2 <title>User Controls</title>
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>
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>
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>
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
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 ⪚ 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
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
55 All controls use machine endianness.
58 <table pgwide="1" frame="none" id="control-id">
59 <title>Control IDs</title>
66 <entry>Description</entry>
71 <entry><constant>V4L2_CID_BASE</constant></entry>
73 <entry>First predefined ID, equal to
74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
77 <entry><constant>V4L2_CID_USER_BASE</constant></entry>
79 <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
82 <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
83 <entry>integer</entry>
84 <entry>Picture brightness, or more precisely, the black
88 <entry><constant>V4L2_CID_CONTRAST</constant></entry>
89 <entry>integer</entry>
90 <entry>Picture contrast or luma gain.</entry>
93 <entry><constant>V4L2_CID_SATURATION</constant></entry>
94 <entry>integer</entry>
95 <entry>Picture color saturation or chroma gain.</entry>
98 <entry><constant>V4L2_CID_HUE</constant></entry>
99 <entry>integer</entry>
100 <entry>Hue or color balance.</entry>
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>
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>
115 <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
116 <entry>integer</entry>
117 <entry>Audio bass adjustment.</entry>
120 <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
121 <entry>integer</entry>
122 <entry>Audio treble adjustment.</entry>
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>
134 <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
135 <entry>boolean</entry>
136 <entry>Loudness mode (bass boost).</entry>
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>
146 <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
147 <entry>boolean</entry>
148 <entry>Automatic white balance (cameras).</entry>
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>
160 <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
161 <entry>integer</entry>
162 <entry>Red chroma balance.</entry>
165 <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
166 <entry>integer</entry>
167 <entry>Blue chroma balance.</entry>
170 <entry><constant>V4L2_CID_GAMMA</constant></entry>
171 <entry>integer</entry>
172 <entry>Gamma adjust.</entry>
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>
182 <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
183 <entry>integer</entry>
184 <entry>Exposure (cameras). [Unit?]</entry>
187 <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
188 <entry>boolean</entry>
189 <entry>Automatic gain/exposure control.</entry>
192 <entry><constant>V4L2_CID_GAIN</constant></entry>
193 <entry>integer</entry>
194 <entry>Gain control.</entry>
197 <entry><constant>V4L2_CID_HFLIP</constant></entry>
198 <entry>boolean</entry>
199 <entry>Mirror the picture horizontally.</entry>
202 <entry><constant>V4L2_CID_VFLIP</constant></entry>
203 <entry>boolean</entry>
204 <entry>Mirror the picture vertically.</entry>
206 <row id="v4l2-power-line-frequency">
207 <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></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>
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
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>
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
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>
247 <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
248 <entry>boolean</entry>
249 <entry>Chroma automatic gain control.</entry>
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>
258 <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
259 <entry>boolean</entry>
260 <entry>Enable the color killer (&ie; force a black & white image in case of a weak video signal).</entry>
262 <row id="v4l2-colorfx">
263 <entry><constant>V4L2_CID_COLORFX</constant></entry>
265 <entry>Selects a color effect. The following values are defined:
270 <entrytbl spanname="descr" cols="2">
273 <entry><constant>V4L2_COLORFX_NONE</constant> </entry>
274 <entry>Color effect is disabled.</entry>
277 <entry><constant>V4L2_COLORFX_ANTIQUE</constant> </entry>
278 <entry>An aging (old photo) effect.</entry>
281 <entry><constant>V4L2_COLORFX_ART_FREEZE</constant> </entry>
282 <entry>Frost color effect.</entry>
285 <entry><constant>V4L2_COLORFX_AQUA</constant> </entry>
286 <entry>Water color, cool tone.</entry>
289 <entry><constant>V4L2_COLORFX_BW</constant> </entry>
290 <entry>Black and white.</entry>
293 <entry><constant>V4L2_COLORFX_EMBOSS</constant> </entry>
294 <entry>Emboss, the highlights and shadows replace light/dark boundaries
295 and low contrast areas are set to a gray background.</entry>
298 <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant> </entry>
299 <entry>Grass green.</entry>
302 <entry><constant>V4L2_COLORFX_NEGATIVE</constant> </entry>
303 <entry>Negative.</entry>
306 <entry><constant>V4L2_COLORFX_SEPIA</constant> </entry>
307 <entry>Sepia tone.</entry>
310 <entry><constant>V4L2_COLORFX_SKETCH</constant> </entry>
311 <entry>Sketch.</entry>
314 <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant> </entry>
315 <entry>Skin whiten.</entry>
318 <entry><constant>V4L2_COLORFX_SKY_BLUE</constant> </entry>
319 <entry>Sky blue.</entry>
322 <entry><constant>V4L2_COLORFX_SOLARIZATION</constant> </entry>
323 <entry>Solarization, the image is partially reversed in tone,
324 only color values above or below a certain threshold are inverted.
328 <entry><constant>V4L2_COLORFX_SILHOUETTE</constant> </entry>
329 <entry>Silhouette (outline).</entry>
332 <entry><constant>V4L2_COLORFX_VIVID</constant> </entry>
333 <entry>Vivid colors.</entry>
336 <entry><constant>V4L2_COLORFX_SET_CBCR</constant> </entry>
337 <entry>The Cb and Cr chroma components are replaced by fixed
338 coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
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.
353 <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
354 <entry>boolean</entry>
355 <entry>Enable Automatic Brightness.</entry>
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>
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>
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>
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
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
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.
415 <entry><constant>V4L2_CID_LASTP1</constant></entry>
417 <entry>End of the predefined control IDs (currently
418 <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
421 <entry><constant>V4L2_CID_PRIVATE_BASE</constant></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>
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>
441 <title>Enumerating all controls</title>
444 &v4l2-queryctrl; queryctrl;
445 &v4l2-querymenu; querymenu;
448 enumerate_menu (void)
450 printf (" Menu items:\n");
452 memset (&querymenu, 0, sizeof (querymenu));
453 querymenu.id = queryctrl.id;
455 for (querymenu.index = queryctrl.minimum;
456 querymenu.index <= queryctrl.maximum;
458 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &querymenu)) {
459 printf (" %s\n", querymenu.name);
464 memset (&queryctrl, 0, sizeof (queryctrl));
466 for (queryctrl.id = V4L2_CID_BASE;
467 queryctrl.id < V4L2_CID_LASTP1;
469 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
470 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
473 printf ("Control %s\n", queryctrl.name);
475 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
481 perror ("VIDIOC_QUERYCTRL");
486 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
488 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
489 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
492 printf ("Control %s\n", queryctrl.name);
494 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
500 perror ("VIDIOC_QUERYCTRL");
508 <title>Changing controls</title>
511 &v4l2-queryctrl; queryctrl;
512 &v4l2-control; control;
514 memset (&queryctrl, 0, sizeof (queryctrl));
515 queryctrl.id = V4L2_CID_BRIGHTNESS;
517 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
518 if (errno != EINVAL) {
519 perror ("VIDIOC_QUERYCTRL");
522 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
524 } else if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) {
525 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
527 memset (&control, 0, sizeof (control));
528 control.id = V4L2_CID_BRIGHTNESS;
529 control.value = queryctrl.default_value;
531 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)) {
532 perror ("VIDIOC_S_CTRL");
537 memset (&control, 0, sizeof (control));
538 control.id = V4L2_CID_CONTRAST;
540 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &control)) {
543 /* The driver may clamp the value or return ERANGE, ignored here */
545 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)
546 && errno != ERANGE) {
547 perror ("VIDIOC_S_CTRL");
550 /* Ignore if V4L2_CID_CONTRAST is unsupported */
551 } else if (errno != EINVAL) {
552 perror ("VIDIOC_G_CTRL");
556 control.id = V4L2_CID_AUDIO_MUTE;
557 control.value = TRUE; /* silence */
560 ioctl (fd, VIDIOC_S_CTRL, &control);
