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<div class="refentry">
<a name="gst-plugins-base-plugins-audioconvert"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gst-plugins-base-plugins-audioconvert.top_of_page"></a>audioconvert</span></h2>
<p>audioconvert</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.properties"></a><h2>Properties</h2>
<div class="informaltable"><table class="informaltable" border="0">
<colgroup>
<col width="150px" class="properties_type">
<col width="300px" class="properties_name">
<col width="200px" class="properties_flags">
</colgroup>
<tbody>
<tr>
<td class="property_type"><a href="../html/gst-plugins-base-libs-GstAudioQuantize.html#GstAudioDitherMethod"><span class="type">GstAudioDitherMethod</span></a></td>
<td class="property_name"><a class="link" href="gst-plugins-base-plugins-audioconvert.html#GstAudioConvert--dithering" title="The “dithering” property">dithering</a></td>
<td class="property_flags">Read / Write</td>
</tr>
<tr>
<td class="property_type"><a href="../html/gst-plugins-base-libs-GstAudioQuantize.html#GstAudioNoiseShapingMethod"><span class="type">GstAudioNoiseShapingMethod</span></a></td>
<td class="property_name"><a class="link" href="gst-plugins-base-plugins-audioconvert.html#GstAudioConvert--noise-shaping" title="The “noise-shaping” property">noise-shaping</a></td>
<td class="property_flags">Read / Write</td>
</tr>
<tr>
<td class="property_type"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstControlSource.html#GstValueArray"><span class="type">GstValueArray</span></a></td>
<td class="property_name"><a class="link" href="gst-plugins-base-plugins-audioconvert.html#GstAudioConvert--mix-matrix" title="The “mix-matrix” property">mix-matrix</a></td>
<td class="property_flags">Read / Write</td>
</tr>
</tbody>
</table></div>
</div>
<a name="GstAudioConvert"></a><div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody><tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="gst-plugins-base-plugins-audioconvert.html#GstAudioConvert-struct" title="struct GstAudioConvert">GstAudioConvert</a></td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen"> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject-struct">GObject</a>
<span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a>
<span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstObject.html#GstObject-struct">GstObject</a>
<span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstElement.html#GstElement-struct">GstElement</a>
<span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransform-struct">GstBaseTransform</a>
<span class="lineart">╰──</span> GstAudioConvert
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.description"></a><h2>Description</h2>
<p>Audioconvert converts raw audio buffers between various possible formats.
It supports integer to float conversion, width/depth conversion,
signedness and endianness conversion and channel transformations
(ie. upmixing and downmixing), as well as dithering and noise-shaping.</p>
<div class="refsect3">
<a name="id-1.2.8.7.3"></a><h4>Example launch line</h4>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting">gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> <span class="gtkdoc opt">-</span>v <span class="gtkdoc opt">-</span>m audiotestsrc <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audio<span class="gtkdoc opt">/</span>x<span class="gtkdoc opt">-</span>raw<span class="gtkdoc opt">,</span>format<span class="gtkdoc opt">=</span>S8<span class="gtkdoc opt">,</span>channels<span class="gtkdoc opt">=</span><span class="number">2</span> <span class="gtkdoc opt">!</span> level <span class="gtkdoc opt">!</span> fakesink silent<span class="gtkdoc opt">=</span>TRUE</pre></td>
</tr>
</tbody>
</table>
</div>
<p>
This pipeline converts audio to 8-bit. The level element shows that
the output levels still match the one for a sine wave.</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting">gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> <span class="gtkdoc opt">-</span>v <span class="gtkdoc opt">-</span>m uridecodebin uri<span class="gtkdoc opt">=</span>file<span class="gtkdoc opt">:</span><span class="gtkdoc slc">///path/to/audio.flac ! audioconvert ! vorbisenc ! oggmux ! filesink location=audio.ogg</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
