <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2153               </row>
2154
2155               <row><entry></entry></row>
2156               <row>
2157                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant>&nbsp;</entry>
2158                 <entry>integer</entry>
2159               </row>
2160               <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2161               </row>
2162
2163               <row><entry></entry></row>
2164               <row>
2165                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant>&nbsp;</entry>
2166                 <entry>integer</entry>
2167               </row>
2168               <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2169               </row>
2170
2171               <row><entry></entry></row>
2172               <row>
2173                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant>&nbsp;</entry>
2174                 <entry>integer</entry>
2175               </row>
2176               <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2177               </row>
2178
2179               <row><entry></entry></row>
2180               <row>
2181                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant>&nbsp;</entry>
2182                 <entry>integer</entry>
2183               </row>
2184               <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2185               </row>
2186
2187               <row><entry></entry></row>
2188               <row>
2189                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant>&nbsp;</entry>
2190                 <entry>integer</entry>
2191               </row>
2192               <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2193               </row>
2194
2195               <row><entry></entry></row>
2196               <row>
2197                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant>&nbsp;</entry>
2198                 <entry>integer</entry>
2199               </row>
2200               <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2201               </row>
2202
2203               <row><entry></entry></row>
2204               <row>
2205                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant>&nbsp;</entry>
2206                 <entry>integer</entry>
2207               </row>
2208               <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2209               </row>
2210
2211               <row><entry></entry></row>
2212               <row>
2213                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant>&nbsp;</entry>
2214                 <entry>integer</entry>
2215               </row>
2216               <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2217               </row>
2218
2219               <row><entry></entry></row>
2220               <row>
2221                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant>&nbsp;</entry>
2222                 <entry>integer</entry>
2223               </row>
2224               <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2225               </row>
2226
2227               <row><entry></entry></row>
2228               <row>
2229                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant>&nbsp;</entry>
2230                 <entry>integer</entry>
2231               </row>
2232               <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2233               </row>
2234
2235               <row><entry></entry></row>
2236               <row>
2237                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant>&nbsp;</entry>
2238                 <entry>integer</entry>
2239               </row>
2240               <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2241               </row>
2242
2243               <row><entry></entry></row>
2244               <row>
2245                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant>&nbsp;</entry>
2246                 <entry>integer</entry>
2247               </row>
2248               <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2249 The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2250 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2251 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2252 encoder or editing process may produce.".
2253 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2254               </row>
2255
2256               <row><entry></entry></row>
2257               <row id="v4l2-mpeg-video-vbv-delay">
2258                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant>&nbsp;</entry>
2259                 <entry>integer</entry>
2260               </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2261 VBV buffer control.</entry>
2262               </row>
2263
2264               <row><entry></entry></row>
2265               <row>
2266                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant>&nbsp;</entry>
2267                 <entry>integer</entry>
2268               </row>
2269               <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2270 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2271 Applicable to the H264 encoder.</entry>
2272               </row>
2273
2274               <row><entry></entry></row>
2275               <row>
2276                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant>&nbsp;</entry>
2277                 <entry>integer</entry>
2278               </row>
2279               <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2280 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2281 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2282 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2283 previous frames. Applicable to the H264 encoder.</entry>
2284               </row>
2285
2286               <row><entry></entry></row>
2287               <row id="v4l2-mpeg-video-header-mode">
2288                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant>&nbsp;</entry>
2289                 <entry>enum&nbsp;v4l2_mpeg_video_header_mode</entry>
2290               </row>
2291               <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2292 it returned together with the first frame. Applicable to encoders.
2293 Possible values are:</entry>
2294               </row>
2295               <row>
2296                 <entrytbl spanname="descr" cols="2">
2297                   <tbody valign="top">
2298                     <row>
2299                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant>&nbsp;</entry>
2300                       <entry>The stream header is returned separately in the first buffer.</entry>
2301                     </row>
2302                     <row>
2303                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant>&nbsp;</entry>
2304                       <entry>The stream header is returned together with the first encoded frame.</entry>
2305                     </row>
2306                   </tbody>
2307                 </entrytbl>
2308               </row>
2309               <row><entry></entry></row>
2310               <row>
2311                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER</constant>&nbsp;</entry>
2312                 <entry>boolean</entry>
2313               </row><row><entry spanname="descr">Repeat the video sequence headers. Repeating these
2314 headers makes random access to the video stream easier. Applicable to the MPEG1, 2 and 4 encoder.</entry>
2315               </row>
2316               <row>
2317                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant>&nbsp;</entry>
2318                 <entry>boolean</entry>
2319               </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2320 Applicable to the MPEG4 decoder.</entry>
2321               </row>
2322               <row><entry></entry></row>
2323               <row>
2324                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant>&nbsp;</entry>
2325                 <entry>integer</entry>
2326               </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2327               </row>
2328               <row><entry></entry></row>
2329               <row>
2330                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant>&nbsp;</entry>
2331                 <entry>integer</entry>
2332               </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2333               </row>
2334
2335               <row><entry></entry></row>
2336               <row>
2337                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant>&nbsp;</entry>
2338                 <entry>boolean</entry>
2339               </row>
2340               <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2341 The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2342               </row>
2343
2344               <row><entry></entry></row>
2345               <row>
2346                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant>&nbsp;</entry>
2347                 <entry>boolean</entry>
2348               </row>
2349               <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2350 Applicable to the H264 encoder.</entry>
2351               </row>
2352
2353               <row><entry></entry></row>
2354               <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2355                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant>&nbsp;</entry>
2356                 <entry>enum&nbsp;v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2357               </row>
2358               <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2359 Applicable to the H264 encoder.
2360 Possible values are:</entry>
2361               </row>
2362               <row>
2363                 <entrytbl spanname="descr" cols="2">
2364                   <tbody valign="top">
2365                     <row>
2366                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant>&nbsp;</entry>
2367                       <entry>Pixels are alternatively from L and R.</entry>
2368                     </row>
2369                     <row>
2370                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant>&nbsp;</entry>
2371                       <entry>L and R are interlaced by column.</entry>
2372                     </row>
2373                     <row>
2374                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant>&nbsp;</entry>
2375                       <entry>L and R are interlaced by row.</entry>
2376                     </row>
2377                     <row>
2378                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant>&nbsp;</entry>
2379                       <entry>L is on the left, R on the right.</entry>
2380                     </row>
2381                     <row>
2382                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant>&nbsp;</entry>
2383                       <entry>L is on top, R on bottom.</entry>
2384                     </row>
2385                     <row>
2386                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant>&nbsp;</entry>
2387                       <entry>One view per frame.</entry>
2388                     </row>
2389                   </tbody>
2390                 </entrytbl>
2391               </row>
2392
2393               <row><entry></entry></row>
2394               <row>
2395                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant>&nbsp;</entry>
2396                 <entry>boolean</entry>
2397               </row>
2398               <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2399 used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2400               </row>
2401
2402               <row><entry></entry></row>
2403               <row id="v4l2-mpeg-video-h264-fmo-map-type">
2404                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant>&nbsp;</entry>
2405                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_map_type</entry>
2406               </row>
2407               <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2408 Applicable to the H264 encoder.
2409 Possible values are:</entry>
2410               </row>
2411               <row>
2412                 <entrytbl spanname="descr" cols="2">
2413                   <tbody valign="top">
2414                     <row>
2415                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant>&nbsp;</entry>
2416                       <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2417                     </row>
2418                     <row>
2419                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant>&nbsp;</entry>
2420                       <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2421                     </row>
2422                     <row>
2423                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant>&nbsp;</entry>
2424                       <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2425                     </row>
2426                     <row>
2427                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant>&nbsp;</entry>
2428                       <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2429                     </row>
2430                     <row>
2431                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant>&nbsp;</entry>
2432                       <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2433                     </row>
2434                     <row>
2435                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant>&nbsp;</entry>
2436                       <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2437                     </row>
2438                     <row>
2439                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant>&nbsp;</entry>
2440                       <entry>User defined map type.</entry>
2441                     </row>
2442                   </tbody>
2443                 </entrytbl>
2444               </row>
2445
2446               <row><entry></entry></row>
2447               <row>
2448                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant>&nbsp;</entry>
2449                 <entry>integer</entry>
2450               </row>
2451               <row><entry spanname="descr">Number of slice groups in FMO.
2452 Applicable to the H264 encoder.</entry>
2453               </row>
2454
2455               <row><entry></entry></row>
2456               <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2457                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant>&nbsp;</entry>
2458                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_change_dir</entry>
2459               </row>
2460               <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2461 Applicable to the H264 encoder.
2462 Possible values are:</entry>
2463               </row>
2464               <row>
2465                 <entrytbl spanname="descr" cols="2">
2466                   <tbody valign="top">
2467                     <row>
2468                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant>&nbsp;</entry>
2469                       <entry>Raster scan or wipe right.</entry>
2470                     </row>
2471                     <row>
2472                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant>&nbsp;</entry>
2473                       <entry>Reverse raster scan or wipe left.</entry>
2474                     </row>
2475                   </tbody>
2476                 </entrytbl>
2477               </row>
2478
2479               <row><entry></entry></row>
2480               <row>
2481                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant>&nbsp;</entry>
2482                 <entry>integer</entry>
2483               </row>
2484               <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2485 Applicable to the H264 encoder.</entry>
2486               </row>
2487
2488               <row><entry></entry></row>
2489               <row>
2490                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant>&nbsp;</entry>
2491                 <entry>integer</entry>
2492               </row>
2493               <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2494 Applicable to the H264 encoder.</entry>
2495               </row>
2496
2497               <row><entry></entry></row>
2498               <row>
2499                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant>&nbsp;</entry>
2500                 <entry>boolean</entry>
2501               </row>
2502               <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2503 Applicable to the H264 encoder.</entry>
2504               </row>
2505
2506               <row><entry></entry></row>
2507               <row>
2508                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant>&nbsp;</entry>
2509                 <entry>integer</entry>
2510               </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2511 The supplied 32-bit integer is interpreted as follows (bit
2512 0 = least significant bit):</entry>
2513               </row>
2514               <row>
2515                 <entrytbl spanname="descr" cols="2">
2516                   <tbody valign="top">
2517                     <row>
2518                       <entry>Bit 0:15</entry>
2519                       <entry>Slice ID</entry>
2520                     </row>
2521                     <row>
2522                       <entry>Bit 16:32</entry>
2523                       <entry>Slice position or order</entry>
2524                     </row>
2525                   </tbody>
2526                 </entrytbl>
2527               </row>
2528
2529               <row><entry></entry></row>
2530               <row>
2531                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant>&nbsp;</entry>
2532                 <entry>boolean</entry>
2533               </row>
2534               <row><entry spanname="descr">Enables H264 hierarchical coding.
2535 Applicable to the H264 encoder.</entry>
2536               </row>
2537
2538               <row><entry></entry></row>
2539               <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2540                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant>&nbsp;</entry>
2541                 <entry>enum&nbsp;v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2542               </row>
2543               <row><entry spanname="descr">Specifies the hierarchical coding type.