565 <section id="extended-controls">
566 <title>Extended Controls</title>
569 <title>Introduction</title>
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
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>
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>
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>
598 <title>The Extended Control API</title>
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
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>
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
622 <para>It is also possible to use an empty control array (count
623 == 0) to check whether the specified control class is
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>
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>
643 All controls use machine endianness.
648 <title>Enumerating Extended Controls</title>
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>
656 &v4l2-queryctrl; qctrl;
658 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
659 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
661 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
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>
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>
680 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
681 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
682 if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
685 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
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 (⪚ <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>
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>
711 <title>Creating Control Panels</title>
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>
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>
727 <section id="mpeg-controls">
728 <title>Codec Control Reference</title>
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>
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>
740 <title>Generic Codec Controls</title>
742 <table pgwide="1" frame="none" id="mpeg-control-id">
743 <title>Codec Control IDs</title>
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" />
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>
759 <row><entry></entry></row>
761 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant> </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>
768 <row><entry></entry></row>
769 <row id="v4l2-mpeg-stream-type">
770 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant> </entry>
771 <entry>enum 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>
779 <entrytbl spanname="descr" cols="2">
782 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant> </entry>
783 <entry>MPEG-2 program stream</entry>
786 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant> </entry>
787 <entry>MPEG-2 transport stream</entry>
790 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant> </entry>
791 <entry>MPEG-1 system stream</entry>
794 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant> </entry>
795 <entry>MPEG-2 DVD-compatible stream</entry>
798 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant> </entry>
799 <entry>MPEG-1 VCD-compatible stream</entry>
802 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant> </entry>
803 <entry>MPEG-2 SVCD-compatible stream</entry>
808 <row><entry></entry></row>
810 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant> </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>
815 <row><entry></entry></row>
817 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant> </entry>
818 <entry>integer</entry>
819 </row><row><entry spanname="descr">Audio Packet ID for
820 the MPEG transport stream (default 256)</entry>
822 <row><entry></entry></row>
824 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant> </entry>
825 <entry>integer</entry>
826 </row><row><entry spanname="descr">Video Packet ID for
827 the MPEG transport stream (default 260)</entry>
829 <row><entry></entry></row>
831 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant> </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>
836 <row><entry></entry></row>
838 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant> </entry>
839 <entry>integer</entry>
840 </row><row><entry spanname="descr">Audio ID for MPEG
843 <row><entry></entry></row>
845 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant> </entry>
846 <entry>integer</entry>
847 </row><row><entry spanname="descr">Video ID for MPEG
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> </entry>
853 <entry>enum v4l2_mpeg_stream_vbi_fmt</entry>
854 </row><row><entry spanname="descr">Some cards can embed
855 VBI data (⪚ 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
862 <entrytbl spanname="descr" cols="2">
865 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant> </entry>
866 <entry>No VBI in the MPEG stream</entry>
869 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant> </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>
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> </entry>
879 <entry>enum v4l2_mpeg_audio_sampling_freq</entry>
880 </row><row><entry spanname="descr">MPEG Audio sampling
881 frequency. Possible values are:</entry>
884 <entrytbl spanname="descr" cols="2">
887 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant> </entry>
888 <entry>44.1 kHz</entry>
891 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant> </entry>
892 <entry>48 kHz</entry>
895 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant> </entry>
896 <entry>32 kHz</entry>
901 <row><entry></entry></row>
902 <row id="v4l2-mpeg-audio-encoding">
903 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant> </entry>
904 <entry>enum 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>
910 <entrytbl spanname="descr" cols="2">
913 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant> </entry>
914 <entry>MPEG-1/2 Layer I encoding</entry>
917 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant> </entry>
918 <entry>MPEG-1/2 Layer II encoding</entry>
921 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant> </entry>
922 <entry>MPEG-1/2 Layer III encoding</entry>
925 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant> </entry>
926 <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
929 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant> </entry>
930 <entry>AC-3 aka ATSC A/52 encoding</entry>
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> </entry>
938 <entry>enum v4l2_mpeg_audio_l1_bitrate</entry>
939 </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
940 Possible values are:</entry>
943 <entrytbl spanname="descr" cols="2">
946 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant> </entry>
947 <entry>32 kbit/s</entry></row>
949 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant> </entry>
950 <entry>64 kbit/s</entry>
953 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant> </entry>
954 <entry>96 kbit/s</entry>
957 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant> </entry>
958 <entry>128 kbit/s</entry>
961 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant> </entry>
962 <entry>160 kbit/s</entry>
965 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant> </entry>
966 <entry>192 kbit/s</entry>
969 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant> </entry>
970 <entry>224 kbit/s</entry>
973 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant> </entry>
974 <entry>256 kbit/s</entry>
977 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant> </entry>
978 <entry>288 kbit/s</entry>
981 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant> </entry>
982 <entry>320 kbit/s</entry>
985 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant> </entry>
986 <entry>352 kbit/s</entry>
989 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant> </entry>
990 <entry>384 kbit/s</entry>
993 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant> </entry>
994 <entry>416 kbit/s</entry>
997 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant> </entry>
998 <entry>448 kbit/s</entry>
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> </entry>
1006 <entry>enum v4l2_mpeg_audio_l2_bitrate</entry>
1007 </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1008 Possible values are:</entry>
1011 <entrytbl spanname="descr" cols="2">
1012 <tbody valign="top">
1014 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant> </entry>
1015 <entry>32 kbit/s</entry>
1018 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant> </entry>
1019 <entry>48 kbit/s</entry>
1022 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant> </entry>
1023 <entry>56 kbit/s</entry>
1026 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant> </entry>
1027 <entry>64 kbit/s</entry>
1030 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant> </entry>
1031 <entry>80 kbit/s</entry>
1034 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant> </entry>
1035 <entry>96 kbit/s</entry>
1038 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant> </entry>
1039 <entry>112 kbit/s</entry>
1042 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant> </entry>
1043 <entry>128 kbit/s</entry>
1046 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant> </entry>
1047 <entry>160 kbit/s</entry>
1050 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant> </entry>
1051 <entry>192 kbit/s</entry>
1054 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant> </entry>
1055 <entry>224 kbit/s</entry>
1058 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant> </entry>
1059 <entry>256 kbit/s</entry>
1062 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant> </entry>
1063 <entry>320 kbit/s</entry>
1066 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant> </entry>
1067 <entry>384 kbit/s</entry>
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> </entry>
1075 <entry>enum v4l2_mpeg_audio_l3_bitrate</entry>
1076 </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1077 Possible values are:</entry>
1080 <entrytbl spanname="descr" cols="2">
1081 <tbody valign="top">
1083 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant> </entry>
1084 <entry>32 kbit/s</entry>
1087 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant> </entry>
1088 <entry>40 kbit/s</entry>
1091 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant> </entry>
1092 <entry>48 kbit/s</entry>
1095 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant> </entry>
1096 <entry>56 kbit/s</entry>
1099 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant> </entry>
1100 <entry>64 kbit/s</entry>
1103 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant> </entry>
1104 <entry>80 kbit/s</entry>
1107 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant> </entry>
1108 <entry>96 kbit/s</entry>
1111 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant> </entry>
1112 <entry>112 kbit/s</entry>
1115 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant> </entry>
1116 <entry>128 kbit/s</entry>
1119 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant> </entry>
1120 <entry>160 kbit/s</entry>
1123 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant> </entry>
1124 <entry>192 kbit/s</entry>
1127 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant> </entry>
1128 <entry>224 kbit/s</entry>
1131 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant> </entry>
1132 <entry>256 kbit/s</entry>
1135 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant> </entry>
1136 <entry>320 kbit/s</entry>
1141 <row><entry></entry></row>
1143 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant> </entry>
1144 <entry>integer</entry>
1145 </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
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> </entry>
1150 <entry>enum v4l2_mpeg_audio_ac3_bitrate</entry>
1151 </row><row><entry spanname="descr">AC-3 bitrate.
1152 Possible values are:</entry>
1155 <entrytbl spanname="descr" cols="2">
1156 <tbody valign="top">
1158 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant> </entry>
1159 <entry>32 kbit/s</entry>
1162 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant> </entry>
1163 <entry>40 kbit/s</entry>
1166 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant> </entry>
1167 <entry>48 kbit/s</entry>
1170 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant> </entry>
1171 <entry>56 kbit/s</entry>
1174 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant> </entry>
1175 <entry>64 kbit/s</entry>
1178 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant> </entry>
1179 <entry>80 kbit/s</entry>
1182 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant> </entry>
1183 <entry>96 kbit/s</entry>
1186 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant> </entry>
1187 <entry>112 kbit/s</entry>
1190 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant> </entry>
1191 <entry>128 kbit/s</entry>
1194 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant> </entry>
1195 <entry>160 kbit/s</entry>
1198 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant> </entry>
1199 <entry>192 kbit/s</entry>
1202 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant> </entry>
1203 <entry>224 kbit/s</entry>
1206 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant> </entry>
1207 <entry>256 kbit/s</entry>
1210 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant> </entry>
1211 <entry>320 kbit/s</entry>
1214 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant> </entry>
1215 <entry>384 kbit/s</entry>
1218 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant> </entry>
1219 <entry>448 kbit/s</entry>
1222 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant> </entry>
1223 <entry>512 kbit/s</entry>
1226 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant> </entry>
1227 <entry>576 kbit/s</entry>
1230 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant> </entry>
1231 <entry>640 kbit/s</entry>
1236 <row><entry></entry></row>
1237 <row id="v4l2-mpeg-audio-mode">
1238 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant> </entry>
1239 <entry>enum v4l2_mpeg_audio_mode</entry>
1240 </row><row><entry spanname="descr">MPEG Audio mode.