The vorbis encoder takes float audio data instead of the integer data
output by most other audio elements. This pipeline decodes a FLAC audio file
(or any other audio file for which decoders are installed) and re-encodes
it into an Ogg/Vorbis audio file.</p>
<p>A mix matrix can be passed to audioconvert, that will govern the
remapping of input to output channels.</p>
</div>
<div class="refsect3">
<a name="id-1.2.8.7.4"></a><h4>Example matrix generation code</h4>
<p>To generate the matrix using code:</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16</pre></td>
<td class="listing_code"><pre class="programlisting">GValue v <span class="gtkdoc opt">=</span> G_VALUE_INIT<span class="gtkdoc opt">;</span>
GValue v2 <span class="gtkdoc opt">=</span> G_VALUE_INIT<span class="gtkdoc opt">;</span>
GValue v3 <span class="gtkdoc opt">=</span> G_VALUE_INIT<span class="gtkdoc opt">;</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-init">g_value_init</a></span> <span class="gtkdoc opt">(&</span>v2<span class="gtkdoc opt">,</span> GST_TYPE_ARRAY<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-init">g_value_init</a></span> <span class="gtkdoc opt">(&</span>v3<span class="gtkdoc opt">,</span> G_TYPE_FLOAT<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Standard-Parameter-and-Value-Types.html#g-value-set-float">g_value_set_float</a></span> <span class="gtkdoc opt">(&</span>v3<span class="gtkdoc opt">,</span> <span class="number">1</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/gstreamer-GstValue.html#gst-value-array-append-value">gst_value_array_append_value</a></span> <span class="gtkdoc opt">(&</span>v2<span class="gtkdoc opt">, &</span>v3<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-unset">g_value_unset</a></span> <span class="gtkdoc opt">(&</span>v3<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">[</span> Repeat <span class="keyword">for</span> as many <span class="gtkdoc kwb">float</span> as your input channels <span class="gtkdoc opt">-</span> unset <span class="keyword">and</span> reinit v3 <span class="gtkdoc opt">]</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-init">g_value_init</a></span> <span class="gtkdoc opt">(&</span>v<span class="gtkdoc opt">,</span> GST_TYPE_ARRAY<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/gstreamer-GstValue.html#gst-value-array-append-value">gst_value_array_append_value</a></span> <span class="gtkdoc opt">(&</span>v<span class="gtkdoc opt">, &</span>v2<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-unset">g_value_unset</a></span> <span class="gtkdoc opt">(&</span>v2<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">[</span> Repeat <span class="keyword">for</span> as many v2<span class="string">'s as your output channels - unset and reinit v2]</span>
<span class="string">g_object_set_property (G_OBJECT (audioconvert), "mix-matrix", &v);</span>
<span class="string">g_value_unset (&v);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
</div>
<div class="refsect3">
<a name="id-1.2.8.7.5"></a><h4>Example launch line</h4>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting">gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> audiotestsrc <span class="gtkdoc opt">!</span> audio<span class="gtkdoc opt">/</span>x<span class="gtkdoc opt">-</span>raw<span class="gtkdoc opt">,</span> channels<span class="gtkdoc opt">=</span><span class="number">4</span> <span class="gtkdoc opt">!</span> audioconvert mix<span class="gtkdoc opt">-</span>matrix<span class="gtkdoc opt">=</span><span class="string">"<<(float)1.0, (float)0.0, (float)0.0, (float)0.0>, <(float)0.0, (float)1.0, (float)0.0, (float)0.0>>"</span> <span class="gtkdoc opt">!</span> audio<span class="gtkdoc opt">/</span>x<span class="gtkdoc opt">-</span>raw<span class="gtkdoc opt">,</span>channels<span class="gtkdoc opt">=</span><span class="number">2</span> <span class="gtkdoc opt">!</span> autoaudiosink</pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