2544 Applicable to the H264 encoder.
2545 Possible values are:</entry>
2546               </row>
2547               <row>
2548                 <entrytbl spanname="descr" cols="2">
2549                   <tbody valign="top">
2550                     <row>
2551                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant>&nbsp;</entry>
2552                       <entry>Hierarchical B coding.</entry>
2553                     </row>
2554                     <row>
2555                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant>&nbsp;</entry>
2556                       <entry>Hierarchical P coding.</entry>
2557                     </row>
2558                   </tbody>
2559                 </entrytbl>
2560               </row>
2561
2562               <row><entry></entry></row>
2563               <row>
2564                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant>&nbsp;</entry>
2565                 <entry>integer</entry>
2566               </row>
2567               <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2568 Applicable to the H264 encoder.</entry>
2569               </row>
2570
2571               <row><entry></entry></row>
2572               <row>
2573                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant>&nbsp;</entry>
2574                 <entry>integer</entry>
2575               </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2576 The supplied 32-bit integer is interpreted as follows (bit
2577 0 = least significant bit):</entry>
2578               </row>
2579               <row>
2580                 <entrytbl spanname="descr" cols="2">
2581                   <tbody valign="top">
2582                     <row>
2583                       <entry>Bit 0:15</entry>
2584                       <entry>QP value</entry>
2585                     </row>
2586                     <row>
2587                       <entry>Bit 16:32</entry>
2588                       <entry>Layer number</entry>
2589                     </row>
2590                   </tbody>
2591                 </entrytbl>
2592               </row>
2593
2594             </tbody>
2595           </tgroup>
2596         </table>
2597       </section>
2598
2599       <section>
2600         <title>MFC 5.1 MPEG Controls</title>
2601
2602         <para>The following MPEG class controls deal with MPEG
2603 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2604 in the S5P family of SoCs by Samsung.
2605 </para>
2606
2607         <table pgwide="1" frame="none" id="mfc51-control-id">
2608           <title>MFC 5.1 Control IDs</title>
2609           <tgroup cols="4">
2610             <colspec colname="c1" colwidth="1*" />
2611             <colspec colname="c2" colwidth="6*" />
2612             <colspec colname="c3" colwidth="2*" />
2613             <colspec colname="c4" colwidth="6*" />
2614             <spanspec namest="c1" nameend="c2" spanname="id" />
2615             <spanspec namest="c2" nameend="c4" spanname="descr" />
2616             <thead>
2617               <row>
2618                 <entry spanname="id" align="left">ID</entry>
2619                 <entry align="left">Type</entry>
2620               </row><row><entry spanname="descr" align="left">Description</entry>
2621               </row>
2622             </thead>
2623             <tbody valign="top">
2624               <row><entry></entry></row>
2625               <row>
2626                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant>&nbsp;</entry>
2627                 <entry>integer</entry>
2628               </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2629 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2630 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2631 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2632 Applicable to the H264 decoder.
2633               </entry>
2634               </row>
2635               <row><entry></entry></row>
2636               <row>
2637                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>&nbsp;</entry>
2638                 <entry>integer</entry>
2639               </row><row><entry spanname="descr">Display delay value for H264 decoder.
2640 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2641 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2642 as a reference picture for subsequent frames.
2643 </entry>
2644               </row>
2645               <row><entry></entry></row>
2646               <row>
2647                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant>&nbsp;</entry>
2648                 <entry>integer</entry>
2649               </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2650 Applicable to the H264 encoder.</entry>
2651               </row>
2652               <row><entry></entry></row>
2653               <row>
2654                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant>&nbsp;</entry>
2655                 <entry>boolean</entry>
2656               </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2657 Applicable to encoders.</entry>
2658               </row>
2659               <row><entry></entry></row>
2660               <row>
2661                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant>&nbsp;</entry>
2662                 <entry>integer</entry>
2663               </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2664 0 = least significant bit):</entry>
2665               </row>
2666               <row>
2667                 <entrytbl spanname="descr" cols="2">
2668                   <tbody valign="top">
2669                     <row>
2670                       <entry>Bit 0:7</entry>
2671                       <entry>V chrominance information</entry>
2672                     </row>
2673                     <row>
2674                       <entry>Bit 8:15</entry>
2675                       <entry>U chrominance information</entry>
2676                     </row>
2677                     <row>
2678                       <entry>Bit 16:23</entry>
2679                       <entry>Y luminance information</entry>
2680                     </row>
2681                     <row>
2682                       <entry>Bit 24:31</entry>
2683                       <entry>Must be zero.</entry>
2684                     </row>
2685                   </tbody>
2686                 </entrytbl>
2687               </row>
2688               <row><entry></entry></row>
2689               <row>
2690                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant>&nbsp;</entry>
2691                 <entry>integer</entry>
2692               </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2693 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2694 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2695 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2696 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2697 </entry>
2698               </row>
2699               <row><entry></entry></row>
2700               <row>
2701                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant>&nbsp;</entry>
2702                 <entry>boolean</entry>
2703               </row><row><entry spanname="descr">Adaptive rate control for dark region.
2704 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2705 Applicable to the H264 encoder.</entry>
2706               </row>
2707               <row><entry></entry></row>
2708               <row>
2709                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant>&nbsp;</entry>
2710                 <entry>boolean</entry>
2711               </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2712 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2713 Applicable to the H264 encoder.</entry>
2714               </row>
2715               <row><entry></entry></row>
2716               <row>
2717                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant>&nbsp;</entry>
2718                 <entry>boolean</entry>
2719               </row><row><entry spanname="descr">Adaptive rate control for static region.
2720 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2721 Applicable to the H264 encoder.</entry>
2722               </row>
2723               <row><entry></entry></row>
2724               <row>
2725                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant>&nbsp;</entry>
2726                 <entry>boolean</entry>
2727               </row><row><entry spanname="descr">Adaptive rate control for activity region.
2728 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2729 Applicable to the H264 encoder.</entry>
2730               </row>
2731               <row><entry></entry></row>
2732               <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2733                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant>&nbsp;</entry>
2734                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2735               </row>
2736               <row><entry spanname="descr">
2737 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2738 a chosen data limit then the frame will be skipped.
2739 Possible values are:</entry>
2740               </row>
2741               <row>
2742                 <entrytbl spanname="descr" cols="2">
2743                   <tbody valign="top">
2744                     <row>
2745                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant>&nbsp;</entry>
2746                       <entry>Frame skip mode is disabled.</entry>
2747                     </row>
2748                     <row>
2749                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant>&nbsp;</entry>
2750                       <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2751                     </row>
2752                     <row>
2753                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant>&nbsp;</entry>
2754                       <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2755                     </row>
2756                   </tbody>
2757                 </entrytbl>
2758               </row>
2759               <row><entry></entry></row>
2760               <row>
2761                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant>&nbsp;</entry>
2762                 <entry>integer</entry>
2763               </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2764 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2765 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2766 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2767 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2768 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2769 the stream will meet tight bandwidth contraints. Applicable to encoders.
2770 </entry>
2771               </row>
2772               <row><entry></entry></row>
2773               <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2774                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant>&nbsp;</entry>
2775                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_force_frame_type</entry>
2776               </row>
2777               <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2778 Possible values are:</entry>
2779               </row>
2780               <row>
2781                 <entrytbl spanname="descr" cols="2">
2782                   <tbody valign="top">
2783                     <row>
2784                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant>&nbsp;</entry>
2785                       <entry>Forcing a specific frame type disabled.</entry>
2786                     </row>
2787                     <row>
2788                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant>&nbsp;</entry>
2789                       <entry>Force an I-frame.</entry>
2790                     </row>
2791                     <row>
2792                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant>&nbsp;</entry>
2793                       <entry>Force a non-coded frame.</entry>
2794                     </row>
2795                   </tbody>
2796                 </entrytbl>
2797               </row>
2798             </tbody>
2799           </tgroup>
2800         </table>
2801       </section>
2802
2803       <section>
2804         <title>CX2341x MPEG Controls</title>
2805
2806         <para>The following MPEG class controls deal with MPEG
2807 encoding settings that are specific to the Conexant CX23415 and
2808 CX23416 MPEG encoding chips.</para>
2809
2810         <table pgwide="1" frame="none" id="cx2341x-control-id">
2811           <title>CX2341x Control IDs</title>
2812           <tgroup cols="4">
2813             <colspec colname="c1" colwidth="1*" />
2814             <colspec colname="c2" colwidth="6*" />
2815             <colspec colname="c3" colwidth="2*" />
2816             <colspec colname="c4" colwidth="6*" />
2817             <spanspec namest="c1" nameend="c2" spanname="id" />
2818             <spanspec namest="c2" nameend="c4" spanname="descr" />
2819             <thead>
2820               <row>
2821                 <entry spanname="id" align="left">ID</entry>
2822                 <entry align="left">Type</entry>
2823               </row><row><entry spanname="descr" align="left">Description</entry>
2824               </row>
2825             </thead>
2826             <tbody valign="top">
2827               <row><entry></entry></row>
2828               <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2829                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant>&nbsp;</entry>
2830                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2831               </row><row><entry spanname="descr">Sets the Spatial
2832 Filter mode (default <constant>MANUAL</constant>). Possible values
2833 are:</entry>
2834               </row>
2835               <row>
2836                 <entrytbl spanname="descr" cols="2">
2837                   <tbody valign="top">
2838                     <row>
2839                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2840                       <entry>Choose the filter manually</entry>
2841                     </row>
2842                     <row>
2843                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2844                       <entry>Choose the filter automatically</entry>
2845                     </row>
2846                   </tbody>
2847                 </entrytbl>
2848               </row>
2849               <row><entry></entry></row>
2850               <row>
2851                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant>&nbsp;</entry>
2852                 <entry>integer&nbsp;(0-15)</entry>
2853               </row><row><entry spanname="descr">The setting for the
2854 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2855               </row>
2856               <row><entry></entry></row>
2857               <row id="luma-spatial-filter-type">
2858                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2859                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2860               </row><row><entry spanname="descr">Select the algorithm
2861 to use for the Luma Spatial Filter (default
2862 <constant>1D_HOR</constant>). Possible values:</entry>
2863               </row>
2864               <row>
2865                 <entrytbl spanname="descr" cols="2">
2866                   <tbody valign="top">
2867                     <row>
2868                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2869                       <entry>No filter</entry>
2870                     </row>
2871                     <row>
2872                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2873                       <entry>One-dimensional horizontal</entry>
2874                     </row>
2875                     <row>
2876                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant>&nbsp;</entry>
2877                       <entry>One-dimensional vertical</entry>
2878                     </row>
2879                     <row>
2880                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant>&nbsp;</entry>
2881                       <entry>Two-dimensional separable</entry>
2882                     </row>
2883                     <row>
2884                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant>&nbsp;</entry>
2885                       <entry>Two-dimensional symmetrical
2886 non-separable</entry>
2887                     </row>
2888                   </tbody>
2889                 </entrytbl>
2890               </row>
2891               <row><entry></entry></row>
2892               <row id="chroma-spatial-filter-type">
2893                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2894                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2895               </row><row><entry spanname="descr">Select the algorithm
2896 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2897 Possible values are:</entry>
2898               </row>
2899               <row>
2900                 <entrytbl spanname="descr" cols="2">
2901                   <tbody valign="top">
2902                     <row>
2903                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2904                       <entry>No filter</entry>
2905                     </row>
2906                     <row>
2907                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2908                       <entry>One-dimensional horizontal</entry>
2909                     </row>
2910                   </tbody>
2911                 </entrytbl>
2912               </row>
2913               <row><entry></entry></row>
2914               <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2915                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant>&nbsp;</entry>
2916                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2917               </row><row><entry spanname="descr">Sets the Temporal
2918 Filter mode (default <constant>MANUAL</constant>). Possible values
2919 are:</entry>
2920               </row>
2921               <row>
2922                 <entrytbl spanname="descr" cols="2">
2923                   <tbody valign="top">
2924                     <row>
2925                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2926                       <entry>Choose the filter manually</entry>
2927                     </row>
2928                     <row>
2929                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2930                       <entry>Choose the filter automatically</entry>
2931                     </row>
2932                   </tbody>
2933                 </entrytbl>
2934               </row>
