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  24 <a href="#gst-plugins-base-libs-gstaudiomixerutils.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#gst-plugins-base-libs-gstaudiomixerutils.description" class="shortcut">Description</a>
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  29 <div class="refentry">
  30 <a name="gst-plugins-base-libs-gstaudiomixerutils"></a><div class="titlepage"></div>
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  33 <h2><span class="refentrytitle"><a name="gst-plugins-base-libs-gstaudiomixerutils.top_of_page"></a>gstaudiomixerutils</span></h2>
  34 <p>gstaudiomixerutils — utility functions to find available audio mixers
  35                      from the plugin registry</p>
  36 </td>
  37 <td valign="top" align="right"></td>
  38 </tr></table></div>
  39 <div class="refsynopsisdiv">
  40 <a name="gst-plugins-base-libs-gstaudiomixerutils.synopsis"></a><h2>Synopsis</h2>
  41 <pre class="synopsis">
  42 #include &lt;gst/audio/mixerutils.h&gt;
  43
  44 <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-gstaudiomixerutils.html#GstAudioMixerFilterFunc" title="GstAudioMixerFilterFunc ()">*GstAudioMixerFilterFunc</a>)          (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstmixer.html#GstMixer"><span class="type">GstMixer</span></a> *mixer</code></em>,
  45                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);
  46 <a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> *             <a class="link" href="gst-plugins-base-libs-gstaudiomixerutils.html#gst-audio-default-registry-mixer-filter" title="gst_audio_default_registry_mixer_filter ()">gst_audio_default_registry_mixer_filter</a>
  47                                                         (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstaudiomixerutils.html#GstAudioMixerFilterFunc" title="GstAudioMixerFilterFunc ()"><span class="type">GstAudioMixerFilterFunc</span></a> filter_func</code></em>,
  48                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> first</code></em>,
  49                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);
  50 </pre>
  51 </div>
  52 <div class="refsect1">
  53 <a name="gst-plugins-base-libs-gstaudiomixerutils.description"></a><h2>Description</h2>
  54 <p>
  55 </p>
  56 <div class="refsect2">
  57 <a name="idp8831744"></a><p>
  58 Provides some utility functions to detect available audio mixers
  59 on the system.
  60 </p>
  61 </div>
  62 <p>
  63 </p>
  64 </div>
  65 <div class="refsect1">
  66 <a name="gst-plugins-base-libs-gstaudiomixerutils.details"></a><h2>Details</h2>
  67 <div class="refsect2">
  68 <a name="GstAudioMixerFilterFunc"></a><h3>GstAudioMixerFilterFunc ()</h3>
  69 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (*GstAudioMixerFilterFunc)          (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstmixer.html#GstMixer"><span class="type">GstMixer</span></a> *mixer</code></em>,
  70                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
  71 <p>
  72 Function that will be called by <a class="link" href="gst-plugins-base-libs-gstaudiomixerutils.html#gst-audio-default-registry-mixer-filter" title="gst_audio_default_registry_mixer_filter ()"><code class="function">gst_audio_default_registry_mixer_filter()</code></a>
  73 so the caller can decide which mixer elements should be kept and returned.
  74 When the mixer element is passed to the callback function, it is opened
  75 and in READY state. If you decide to keep the element, you need to set it
  76 back to NULL state yourself (unless you want to keep it opened of course).
  77 </p>
  78 <div class="variablelist"><table border="0">
  79 <col align="left" valign="top">
  80 <tbody>
  81 <tr>
  82 <td><p><span class="term"><em class="parameter"><code>mixer</code></em> :</span></p></td>
  83 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a> implementing the <a class="link" href="gst-plugins-base-libs-gstmixer.html#GstMixer"><span class="type">GstMixer</span></a> interface</td>
  84 </tr>
  85 <tr>
  86 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
  87 <td>user data</td>
  88 </tr>
  89 <tr>
  90 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
  91 <td>TRUE if the element should be kept, FALSE otherwise.</td>
  92 </tr>
  93 </tbody>
  94 </table></div>
  95 </div>
  96 <hr>
  97 <div class="refsect2">
  98 <a name="gst-audio-default-registry-mixer-filter"></a><h3>gst_audio_default_registry_mixer_filter ()</h3>
  99 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> *             gst_audio_default_registry_mixer_filter
 100                                                         (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstaudiomixerutils.html#GstAudioMixerFilterFunc" title="GstAudioMixerFilterFunc ()"><span class="type">GstAudioMixerFilterFunc</span></a> filter_func</code></em>,
 101                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> first</code></em>,
 102                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
 103 <p>
 104 Utility function to find audio mixer elements.
 105 </p>
 106 <p>
 107 Will traverse the default plugin registry in order of plugin rank and
 108 find usable audio mixer elements. The caller may optionally fine-tune
 109 the selection by specifying a filter function.
 110 </p>
 111 <div class="variablelist"><table border="0">
 112 <col align="left" valign="top">
 113 <tbody>
 114 <tr>
 115 <td><p><span class="term"><em class="parameter"><code>filter_func</code></em> :</span></p></td>
 116 <td>filter function, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a>
 117 </td>
 118 </tr>
 119 <tr>
 120 <td><p><span class="term"><em class="parameter"><code>first</code></em> :</span></p></td>
 121 <td>set to <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><span class="type">TRUE</span></a> if you only want the first suitable mixer element</td>
 122 </tr>
 123 <tr>
 124 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 125 <td>user data to pass to the filter function</td>
 126 </tr>
 127 <tr>
 128 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 129 <td>a <a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#GList"><span class="type">GList</span></a> of audio mixer <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a>s. You must free each
 130 element in the list by setting it to NULL state and calling
 131 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html#gst-object-unref"><code class="function">gst_object_unref()</code></a>. After that the list itself should be freed
 132 using <a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#g-list-free"><code class="function">g_list_free()</code></a>.</td>
 133 </tr>
 134 </tbody>
 135 </table></div>
 136 <p class="since">Since 0.10.2</p>
 137 </div>
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