1241 Possible values are:</entry>
1244 <entrytbl spanname="descr" cols="2">
1245 <tbody valign="top">
1247 <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant> </entry>
1248 <entry>Stereo</entry>
1251 <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant> </entry>
1252 <entry>Joint Stereo</entry>
1255 <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant> </entry>
1256 <entry>Bilingual</entry>
1259 <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant> </entry>
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> </entry>
1268 <entry>enum 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
1276 <entrytbl spanname="descr" cols="2">
1277 <tbody valign="top">
1279 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant> </entry>
1280 <entry>Subbands 4-31 in intensity stereo</entry>
1283 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant> </entry>
1284 <entry>Subbands 8-31 in intensity stereo</entry>
1287 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant> </entry>
1288 <entry>Subbands 12-31 in intensity stereo</entry>
1291 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant> </entry>
1292 <entry>Subbands 16-31 in intensity stereo</entry>
1297 <row><entry></entry></row>
1298 <row id="v4l2-mpeg-audio-emphasis">
1299 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant> </entry>
1300 <entry>enum v4l2_mpeg_audio_emphasis</entry>
1301 </row><row><entry spanname="descr">Audio Emphasis.
1302 Possible values are:</entry>
1305 <entrytbl spanname="descr" cols="2">
1306 <tbody valign="top">
1308 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant> </entry>
1312 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant> </entry>
1313 <entry>50/15 microsecond emphasis</entry>
1316 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant> </entry>
1317 <entry>CCITT J.17</entry>
1322 <row><entry></entry></row>
1323 <row id="v4l2-mpeg-audio-crc">
1324 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant> </entry>
1325 <entry>enum v4l2_mpeg_audio_crc</entry>
1326 </row><row><entry spanname="descr">CRC method. Possible
1330 <entrytbl spanname="descr" cols="2">
1331 <tbody valign="top">
1333 <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant> </entry>
1337 <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant> </entry>
1338 <entry>16 bit parity check</entry>
1343 <row><entry></entry></row>
1345 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant> </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>
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> </entry>
1355 <entry>enum 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>
1360 <entrytbl spanname="descr" cols="2">
1361 <tbody valign="top">
1363 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant> </entry>
1364 <entry>Automatically determines the best playback mode.</entry>
1367 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant> </entry>
1368 <entry>Stereo playback.</entry>
1371 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant> </entry>
1372 <entry>Left channel playback.</entry>
1375 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant> </entry>
1376 <entry>Right channel playback.</entry>
1379 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant> </entry>
1380 <entry>Mono playback.</entry>
1383 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant> </entry>
1384 <entry>Stereo playback with swapped left and right channels.</entry>
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> </entry>
1392 <entry>enum v4l2_mpeg_audio_dec_playback</entry>
1393 </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1395 <row><entry></entry></row>
1396 <row id="v4l2-mpeg-video-encoding">
1397 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant> </entry>
1398 <entry>enum 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>
1404 <entrytbl spanname="descr" cols="2">
1405 <tbody valign="top">
1407 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant> </entry>
1408 <entry>MPEG-1 Video encoding</entry>
1411 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant> </entry>
1412 <entry>MPEG-2 Video encoding</entry>
1415 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant> </entry>
1416 <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1421 <row><entry></entry></row>
1422 <row id="v4l2-mpeg-video-aspect">
1423 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant> </entry>
1424 <entry>enum v4l2_mpeg_video_aspect</entry>
1425 </row><row><entry spanname="descr">Video aspect.
1426 Possible values are:</entry>
1429 <entrytbl spanname="descr" cols="2">
1430 <tbody valign="top">
1432 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant> </entry>
1435 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant> </entry>
1438 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant> </entry>
1441 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant> </entry>
1446 <row><entry></entry></row>
1448 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant> </entry>
1449 <entry>integer</entry>
1450 </row><row><entry spanname="descr">Number of B-Frames
1453 <row><entry></entry></row>
1455 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant> </entry>
1456 <entry>integer</entry>
1457 </row><row><entry spanname="descr">GOP size (default
1460 <row><entry></entry></row>
1462 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant> </entry>
1463 <entry>boolean</entry>
1464 </row><row><entry spanname="descr">GOP closure (default
1467 <row><entry></entry></row>
1469 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant> </entry>
1470 <entry>boolean</entry>
1471 </row><row><entry spanname="descr">Enable 3:2 pulldown
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> </entry>
1477 <entry>enum v4l2_mpeg_video_bitrate_mode</entry>
1478 </row><row><entry spanname="descr">Video bitrate mode.
1479 Possible values are:</entry>
1482 <entrytbl spanname="descr" cols="2">
1483 <tbody valign="top">
1485 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant> </entry>
1486 <entry>Variable bitrate</entry>
1489 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant> </entry>
1490 <entry>Constant bitrate</entry>
1495 <row><entry></entry></row>
1497 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant> </entry>
1498 <entry>integer</entry>
1499 </row><row><entry spanname="descr">Video bitrate in bits
1502 <row><entry></entry></row>
1504 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant> </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
1511 <row><entry></entry></row>
1513 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant> </entry>
1514 <entry>integer</entry>
1515 </row><row><entry spanname="descr">For every captured
1516 frame, skip this many subsequent frames (default 0).</entry>
1518 <row><entry></entry></row>
1520 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant> </entry>
1521 <entry>boolean</entry>
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>
1527 <row><entry></entry></row>
1529 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant> </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>
1536 <entrytbl spanname="descr" cols="2">
1537 <tbody valign="top">
1539 <entry>Bit 0:7</entry>
1540 <entry>V chrominance information</entry>
1543 <entry>Bit 8:15</entry>
1544 <entry>U chrominance information</entry>
1547 <entry>Bit 16:23</entry>
1548 <entry>Y luminance information</entry>
1551 <entry>Bit 24:31</entry>
1552 <entry>Must be zero.</entry>
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> </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>
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> </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>
1574 <row><entry></entry></row>
1576 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant> </entry>
1577 <entry>boolean</entry>
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.
1584 <row><entry></entry></row>
1586 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant> </entry>
1587 <entry>boolean</entry>
1589 <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1590 Applicable to the H264 encoder.</entry>
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> </entry>
1596 <entry>enum v4l2_mpeg_video_h264_vui_sar_idc</entry>
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>
1602 <entrytbl spanname="descr" cols="2">
1603 <tbody valign="top">
1606 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant> </entry>
1607 <entry>Unspecified</entry>
1610 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant> </entry>
1614 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant> </entry>
1615 <entry>12x11</entry>
1618 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant> </entry>
1619 <entry>10x11</entry>
1622 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant> </entry>
1623 <entry>16x11</entry>
1626 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant> </entry>
1627 <entry>40x33</entry>
1630 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant> </entry>
1631 <entry>24x11</entry>
1634 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant> </entry>
1635 <entry>20x11</entry>
1638 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant> </entry>
1639 <entry>32x11</entry>
1642 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant> </entry>
1643 <entry>80x33</entry>
1646 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant> </entry>
1647 <entry>18x11</entry>
1650 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant> </entry>
1651 <entry>15x11</entry>
1654 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant> </entry>
1655 <entry>64x33</entry>
1658 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant> </entry>
1659 <entry>160x99</entry>
1662 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant> </entry>
1666 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant> </entry>
1670 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant> </entry>
1674 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant> </entry>
1675 <entry>Extended SAR</entry>
1681 <row><entry></entry></row>
1683 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant> </entry>
1684 <entry>integer</entry>
1686 <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1687 Applicable to the H264 encoder.</entry>
1690 <row><entry></entry></row>
1692 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant> </entry>
1693 <entry>integer</entry>
1695 <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1696 Applicable to the H264 encoder.</entry>
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> </entry>
1702 <entry>enum v4l2_mpeg_video_h264_level</entry>
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>
1709 <entrytbl spanname="descr" cols="2">
1710 <tbody valign="top">
1712 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant> </entry>
1713 <entry>Level 1.0</entry>
1716 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant> </entry>
1717 <entry>Level 1B</entry>
1720 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant> </entry>
1721 <entry>Level 1.1</entry>
1724 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant> </entry>
1725 <entry>Level 1.2</entry>
1728 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant> </entry>
1729 <entry>Level 1.3</entry>
1732 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant> </entry>
1733 <entry>Level 2.0</entry>
1736 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant> </entry>
1737 <entry>Level 2.1</entry>
1740 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant> </entry>
1741 <entry>Level 2.2</entry>
1744 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant> </entry>
1745 <entry>Level 3.0</entry>
1748 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant> </entry>
1749 <entry>Level 3.1</entry>
1752 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant> </entry>
1753 <entry>Level 3.2</entry>
1756 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant> </entry>
1757 <entry>Level 4.0</entry>
1760 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant> </entry>
1761 <entry>Level 4.1</entry>
1764 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant> </entry>
1765 <entry>Level 4.2</entry>
1768 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant> </entry>
1769 <entry>Level 5.0</entry>
1772 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant> </entry>
1773 <entry>Level 5.1</entry>
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> </entry>
1782 <entry>enum v4l2_mpeg_video_mpeg4_level</entry>
1784 <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1785 Applicable to the MPEG4 encoder.