2935               <row><entry></entry></row>
2936               <row>
2937                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant>&nbsp;</entry>
2938                 <entry>integer&nbsp;(0-31)</entry>
2939               </row><row><entry spanname="descr">The setting for the
2940 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2941 capturing and 0 for scaled capturing.)</entry>
2942               </row>
2943               <row><entry></entry></row>
2944               <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2945                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant>&nbsp;</entry>
2946                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2947               </row><row><entry spanname="descr">Median Filter Type
2948 (default <constant>OFF</constant>). Possible values are:</entry>
2949               </row>
2950               <row>
2951                 <entrytbl spanname="descr" cols="2">
2952                   <tbody valign="top">
2953                     <row>
2954                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2955                       <entry>No filter</entry>
2956                     </row>
2957                     <row>
2958                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant>&nbsp;</entry>
2959                       <entry>Horizontal filter</entry>
2960                     </row>
2961                     <row>
2962                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant>&nbsp;</entry>
2963                       <entry>Vertical filter</entry>
2964                     </row>
2965                     <row>
2966                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant>&nbsp;</entry>
2967                       <entry>Horizontal and vertical filter</entry>
2968                     </row>
2969                     <row>
2970                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant>&nbsp;</entry>
2971                       <entry>Diagonal filter</entry>
2972                     </row>
2973                   </tbody>
2974                 </entrytbl>
2975               </row>
2976               <row><entry></entry></row>
2977               <row>
2978                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2979                 <entry>integer&nbsp;(0-255)</entry>
2980               </row><row><entry spanname="descr">Threshold above which
2981 the luminance median filter is enabled (default 0)</entry>
2982               </row>
2983               <row><entry></entry></row>
2984               <row>
2985                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
2986                 <entry>integer&nbsp;(0-255)</entry>
2987               </row><row><entry spanname="descr">Threshold below which
2988 the luminance median filter is enabled (default 255)</entry>
2989               </row>
2990               <row><entry></entry></row>
2991               <row>
2992                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2993                 <entry>integer&nbsp;(0-255)</entry>
2994               </row><row><entry spanname="descr">Threshold above which
2995 the chroma median filter is enabled (default 0)</entry>
2996               </row>
2997               <row><entry></entry></row>
2998               <row>
2999                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3000                 <entry>integer&nbsp;(0-255)</entry>
3001               </row><row><entry spanname="descr">Threshold below which
3002 the chroma median filter is enabled (default 255)</entry>
3003               </row>
3004               <row><entry></entry></row>
3005               <row>
3006                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant>&nbsp;</entry>
3007                 <entry>boolean</entry>
3008               </row>
3009               <row><entry spanname="descr">The CX2341X MPEG encoder
3010 can insert one empty MPEG-2 PES packet into the stream between every
3011 four video frames. The packet size is 2048 bytes, including the
3012 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
3013 (private stream 2). The payload consists of 0x00 bytes, to be filled
3014 in by the application. 0 = do not insert, 1 = insert packets.</entry>
3015               </row>
3016             </tbody>
3017           </tgroup>
3018         </table>
3019       </section>
3020
3021     <section>
3022       <title>VPX Control Reference</title>
3023
3024       <para>The VPX controls include controls for encoding parameters
3025       of VPx video codec.</para>
3026
3027       <table pgwide="1" frame="none" id="vpx-control-id">
3028       <title>VPX Control IDs</title>
3029
3030       <tgroup cols="4">
3031         <colspec colname="c1" colwidth="1*" />
3032         <colspec colname="c2" colwidth="6*" />
3033         <colspec colname="c3" colwidth="2*" />
3034         <colspec colname="c4" colwidth="6*" />
3035         <spanspec namest="c1" nameend="c2" spanname="id" />
3036         <spanspec namest="c2" nameend="c4" spanname="descr" />
3037         <thead>
3038           <row>
3039             <entry spanname="id" align="left">ID</entry>
3040             <entry align="left">Type</entry>
3041           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3042           </row>
3043         </thead>
3044         <tbody valign="top">
3045           <row><entry></entry></row>
3046
3047               <row><entry></entry></row>
3048               <row id="v4l2-vpx-num-partitions">
3049                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS</constant></entry>
3050                 <entry>enum v4l2_vp8_num_partitions</entry>
3051               </row>
3052               <row><entry spanname="descr">The number of token partitions to use in VP8 encoder.
3053 Possible values are:</entry>
3054               </row>
3055               <row>
3056                 <entrytbl spanname="descr" cols="2">
3057                   <tbody valign="top">
3058                     <row>
3059                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_PARTITION</constant></entry>
3060                       <entry>1 coefficient partition</entry>
3061                     </row>
3062                     <row>
3063                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_PARTITIONS</constant></entry>
3064                       <entry>2 coefficient partitions</entry>
3065                     </row>
3066                     <row>
3067                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_4_PARTITIONS</constant></entry>
3068                       <entry>4 coefficient partitions</entry>
3069                     </row>
3070                     <row>
3071                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_8_PARTITIONS</constant></entry>
3072                       <entry>8 coefficient partitions</entry>
3073                     </row>
3074                   </tbody>
3075                 </entrytbl>
3076               </row>
3077
3078               <row><entry></entry></row>
3079               <row>
3080                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_IMD_DISABLE_4X4</constant></entry>
3081                 <entry>boolean</entry>
3082               </row>
3083               <row><entry spanname="descr">Setting this prevents intra 4x4 mode in the intra mode decision.</entry>
3084               </row>
3085
3086               <row><entry></entry></row>
3087               <row id="v4l2-vpx-num-ref-frames">
3088                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_REF_FRAMES</constant></entry>
3089                 <entry>enum v4l2_vp8_num_ref_frames</entry>
3090               </row>
3091               <row><entry spanname="descr">The number of reference pictures for encoding P frames.
3092 Possible values are:</entry>
3093               </row>
3094               <row>
3095                 <entrytbl spanname="descr" cols="2">
3096                   <tbody valign="top">
3097                     <row>
3098                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_REF_FRAME</constant></entry>
3099                       <entry>Last encoded frame will be searched</entry>
3100                     </row>
3101                     <row>
3102                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_REF_FRAME</constant></entry>
3103                       <entry>Two frames will be searched among the last encoded frame, the golden frame
3104 and the alternate reference (altref) frame. The encoder implementation will decide which two are chosen.</entry>
3105                     </row>
3106                     <row>
3107                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_3_REF_FRAME</constant></entry>
3108                       <entry>The last encoded frame, the golden frame and the altref frame will be searched.</entry>
3109                     </row>
3110                   </tbody>
3111                 </entrytbl>
3112               </row>
3113
3114               <row><entry></entry></row>
3115               <row>
3116                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_LEVEL</constant></entry>
3117                 <entry>integer</entry>
3118               </row>
3119               <row><entry spanname="descr">Indicates the loop filter level. The adjustment of the loop
3120 filter level is done via a delta value against a baseline loop filter value.</entry>
3121               </row>
3122
3123               <row><entry></entry></row>
3124               <row>
3125                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_SHARPNESS</constant></entry>
3126                 <entry>integer</entry>
3127               </row>
3128               <row><entry spanname="descr">This parameter affects the loop filter. Anything above
3129 zero weakens the deblocking effect on the loop filter.</entry>
3130               </row>
3131
3132               <row><entry></entry></row>
3133               <row>
3134                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD</constant></entry>
3135                 <entry>integer</entry>
3136               </row>
3137               <row><entry spanname="descr">Sets the refresh period for the golden frame. The period is defined
3138 in number of frames. For a value of 'n', every nth frame starting from the first key frame will be taken as a golden frame.
3139 For eg. for encoding sequence of 0, 1, 2, 3, 4, 5, 6, 7 where the golden frame refresh period is set as 4, the frames
3140 0, 4, 8 etc will be taken as the golden frames as frame 0 is always a key frame.</entry>
3141               </row>
3142
3143               <row><entry></entry></row>
3144               <row id="v4l2-vpx-golden-frame-sel">
3145                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_SEL</constant></entry>
3146                 <entry>enum v4l2_vp8_golden_frame_sel</entry>
3147               </row>
3148               <row><entry spanname="descr">Selects the golden frame for encoding.
3149 Possible values are:</entry>
3150               </row>
3151               <row>
3152                 <entrytbl spanname="descr" cols="2">
3153                   <tbody valign="top">
3154                     <row>
3155                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_PREV</constant></entry>
3156                       <entry>Use the (n-2)th frame as a golden frame, current frame index being 'n'.</entry>
3157                     </row>
3158                     <row>
3159                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_REF_PERIOD</constant></entry>
3160                       <entry>Use the previous specific frame indicated by
3161 V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD as a golden frame.</entry>
3162                     </row>
3163                   </tbody>
3164                 </entrytbl>
3165               </row>
3166
3167               <row><entry></entry></row>
3168               <row>
3169                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MIN_QP</constant></entry>
3170                 <entry>integer</entry>
3171               </row>
3172               <row><entry spanname="descr">Minimum quantization parameter for VP8.</entry>
3173               </row>
3174
3175               <row><entry></entry></row>
3176               <row>
3177                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MAX_QP</constant></entry>
3178                 <entry>integer</entry>
3179               </row>
3180               <row><entry spanname="descr">Maximum quantization parameter for VP8.</entry>
3181               </row>
3182
3183               <row><entry></entry></row>
3184               <row>
3185                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_I_FRAME_QP</constant>&nbsp;</entry>
3186                 <entry>integer</entry>
3187               </row>
3188               <row><entry spanname="descr">Quantization parameter for an I frame for VP8.</entry>
3189               </row>
3190
3191               <row><entry></entry></row>
3192               <row>
3193                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP</constant>&nbsp;</entry>
3194                 <entry>integer</entry>
3195               </row>
3196               <row><entry spanname="descr">Quantization parameter for a P frame for VP8.</entry>
3197               </row>
3198
3199               <row><entry></entry></row>
3200               <row>
3201                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_PROFILE</constant>&nbsp;</entry>
3202                 <entry>integer</entry>
3203               </row>
3204               <row><entry spanname="descr">Select the desired profile for VPx encoder.
3205 Acceptable values are 0, 1, 2 and 3 corresponding to encoder profiles 0, 1, 2 and 3.</entry>
3206               </row>
3207
3208           <row><entry></entry></row>
3209         </tbody>
3210       </tgroup>
3211       </table>
3212
3213       </section>
3214     </section>
3215
3216     <section id="camera-controls">
3217       <title>Camera Control Reference</title>
3218
3219       <para>The Camera class includes controls for mechanical (or
3220 equivalent digital) features of a device such as controllable lenses
3221 or sensors.</para>
3222
3223     <table pgwide="1" frame="none" id="camera-control-id">
3224       <title>Camera Control IDs</title>
3225       <tgroup cols="4">
3226         <colspec colname="c1" colwidth="1*" />
3227         <colspec colname="c2" colwidth="6*" />
3228         <colspec colname="c3" colwidth="2*" />
3229         <colspec colname="c4" colwidth="6*" />
3230         <spanspec namest="c1" nameend="c2" spanname="id" />
3231         <spanspec namest="c2" nameend="c4" spanname="descr" />
3232         <thead>
3233           <row>
3234             <entry spanname="id" align="left">ID</entry>
3235             <entry align="left">Type</entry>
3236           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3237           </row>
3238         </thead>
3239         <tbody valign="top">
3240           <row><entry></entry></row>
3241           <row>
3242             <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant>&nbsp;</entry>
3243             <entry>class</entry>
3244           </row><row><entry spanname="descr">The Camera class
3245 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3246 description of this control class.</entry>
3247           </row>
3248           <row><entry></entry></row>
3249
3250           <row id="v4l2-exposure-auto-type">
3251             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant>&nbsp;</entry>
3252             <entry>enum&nbsp;v4l2_exposure_auto_type</entry>
3253           </row><row><entry spanname="descr">Enables automatic
3254 adjustments of the exposure time and/or iris aperture. The effect of
3255 manual changes of the exposure time or iris aperture while these
3256 features are enabled is undefined, drivers should ignore such
3257 requests. Possible values are:</entry>
3258           </row>
3259           <row>
3260             <entrytbl spanname="descr" cols="2">
3261               <tbody valign="top">
3262                 <row>
3263                   <entry><constant>V4L2_EXPOSURE_AUTO</constant>&nbsp;</entry>
3264                       <entry>Automatic exposure time, automatic iris
3265 aperture.</entry>
3266                 </row>
3267                 <row>
3268                   <entry><constant>V4L2_EXPOSURE_MANUAL</constant>&nbsp;</entry>
3269                   <entry>Manual exposure time, manual iris.</entry>
3270                 </row>
3271                 <row>
3272                   <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant>&nbsp;</entry>
3273                   <entry>Manual exposure time, auto iris.</entry>
3274                 </row>
3275                 <row>
3276                   <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant>&nbsp;</entry>
3277                   <entry>Auto exposure time, manual iris.</entry>
3278                 </row>
3279               </tbody>
3280             </entrytbl>
3281           </row>
3282           <row><entry></entry></row>
3283
3284           <row>
3285             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant>&nbsp;</entry>
3286             <entry>integer</entry>
3287           </row><row><entry spanname="descr">Determines the exposure
3288 time of the camera sensor. The exposure time is limited by the frame
3289 interval. Drivers should interpret the values as 100 &micro;s units,
3290 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3291 and 100000 for 10 seconds.</entry>
3292           </row>
3293           <row><entry></entry></row>
3294
3295           <row>
3296             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant>&nbsp;</entry>
3297             <entry>boolean</entry>
3298           </row><row><entry spanname="descr">When
3299 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3300 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3301 this control determines if the device may dynamically vary the frame
3302 rate. By default this feature is disabled (0) and the frame rate must
3303 remain constant.</entry>
3304           </row>
3305           <row><entry></entry></row>
3306
3307           <row>
3308             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant>&nbsp;</entry>
3309             <entry>integer menu</entry>
3310           </row><row><entry spanname="descr"> Determines the automatic
3311 exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3312 control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3313 or <constant>APERTURE_PRIORITY</constant>.
