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  24 <a href="#gst-plugins-base-libs-gstmultichannel.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#gst-plugins-base-libs-gstmultichannel.description" class="shortcut">Description</a>
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  29 <div class="refentry">
  30 <a name="gst-plugins-base-libs-gstmultichannel"></a><div class="titlepage"></div>
  31 <div class="refnamediv"><table width="100%"><tr>
  32 <td valign="top">
  33 <h2><span class="refentrytitle"><a name="gst-plugins-base-libs-gstmultichannel.top_of_page"></a>gstmultichannel</span></h2>
  34 <p>gstmultichannel — Support for multichannel audio elements</p>
  35 </td>
  36 <td valign="top" align="right"></td>
  37 </tr></table></div>
  38 <div class="refsynopsisdiv">
  39 <a name="gst-plugins-base-libs-gstmultichannel.synopsis"></a><h2>Synopsis</h2>
  40 <pre class="synopsis">
  41 #include &lt;gst/audio/multichannel.h&gt;
  42
  43 enum                <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition">GstAudioChannelPosition</a>;
  44 <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="returnvalue">GstAudioChannelPosition</span></a> * <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-fixate-channel-positions" title="gst_audio_fixate_channel_positions ()">gst_audio_fixate_channel_positions</a>
  45                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>);
  46 <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="returnvalue">GstAudioChannelPosition</span></a> * <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-get-channel-positions" title="gst_audio_get_channel_positions ()">gst_audio_get_channel_positions</a>
  47                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>);
  48 <span class="returnvalue">void</span>                <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-set-caps-channel-positions-list" title="gst_audio_set_caps_channel_positions_list ()">gst_audio_set_caps_channel_positions_list</a>
  49                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
  50                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
  51                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> num_positions</code></em>);
  52 <span class="returnvalue">void</span>                <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-set-channel-positions" title="gst_audio_set_channel_positions ()">gst_audio_set_channel_positions</a>     (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>,
  53                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>);
  54 <span class="returnvalue">void</span>                <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-set-structure-channel-positions-list" title="gst_audio_set_structure_channel_positions_list ()">gst_audio_set_structure_channel_positions_list</a>
  55                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>,
  56                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
  57                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> num_positions</code></em>);
  58 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#gst-audio-check-channel-positions" title="gst_audio_check_channel_positions ()">gst_audio_check_channel_positions</a>   (<em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
  59                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> channels</code></em>);
  60 </pre>
  61 </div>
  62 <div class="refsect1">
  63 <a name="gst-plugins-base-libs-gstmultichannel.description"></a><h2>Description</h2>
  64 <p>
  65 This module contains some helper functions and a enum to work with
  66 multichannel audio.
  67 </p>
  68 </div>
  69 <div class="refsect1">
  70 <a name="gst-plugins-base-libs-gstmultichannel.details"></a><h2>Details</h2>
  71 <div class="refsect2">
  72 <a name="GstAudioChannelPosition"></a><h3>enum GstAudioChannelPosition</h3>
  73 <pre class="programlisting">typedef enum {
  74   GST_AUDIO_CHANNEL_POSITION_INVALID = -1,
  75
  76   /* Main front speakers. Mono and left/right are mututally exclusive! */
  77   GST_AUDIO_CHANNEL_POSITION_FRONT_MONO,
  78   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
  79   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
  80
  81   /* rear. Left/right and center are mututally exclusive! */
  82   GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,
  83   GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
  84   GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
  85
  86   /* subwoofer/low-frequency */
  87   GST_AUDIO_CHANNEL_POSITION_LFE,
  88
  89   /* Center front speakers. Center and left/right_of_center cannot be
  90    * used together! */
  91   GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
  92   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,
  93   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER,
  94
  95   /* sides */
  96   GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
  97   GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,
  98
  99   /* for multi-channel input and output with more than 8 channels,
 100    * incompatible with all other positions, either all positions
 101    * are defined or all positions are undefined, but can't mix'n'match  */
 102   GST_AUDIO_CHANNEL_POSITION_NONE,
 103 } GstAudioChannelPosition;