1786 Possible values are:</entry>
1789 <entrytbl spanname="descr" cols="2">
1790 <tbody valign="top">
1792 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant> </entry>
1793 <entry>Level 0</entry>
1796 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant> </entry>
1797 <entry>Level 0b</entry>
1800 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant> </entry>
1801 <entry>Level 1</entry>
1804 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant> </entry>
1805 <entry>Level 2</entry>
1808 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant> </entry>
1809 <entry>Level 3</entry>
1812 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant> </entry>
1813 <entry>Level 3b</entry>
1816 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant> </entry>
1817 <entry>Level 4</entry>
1820 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant> </entry>
1821 <entry>Level 5</entry>
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> </entry>
1830 <entry>enum v4l2_mpeg_video_h264_profile</entry>
1832 <row><entry spanname="descr">The profile information for H264.
1833 Applicable to the H264 encoder.
1834 Possible values are:</entry>
1837 <entrytbl spanname="descr" cols="2">
1838 <tbody valign="top">
1840 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant> </entry>
1841 <entry>Baseline profile</entry>
1844 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant> </entry>
1845 <entry>Constrained Baseline profile</entry>
1848 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant> </entry>
1849 <entry>Main profile</entry>
1852 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant> </entry>
1853 <entry>Extended profile</entry>
1856 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant> </entry>
1857 <entry>High profile</entry>
1860 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant> </entry>
1861 <entry>High 10 profile</entry>
1864 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant> </entry>
1865 <entry>High 422 profile</entry>
1868 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant> </entry>
1869 <entry>High 444 Predictive profile</entry>
1872 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant> </entry>
1873 <entry>High 10 Intra profile</entry>
1876 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant> </entry>
1877 <entry>High 422 Intra profile</entry>
1880 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant> </entry>
1881 <entry>High 444 Intra profile</entry>
1884 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant> </entry>
1885 <entry>CAVLC 444 Intra profile</entry>
1888 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant> </entry>
1889 <entry>Scalable Baseline profile</entry>
1892 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant> </entry>
1893 <entry>Scalable High profile</entry>
1896 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant> </entry>
1897 <entry>Scalable High Intra profile</entry>
1900 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant> </entry>
1901 <entry>Stereo High profile</entry>
1904 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant> </entry>
1905 <entry>Multiview High profile</entry>
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> </entry>
1915 <entry>enum v4l2_mpeg_video_mpeg4_profile</entry>
1917 <row><entry spanname="descr">The profile information for MPEG4.
1918 Applicable to the MPEG4 encoder.
1919 Possible values are:</entry>
1922 <entrytbl spanname="descr" cols="2">
1923 <tbody valign="top">
1925 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant> </entry>
1926 <entry>Simple profile</entry>
1929 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant> </entry>
1930 <entry>Advanced Simple profile</entry>
1933 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant> </entry>
1934 <entry>Core profile</entry>
1937 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant> </entry>
1938 <entry>Simple Scalable profile</entry>
1941 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant> </entry>
1948 <row><entry></entry></row>
1950 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant> </entry>
1951 <entry>integer</entry>
1953 <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1954 Applicable to the encoder.
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> </entry>
1961 <entry>enum v4l2_mpeg_video_multi_slice_mode</entry>
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>
1968 <entrytbl spanname="descr" cols="2">
1969 <tbody valign="top">
1971 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant> </entry>
1972 <entry>Single slice per frame.</entry>
1975 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant> </entry>
1976 <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1979 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant> </entry>
1980 <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1986 <row><entry></entry></row>
1988 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant> </entry>
1989 <entry>integer</entry>
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>
1996 <row><entry></entry></row>
1998 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant> </entry>
1999 <entry>integer</entry>
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>
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> </entry>
2009 <entry>enum v4l2_mpeg_video_h264_loop_filter_mode</entry>
2011 <row><entry spanname="descr">Loop filter mode for H264 encoder.
2012 Possible values are:</entry>
2015 <entrytbl spanname="descr" cols="2">
2016 <tbody valign="top">
2018 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant> </entry>
2019 <entry>Loop filter is enabled.</entry>
2022 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant> </entry>
2023 <entry>Loop filter is disabled.</entry>
2026 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant> </entry>
2027 <entry>Loop filter is disabled at the slice boundary.</entry>
2033 <row><entry></entry></row>
2035 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant> </entry>
2036 <entry>integer</entry>
2038 <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2039 Applicable to the H264 encoder.</entry>
2042 <row><entry></entry></row>
2044 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant> </entry>
2045 <entry>integer</entry>
2047 <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2048 Applicable to the H264 encoder.</entry>
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> </entry>
2054 <entry>enum v4l2_mpeg_video_h264_entropy_mode</entry>
2056 <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2057 Applicable to the H264 encoder.
2058 Possible values are:</entry>
2061 <entrytbl spanname="descr" cols="2">
2062 <tbody valign="top">
2064 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant> </entry>
2065 <entry>Use CAVLC entropy coding.</entry>
2068 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant> </entry>
2069 <entry>Use CABAC entropy coding.</entry>
2075 <row><entry></entry></row>
2077 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant> </entry>
2078 <entry>boolean</entry>
2080 <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2083 <row><entry></entry></row>
2085 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant> </entry>
2086 <entry>integer</entry>
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>
2093 <row><entry></entry></row>
2095 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant> </entry>
2096 <entry>boolean</entry>
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>
2106 <row><entry></entry></row>
2108 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant> </entry>
2109 <entry>boolean</entry>
2111 <row><entry spanname="descr">Macroblock level rate control enable.
2112 Applicable to the MPEG4 and H264 encoders.</entry>
2115 <row><entry></entry></row>
2117 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant> </entry>
2118 <entry>boolean</entry>
2120 <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2123 <row><entry></entry></row>
2125 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant> </entry>
2126 <entry>integer</entry>
2128 <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2131 <row><entry></entry></row>
2133 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant> </entry>
2134 <entry>integer</entry>
2136 <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2139 <row><entry></entry></row>
2141 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant> </entry>
2142 <entry>integer</entry>
2144 <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2147 <row><entry></entry></row>
2149 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant> </entry>
2150 <entry>integer</entry>
2152 <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2155 <row><entry></entry></row>
2157 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant> </entry>
2158 <entry>integer</entry>
2160 <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2163 <row><entry></entry></row>
2165 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant> </entry>
2166 <entry>integer</entry>
2168 <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2171 <row><entry></entry></row>
2173 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant> </entry>
2174 <entry>integer</entry>
2176 <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2179 <row><entry></entry></row>
2181 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant> </entry>
2182 <entry>integer</entry>
2184 <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2187 <row><entry></entry></row>
2189 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant> </entry>
2190 <entry>integer</entry>
2192 <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2195 <row><entry></entry></row>
2197 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant> </entry>
2198 <entry>integer</entry>
2200 <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2203 <row><entry></entry></row>
2205 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant> </entry>
2206 <entry>integer</entry>
2208 <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2211 <row><entry></entry></row>
2213 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant> </entry>
2214 <entry>integer</entry>
2216 <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2219 <row><entry></entry></row>
2221 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant> </entry>
2222 <entry>integer</entry>
2224 <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2227 <row><entry></entry></row>
2229 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant> </entry>
2230 <entry>integer</entry>
2232 <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2235 <row><entry></entry></row>
2237 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant> </entry>
2238 <entry>integer</entry>
2240 <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2243 <row><entry></entry></row>
2245 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant> </entry>
2246 <entry>integer</entry>
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>
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> </entry>
2259 <entry>integer</entry>
2260 </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2261 VBV buffer control.</entry>
2264 <row><entry></entry></row>
2266 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant> </entry>
2267 <entry>integer</entry>
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>
2274 <row><entry></entry></row>
2276 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant> </entry>
2277 <entry>integer</entry>
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>
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> </entry>
2289 <entry>enum v4l2_mpeg_video_header_mode</entry>
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>
2296 <entrytbl spanname="descr" cols="2">
2297 <tbody valign="top">
2299 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant> </entry>
2300 <entry>The stream header is returned separately in the first buffer.</entry>
2303 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant> </entry>
2304 <entry>The stream header is returned together with the first encoded frame.</entry>
2309 <row><entry></entry></row>
2311 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER</constant> </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>
2317 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant> </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>
2322 <row><entry></entry></row>
2324 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant> </entry>
2325 <entry>integer</entry>
2326 </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2328 <row><entry></entry></row>
2330 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant> </entry>
2331 <entry>integer</entry>
2332 </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2335 <row><entry></entry></row>
2337 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant> </entry>
2338 <entry>boolean</entry>
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>
2344 <row><entry></entry></row>
2346 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant> </entry>
2347 <entry>boolean</entry>
2349 <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2350 Applicable to the H264 encoder.</entry>
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> </entry>
2356 <entry>enum v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2358 <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2359 Applicable to the H264 encoder.