3314 It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3315 units, where the value 1000 stands for +1 EV.
3316 <para>Increasing the exposure compensation value is equivalent to decreasing
3317 the exposure value (EV) and will increase the amount of light at the image
3318 sensor. The camera performs the exposure compensation by adjusting absolute
3319 exposure time and/or aperture.</para></entry>
3320           </row>
3321           <row><entry></entry></row>
3322
3323           <row id="v4l2-exposure-metering">
3324             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant>&nbsp;</entry>
3325             <entry>enum&nbsp;v4l2_exposure_metering</entry>
3326           </row><row><entry spanname="descr">Determines how the camera measures
3327 the amount of light available for the frame exposure. Possible values are:</entry>
3328           </row>
3329           <row>
3330             <entrytbl spanname="descr" cols="2">
3331               <tbody valign="top">
3332                 <row>
3333                   <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant>&nbsp;</entry>
3334                   <entry>Use the light information coming from the entire frame
3335 and average giving no weighting to any particular portion of the metered area.
3336                   </entry>
3337                 </row>
3338                 <row>
3339                   <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant>&nbsp;</entry>
3340                   <entry>Average the light information coming from the entire frame
3341 giving priority to the center of the metered area.</entry>
3342                 </row>
3343                 <row>
3344                   <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant>&nbsp;</entry>
3345                   <entry>Measure only very small area at the center of the frame.</entry>
3346                 </row>
3347                 <row>
3348                   <entry><constant>V4L2_EXPOSURE_METERING_MATRIX</constant>&nbsp;</entry>
3349                   <entry>A multi-zone metering. The light intensity is measured
3350 in several points of the frame and the the results are combined. The
3351 algorithm of the zones selection and their significance in calculating the
3352 final value is device dependent.</entry>
3353                 </row>
3354               </tbody>
3355             </entrytbl>
3356           </row>
3357           <row><entry></entry></row>
3358
3359           <row>
3360             <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant>&nbsp;</entry>
3361             <entry>integer</entry>
3362           </row><row><entry spanname="descr">This control turns the
3363 camera horizontally by the specified amount. The unit is undefined. A
3364 positive value moves the camera to the right (clockwise when viewed
3365 from above), a negative value to the left. A value of zero does not
3366 cause motion. This is a write-only control.</entry>
3367           </row>
3368           <row><entry></entry></row>
3369
3370           <row>
3371             <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant>&nbsp;</entry>
3372             <entry>integer</entry>
3373           </row><row><entry spanname="descr">This control turns the
3374 camera vertically by the specified amount. The unit is undefined. A
3375 positive value moves the camera up, a negative value down. A value of
3376 zero does not cause motion. This is a write-only control.</entry>
3377           </row>
3378           <row><entry></entry></row>
3379
3380           <row>
3381             <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant>&nbsp;</entry>
3382             <entry>button</entry>
3383           </row><row><entry spanname="descr">When this control is set,
3384 the camera moves horizontally to the default position.</entry>
3385           </row>
3386           <row><entry></entry></row>
3387
3388           <row>
3389             <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant>&nbsp;</entry>
3390             <entry>button</entry>
3391           </row><row><entry spanname="descr">When this control is set,
3392 the camera moves vertically to the default position.</entry>
3393           </row>
3394           <row><entry></entry></row>
3395
3396           <row>
3397             <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant>&nbsp;</entry>
3398             <entry>integer</entry>
3399           </row><row><entry spanname="descr">This control
3400 turns the camera horizontally to the specified position. Positive
3401 values move the camera to the right (clockwise when viewed from above),
3402 negative values to the left. Drivers should interpret the values as arc
3403 seconds, with valid values between -180 * 3600 and +180 * 3600
3404 inclusive.</entry>
3405           </row>
3406           <row><entry></entry></row>
3407
3408           <row>
3409             <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant>&nbsp;</entry>
3410             <entry>integer</entry>
3411           </row><row><entry spanname="descr">This control
3412 turns the camera vertically to the specified position. Positive values
3413 move the camera up, negative values down. Drivers should interpret the
3414 values as arc seconds, with valid values between -180 * 3600 and +180
3415 * 3600 inclusive.</entry>
3416           </row>
3417           <row><entry></entry></row>
3418
3419           <row>
3420             <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant>&nbsp;</entry>
3421             <entry>integer</entry>
3422           </row><row><entry spanname="descr">This control sets the
3423 focal point of the camera to the specified position. The unit is
3424 undefined. Positive values set the focus closer to the camera,
3425 negative values towards infinity.</entry>
3426           </row>
3427           <row><entry></entry></row>
3428
3429           <row>
3430             <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant>&nbsp;</entry>
3431             <entry>integer</entry>
3432           </row><row><entry spanname="descr">This control moves the
3433 focal point of the camera by the specified amount. The unit is
3434 undefined. Positive values move the focus closer to the camera,
3435 negative values towards infinity. This is a write-only control.</entry>
3436           </row>
3437           <row><entry></entry></row>
3438
3439           <row>
3440             <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant>&nbsp;</entry>
3441             <entry>boolean</entry>
3442           </row><row><entry spanname="descr">Enables continuous automatic
3443 focus adjustments. The effect of manual focus adjustments while this feature
3444 is enabled is undefined, drivers should ignore such requests.</entry>
3445           </row>
3446           <row><entry></entry></row>
3447
3448           <row>
3449             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant>&nbsp;</entry>
3450             <entry>button</entry>
3451           </row><row><entry spanname="descr">Starts single auto focus process.
3452 The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3453 is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3454 such requests.</entry>
3455           </row>
3456           <row><entry></entry></row>
3457
3458           <row>
3459             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant>&nbsp;</entry>
3460             <entry>button</entry>
3461           </row><row><entry spanname="descr">Aborts automatic focusing
3462 started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3463 effective only when the continuous autofocus is disabled, that is when
3464 <constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3465 </constant> (0).</entry>
3466           </row>
3467           <row><entry></entry></row>
3468
3469           <row id="v4l2-auto-focus-status">
3470             <entry spanname="id">
3471               <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>&nbsp;</entry>
3472             <entry>bitmask</entry>
3473           </row>
3474           <row><entry spanname="descr">The automatic focus status. This is a read-only
3475           control.</entry>
3476           </row>
3477           <row>
3478             <entrytbl spanname="descr" cols="2">
3479               <tbody valign="top">
3480                 <row>
3481                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant>&nbsp;</entry>
3482                   <entry>Automatic focus is not active.</entry>
3483                 </row>
3484                 <row>
3485                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant>&nbsp;</entry>
3486                   <entry>Automatic focusing is in progress.</entry>
3487                 </row>
3488                 <row>
3489                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant>&nbsp;</entry>
3490                   <entry>Focus has been reached.</entry>
3491                 </row>
3492                 <row>
3493                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant>&nbsp;</entry>
3494                   <entry>Automatic focus has failed, the driver will not
3495                   transition from this state until another action is
3496                   performed by an application.</entry>
3497                 </row>
3498               </tbody>
3499             </entrytbl>
3500           </row>
3501           <row><entry spanname="descr">
3502 Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3503 </constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3504 control value.</entry>
3505           </row>
3506           <row><entry></entry></row>
3507
3508           <row id="v4l2-auto-focus-range">
3509             <entry spanname="id">
3510               <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant>&nbsp;</entry>
3511             <entry>enum&nbsp;v4l2_auto_focus_range</entry>
3512           </row>
3513           <row><entry spanname="descr">Determines auto focus distance range
3514 for which lens may be adjusted. </entry>
3515           </row>
3516           <row>
3517             <entrytbl spanname="descr" cols="2">
3518               <tbody valign="top">
3519                 <row>
3520                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant>&nbsp;</entry>
3521                   <entry>The camera automatically selects the focus range.</entry>
3522                 </row>
3523                 <row>
3524                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant>&nbsp;</entry>
3525                   <entry>Normal distance range, limited for best automatic focus
3526 performance.</entry>
3527                 </row>
3528                 <row>
3529                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant>&nbsp;</entry>
3530                   <entry>Macro (close-up) auto focus. The camera will
3531 use its minimum possible distance for auto focus.</entry>
3532                 </row>
3533                 <row>
3534                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant>&nbsp;</entry>
3535                   <entry>The lens is set to focus on an object at infinite distance.</entry>
3536                 </row>
3537               </tbody>
3538             </entrytbl>
3539           </row>
3540           <row><entry></entry></row>
3541
3542           <row>
3543             <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant>&nbsp;</entry>
3544             <entry>integer</entry>
3545           </row><row><entry spanname="descr">Specify the objective lens
3546 focal length as an absolute value. The zoom unit is driver-specific and its
3547 value should be a positive integer.</entry>
3548           </row>
3549           <row><entry></entry></row>
3550
3551           <row>
3552             <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant>&nbsp;</entry>
3553             <entry>integer</entry>
3554           </row><row><entry spanname="descr">Specify the objective lens
3555 focal length relatively to the current value. Positive values move the zoom
3556 lens group towards the telephoto direction, negative values towards the
3557 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3558           </row>
3559           <row><entry></entry></row>
3560
3561           <row>
3562             <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant>&nbsp;</entry>
3563             <entry>integer</entry>
3564           </row><row><entry spanname="descr">Move the objective lens group
3565 at the specified speed until it reaches physical device limits or until an
3566 explicit request to stop the movement. A positive value moves the zoom lens
3567 group towards the telephoto direction. A value of zero stops the zoom lens
3568 group movement. A negative value moves the zoom lens group towards the
3569 wide-angle direction. The zoom speed unit is driver-specific.</entry>
3570           </row>
3571           <row><entry></entry></row>
3572
3573           <row>
3574             <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
3575             <entry>integer</entry>
3576           </row><row><entry spanname="descr">This control sets the
3577 camera's aperture to the specified value. The unit is undefined.
3578 Larger values open the iris wider, smaller values close it.</entry>
3579           </row>
3580           <row><entry></entry></row>
3581
3582           <row>
3583             <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
3584             <entry>integer</entry>
3585           </row><row><entry spanname="descr">This control modifies the
3586 camera's aperture by the specified amount. The unit is undefined.