 104 </pre>
 105 <p>
 106 Audio channel positions.
 107 </p>
 108 <div class="variablelist"><table border="0">
 109 <col align="left" valign="top">
 110 <tbody>
 111 <tr>
 112 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-INVALID:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_INVALID</code></span></p></td>
 113 <td>invalid position
 114 </td>
 115 </tr>
 116 <tr>
 117 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-MONO:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_MONO</code></span></p></td>
 118 <td>front mono
 119 </td>
 120 </tr>
 121 <tr>
 122 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-LEFT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT</code></span></p></td>
 123 <td>front left
 124 </td>
 125 </tr>
 126 <tr>
 127 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-RIGHT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT</code></span></p></td>
 128 <td>front right
 129 </td>
 130 </tr>
 131 <tr>
 132 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-REAR-CENTER:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_REAR_CENTER</code></span></p></td>
 133 <td>rear center
 134 </td>
 135 </tr>
 136 <tr>
 137 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-REAR-LEFT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_REAR_LEFT</code></span></p></td>
 138 <td>rear left
 139 </td>
 140 </tr>
 141 <tr>
 142 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-REAR-RIGHT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT</code></span></p></td>
 143 <td>rear right
 144 </td>
 145 </tr>
 146 <tr>
 147 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-LFE:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_LFE</code></span></p></td>
 148 <td>subwoofer
 149 </td>
 150 </tr>
 151 <tr>
 152 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-CENTER:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER</code></span></p></td>
 153 <td>front center
 154 </td>
 155 </tr>
 156 <tr>
 157 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-LEFT-OF-CENTER:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER</code></span></p></td>
 158 <td>front left of center
 159 </td>
 160 </tr>
 161 <tr>
 162 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-FRONT-RIGHT-OF-CENTER:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER</code></span></p></td>
 163 <td>front right of center
 164 </td>
 165 </tr>
 166 <tr>
 167 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-SIDE-LEFT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT</code></span></p></td>
 168 <td>side left
 169 </td>
 170 </tr>
 171 <tr>
 172 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-SIDE-RIGHT:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT</code></span></p></td>
 173 <td>side right
 174 </td>
 175 </tr>
 176 <tr>
 177 <td><p><a name="GST-AUDIO-CHANNEL-POSITION-NONE:CAPS"></a><span class="term"><code class="literal">GST_AUDIO_CHANNEL_POSITION_NONE</code></span></p></td>
 178 <td>used for position-less channels, e.g.
 179     from a sound card that records 1024 channels; mutually exclusive with
 180     any other channel position
 181 </td>
 182 </tr>
 183 </tbody>
 184 </table></div>
 185 </div>
 186 <hr>
 187 <div class="refsect2">
 188 <a name="gst-audio-fixate-channel-positions"></a><h3>gst_audio_fixate_channel_positions ()</h3>
 189 <pre class="programlisting"><a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="returnvalue">GstAudioChannelPosition</span></a> * gst_audio_fixate_channel_positions
 190                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>);</pre>
 191 <p>
 192 Custom fixate function. Elements that implement some sort of
 193 channel conversion algorithm should use this function for
 194 fixating on GstAudioChannelPosition properties. It will take
 195 care of equal channel positioning (left/right). Caller <a href="http://library.gnome.org/devel/glib/unstable/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a>s
 196 the return value. The input properties may be (and are supposed
 197 to be) unfixed.
 198 Note that this function is mostly a hack because we currently
 199 have no way to add default fixation functions for new GTypes.