2360 Possible values are:</entry>
2363 <entrytbl spanname="descr" cols="2">
2364 <tbody valign="top">
2366 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant> </entry>
2367 <entry>Pixels are alternatively from L and R.</entry>
2370 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant> </entry>
2371 <entry>L and R are interlaced by column.</entry>
2374 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant> </entry>
2375 <entry>L and R are interlaced by row.</entry>
2378 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant> </entry>
2379 <entry>L is on the left, R on the right.</entry>
2382 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant> </entry>
2383 <entry>L is on top, R on bottom.</entry>
2386 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant> </entry>
2387 <entry>One view per frame.</entry>
2393 <row><entry></entry></row>
2395 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant> </entry>
2396 <entry>boolean</entry>
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>
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> </entry>
2405 <entry>enum v4l2_mpeg_video_h264_fmo_map_type</entry>
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>
2412 <entrytbl spanname="descr" cols="2">
2413 <tbody valign="top">
2415 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant> </entry>
2416 <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2419 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant> </entry>
2420 <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2423 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant> </entry>
2424 <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2427 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant> </entry>
2428 <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2431 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant> </entry>
2432 <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2435 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant> </entry>
2436 <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2439 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant> </entry>
2440 <entry>User defined map type.</entry>
2446 <row><entry></entry></row>
2448 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant> </entry>
2449 <entry>integer</entry>
2451 <row><entry spanname="descr">Number of slice groups in FMO.
2452 Applicable to the H264 encoder.</entry>
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> </entry>
2458 <entry>enum v4l2_mpeg_video_h264_fmo_change_dir</entry>
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>
2465 <entrytbl spanname="descr" cols="2">
2466 <tbody valign="top">
2468 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant> </entry>
2469 <entry>Raster scan or wipe right.</entry>
2472 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant> </entry>
2473 <entry>Reverse raster scan or wipe left.</entry>
2479 <row><entry></entry></row>
2481 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant> </entry>
2482 <entry>integer</entry>
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>
2488 <row><entry></entry></row>
2490 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant> </entry>
2491 <entry>integer</entry>
2493 <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2494 Applicable to the H264 encoder.</entry>
2497 <row><entry></entry></row>
2499 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant> </entry>
2500 <entry>boolean</entry>
2502 <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2503 Applicable to the H264 encoder.</entry>
2506 <row><entry></entry></row>
2508 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant> </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>
2515 <entrytbl spanname="descr" cols="2">
2516 <tbody valign="top">
2518 <entry>Bit 0:15</entry>
2519 <entry>Slice ID</entry>
2522 <entry>Bit 16:32</entry>
2523 <entry>Slice position or order</entry>
2529 <row><entry></entry></row>
2531 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant> </entry>
2532 <entry>boolean</entry>
2534 <row><entry spanname="descr">Enables H264 hierarchical coding.
2535 Applicable to the H264 encoder.</entry>
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> </entry>
2541 <entry>enum v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2543 <row><entry spanname="descr">Specifies the hierarchical coding type.
2544 Applicable to the H264 encoder.
2545 Possible values are:</entry>
2548 <entrytbl spanname="descr" cols="2">
2549 <tbody valign="top">
2551 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant> </entry>
2552 <entry>Hierarchical B coding.</entry>
2555 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant> </entry>
2556 <entry>Hierarchical P coding.</entry>
2562 <row><entry></entry></row>
2564 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant> </entry>
2565 <entry>integer</entry>
2567 <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2568 Applicable to the H264 encoder.</entry>
2571 <row><entry></entry></row>
2573 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant> </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>
2580 <entrytbl spanname="descr" cols="2">
2581 <tbody valign="top">
2583 <entry>Bit 0:15</entry>
2584 <entry>QP value</entry>
2587 <entry>Bit 16:32</entry>
2588 <entry>Layer number</entry>
2600 <title>MFC 5.1 MPEG Controls</title>
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.
2607 <table pgwide="1" frame="none" id="mfc51-control-id">
2608 <title>MFC 5.1 Control IDs</title>
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" />
2618 <entry spanname="id" align="left">ID</entry>
2619 <entry align="left">Type</entry>
2620 </row><row><entry spanname="descr" align="left">Description</entry>
2623 <tbody valign="top">
2624 <row><entry></entry></row>
2626 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant> </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.
2635 <row><entry></entry></row>
2637 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant> </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.
2645 <row><entry></entry></row>
2647 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant> </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>
2652 <row><entry></entry></row>
2654 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant> </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>
2659 <row><entry></entry></row>
2661 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant> </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>
2667 <entrytbl spanname="descr" cols="2">
2668 <tbody valign="top">
2670 <entry>Bit 0:7</entry>
2671 <entry>V chrominance information</entry>
2674 <entry>Bit 8:15</entry>
2675 <entry>U chrominance information</entry>
2678 <entry>Bit 16:23</entry>
2679 <entry>Y luminance information</entry>
2682 <entry>Bit 24:31</entry>
2683 <entry>Must be zero.</entry>
2688 <row><entry></entry></row>
2690 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant> </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>
2699 <row><entry></entry></row>
2701 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant> </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>
2707 <row><entry></entry></row>
2709 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant> </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>
2715 <row><entry></entry></row>
2717 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant> </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>
2723 <row><entry></entry></row>
2725 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant> </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>
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> </entry>
2734 <entry>enum v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
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>
2742 <entrytbl spanname="descr" cols="2">
2743 <tbody valign="top">
2745 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant> </entry>
2746 <entry>Frame skip mode is disabled.</entry>
2749 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant> </entry>
2750 <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2753 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant> </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>
2759 <row><entry></entry></row>
2761 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant> </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.