3587 Positive values open the iris one step further, negative values close
3588 it one step further. This is a write-only control.</entry>
3589           </row>
3590           <row><entry></entry></row>
3591
3592           <row>
3593             <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
3594             <entry>boolean</entry>
3595           </row><row><entry spanname="descr">Prevent video from being acquired
3596 by the camera. When this control is set to <constant>TRUE</constant> (1), no
3597 image can be captured by the camera. Common means to enforce privacy are
3598 mechanical obturation of the sensor and firmware image processing, but the
3599 device is not restricted to these methods. Devices that implement the privacy
3600 control must support read access and may support write access.</entry>
3601           </row>
3602
3603           <row>
3604             <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant>&nbsp;</entry>
3605             <entry>integer</entry>
3606           </row><row><entry spanname="descr">Switch the band-stop filter of a
3607 camera sensor on or off, or specify its strength. Such band-stop filters can
3608 be used, for example, to filter out the fluorescent light component.</entry>
3609           </row>
3610           <row><entry></entry></row>
3611
3612           <row id="v4l2-auto-n-preset-white-balance">
3613             <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
3614             <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
3615           </row><row><entry spanname="descr">Sets white balance to automatic,
3616 manual or a preset. The presets determine color temperature of the light as
3617 a hint to the camera for white balance adjustments resulting in most accurate
3618 color representation. The following white balance presets are listed in order
3619 of increasing color temperature.</entry>
3620           </row>
3621           <row>
3622             <entrytbl spanname="descr" cols="2">
3623               <tbody valign="top">
3624                 <row>
3625                   <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
3626                   <entry>Manual white balance.</entry>
3627                 </row>
3628                 <row>
3629                   <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
3630                   <entry>Automatic white balance adjustments.</entry>
3631                 </row>
3632                 <row>
3633                   <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
3634                   <entry>White balance setting for incandescent (tungsten) lighting.
3635 It generally cools down the colors and corresponds approximately to 2500...3500 K
3636 color temperature range.</entry>
3637                 </row>
3638                 <row>
3639                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
3640                   <entry>White balance preset for fluorescent lighting.
3641 It corresponds approximately to 4000...5000 K color temperature.</entry>
3642                 </row>
3643                 <row>
3644                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
3645                   <entry>With this setting the camera will compensate for
3646 fluorescent H lighting.</entry>
3647                 </row>
3648                 <row>
3649                   <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
3650                   <entry>White balance setting for horizon daylight.
3651 It corresponds approximately to 5000 K color temperature.</entry>
3652                 </row>
3653                 <row>
3654                   <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
3655                   <entry>White balance preset for daylight (with clear sky).
3656 It corresponds approximately to 5000...6500 K color temperature.</entry>
3657                 </row>
3658                 <row>
3659                   <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
3660                   <entry>With this setting the camera will compensate for the flash
3661 light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3662 color temperature.</entry>
3663                 </row>
3664                 <row>
3665                   <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
3666                   <entry>White balance preset for moderately overcast sky.
3667 This option corresponds approximately to 6500...8000 K color temperature
3668 range.</entry>
3669                 </row>
3670                 <row>
3671                   <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
3672                   <entry>White balance preset for shade or heavily overcast
3673 sky. It corresponds approximately to 9000...10000 K color temperature.
3674 </entry>
3675                 </row>
3676               </tbody>
3677             </entrytbl>
3678           </row>
3679           <row><entry></entry></row>
3680
3681           <row id="v4l2-wide-dynamic-range">
3682             <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3683             <entry>boolean</entry>
3684           </row>
3685           <row>
3686             <entry spanname="descr">Enables or disables the camera's wide dynamic
3687 range feature. This feature allows to obtain clear images in situations where
3688 intensity of the illumination varies significantly throughout the scene, i.e.
3689 there are simultaneously very dark and very bright areas. It is most commonly
3690 realized in cameras by combining two subsequent frames with different exposure
3691 times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3692 control in the future, if more options are required.</para></footnote></entry>
3693           </row>
3694           <row><entry></entry></row>
3695
3696           <row id="v4l2-image-stabilization">
3697             <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3698             <entry>boolean</entry>
3699           </row>
3700           <row>
3701             <entry spanname="descr">Enables or disables image stabilization.
3702               <footnoteref linkend="ctypeconv"/></entry>
3703           </row>
3704           <row><entry></entry></row>
3705
3706           <row>
3707             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
3708             <entry>integer menu</entry>
3709           </row><row><entry spanname="descr">Determines ISO equivalent of an
3710 image sensor indicating the sensor's sensitivity to light. The numbers are
3711 expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3712 where doubling the sensor sensitivity is represented by doubling the numerical
3713 ISO value. Applications should interpret the values as standard ISO values
3714 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3715 usually support only a subset of standard ISO values. The effect of setting
3716 this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3717 control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3718 </constant> is undefined, drivers should ignore such requests.</entry>
3719           </row>
3720           <row><entry></entry></row>
3721
3722           <row id="v4l2-iso-sensitivity-auto-type">
3723             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3724             <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
3725           </row><row><entry spanname="descr">Enables or disables automatic ISO
3726 sensitivity adjustments.</entry>
3727           </row>
3728           <row>
3729             <entrytbl spanname="descr" cols="2">
3730               <tbody valign="top">
3731                 <row>
3732                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
3733                   <entry>Manual ISO sensitivity.</entry>
3734                 </row>
3735                 <row>
3736                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3737                   <entry>Automatic ISO sensitivity adjustments.</entry>
3738                 </row>
3739               </tbody>
3740             </entrytbl>
3741           </row>
3742           <row><entry></entry></row>
3743
3744           <row id="v4l2-scene-mode">
3745             <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant>&nbsp;</entry>
3746             <entry>enum&nbsp;v4l2_scene_mode</entry>
3747           </row><row><entry spanname="descr">This control allows to select
3748 scene programs as the camera automatic modes optimized for common shooting
3749 scenes. Within these modes the camera determines best exposure, aperture,
3750 focusing, light metering, white balance and equivalent sensitivity. The
3751 controls of those parameters are influenced by the scene mode control.
3752 An exact behavior in each mode is subject to the camera specification.
3753
3754 <para>When the scene mode feature is not used, this control should be set to
3755 <constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3756 related controls are accessible. The following scene programs are defined:
3757 </para>
3758 </entry>
3759           </row>
3760           <row>
3761             <entrytbl spanname="descr" cols="2">
3762               <tbody valign="top">
3763                 <row>
3764                   <entry><constant>V4L2_SCENE_MODE_NONE</constant>&nbsp;</entry>
3765                   <entry>The scene mode feature is disabled.</entry>
3766                 </row>
3767                 <row>
3768                   <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant>&nbsp;</entry>
3769                   <entry>Backlight. Compensates for dark shadows when light is
3770                   coming from behind a subject, also by automatically turning
3771                   on the flash.</entry>
3772                 </row>
3773                 <row>
3774                   <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant>&nbsp;</entry>
3775                   <entry>Beach and snow. This mode compensates for all-white or
3776 bright scenes, which tend to look gray and low contrast, when camera's automatic
3777 exposure is based on an average scene brightness. To compensate, this mode
3778 automatically slightly overexposes the frames. The white balance may also be
3779 adjusted to compensate for the fact that reflected snow looks bluish rather
3780 than white.</entry>
3781                 </row>
3782                 <row>
3783                   <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant>&nbsp;</entry>
3784                   <entry>Candle light. The camera generally raises the ISO
3785 sensitivity and lowers the shutter speed. This mode compensates for relatively
3786 close subject in the scene. The flash is disabled in order to preserve the
3787 ambiance of the light.</entry>
3788                 </row>
3789                 <row>
3790                   <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant>&nbsp;</entry>
3791                   <entry>Dawn and dusk. Preserves the colors seen in low
3792 natural light before dusk and after down. The camera may turn off the flash,
3793 and automatically focus at infinity. It will usually boost saturation and
3794 lower the shutter speed.</entry>
3795                 </row>
3796                 <row>
3797                   <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant>&nbsp;</entry>
3798                   <entry>Fall colors. Increases saturation and adjusts white
3799 balance for color enhancement. Pictures of autumn leaves get saturated reds
3800 and yellows.</entry>
3801                 </row>
3802                 <row>
3803                   <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant>&nbsp;</entry>
3804                   <entry>Fireworks. Long exposure times are used to capture
3805 the expanding burst of light from a firework. The camera may invoke image
3806 stabilization.</entry>
3807                 </row>
3808                 <row>
3809                   <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant>&nbsp;</entry>
3810                   <entry>Landscape. The camera may choose a small aperture to
3811 provide deep depth of field and long exposure duration to help capture detail
3812 in dim light conditions. The focus is fixed at infinity. Suitable for distant
3813 and wide scenery.</entry>
3814                 </row>
3815                 <row>
3816                   <entry><constant>V4L2_SCENE_MODE_NIGHT</constant>&nbsp;</entry>
3817                   <entry>Night, also known as Night Landscape. Designed for low
3818 light conditions, it preserves detail in the dark areas without blowing out bright
3819 objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3820 with a relatively long exposure time, and turns flash off. As such, there will be
3821 increased image noise and the possibility of blurred image.</entry>
3822                 </row>
3823                 <row>
3824                   <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant>&nbsp;</entry>
3825                   <entry>Party and indoor. Designed to capture indoor scenes
3826 that are lit by indoor background lighting as well as the flash. The camera
3827 usually increases ISO sensitivity, and adjusts exposure for the low light
3828 conditions.</entry>
3829                 </row>
3830                 <row>
3831                   <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant>&nbsp;</entry>
3832                   <entry>Portrait. The camera adjusts the aperture so that the
3833 depth of field is reduced, which helps to isolate the subject against a smooth
3834 background. Most cameras recognize the presence of faces in the scene and focus
3835 on them. The color hue is adjusted to enhance skin tones. The intensity of the
3836 flash is often reduced.</entry>
3837                 </row>
3838                 <row>
3839                   <entry><constant>V4L2_SCENE_MODE_SPORTS</constant>&nbsp;</entry>
3840                   <entry>Sports. Significantly increases ISO and uses a fast
3841 shutter speed to freeze motion of rapidly-moving subjects. Increased image
3842 noise may be seen in this mode.</entry>
3843                 </row>
3844                 <row>
3845                   <entry><constant>V4L2_SCENE_MODE_SUNSET</constant>&nbsp;</entry>
3846                   <entry>Sunset. Preserves deep hues seen in sunsets and
3847 sunrises. It bumps up the saturation.</entry>
3848                 </row>
3849                 <row>
3850                   <entry><constant>V4L2_SCENE_MODE_TEXT</constant>&nbsp;</entry>
3851                   <entry>Text. It applies extra contrast and sharpness, it is
3852 typically a black-and-white mode optimized for readability. Automatic focus
3853 may be switched to close-up mode and this setting may also involve some
3854 lens-distortion correction.</entry>
3855                 </row>
3856               </tbody>
3857             </entrytbl>
3858           </row>
3859           <row><entry></entry></row>
3860
3861           <row>
3862             <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3863             <entry>bitmask</entry>
3864           </row>
3865           <row>
3866             <entry spanname="descr">This control locks or unlocks the automatic
3867 focus, exposure and white balance. The automatic adjustments can be paused
3868 independently by setting the corresponding lock bit to 1. The camera then retains
3869 the settings until the lock bit is cleared. The following lock bits are defined:
3870 </entry>
3871           </row>
3872           <row>
3873             <entrytbl spanname="descr" cols="2">
3874               <tbody valign="top">
3875                 <row>
3876                   <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3877                   <entry>Automatic exposure adjustments lock.</entry>
3878                 </row>
3879                 <row>
3880                   <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3881                   <entry>Automatic white balance adjustments lock.</entry>
3882                 </row>
3883                 <row>
3884                   <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3885                   <entry>Automatic focus lock.</entry>
3886                 </row>
3887               </tbody>
3888             </entrytbl>
3889           </row>
3890           <row><entry spanname="descr">
3891 When a given algorithm is not enabled, drivers should ignore requests
3892 to lock it and should return no error. An example might be an application
3893 setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3894 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3895 <constant>FALSE</constant>. The value of this control may be changed
3896 by exposure, white balance or focus controls.</entry>
3897           </row>
3898           <row><entry></entry></row>
3899
3900         </tbody>
3901       </tgroup>
3902     </table>
3903   </section>
3904
3905     <section id="fm-tx-controls">
3906       <title>FM Transmitter Control Reference</title>
3907
3908       <para>The FM Transmitter (FM_TX) class includes controls for common features of
3909 FM transmissions capable devices. Currently this class includes parameters for audio
3910 compression, pilot tone generation, audio deviation limiter, RDS transmission and
3911 tuning power features.</para>
3912
3913       <table pgwide="1" frame="none" id="fm-tx-control-id">
3914       <title>FM_TX Control IDs</title>
3915
3916       <tgroup cols="4">
3917         <colspec colname="c1" colwidth="1*" />
3918         <colspec colname="c2" colwidth="6*" />
3919         <colspec colname="c3" colwidth="2*" />
3920         <colspec colname="c4" colwidth="6*" />
3921         <spanspec namest="c1" nameend="c2" spanname="id" />
3922         <spanspec namest="c2" nameend="c4" spanname="descr" />
3923         <thead>
3924           <row>
3925             <entry spanname="id" align="left">ID</entry>
3926             <entry align="left">Type</entry>
3927           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3928           </row>
3929         </thead>
3930         <tbody valign="top">
3931           <row><entry></entry></row>
3932           <row>
3933             <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant>&nbsp;</entry>
3934             <entry>class</entry>
3935           </row><row><entry spanname="descr">The FM_TX class
3936 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3937 description of this control class.</entry>
3938           </row>
3939           <row>
3940             <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant>&nbsp;</entry>
3941             <entry>integer</entry>
3942           </row>
3943           <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3944 The range and step are driver-specific.</entry>
3945           </row>
3946           <row>
3947             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant>&nbsp;</entry>
3948             <entry>integer</entry>
3949           </row>
3950           <row><entry spanname="descr">Sets the RDS Programme Identification field
3951 for transmission.</entry>
3952           </row>
3953           <row>
3954             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant>&nbsp;</entry>
3955             <entry>integer</entry>
3956           </row>
3957           <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3958 This encodes up to 31 pre-defined programme types.</entry>
3959           </row>
3960           <row>
3961             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant>&nbsp;</entry>
3962             <entry>string</entry>
3963           </row>
3964           <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
3965 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
3966 identification and selection.  In Annex E of <xref linkend="iec62106" />, the RDS specification,
3967 there is a full description of the correct character encoding for Programme Service name strings.