 200 </p>
 201 <div class="variablelist"><table border="0">
 202 <col align="left" valign="top">
 203 <tbody>
 204 <tr>
 205 <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td>
 206 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> containing a (possibly unfixed)
 207 "channel-positions" field.</td>
 208 </tr>
 209 <tr>
 210 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 211 <td>fixed values that the caller could use as a fixed
 212 set of <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> values.</td>
 213 </tr>
 214 </tbody>
 215 </table></div>
 216 </div>
 217 <hr>
 218 <div class="refsect2">
 219 <a name="gst-audio-get-channel-positions"></a><h3>gst_audio_get_channel_positions ()</h3>
 220 <pre class="programlisting"><a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="returnvalue">GstAudioChannelPosition</span></a> * gst_audio_get_channel_positions
 221                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>);</pre>
 222 <p>
 223 Retrieves a number of (fixed!) audio channel positions from
 224 the provided <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> and returns it as a newly allocated
 225 array. The caller should <a href="http://library.gnome.org/devel/glib/unstable/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> this array. The caller
 226 should also check that the members in this <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> are
 227 indeed "fixed" before calling this function.
 228 </p>
 229 <div class="variablelist"><table border="0">
 230 <col align="left" valign="top">
 231 <tbody>
 232 <tr>
 233 <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td>
 234 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> to retrieve channel positions from.</td>
 235 </tr>
 236 <tr>
 237 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 238 <td>a newly allocated array containing the channel
 239 positions as provided in the given <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a>. Returns
 240 NULL on error.</td>
 241 </tr>
 242 </tbody>
 243 </table></div>
 244 </div>
 245 <hr>
 246 <div class="refsect2">
 247 <a name="gst-audio-set-caps-channel-positions-list"></a><h3>gst_audio_set_caps_channel_positions_list ()</h3>
 248 <pre class="programlisting"><span class="returnvalue">void</span>                gst_audio_set_caps_channel_positions_list
 249                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
 250                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
 251                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> num_positions</code></em>);</pre>
 252 <p>
 253 Sets a (possibly non-fixed) list of possible audio channel
 254 positions (given in pos) on the given caps. Each of the
 255 structures of the caps, after this function has been called,
 256 will contain a "channel-positions" field with an array.
 257 Each value in the array will contain each of the values given
 258 in the pos array. Note that the size of the caps might be
 259 increased by this, since each structure with a "channel-
 260 positions" field needs to have a fixed "channels" field.
 261 The input caps is not required to have this.
 262 </p>
 263 <div class="variablelist"><table border="0">
 264 <col align="left" valign="top">
 265 <tbody>
 266 <tr>
 267 <td><p><span class="term"><em class="parameter"><code>caps</code></em> :</span></p></td>
 268 <td>
 269 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> to set the list of channel positions on.</td>
 270 </tr>
 271 <tr>
 272 <td><p><span class="term"><em class="parameter"><code>pos</code></em> :</span></p></td>
 273 <td>the array containing one or more possible audio
 274 channel positions that we should add in each value
 275 of the array in the given structure.</td>
 276 </tr>
 277 <tr>
 278 <td><p><span class="term"><em class="parameter"><code>num_positions</code></em> :</span></p></td>
 279 <td>the number of values in pos.</td>
 280 </tr>
 281 </tbody>
 282 </table></div>
 283 </div>
 284 <hr>
 285 <div class="refsect2">
 286 <a name="gst-audio-set-channel-positions"></a><h3>gst_audio_set_channel_positions ()</h3>
 287 <pre class="programlisting"><span class="returnvalue">void</span>                gst_audio_set_channel_positions     (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>,
 288                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>);</pre>
 289 <p>
 290 Adds a "channel-positions" field to the given <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a>,
 291 which will represent the channel positions as given in the
 292 provided <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> array.
 293 </p>
 294 <div class="variablelist"><table border="0">
 295 <col align="left" valign="top">
 296 <tbody>
 297 <tr>
 298 <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td>
 299 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> to set channel positions on.</td>
 300 </tr>
 301 <tr>
 302 <td><p><span class="term"><em class="parameter"><code>pos</code></em> :</span></p></td>
 303 <td>an array of channel positions. The number of members
 304 in this array should be equal to the (fixed!) number
 305 of the "channels" field in the given <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a>.</td>
 306 </tr>
 307 </tbody>
 308 </table></div>
 309 </div>
 310 <hr>
 311 <div class="refsect2">
 312 <a name="gst-audio-set-structure-channel-positions-list"></a><h3>gst_audio_set_structure_channel_positions_list ()</h3>
 313 <pre class="programlisting"><span class="returnvalue">void</span>                gst_audio_set_structure_channel_positions_list
 314                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> *str</code></em>,
 315                                                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
 316                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> num_positions</code></em>);</pre>
 317 <p>
 318 Sets a (possibly non-fixed) list of possible audio channel
 319 positions (given in pos) on the given structure. The
 320 structure, after this function has been called, will contain
 321 a "channel-positions" field with an array of the size of
 322 the "channels" field value in the given structure (note
 323 that this means that the channels field in the provided
 324 structure should be fixed!). Each value in the array will
 325 contain each of the values given in the pos array.