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> </entry>
2775 <entry>enum v4l2_mpeg_mfc51_video_force_frame_type</entry>
2777 <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2778 Possible values are:</entry>
2781 <entrytbl spanname="descr" cols="2">
2782 <tbody valign="top">
2784 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant> </entry>
2785 <entry>Forcing a specific frame type disabled.</entry>
2788 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant> </entry>
2789 <entry>Force an I-frame.</entry>
2792 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant> </entry>
2793 <entry>Force a non-coded frame.</entry>
2804 <title>CX2341x MPEG Controls</title>
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>
2810 <table pgwide="1" frame="none" id="cx2341x-control-id">
2811 <title>CX2341x Control IDs</title>
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" />
2821 <entry spanname="id" align="left">ID</entry>
2822 <entry align="left">Type</entry>
2823 </row><row><entry spanname="descr" align="left">Description</entry>
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> </entry>
2830 <entry>enum 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
2836 <entrytbl spanname="descr" cols="2">
2837 <tbody valign="top">
2839 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant> </entry>
2840 <entry>Choose the filter manually</entry>
2843 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant> </entry>
2844 <entry>Choose the filter automatically</entry>
2849 <row><entry></entry></row>
2851 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant> </entry>
2852 <entry>integer (0-15)</entry>
2853 </row><row><entry spanname="descr">The setting for the
2854 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
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> </entry>
2859 <entry>enum 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>
2865 <entrytbl spanname="descr" cols="2">
2866 <tbody valign="top">
2868 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2869 <entry>No filter</entry>
2872 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2873 <entry>One-dimensional horizontal</entry>
2876 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant> </entry>
2877 <entry>One-dimensional vertical</entry>
2880 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant> </entry>
2881 <entry>Two-dimensional separable</entry>
2884 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant> </entry>
2885 <entry>Two-dimensional symmetrical
2886 non-separable</entry>
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> </entry>
2894 <entry>enum 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>
2900 <entrytbl spanname="descr" cols="2">
2901 <tbody valign="top">
2903 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2904 <entry>No filter</entry>
2907 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2908 <entry>One-dimensional horizontal</entry>
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> </entry>
2916 <entry>enum 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
2922 <entrytbl spanname="descr" cols="2">
2923 <tbody valign="top">
2925 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant> </entry>
2926 <entry>Choose the filter manually</entry>
2929 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant> </entry>
2930 <entry>Choose the filter automatically</entry>
2935 <row><entry></entry></row>
2937 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant> </entry>
2938 <entry>integer (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>
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> </entry>
2946 <entry>enum 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>
2951 <entrytbl spanname="descr" cols="2">
2952 <tbody valign="top">
2954 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant> </entry>
2955 <entry>No filter</entry>
2958 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant> </entry>
2959 <entry>Horizontal filter</entry>
2962 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant> </entry>
2963 <entry>Vertical filter</entry>
2966 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant> </entry>
2967 <entry>Horizontal and vertical filter</entry>
2970 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant> </entry>
2971 <entry>Diagonal filter</entry>
2976 <row><entry></entry></row>
2978 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2979 <entry>integer (0-255)</entry>
2980 </row><row><entry spanname="descr">Threshold above which
2981 the luminance median filter is enabled (default 0)</entry>
2983 <row><entry></entry></row>
2985 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant> </entry>
2986 <entry>integer (0-255)</entry>
2987 </row><row><entry spanname="descr">Threshold below which
2988 the luminance median filter is enabled (default 255)</entry>
2990 <row><entry></entry></row>
2992 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2993 <entry>integer (0-255)</entry>
2994 </row><row><entry spanname="descr">Threshold above which
2995 the chroma median filter is enabled (default 0)</entry>
2997 <row><entry></entry></row>
2999 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant> </entry>
3000 <entry>integer (0-255)</entry>
3001 </row><row><entry spanname="descr">Threshold below which
3002 the chroma median filter is enabled (default 255)</entry>
3004 <row><entry></entry></row>
3006 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant> </entry>
3007 <entry>boolean</entry>
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>
3022 <title>VPX Control Reference</title>
3024 <para>The VPX controls include controls for encoding parameters
3025 of VPx video codec.</para>
3027 <table pgwide="1" frame="none" id="vpx-control-id">
3028 <title>VPX Control IDs</title>
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" />
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>
3044 <tbody valign="top">
3045 <row><entry></entry></row>
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>
3052 <row><entry spanname="descr">The number of token partitions to use in VP8 encoder.
3053 Possible values are:</entry>
3056 <entrytbl spanname="descr" cols="2">
3057 <tbody valign="top">
3059 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_PARTITION</constant></entry>
3060 <entry>1 coefficient partition</entry>
3063 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_PARTITIONS</constant></entry>
3064 <entry>2 coefficient partitions</entry>
3067 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_4_PARTITIONS</constant></entry>
3068 <entry>4 coefficient partitions</entry>
3071 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_8_PARTITIONS</constant></entry>
3072 <entry>8 coefficient partitions</entry>
3078 <row><entry></entry></row>
3080 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_IMD_DISABLE_4X4</constant></entry>
3081 <entry>boolean</entry>
3083 <row><entry spanname="descr">Setting this prevents intra 4x4 mode in the intra mode decision.</entry>
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>
3091 <row><entry spanname="descr">The number of reference pictures for encoding P frames.
3092 Possible values are:</entry>
3095 <entrytbl spanname="descr" cols="2">
3096 <tbody valign="top">
3098 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_REF_FRAME</constant></entry>
3099 <entry>Last encoded frame will be searched</entry>
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>
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>
3114 <row><entry></entry></row>
3116 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_LEVEL</constant></entry>
3117 <entry>integer</entry>
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>
3123 <row><entry></entry></row>
3125 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_SHARPNESS</constant></entry>
3126 <entry>integer</entry>
3128 <row><entry spanname="descr">This parameter affects the loop filter. Anything above
3129 zero weakens the deblocking effect on the loop filter.</entry>
3132 <row><entry></entry></row>
3134 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD</constant></entry>
3135 <entry>integer</entry>
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>
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>
3148 <row><entry spanname="descr">Selects the golden frame for encoding.
3149 Possible values are:</entry>
3152 <entrytbl spanname="descr" cols="2">
3153 <tbody valign="top">
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>
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>
3167 <row><entry></entry></row>
3169 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MIN_QP</constant></entry>
3170 <entry>integer</entry>
3172 <row><entry spanname="descr">Minimum quantization parameter for VP8.</entry>
3175 <row><entry></entry></row>
3177 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MAX_QP</constant></entry>
3178 <entry>integer</entry>
3180 <row><entry spanname="descr">Maximum quantization parameter for VP8.</entry>
3183 <row><entry></entry></row>
3185 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_I_FRAME_QP</constant> </entry>
3186 <entry>integer</entry>
3188 <row><entry spanname="descr">Quantization parameter for an I frame for VP8.</entry>
3191 <row><entry></entry></row>
3193 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP</constant> </entry>
3194 <entry>integer</entry>
3196 <row><entry spanname="descr">Quantization parameter for a P frame for VP8.</entry>
3199 <row><entry></entry></row>
3201 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_PROFILE</constant> </entry>
3202 <entry>integer</entry>
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>
3208 <row><entry></entry></row>
3216 <section id="camera-controls">
3217 <title>Camera Control Reference</title>
3219 <para>The Camera class includes controls for mechanical (or
3220 equivalent digital) features of a device such as controllable lenses
3223 <table pgwide="1" frame="none" id="camera-control-id">
3224 <title>Camera Control IDs</title>
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" />
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>
3239 <tbody valign="top">
3240 <row><entry></entry></row>
3242 <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant> </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>
3248 <row><entry></entry></row>
3250 <row id="v4l2-exposure-auto-type">
3251 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant> </entry>
3252 <entry>enum 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>
3260 <entrytbl spanname="descr" cols="2">
3261 <tbody valign="top">
3263 <entry><constant>V4L2_EXPOSURE_AUTO</constant> </entry>
3264 <entry>Automatic exposure time, automatic iris
3268 <entry><constant>V4L2_EXPOSURE_MANUAL</constant> </entry>
3269 <entry>Manual exposure time, manual iris.</entry>
3272 <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant> </entry>
3273 <entry>Manual exposure time, auto iris.</entry>
3276 <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant> </entry>
3277 <entry>Auto exposure time, manual iris.</entry>
3282 <row><entry></entry></row>
3285 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant> </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 µs units,
3290 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3291 and 100000 for 10 seconds.</entry>
3293 <row><entry></entry></row>
3296 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant> </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>
3305 <row><entry></entry></row>
3308 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant> </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>
3321 <row><entry></entry></row>
3323 <row id="v4l2-exposure-metering">
3324 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant> </entry>
3325 <entry>enum 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>
3330 <entrytbl spanname="descr" cols="2">
3331 <tbody valign="top">
3333 <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant> </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.