3968 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
3969 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
3970 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
3971           </row>
3972           <row>
3973             <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant>&nbsp;</entry>
3974             <entry>string</entry>
3975           </row>
3976           <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
3977 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
3978 programme-related information or any other text. In these cases, RadioText should be used in addition to
3979 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
3980 in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
3981 used to transmit it, either 32 (2A block) or 64 (2B block).  However, it is also possible
3982 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
3983 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
3984           </row>
3985           <row>
3986             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant>&nbsp;</entry>
3987             <entry>boolean</entry>
3988           </row>
3989           <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
3990 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
3991 distortion and prevent overmodulation.
3992 </entry>
3993           </row>
3994           <row>
3995             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant>&nbsp;</entry>
3996             <entry>integer</entry>
3997           </row>
3998           <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
3999 Unit is in useconds. Step and range are driver-specific.</entry>
4000           </row>
4001           <row>
4002             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant>&nbsp;</entry>
4003             <entry>integer</entry>
4004           </row>
4005           <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
4006 The range and step are driver-specific.</entry>
4007           </row>
4008           <row>
4009             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant>&nbsp;</entry>
4010             <entry>boolean</entry>
4011           </row>
4012           <row><entry spanname="descr">Enables or disables the audio compression feature.
4013 This feature amplifies signals below the threshold by a fixed gain and compresses audio
4014 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
4015           </row>
4016           <row>
4017             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant>&nbsp;</entry>
4018             <entry>integer</entry>
4019           </row>
4020           <row><entry spanname="descr">Sets the gain for audio compression feature. It is
4021 a dB value. The range and step are driver-specific.</entry>
4022           </row>
4023           <row>
4024             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant>&nbsp;</entry>
4025             <entry>integer</entry>
4026           </row>
4027           <row><entry spanname="descr">Sets the threshold level for audio compression freature.
4028 It is a dB value. The range and step are driver-specific.</entry>
4029           </row>
4030           <row>
4031             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant>&nbsp;</entry>
4032             <entry>integer</entry>
4033           </row>
4034           <row><entry spanname="descr">Sets the attack time for audio compression feature.
4035 It is a useconds value. The range and step are driver-specific.</entry>
4036           </row>
4037           <row>
4038             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant>&nbsp;</entry>
4039             <entry>integer</entry>
4040           </row>
4041           <row><entry spanname="descr">Sets the release time for audio compression feature.
4042 It is a useconds value. The range and step are driver-specific.</entry>
4043           </row>
4044           <row>
4045             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant>&nbsp;</entry>
4046             <entry>boolean</entry>
4047           </row>
4048           <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
4049           </row>
4050           <row>
4051             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant>&nbsp;</entry>
4052             <entry>integer</entry>
4053           </row>
4054           <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
4055 in Hz. The range and step are driver-specific.</entry>
4056           </row>
4057           <row>
4058             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant>&nbsp;</entry>
4059             <entry>integer</entry>
4060           </row>
4061           <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
4062 in Hz. The range and step are driver-specific.</entry>
4063           </row>
4064           <row>
4065             <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant>&nbsp;</entry>
4066             <entry>enum v4l2_preemphasis</entry>
4067           </row>
4068           <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
4069 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4070 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_preemphasis
4071 defines possible values for pre-emphasis. Here they are:</entry>
4072         </row><row>
4073         <entrytbl spanname="descr" cols="2">
4074                   <tbody valign="top">
4075                     <row>
4076                       <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant>&nbsp;</entry>
4077                       <entry>No pre-emphasis is applied.</entry>
4078                     </row>
4079                     <row>
4080                       <entry><constant>V4L2_PREEMPHASIS_50_uS</constant>&nbsp;</entry>
4081                       <entry>A pre-emphasis of 50 uS is used.</entry>
4082                     </row>
4083                     <row>
4084                       <entry><constant>V4L2_PREEMPHASIS_75_uS</constant>&nbsp;</entry>
4085                       <entry>A pre-emphasis of 75 uS is used.</entry>
4086                     </row>
4087                   </tbody>
4088                 </entrytbl>
4089
4090           </row>
4091           <row>
4092             <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant>&nbsp;</entry>
4093             <entry>integer</entry>
4094           </row>
4095           <row><entry spanname="descr">Sets the output power level for signal transmission.
4096 Unit is in dBuV. Range and step are driver-specific.</entry>
4097           </row>
4098           <row>
4099             <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant>&nbsp;</entry>
4100             <entry>integer</entry>
4101           </row>
4102           <row><entry spanname="descr">This selects the value of antenna tuning capacitor
4103 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
4104           </row>
4105           <row><entry></entry></row>
4106         </tbody>
4107       </tgroup>
4108       </table>
4109
4110 <para>For more details about RDS specification, refer to
4111 <xref linkend="iec62106" /> document, from CENELEC.</para>
4112     </section>
4113
4114     <section id="flash-controls">
4115       <title>Flash Control Reference</title>
4116
4117       <note>
4118         <title>Experimental</title>
4119
4120         <para>This is an <link linkend="experimental">experimental</link>
4121 interface and may change in the future.</para>
4122       </note>
4123
4124       <para>
4125         The V4L2 flash controls are intended to provide generic access
4126         to flash controller devices. Flash controller devices are
4127         typically used in digital cameras.
4128       </para>
4129
4130       <para>
4131         The interface can support both LED and xenon flash devices. As
4132         of writing this, there is no xenon flash driver using this
4133         interface.
4134       </para>
4135
4136       <section id="flash-controls-use-cases">
4137         <title>Supported use cases</title>
4138
4139         <section>
4140           <title>Unsynchronised LED flash (software strobe)</title>
4141
4142           <para>
4143             Unsynchronised LED flash is controlled directly by the
4144             host as the sensor. The flash must be enabled by the host
4145             before the exposure of the image starts and disabled once
4146             it ends. The host is fully responsible for the timing of
4147             the flash.
4148           </para>
4149
4150           <para>Example of such device: Nokia N900.</para>
4151         </section>
4152
4153         <section>
4154           <title>Synchronised LED flash (hardware strobe)</title>
4155
4156           <para>
4157             The synchronised LED flash is pre-programmed by the host
4158             (power and timeout) but controlled by the sensor through a
4159             strobe signal from the sensor to the flash.
4160           </para>
4161
4162           <para>
4163             The sensor controls the flash duration and timing. This
4164             information typically must be made available to the
4165             sensor.
4166           </para>
4167
4168         </section>
4169
4170         <section>
4171           <title>LED flash as torch</title>
4172
4173           <para>
4174             LED flash may be used as torch in conjunction with another
4175             use case involving camera or individually.
4176           </para>
4177
4178
4179           <table pgwide="1" frame="none" id="flash-control-id">
4180           <title>Flash Control IDs</title>
4181
4182           <tgroup cols="4">
4183         <colspec colname="c1" colwidth="1*" />
4184         <colspec colname="c2" colwidth="6*" />
4185         <colspec colname="c3" colwidth="2*" />
4186         <colspec colname="c4" colwidth="6*" />
4187         <spanspec namest="c1" nameend="c2" spanname="id" />
4188         <spanspec namest="c2" nameend="c4" spanname="descr" />
4189         <thead>
4190           <row>
4191             <entry spanname="id" align="left">ID</entry>
4192             <entry align="left">Type</entry>
4193           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4194           </row>
4195         </thead>
4196         <tbody valign="top">
4197           <row><entry></entry></row>
4198           <row>
4199             <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4200             <entry>class</entry>
4201           </row>
4202           <row>
4203             <entry spanname="descr">The FLASH class descriptor.</entry>
4204           </row>
4205           <row>
4206             <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
4207             <entry>menu</entry>
4208           </row>
4209           <row id="v4l2-flash-led-mode">
4210             <entry spanname="descr">Defines the mode of the flash LED,
4211             the high-power white LED attached to the flash controller.
4212             Setting this control may not be possible in presence of
4213             some faults. See V4L2_CID_FLASH_FAULT.</entry>
4214           </row>
4215           <row>
4216             <entrytbl spanname="descr" cols="2">
4217               <tbody valign="top">
4218                 <row>
4219                   <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4220                   <entry>Off.</entry>
4221                 </row>
4222                 <row>
4223                   <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4224                   <entry>Flash mode.</entry>
4225                 </row>
4226                 <row>
4227                   <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4228                   <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4229                 </row>
4230               </tbody>
4231             </entrytbl>
4232           </row>
4233           <row>
4234             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4235             <entry>menu</entry>
4236           </row>
4237           <row id="v4l2-flash-strobe-source"><entry
4238           spanname="descr">Defines the source of the flash LED
4239           strobe.</entry>
4240           </row>
4241           <row>
4242             <entrytbl spanname="descr" cols="2">
4243               <tbody valign="top">
4244                 <row>
4245                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4246                   <entry>The flash strobe is triggered by using
4247                   the V4L2_CID_FLASH_STROBE control.</entry>
4248                 </row>
4249                 <row>
4250                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4251                   <entry>The flash strobe is triggered by an
4252                   external source. Typically this is a sensor,
4253                   which makes it possible to synchronises the
4254                   flash strobe start to exposure start.</entry>
4255                 </row>
4256               </tbody>
4257             </entrytbl>
4258           </row>
4259           <row>
4260             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4261             <entry>button</entry>
4262           </row>
4263           <row>
4264             <entry spanname="descr">Strobe flash. Valid when
4265             V4L2_CID_FLASH_LED_MODE is set to
4266             V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4267             is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4268             control may not be possible in presence of some faults.
