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<a href="#gst-plugins-base-libs-gststreamvolume.description" class="shortcut">Description</a>
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<a href="#gst-plugins-base-libs-gststreamvolume.object-hierarchy" class="shortcut">Object Hierarchy</a>
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<a href="#gst-plugins-base-libs-gststreamvolume.prerequisites" class="shortcut">Prerequisites</a>
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<a href="#gst-plugins-base-libs-gststreamvolume.properties" class="shortcut">Properties</a>
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<div class="refentry">
<a name="gst-plugins-base-libs-gststreamvolume"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gst-plugins-base-libs-gststreamvolume.top_of_page"></a>gststreamvolume</span></h2>
<p>gststreamvolume — Interface for elements that provide a stream volume</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="gst-plugins-base-libs-gststreamvolume.synopsis"></a><h2>Synopsis</h2>
<a name="GstStreamVolume"></a><pre class="synopsis">
#include <gst/audio/streamvolume.h>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume-struct" title="GstStreamVolume">GstStreamVolume</a>;
enum <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat">GstStreamVolumeFormat</a>;
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-get-volume" title="gst_stream_volume_get_volume ()">gst_stream_volume_get_volume</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> format</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-set-volume" title="gst_stream_volume_set_volume ()">gst_stream_volume_set_volume</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> format</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> val</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-get-mute" title="gst_stream_volume_get_mute ()">gst_stream_volume_get_mute</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-set-mute" title="gst_stream_volume_set_mute ()">gst_stream_volume_set_mute</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> mute</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-convert-volume" title="gst_stream_volume_convert_volume ()">gst_stream_volume_convert_volume</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> from</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> to</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> val</code></em>);
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="synopsis">
GInterface
+----GstStreamVolume
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.prerequisites"></a><h2>Prerequisites</h2>
<p>
GstStreamVolume requires
<a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject">GObject</a>.</p>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.properties"></a><h2>Properties</h2>
<pre class="synopsis">
"<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume--mute" title='The "mute" property'>mute</a>" <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> : Read / Write
"<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume--volume" title='The "volume" property'>volume</a>" <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read / Write
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.description"></a><h2>Description</h2>
<p>
</p>
<div class="refsect2">
<a name="id-1.2.6.18.7.2.1"></a><p>
This interface is implemented by elements that provide a stream volume. Examples for
such elements are <span class="type">volume</span> and <span class="type">playbin</span>.
</p>
<p>
Applications can use this interface to get or set the current stream volume. For this
the "volume" <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> property can be used or the helper functions <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-set-volume" title="gst_stream_volume_set_volume ()"><code class="function">gst_stream_volume_set_volume()</code></a>
and <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-get-volume" title="gst_stream_volume_get_volume ()"><code class="function">gst_stream_volume_get_volume()</code></a>. This volume is always a linear factor, i.e. 0.0 is muted
1.0 is 100%. For showing the volume in a GUI it might make sense to convert it to
a different format by using <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-convert-volume" title="gst_stream_volume_convert_volume ()"><code class="function">gst_stream_volume_convert_volume()</code></a>. Volume sliders should usually
use a cubic volume.
</p>
<p>
Separate from the volume the stream can also be muted by the "mute" <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> property or
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-set-mute" title="gst_stream_volume_set_mute ()"><code class="function">gst_stream_volume_set_mute()</code></a> and <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-get-mute" title="gst_stream_volume_get_mute ()"><code class="function">gst_stream_volume_get_mute()</code></a>.
</p>
<p>
Elements that provide some kind of stream volume should implement the "volume" and
"mute" <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> properties and handle setting and getting of them properly.
The volume property is defined to be a linear volume factor.
</p>
</div>
<p>
</p>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GstStreamVolume-struct"></a><h3>GstStreamVolume</h3>
<pre class="programlisting">typedef struct _GstStreamVolume GstStreamVolume;</pre>
</div>
<hr>
<div class="refsect2">
<a name="GstStreamVolumeFormat"></a><h3>enum GstStreamVolumeFormat</h3>
<pre class="programlisting">typedef enum {
GST_STREAM_VOLUME_FORMAT_LINEAR = 0,
GST_STREAM_VOLUME_FORMAT_CUBIC,
GST_STREAM_VOLUME_FORMAT_DB
} GstStreamVolumeFormat;
</pre>
<p>
Different representations of a stream volume. <a class="link" href="gst-plugins-base-libs-gststreamvolume.html#gst-stream-volume-convert-volume" title="gst_stream_volume_convert_volume ()"><code class="function">gst_stream_volume_convert_volume()</code></a>
allows to convert between the different representations.