3339 <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant> </entry>
3340 <entry>Average the light information coming from the entire frame
3341 giving priority to the center of the metered area.</entry>
3344 <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant> </entry>
3345 <entry>Measure only very small area at the center of the frame.</entry>
3348 <entry><constant>V4L2_EXPOSURE_METERING_MATRIX</constant> </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>
3357 <row><entry></entry></row>
3360 <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant> </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>
3368 <row><entry></entry></row>
3371 <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant> </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>
3378 <row><entry></entry></row>
3381 <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant> </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>
3386 <row><entry></entry></row>
3389 <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant> </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>
3394 <row><entry></entry></row>
3397 <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant> </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
3406 <row><entry></entry></row>
3409 <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant> </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>
3417 <row><entry></entry></row>
3420 <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant> </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>
3427 <row><entry></entry></row>
3430 <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant> </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>
3437 <row><entry></entry></row>
3440 <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant> </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>
3446 <row><entry></entry></row>
3449 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant> </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>
3456 <row><entry></entry></row>
3459 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant> </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>
3467 <row><entry></entry></row>
3469 <row id="v4l2-auto-focus-status">
3470 <entry spanname="id">
3471 <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant> </entry>
3472 <entry>bitmask</entry>
3474 <row><entry spanname="descr">The automatic focus status. This is a read-only
3478 <entrytbl spanname="descr" cols="2">
3479 <tbody valign="top">
3481 <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant> </entry>
3482 <entry>Automatic focus is not active.</entry>
3485 <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant> </entry>
3486 <entry>Automatic focusing is in progress.</entry>
3489 <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant> </entry>
3490 <entry>Focus has been reached.</entry>
3493 <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant> </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>
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>
3506 <row><entry></entry></row>
3508 <row id="v4l2-auto-focus-range">
3509 <entry spanname="id">
3510 <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant> </entry>
3511 <entry>enum v4l2_auto_focus_range</entry>
3513 <row><entry spanname="descr">Determines auto focus distance range
3514 for which lens may be adjusted. </entry>
3517 <entrytbl spanname="descr" cols="2">
3518 <tbody valign="top">
3520 <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant> </entry>
3521 <entry>The camera automatically selects the focus range.</entry>
3524 <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant> </entry>
3525 <entry>Normal distance range, limited for best automatic focus
3526 performance.</entry>
3529 <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant> </entry>
3530 <entry>Macro (close-up) auto focus. The camera will
3531 use its minimum possible distance for auto focus.</entry>
3534 <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant> </entry>
3535 <entry>The lens is set to focus on an object at infinite distance.</entry>
3540 <row><entry></entry></row>
3543 <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant> </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>
3549 <row><entry></entry></row>
3552 <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant> </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>
3559 <row><entry></entry></row>
3562 <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant> </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>
3571 <row><entry></entry></row>
3574 <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant> </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>
3580 <row><entry></entry></row>
3583 <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant> </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>
3590 <row><entry></entry></row>
3593 <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant> </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>
3604 <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant> </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>
3610 <row><entry></entry></row>
3612 <row id="v4l2-auto-n-preset-white-balance">
3613 <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant> </entry>
3614 <entry>enum 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>
3622 <entrytbl spanname="descr" cols="2">
3623 <tbody valign="top">
3625 <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant> </entry>
3626 <entry>Manual white balance.</entry>
3629 <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant> </entry>
3630 <entry>Automatic white balance adjustments.</entry>
3633 <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant> </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>
3639 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant> </entry>
3640 <entry>White balance preset for fluorescent lighting.
3641 It corresponds approximately to 4000...5000 K color temperature.</entry>
3644 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant> </entry>
3645 <entry>With this setting the camera will compensate for
3646 fluorescent H lighting.</entry>
3649 <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant> </entry>
3650 <entry>White balance setting for horizon daylight.
3651 It corresponds approximately to 5000 K color temperature.</entry>
3654 <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant> </entry>
3655 <entry>White balance preset for daylight (with clear sky).
3656 It corresponds approximately to 5000...6500 K color temperature.</entry>
3659 <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant> </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>
3665 <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant> </entry>
3666 <entry>White balance preset for moderately overcast sky.
3667 This option corresponds approximately to 6500...8000 K color temperature
3671 <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant> </entry>
3672 <entry>White balance preset for shade or heavily overcast
3673 sky. It corresponds approximately to 9000...10000 K color temperature.
3679 <row><entry></entry></row>
3681 <row id="v4l2-wide-dynamic-range">
3682 <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3683 <entry>boolean</entry>
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>
3694 <row><entry></entry></row>
3696 <row id="v4l2-image-stabilization">
3697 <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3698 <entry>boolean</entry>
3701 <entry spanname="descr">Enables or disables image stabilization.
3702 <footnoteref linkend="ctypeconv"/></entry>
3704 <row><entry></entry></row>
3707 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant> </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>
3720 <row><entry></entry></row>
3722 <row id="v4l2-iso-sensitivity-auto-type">
3723 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant> </entry>
3724 <entry>enum v4l2_iso_sensitivity_type</entry>
3725 </row><row><entry spanname="descr">Enables or disables automatic ISO
3726 sensitivity adjustments.</entry>
3729 <entrytbl spanname="descr" cols="2">
3730 <tbody valign="top">
3732 <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant> </entry>
3733 <entry>Manual ISO sensitivity.</entry>
3736 <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant> </entry>
3737 <entry>Automatic ISO sensitivity adjustments.</entry>
3742 <row><entry></entry></row>
3744 <row id="v4l2-scene-mode">
3745 <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant> </entry>
3746 <entry>enum 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.
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:
3761 <entrytbl spanname="descr" cols="2">
3762 <tbody valign="top">
3764 <entry><constant>V4L2_SCENE_MODE_NONE</constant> </entry>
3765 <entry>The scene mode feature is disabled.</entry>
3768 <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant> </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>
3774 <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant> </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
3783 <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant> </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>
3790 <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant> </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>
3797 <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant> </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>
3803 <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant> </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>
3809 <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant> </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>
3816 <entry><constant>V4L2_SCENE_MODE_NIGHT</constant> </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>
3824 <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant> </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
3831 <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant> </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>
3839 <entry><constant>V4L2_SCENE_MODE_SPORTS</constant> </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>
3845 <entry><constant>V4L2_SCENE_MODE_SUNSET</constant> </entry>
3846 <entry>Sunset. Preserves deep hues seen in sunsets and
3847 sunrises. It bumps up the saturation.</entry>
3850 <entry><constant>V4L2_SCENE_MODE_TEXT</constant> </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>
3859 <row><entry></entry></row>
3862 <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3863 <entry>bitmask</entry>
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:
3873 <entrytbl spanname="descr" cols="2">
3874 <tbody valign="top">
3876 <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3877 <entry>Automatic exposure adjustments lock.</entry>
3880 <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3881 <entry>Automatic white balance adjustments lock.</entry>
3884 <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3885 <entry>Automatic focus lock.</entry>
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>
3898 <row><entry></entry></row>
3905 <section id="fm-tx-controls">
3906 <title>FM Transmitter Control Reference</title>
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>
3913 <table pgwide="1" frame="none" id="fm-tx-control-id">
3914 <title>FM_TX Control IDs</title>
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" />
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>
3930 <tbody valign="top">
3931 <row><entry></entry></row>
3933 <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant> </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>
3940 <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant> </entry>
3941 <entry>integer</entry>
3943 <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3944 The range and step are driver-specific.</entry>
3947 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant> </entry>
3948 <entry>integer</entry>
3950 <row><entry spanname="descr">Sets the RDS Programme Identification field
3951 for transmission.</entry>
3954 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant> </entry>
3955 <entry>integer</entry>
3957 <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3958 This encodes up to 31 pre-defined programme types.</entry>
3961 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant> </entry>
3962 <entry>string</entry>
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>
3973 <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant> </entry>
3974 <entry>string</entry>
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>
3986 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant> </entry>
3987 <entry>boolean</entry>
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.
3995 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant> </entry>
3996 <entry>integer</entry>
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>
4002 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant> </entry>
4003 <entry>integer</entry>
4005 <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
4006 The range and step are driver-specific.</entry>
4009 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant> </entry>
4010 <entry>boolean</entry>
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>
4017 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant> </entry>
4018 <entry>integer</entry>
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>
4024 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant> </entry>
4025 <entry>integer</entry>
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>
4031 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant> </entry>
4032 <entry>integer</entry>
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>
4038 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant> </entry>
4039 <entry>integer</entry>
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>
4045 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant> </entry>
4046 <entry>boolean</entry>
4048 <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
4051 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant> </entry>
4052 <entry>integer</entry>
4054 <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
4055 in Hz. The range and step are driver-specific.</entry>
4058 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant> </entry>
4059 <entry>integer</entry>
4061 <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
4062 in Hz. The range and step are driver-specific.</entry>
4065 <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant> </entry>
4066 <entry>enum v4l2_preemphasis</entry>
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 v4l2_preemphasis
4071 defines possible values for pre-emphasis. Here they are:</entry>
4073 <entrytbl spanname="descr" cols="2">
4074 <tbody valign="top">
4076 <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant> </entry>
4077 <entry>No pre-emphasis is applied.</entry>
4080 <entry><constant>V4L2_PREEMPHASIS_50_uS</constant> </entry>
4081 <entry>A pre-emphasis of 50 uS is used.</entry>
4084 <entry><constant>V4L2_PREEMPHASIS_75_uS</constant> </entry>
4085 <entry>A pre-emphasis of 75 uS is used.</entry>
4092 <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant> </entry>
4093 <entry>integer</entry>
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>
4099 <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant> </entry>
4100 <entry>integer</entry>
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>
4105 <row><entry></entry></row>
4110 <para>For more details about RDS specification, refer to
4111 <xref linkend="iec62106" /> document, from CENELEC.</para>
4114 <section id="flash-controls">
4115 <title>Flash Control Reference</title>
4118 <title>Experimental</title>
4120 <para>This is an <link linkend="experimental">experimental</link>
4121 interface and may change in the future.</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.