4269             See V4L2_CID_FLASH_FAULT.</entry>
4270           </row>
4271           <row>
4272             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4273             <entry>button</entry>
4274           </row>
4275           <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4276           </row>
4277           <row>
4278             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4279             <entry>boolean</entry>
4280           </row>
4281           <row>
4282             <entry spanname="descr">Strobe status: whether the flash
4283             is strobing at the moment or not. This is a read-only
4284             control.</entry>
4285           </row>
4286           <row>
4287             <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4288             <entry>integer</entry>
4289           </row>
4290           <row>
4291             <entry spanname="descr">Hardware timeout for flash. The
4292             flash strobe is stopped after this period of time has
4293             passed from the start of the strobe.</entry>
4294           </row>
4295           <row>
4296             <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4297             <entry>integer</entry>
4298           </row>
4299           <row>
4300             <entry spanname="descr">Intensity of the flash strobe when
4301             the flash LED is in flash mode
4302             (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4303             (mA) if possible.</entry>
4304           </row>
4305           <row>
4306             <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4307             <entry>integer</entry>
4308           </row>
4309           <row>
4310             <entry spanname="descr">Intensity of the flash LED in
4311             torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4312             milliamps (mA) if possible. Setting this control may not
4313             be possible in presence of some faults. See
4314             V4L2_CID_FLASH_FAULT.</entry>
4315           </row>
4316           <row>
4317             <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4318             <entry>integer</entry>
4319           </row>
4320           <row>
4321             <entry spanname="descr">Intensity of the indicator LED.
4322             The indicator LED may be fully independent of the flash
4323             LED. The unit should be microamps (uA) if possible.</entry>
4324           </row>
4325           <row>
4326             <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4327             <entry>bitmask</entry>
4328           </row>
4329           <row>
4330             <entry spanname="descr">Faults related to the flash. The
4331             faults tell about specific problems in the flash chip
4332             itself or the LEDs attached to it. Faults may prevent
4333             further use of some of the flash controls. In particular,
4334             V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4335             if the fault affects the flash LED. Exactly which faults
4336             have such an effect is chip dependent. Reading the faults
4337             resets the control and returns the chip to a usable state
4338             if possible.</entry>
4339           </row>
4340           <row>
4341             <entrytbl spanname="descr" cols="2">
4342               <tbody valign="top">
4343                 <row>
4344                   <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4345                   <entry>Flash controller voltage to the flash LED
4346                   has exceeded the limit specific to the flash
4347                   controller.</entry>
4348                 </row>
4349                 <row>
4350                   <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4351                   <entry>The flash strobe was still on when
4352                   the timeout set by the user ---
4353                   V4L2_CID_FLASH_TIMEOUT control --- has expired.
4354                   Not all flash controllers may set this in all
4355                   such conditions.</entry>
4356                 </row>
4357                 <row>
4358                   <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4359                   <entry>The flash controller has overheated.</entry>
4360                 </row>
4361                 <row>
4362                   <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4363                   <entry>The short circuit protection of the flash
4364                   controller has been triggered.</entry>
4365                 </row>
4366                 <row>
4367                   <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4368                   <entry>Current in the LED power supply has exceeded the limit
4369                   specific to the flash controller.</entry>
4370                 </row>
4371                 <row>
4372                   <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4373                   <entry>The flash controller has detected a short or open
4374                   circuit condition on the indicator LED.</entry>
4375                 </row>
4376               </tbody>
4377             </entrytbl>
4378           </row>
4379           <row>
4380             <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4381             <entry>boolean</entry>
4382           </row>
4383           <row><entry spanname="descr">Enable or disable charging of the xenon
4384           flash capacitor.</entry>
4385           </row>
4386           <row>
4387             <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4388             <entry>boolean</entry>
4389           </row>
4390           <row>
4391             <entry spanname="descr">Is the flash ready to strobe?
4392             Xenon flashes require their capacitors charged before
4393             strobing. LED flashes often require a cooldown period
4394             after strobe during which another strobe will not be
4395             possible. This is a read-only control.</entry>
4396           </row>
4397           <row><entry></entry></row>
4398         </tbody>
4399           </tgroup>
4400           </table>
4401         </section>
4402       </section>
4403     </section>
4404
4405     <section id="jpeg-controls">
4406       <title>JPEG Control Reference</title>
4407       <para>The JPEG class includes controls for common features of JPEG
4408       encoders and decoders. Currently it includes features for codecs
4409       implementing progressive baseline DCT compression process with
4410       Huffman entrophy coding.</para>
4411       <table pgwide="1" frame="none" id="jpeg-control-id">
4412       <title>JPEG Control IDs</title>
4413
4414       <tgroup cols="4">
4415         <colspec colname="c1" colwidth="1*" />
4416         <colspec colname="c2" colwidth="6*" />
4417         <colspec colname="c3" colwidth="2*" />
4418         <colspec colname="c4" colwidth="6*" />
4419         <spanspec namest="c1" nameend="c2" spanname="id" />
4420         <spanspec namest="c2" nameend="c4" spanname="descr" />
4421         <thead>
4422           <row>
4423             <entry spanname="id" align="left">ID</entry>
4424             <entry align="left">Type</entry>
4425           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4426           </row>
4427         </thead>
4428         <tbody valign="top">
4429           <row><entry></entry></row>
4430           <row>
4431             <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant>&nbsp;</entry>
4432             <entry>class</entry>
4433           </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4434           &VIDIOC-QUERYCTRL; for this control will return a description of this
4435           control class.
4436
4437         </entry>
4438           </row>
4439           <row>
4440             <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4441             <entry>menu</entry>
4442           </row>
4443           <row id="v4l2-jpeg-chroma-subsampling">
4444             <entry spanname="descr">The chroma subsampling factors describe how
4445             each component of an input image is sampled, in respect to maximum
4446             sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4447             clause A.1.1. for more details. The <constant>
4448             V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4449             Cb and Cr components are downsampled after coverting an input image
4450             from RGB to Y'CbCr color space.
4451             </entry>
4452           </row>
4453           <row>
4454             <entrytbl spanname="descr" cols="2">
4455               <tbody valign="top">
4456                 <row>
4457                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4458                   </entry><entry>No chroma subsampling, each pixel has
4459                   Y, Cr and Cb values.</entry>
4460                 </row>
4461                 <row>
4462                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4463                   </entry><entry>Horizontally subsample Cr, Cb components
4464                   by a factor of 2.</entry>
4465                 </row>
4466                 <row>
4467                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4468                   </entry><entry>Subsample Cr, Cb components horizontally
4469                   and vertically by 2.</entry>
4470                 </row>
4471                 <row>
4472                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4473                   </entry><entry>Horizontally subsample Cr, Cb components
4474                   by a factor of 4.</entry>
4475                 </row>
4476                 <row>
4477                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4478                   </entry><entry>Subsample Cr, Cb components horizontally
4479                   by 4 and vertically by 2.</entry>
4480                 </row>
4481                 <row>
4482                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4483                   </entry><entry>Use only luminance component.</entry>
4484                 </row>
4485               </tbody>
4486             </entrytbl>
4487           </row>
4488           <row>
4489             <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4490             </entry><entry>integer</entry>
4491           </row>
4492           <row><entry spanname="descr">
4493               The restart interval determines an interval of inserting RSTm
4494               markers (m = 0..7). The purpose of these markers is to additionally
4495               reinitialize the encoder process, in order to process blocks of
4496               an image independently.
4497               For the lossy compression processes the restart interval unit is
4498               MCU (Minimum Coded Unit) and its value is contained in DRI
4499               (Define Restart Interval) marker. If <constant>
4500               V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4501               DRI and RSTm markers will not be inserted.
4502             </entry>
4503           </row>
4504           <row id="jpeg-quality-control">
4505             <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4506             <entry>integer</entry>
4507           </row>
4508           <row>
4509             <entry spanname="descr">
4510               <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4511               determines trade-off between image quality and size.
4512               It provides simpler method for applications to control image quality,
4513               without a need for direct reconfiguration of luminance and chrominance
4514               quantization tables.
4515
4516               In cases where a driver uses quantization tables configured directly
4517               by an application, using interfaces defined elsewhere, <constant>
4518               V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4519               by driver to 0.
4520
4521               <para>The value range of this control is driver-specific. Only
4522               positive, non-zero values are meaningful. The recommended range
4523               is 1 - 100, where larger values correspond to better image quality.
4524               </para>
4525             </entry>
4526             </row>
4527           <row id="jpeg-active-marker-control">
4528             <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4529             <entry>bitmask</entry>
4530           </row>
4531           <row>
4532             <entry spanname="descr">Specify which JPEG markers are included
4533             in compressed stream. This control is valid only for encoders.
4534             </entry>
4535           </row>
4536           <row>
4537             <entrytbl spanname="descr" cols="2">
4538               <tbody valign="top">
4539                 <row>
4540                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4541                   <entry>Application data segment APP<subscript>0</subscript>.</entry>
4542                 </row><row>
4543                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4544                   <entry>Application data segment APP<subscript>1</subscript>.</entry>
4545                 </row><row>
4546                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4547                   <entry>Comment segment.</entry>
4548                 </row><row>
4549                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4550                   <entry>Quantization tables segment.</entry>
4551                 </row><row>
4552                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4553                   <entry>Huffman tables segment.</entry>
4554                 </row>
4555               </tbody>
4556             </entrytbl>
4557           </row>
4558           <row><entry></entry></row>
4559         </tbody>
4560       </tgroup>
4561       </table>
4562       <para>For more details about JPEG specification, refer
4563       to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4564       <xref linkend="w3c-jpeg-jfif"/>.</para>
4565     </section>
4566
4567     <section id="image-source-controls">
4568       <title>Image Source Control Reference</title>
4569
4570       <note>
4571         <title>Experimental</title>
4572
4573         <para>This is an <link
4574         linkend="experimental">experimental</link> interface and may
4575         change in the future.</para>
4576       </note>
4577
4578       <para>
4579         The Image Source control class is intended for low-level
4580         control of image source devices such as image sensors. The
4581         devices feature an analogue to digital converter and a bus
4582         transmitter to transmit the image data out of the device.
4583       </para>
4584
4585       <table pgwide="1" frame="none" id="image-source-control-id">
4586       <title>Image Source Control IDs</title>
4587
4588       <tgroup cols="4">
4589         <colspec colname="c1" colwidth="1*" />
4590         <colspec colname="c2" colwidth="6*" />
4591         <colspec colname="c3" colwidth="2*" />
4592         <colspec colname="c4" colwidth="6*" />
4593         <spanspec namest="c1" nameend="c2" spanname="id" />
4594         <spanspec namest="c2" nameend="c4" spanname="descr" />
4595         <thead>
4596           <row>
4597             <entry spanname="id" align="left">ID</entry>
4598             <entry align="left">Type</entry>
4599           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4600           </row>
4601         </thead>
4602         <tbody valign="top">
4603           <row><entry></entry></row>
4604           <row>
4605             <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4606             <entry>class</entry>
4607           </row>
4608           <row>
4609             <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4610           </row>
4611           <row>
4612             <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4613             <entry>integer</entry>
4614           </row>
4615           <row>
4616             <entry spanname="descr">Vertical blanking. The idle period
4617             after every frame during which no image data is produced.