</p>
<p>
Formulas to convert from a linear to a cubic or dB volume are
cbrt(val) and 20 * log10 (val).
</p>
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<td><p><a name="GST-STREAM-VOLUME-FORMAT-LINEAR:CAPS"></a><span class="term"><code class="literal">GST_STREAM_VOLUME_FORMAT_LINEAR</code></span></p></td>
<td>Linear scale factor, 1.0 = 100%
</td>
</tr>
<tr>
<td><p><a name="GST-STREAM-VOLUME-FORMAT-CUBIC:CAPS"></a><span class="term"><code class="literal">GST_STREAM_VOLUME_FORMAT_CUBIC</code></span></p></td>
<td>Cubic volume scale
</td>
</tr>
<tr>
<td><p><a name="GST-STREAM-VOLUME-FORMAT-DB:CAPS"></a><span class="term"><code class="literal">GST_STREAM_VOLUME_FORMAT_DB</code></span></p></td>
<td>Logarithmic volume scale (dB, amplitude not power)
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-stream-volume-get-volume"></a><h3>gst_stream_volume_get_volume ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> gst_stream_volume_get_volume (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> format</code></em>);</pre>
<div class="variablelist"><table border="0" class="variablelist">
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<td><p><span class="term"><em class="parameter"><code>volume</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> that should be used</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>format</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> which should be returned</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The current stream volume as linear factor</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-stream-volume-set-volume"></a><h3>gst_stream_volume_set_volume ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_stream_volume_set_volume (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> format</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> val</code></em>);</pre>
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<td><p><span class="term"><em class="parameter"><code>volume</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> that should be used</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>format</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> of <em class="parameter"><code>val</code></em>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>val</code></em> :</span></p></td>
<td>Linear volume factor that should be set</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-stream-volume-get-mute"></a><h3>gst_stream_volume_get_mute ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_stream_volume_get_mute (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>);</pre>
<div class="variablelist"><table border="0" class="variablelist">
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<td><p><span class="term"><em class="parameter"><code>volume</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> that should be used</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>Returns <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the stream is muted</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-stream-volume-set-mute"></a><h3>gst_stream_volume_set_mute ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_stream_volume_set_mute (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> *volume</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> mute</code></em>);</pre>
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<td><p><span class="term"><em class="parameter"><code>volume</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolume"><span class="type">GstStreamVolume</span></a> that should be used</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>mute</code></em> :</span></p></td>
<td>Mute state that should be set</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-stream-volume-convert-volume"></a><h3>gst_stream_volume_convert_volume ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> gst_stream_volume_convert_volume (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> from</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> to</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> val</code></em>);</pre>
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<td><p><span class="term"><em class="parameter"><code>from</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> to convert from</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>to</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gststreamvolume.html#GstStreamVolumeFormat" title="enum GstStreamVolumeFormat"><span class="type">GstStreamVolumeFormat</span></a> to convert to</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>val</code></em> :</span></p></td>
<td>Volume in <em class="parameter"><code>from</code></em> format that should be converted</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>the converted volume</td>
</tr>
</tbody>
</table></div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gststreamvolume.property-details"></a><h2>Property Details</h2>
<div class="refsect2">
<a name="GstStreamVolume--mute"></a><h3>The <code class="literal">"mute"</code> property</h3>
<pre class="programlisting"> "mute" <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> : Read / Write</pre>
<p>Mute the audio channel without changing the volume.</p>
<p>Default value: FALSE</p>
</div>
<hr>
<div class="refsect2">
<a name="GstStreamVolume--volume"></a><h3>The <code class="literal">"volume"</code> property</h3>
<pre class="programlisting"> "volume" <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read / Write</pre>
<p>Linear volume factor, 1.0=100%.</p>
<p>Allowed values: >= 0</p>
<p>Default value: 1</p>
</div>
</div>
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