4131 The interface can support both LED and xenon flash devices. As
4132 of writing this, there is no xenon flash driver using this
4136 <section id="flash-controls-use-cases">
4137 <title>Supported use cases</title>
4140 <title>Unsynchronised LED flash (software strobe)</title>
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
4150 <para>Example of such device: Nokia N900.</para>
4154 <title>Synchronised LED flash (hardware strobe)</title>
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.
4163 The sensor controls the flash duration and timing. This
4164 information typically must be made available to the
4171 <title>LED flash as torch</title>
4174 LED flash may be used as torch in conjunction with another
4175 use case involving camera or individually.
4179 <table pgwide="1" frame="none" id="flash-control-id">
4180 <title>Flash Control IDs</title>
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" />
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>
4196 <tbody valign="top">
4197 <row><entry></entry></row>
4199 <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4200 <entry>class</entry>
4203 <entry spanname="descr">The FLASH class descriptor.</entry>
4206 <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
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>
4216 <entrytbl spanname="descr" cols="2">
4217 <tbody valign="top">
4219 <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4223 <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4224 <entry>Flash mode.</entry>
4227 <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4228 <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4234 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4237 <row id="v4l2-flash-strobe-source"><entry
4238 spanname="descr">Defines the source of the flash LED
4242 <entrytbl spanname="descr" cols="2">
4243 <tbody valign="top">
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>
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>
4260 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4261 <entry>button</entry>
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>
4272 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4273 <entry>button</entry>
4275 <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4278 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4279 <entry>boolean</entry>
4282 <entry spanname="descr">Strobe status: whether the flash
4283 is strobing at the moment or not. This is a read-only
4287 <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4288 <entry>integer</entry>
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>
4296 <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4297 <entry>integer</entry>
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>
4306 <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4307 <entry>integer</entry>
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>
4317 <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4318 <entry>integer</entry>
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>
4326 <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4327 <entry>bitmask</entry>
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>
4341 <entrytbl spanname="descr" cols="2">
4342 <tbody valign="top">
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
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>
4358 <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4359 <entry>The flash controller has overheated.</entry>
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>
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>
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>
4380 <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4381 <entry>boolean</entry>
4383 <row><entry spanname="descr">Enable or disable charging of the xenon
4384 flash capacitor.</entry>
4387 <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4388 <entry>boolean</entry>
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>
4397 <row><entry></entry></row>
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>
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" />
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>
4428 <tbody valign="top">
4429 <row><entry></entry></row>
4431 <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant> </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
4440 <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
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.
4454 <entrytbl spanname="descr" cols="2">
4455 <tbody valign="top">
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>
4462 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4463 </entry><entry>Horizontally subsample Cr, Cb components
4464 by a factor of 2.</entry>
4467 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4468 </entry><entry>Subsample Cr, Cb components horizontally
4469 and vertically by 2.</entry>
4472 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4473 </entry><entry>Horizontally subsample Cr, Cb components
4474 by a factor of 4.</entry>
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>
4482 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4483 </entry><entry>Use only luminance component.</entry>
4489 <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4490 </entry><entry>integer</entry>
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.
4504 <row id="jpeg-quality-control">
4505 <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4506 <entry>integer</entry>
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.
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
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.
4527 <row id="jpeg-active-marker-control">
4528 <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4529 <entry>bitmask</entry>
4532 <entry spanname="descr">Specify which JPEG markers are included
4533 in compressed stream. This control is valid only for encoders.
4537 <entrytbl spanname="descr" cols="2">
4538 <tbody valign="top">
4540 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4541 <entry>Application data segment APP<subscript>0</subscript>.</entry>
4543 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4544 <entry>Application data segment APP<subscript>1</subscript>.</entry>
4546 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4547 <entry>Comment segment.</entry>
4549 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4550 <entry>Quantization tables segment.</entry>
4552 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4553 <entry>Huffman tables segment.</entry>
4558 <row><entry></entry></row>
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>
4567 <section id="image-source-controls">
4568 <title>Image Source Control Reference</title>
4571 <title>Experimental</title>
4573 <para>This is an <link
4574 linkend="experimental">experimental</link> interface and may
4575 change in the future.</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.
4585 <table pgwide="1" frame="none" id="image-source-control-id">
4586 <title>Image Source Control IDs</title>
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" />
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>
4602 <tbody valign="top">
4603 <row><entry></entry></row>
4605 <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4606 <entry>class</entry>
4609 <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4612 <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4613 <entry>integer</entry>
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>
4625 <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4626 <entry>integer</entry>
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
4635 <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4636 <entry>integer</entry>
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
4645 <row><entry></entry></row>
4652 <section id="image-process-controls">
4653 <title>Image Process Control Reference</title>
4656 <title>Experimental</title>
4658 <para>This is an <link
4659 linkend="experimental">experimental</link> interface and may
4660 change in the future.</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
4671 <table pgwide="1" frame="none" id="image-process-control-id">
4672 <title>Image Source Control IDs</title>
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" />
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>
4688 <tbody valign="top">
4689 <row><entry></entry></row>
4691 <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4692 <entry>class</entry>
4695 <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4698 <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4699 <entry>integer menu</entry>
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>
4719 <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4720 <entry>64-bit integer</entry>
4723 <entry spanname="descr">Pixel rate in the source pads of
4724 the subdev. This control is read-only and its unit is
4729 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
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
4738 <row><entry></entry></row>
4745 <section id="dv-controls">
4746 <title>Digital Video Control Reference</title>
4749 <title>Experimental</title>
4751 <para>This is an <link
4752 linkend="experimental">experimental</link> interface and may
4753 change in the future.</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.
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>
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>
4779 <table pgwide="1" frame="none" id="dv-control-id">
4780 <title>Digital Video Control IDs</title>
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" />
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>
4796 <tbody valign="top">
4797 <row><entry></entry></row>
4799 <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4800 <entry>class</entry>
4803 <entry spanname="descr">The Digital Video class descriptor.</entry>
4806 <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4807 <entry>bitmask</entry>
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.
4819 <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4820 <entry>bitmask</entry>
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.
4832 <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4833 <entry>bitmask</entry>
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.
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>
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.
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>
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 << (N-8)) - (235 << (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.
4871 <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4872 <entry>bitmask</entry>
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.
4885 <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4886 <entry>enum v4l2_dv_rgb_range</entry>
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 << (N-8)) - (235 << (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.
4899 <row><entry></entry></row>
4906 <section id="fm-rx-controls">
4907 <title>FM Receiver Control Reference</title>
4909 <para>The FM Receiver (FM_RX) class includes controls for common features of
4910 FM Reception capable devices.</para>
4912 <table pgwide="1" frame="none" id="fm-rx-control-id">
4913 <title>FM_RX Control IDs</title>
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" />
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>
4929 <tbody valign="top">
4930 <row><entry></entry></row>
4932 <entry spanname="id"><constant>V4L2_CID_FM_RX_CLASS</constant> </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>
4939 <entry spanname="id"><constant>V4L2_CID_RDS_RECEPTION</constant> </entry>
4940 <entry>boolean</entry>
4941 </row><row><entry spanname="descr">Enables/disables RDS
4942 reception by the radio tuner</entry>
4945 <entry spanname="id"><constant>V4L2_CID_TUNE_DEEMPHASIS</constant> </entry>
4946 <entry>enum v4l2_deemphasis</entry>
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 v4l2_deemphasis
4951 defines possible values for de-emphasis. Here they are:</entry>
4953 <entrytbl spanname="descr" cols="2">
4954 <tbody valign="top">
4956 <entry><constant>V4L2_DEEMPHASIS_DISABLED</constant> </entry>
4957 <entry>No de-emphasis is applied.</entry>
4960 <entry><constant>V4L2_DEEMPHASIS_50_uS</constant> </entry>
4961 <entry>A de-emphasis of 50 uS is used.</entry>
4964 <entry><constant>V4L2_DEEMPHASIS_75_uS</constant> </entry>
4965 <entry>A de-emphasis of 75 uS is used.</entry>
4971 <row><entry></entry></row>