4618             The unit of vertical blanking is a line. Every line has
4619             length of the image width plus horizontal blanking at the
4620             pixel rate defined by
4621             <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4622             same sub-device.</entry>
4623           </row>
4624           <row>
4625             <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4626             <entry>integer</entry>
4627           </row>
4628           <row>
4629             <entry spanname="descr">Horizontal blanking. The idle
4630             period after every line of image data during which no
4631             image data is produced. The unit of horizontal blanking is
4632             pixels.</entry>
4633           </row>
4634           <row>
4635             <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4636             <entry>integer</entry>
4637           </row>
4638           <row>
4639             <entry spanname="descr">Analogue gain is gain affecting
4640             all colour components in the pixel matrix. The gain
4641             operation is performed in the analogue domain before A/D
4642             conversion.
4643             </entry>
4644           </row>
4645           <row><entry></entry></row>
4646         </tbody>
4647       </tgroup>
4648       </table>
4649
4650     </section>
4651
4652     <section id="image-process-controls">
4653       <title>Image Process Control Reference</title>
4654
4655       <note>
4656         <title>Experimental</title>
4657
4658         <para>This is an <link
4659         linkend="experimental">experimental</link> interface and may
4660         change in the future.</para>
4661       </note>
4662
4663       <para>
4664         The Image Source control class is intended for low-level control of
4665         image processing functions. Unlike
4666         <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4667         this class affect processing the image, and do not control capturing
4668         of it.
4669       </para>
4670
4671       <table pgwide="1" frame="none" id="image-process-control-id">
4672       <title>Image Source Control IDs</title>
4673
4674       <tgroup cols="4">
4675         <colspec colname="c1" colwidth="1*" />
4676         <colspec colname="c2" colwidth="6*" />
4677         <colspec colname="c3" colwidth="2*" />
4678         <colspec colname="c4" colwidth="6*" />
4679         <spanspec namest="c1" nameend="c2" spanname="id" />
4680         <spanspec namest="c2" nameend="c4" spanname="descr" />
4681         <thead>
4682           <row>
4683             <entry spanname="id" align="left">ID</entry>
4684             <entry align="left">Type</entry>
4685           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4686           </row>
4687         </thead>
4688         <tbody valign="top">
4689           <row><entry></entry></row>
4690           <row>
4691             <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4692             <entry>class</entry>
4693           </row>
4694           <row>
4695             <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4696           </row>
4697           <row>
4698             <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4699             <entry>integer menu</entry>
4700           </row>
4701           <row>
4702             <entry spanname="descr">Data bus frequency. Together with the
4703             media bus pixel code, bus type (clock cycles per sample), the
4704             data bus frequency defines the pixel rate
4705             (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4706             pixel array (or possibly elsewhere, if the device is not an
4707             image sensor). The frame rate can be calculated from the pixel
4708             clock, image width and height and horizontal and vertical
4709             blanking. While the pixel rate control may be defined elsewhere
4710             than in the subdev containing the pixel array, the frame rate
4711             cannot be obtained from that information. This is because only
4712             on the pixel array it can be assumed that the vertical and
4713             horizontal blanking information is exact: no other blanking is
4714             allowed in the pixel array. The selection of frame rate is
4715             performed by selecting the desired horizontal and vertical
4716             blanking. The unit of this control is Hz. </entry>
4717           </row>
4718           <row>
4719             <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4720             <entry>64-bit integer</entry>
4721           </row>
4722           <row>
4723             <entry spanname="descr">Pixel rate in the source pads of
4724             the subdev. This control is read-only and its unit is
4725             pixels / second.
4726             </entry>
4727           </row>
4728           <row>
4729             <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4730             <entry>menu</entry>
4731           </row>
4732           <row id="v4l2-test-pattern">
4733             <entry spanname="descr"> Some capture/display/sensor devices have
4734             the capability to generate test pattern images. These hardware
4735             specific test patterns can be used to test if a device is working
4736             properly.</entry>
4737           </row>
4738           <row><entry></entry></row>
4739         </tbody>
4740       </tgroup>
4741       </table>
4742
4743     </section>
4744
4745     <section id="dv-controls">
4746       <title>Digital Video Control Reference</title>
4747
4748       <note>
4749         <title>Experimental</title>
4750
4751         <para>This is an <link
4752         linkend="experimental">experimental</link> interface and may
4753         change in the future.</para>
4754       </note>
4755
4756       <para>
4757         The Digital Video control class is intended to control receivers
4758         and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4759         <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4760         (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4761         These controls are generally expected to be private to the receiver or transmitter
4762         subdevice that implements them, so they are only exposed on the
4763         <filename>/dev/v4l-subdev*</filename> device node.
4764       </para>
4765
4766       <para>Note that these devices can have multiple input or output pads which are
4767       hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4768       transmit video from/to only one of those pads, the other pads can still be
4769       active when it comes to EDID (Extended Display Identification Data,
4770       <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4771       Protection System, <xref linkend="hdcp" />) processing, allowing the device
4772       to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4773       switching between connectors.</para>
4774
4775       <para>These pads appear in several of the controls in this section as
4776       bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4777       etc. The maximum value of the control is the set of valid pads.</para>
4778
4779       <table pgwide="1" frame="none" id="dv-control-id">
4780       <title>Digital Video Control IDs</title>
4781
4782       <tgroup cols="4">
4783         <colspec colname="c1" colwidth="1*" />
4784         <colspec colname="c2" colwidth="6*" />
4785         <colspec colname="c3" colwidth="2*" />
4786         <colspec colname="c4" colwidth="6*" />
4787         <spanspec namest="c1" nameend="c2" spanname="id" />
4788         <spanspec namest="c2" nameend="c4" spanname="descr" />
4789         <thead>
4790           <row>
4791             <entry spanname="id" align="left">ID</entry>
4792             <entry align="left">Type</entry>
4793           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4794           </row>
4795         </thead>
4796         <tbody valign="top">
4797           <row><entry></entry></row>
4798           <row>
4799             <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4800             <entry>class</entry>
4801           </row>
4802           <row>
4803             <entry spanname="descr">The Digital Video class descriptor.</entry>
4804           </row>
4805           <row>
4806             <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4807             <entry>bitmask</entry>
4808           </row>
4809           <row>
4810             <entry spanname="descr">Many connectors have a hotplug pin which is high
4811             if EDID information is available from the source. This control shows the
4812             state of the hotplug pin as seen by the transmitter.
4813             Each bit corresponds to an output pad on the transmitter. If an output pad
4814             does not have an associated hotplug pin, then the bit for that pad will be 0.
4815             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4816             </entry>
4817           </row>
4818           <row>
4819             <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4820             <entry>bitmask</entry>
4821           </row>
4822           <row>
4823             <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
4824             clock lines. This normally means that the sink has left/entered standby (i.e.
4825             the transmitter can sense that the receiver is ready to receive video).
4826             Each bit corresponds to an output pad on the transmitter. If an output pad
4827             does not have an associated Rx Sense, then the bit for that pad will be 0.
4828             This read-only control is applicable to DVI-D and HDMI devices.
4829             </entry>
4830           </row>
4831           <row>
4832             <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4833             <entry>bitmask</entry>
4834           </row>
4835           <row>
4836             <entry spanname="descr">When the transmitter sees the hotplug signal from the
4837             receiver it will attempt to read the EDID. If set, then the transmitter has read
4838             at least the first block (= 128 bytes).
4839             Each bit corresponds to an output pad on the transmitter. If an output pad
4840             does not support EDIDs, then the bit for that pad will be 0.
4841             This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4842             </entry>
4843           </row>
4844           <row>
4845             <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
4846             <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
4847           </row>
4848           <row>
4849             <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
4850             or in HDMI mode (video + audio + auxiliary data). This control selects which mode
4851             to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
4852             This control is applicable to HDMI connectors.
4853             </entry>
4854           </row>
4855           <row>
4856             <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
4857             <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
4858           </row>
4859           <row>
4860             <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
4861             follows the RGB quantization range specified in the standard for the video interface
4862             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4863             to be compatible with sinks that have not implemented the standard correctly
4864             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4865             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4866             where N is the number of bits per component.
4867             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4868             </entry>
4869           </row>
4870           <row>
4871             <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4872             <entry>bitmask</entry>
4873           </row>
4874           <row>
4875             <entry spanname="descr">Detects whether the receiver receives power from the source
4876             (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
4877             which contains EDID information, such that the source can read the EDID even if
4878             the sink is in standby/power off.
4879             Each bit corresponds to an input pad on the transmitter. If an input pad
4880             cannot detect whether power is present, then the bit for that pad will be 0.
4881             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4882             </entry>
4883           </row>
4884           <row>
4885             <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4886             <entry>enum v4l2_dv_rgb_range</entry>
4887           </row>
4888           <row>
4889             <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
4890             follows the RGB quantization range specified in the standard for the video interface
4891             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4892             to be compatible with sources that have not implemented the standard correctly
4893             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4894             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4895             where N is the number of bits per component.
4896             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4897             </entry>
4898           </row>
4899           <row><entry></entry></row>
4900         </tbody>
4901       </tgroup>
4902       </table>
4903
4904     </section>
4905
4906     <section id="fm-rx-controls">
4907       <title>FM Receiver Control Reference</title>
4908
4909       <para>The FM Receiver (FM_RX) class includes controls for common features of
4910       FM Reception capable devices.</para>
4911
4912       <table pgwide="1" frame="none" id="fm-rx-control-id">
4913       <title>FM_RX Control IDs</title>
4914
4915       <tgroup cols="4">
4916         <colspec colname="c1" colwidth="1*" />
4917         <colspec colname="c2" colwidth="6*" />
4918         <colspec colname="c3" colwidth="2*" />
4919         <colspec colname="c4" colwidth="6*" />
4920         <spanspec namest="c1" nameend="c2" spanname="id" />
4921         <spanspec namest="c2" nameend="c4" spanname="descr" />
4922         <thead>
4923           <row>
4924             <entry spanname="id" align="left">ID</entry>
4925             <entry align="left">Type</entry>
4926           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4927           </row>
4928         </thead>
4929         <tbody valign="top">
4930           <row><entry></entry></row>
4931           <row>
4932             <entry spanname="id"><constant>V4L2_CID_FM_RX_CLASS</constant>&nbsp;</entry>
4933             <entry>class</entry>
4934           </row><row><entry spanname="descr">The FM_RX class
4935 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
4936 description of this control class.</entry>
4937           </row>
4938           <row>
4939             <entry spanname="id"><constant>V4L2_CID_RDS_RECEPTION</constant>&nbsp;</entry>
4940             <entry>boolean</entry>
4941           </row><row><entry spanname="descr">Enables/disables RDS
4942           reception by the radio tuner</entry>
4943           </row>
4944           <row>
4945             <entry spanname="id"><constant>V4L2_CID_TUNE_DEEMPHASIS</constant>&nbsp;</entry>
4946             <entry>enum v4l2_deemphasis</entry>
4947           </row>
4948           <row id="v4l2-deemphasis"><entry spanname="descr">Configures the de-emphasis value for reception.
4949 A de-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4950 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_deemphasis
4951 defines possible values for de-emphasis. Here they are:</entry>
4952         </row><row>
4953         <entrytbl spanname="descr" cols="2">
4954                   <tbody valign="top">
4955                     <row>
4956                       <entry><constant>V4L2_DEEMPHASIS_DISABLED</constant>&nbsp;</entry>
4957                       <entry>No de-emphasis is applied.</entry>
4958                     </row>
4959                     <row>
4960                       <entry><constant>V4L2_DEEMPHASIS_50_uS</constant>&nbsp;</entry>
4961                       <entry>A de-emphasis of 50 uS is used.</entry>
4962                     </row>
4963                     <row>
4964                       <entry><constant>V4L2_DEEMPHASIS_75_uS</constant>&nbsp;</entry>
4965                       <entry>A de-emphasis of 75 uS is used.</entry>
4966                     </row>
4967                   </tbody>
4968                 </entrytbl>
4969
4970           </row>
4971           <row><entry></entry></row>
4972         </tbody>
4973       </tgroup>
4974       </table>
4975
4976       </section>
4977 </section>