 326 </p>
 327 <div class="variablelist"><table border="0">
 328 <col align="left" valign="top">
 329 <tbody>
 330 <tr>
 331 <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td>
 332 <td>
 333 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#GstStructure"><span class="type">GstStructure</span></a> to set the list of channel positions
 334 on.</td>
 335 </tr>
 336 <tr>
 337 <td><p><span class="term"><em class="parameter"><code>pos</code></em> :</span></p></td>
 338 <td>the array containing one or more possible audio
 339 channel positions that we should add in each value
 340 of the array in the given structure.</td>
 341 </tr>
 342 <tr>
 343 <td><p><span class="term"><em class="parameter"><code>num_positions</code></em> :</span></p></td>
 344 <td>the number of values in pos.</td>
 345 </tr>
 346 </tbody>
 347 </table></div>
 348 </div>
 349 <hr>
 350 <div class="refsect2">
 351 <a name="gst-audio-check-channel-positions"></a><h3>gst_audio_check_channel_positions ()</h3>
 352 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_audio_check_channel_positions   (<em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a> *pos</code></em>,
 353                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> channels</code></em>);</pre>
 354 <p>
 355 This functions checks if the given channel positions are valid. Channel
 356 positions are valid if:
 357 </p>
 358 <div class="itemizedlist"><ul class="itemizedlist" type="disc">
 359 <li class="listitem"><p>No channel positions appears twice or all positions are <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GST-AUDIO-CHANNEL-POSITION-NONE:CAPS"><code class="literal">GST_AUDIO_CHANNEL_POSITION_NONE</code></a>.
 360   </p></li>
 361 <li class="listitem"><p>Either all or none of the channel positions are <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GST-AUDIO-CHANNEL-POSITION-NONE:CAPS"><code class="literal">GST_AUDIO_CHANNEL_POSITION_NONE</code></a>.
 362   </p></li>
 363 <li class="listitem"><p><a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GST-AUDIO-CHANNEL-POSITION-FRONT-MONO:CAPS"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_MONO</code></a> and <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GST-AUDIO-CHANNEL-POSITION-FRONT-LEFT:CAPS"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT</code></a> or <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GST-AUDIO-CHANNEL-POSITION-FRONT-RIGHT:CAPS"><code class="literal">GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT</code></a> don't appear together in the given positions.
 364   </p></li>
 365 </ul></div>
 366 <p>
 367 </p>
 368 <div class="variablelist"><table border="0">
 369 <col align="left" valign="top">
 370 <tbody>
 371 <tr>
 372 <td><p><span class="term"><em class="parameter"><code>pos</code></em> :</span></p></td>
 373 <td>An array of <a class="link" href="gst-plugins-base-libs-gstmultichannel.html#GstAudioChannelPosition" title="enum GstAudioChannelPosition"><span class="type">GstAudioChannelPosition</span></a>.</td>
 374 </tr>
 375 <tr>
 376 <td><p><span class="term"><em class="parameter"><code>channels</code></em> :</span></p></td>
 377 <td>The number of elements in <em class="parameter"><code>pos</code></em>.</td>
 378 </tr>
 379 <tr>
 380 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 381 <td>
 382 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the given channel positions are valid
 383 and <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> otherwise.</td>
 384 </tr>
 385 </tbody>
 386 </table></div>
 387 <p class="since">Since 0.10.20</p>
 388 </div>
 389 </div>
 390 </div>
 391 <div class="footer">
 392 <hr>
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