<div class="blockquote"><blockquote class="blockquote"><p>If an empty mix matrix is specified, a (potentially truncated)
identity matrix will be generated.</p></blockquote></div>
</div>
<div class="refsect3">
<a name="id-1.2.8.7.6"></a><h4>Example empty matrix generation code</h4>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5</pre></td>
<td class="listing_code"><pre class="programlisting">GValue v <span class="gtkdoc opt">=</span> G_VALUE_INIT<span class="gtkdoc opt">;</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-init">g_value_init</a></span> <span class="gtkdoc opt">(&</span>v<span class="gtkdoc opt">,</span> GST_TYPE_ARRAY<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-set-property">g_object_set_property</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>audioconvert<span class="gtkdoc opt">),</span> <span class="string">"mix-matrix"</span><span class="gtkdoc opt">, &</span>v<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#g-value-unset">g_value_unset</a></span> <span class="gtkdoc opt">(&</span>v<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
</div>
<div class="refsect3">
<a name="id-1.2.8.7.7"></a><h4>Example empty matrix launch line</h4>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting">gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> <span class="gtkdoc opt">-</span>v audiotestsrc <span class="gtkdoc opt">!</span> audio<span class="gtkdoc opt">/</span>x<span class="gtkdoc opt">-</span>raw<span class="gtkdoc opt">,</span>channels<span class="gtkdoc opt">=</span><span class="number">8</span> <span class="gtkdoc opt">!</span> audioconvert mix<span class="gtkdoc opt">-</span>matrix<span class="gtkdoc opt">=</span><span class="string">"<>"</span> <span class="gtkdoc opt">!</span> audio<span class="gtkdoc opt">/</span>x<span class="gtkdoc opt">-</span>raw<span class="gtkdoc opt">,</span>channels<span class="gtkdoc opt">=</span><span class="number">16</span><span class="gtkdoc opt">,</span>channel<span class="gtkdoc opt">-</span>mask<span class="gtkdoc opt">=</span>\<span class="gtkdoc opt">(</span>bitmask\<span class="gtkdoc opt">)</span><span class="number">0x0000000000000000</span> <span class="gtkdoc opt">!</span> fakesink</pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
</div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<div class="refsect2">
<a name="id-1.2.8.7.8.1"></a><h3>Element Information</h3>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">plugin</span></p></td>
<td>
<a class="link" href="gst-plugins-base-plugins-plugin-audioconvert.html#plugin-audioconvert">audioconvert</a>
</td>
</tr>
<tr>
<td><p><span class="term">author</span></p></td>
<td>Benjamin Otte <otte@gnome.org></td>
</tr>
<tr>
<td><p><span class="term">class</span></p></td>
<td>Filter/Converter/Audio</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.8.7.8.2"></a><h3>Element Pads</h3>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">name</span></p></td>
<td>sink</td>
</tr>
<tr>
<td><p><span class="term">direction</span></p></td>
<td>sink</td>
</tr>
<tr>
<td><p><span class="term">presence</span></p></td>
<td>always</td>
</tr>
<tr>
<td><p><span class="term">details</span></p></td>
<td>audio/x-raw, format=(string){ S8, U8, S16LE, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td>
</tr>
</tbody>
</table></div>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">name</span></p></td>
<td>src</td>
</tr>
<tr>
<td><p><span class="term">direction</span></p></td>
<td>source</td>
</tr>
<tr>
<td><p><span class="term">presence</span></p></td>
<td>always</td>
</tr>
<tr>
<td><p><span class="term">details</span></p></td>
<td>audio/x-raw, format=(string){ S8, U8, S16LE, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.functions_details"></a><h2>Functions</h2>
<p></p>
</div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstAudioConvert-struct"></a><h3>struct GstAudioConvert</h3>
<pre class="programlisting">struct GstAudioConvert;</pre>
<p>The audioconvert object structure.</p>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-plugins-audioconvert.property-details"></a><h2>Property Details</h2>
<div class="refsect2">
<a name="GstAudioConvert--dithering"></a><h3>The <code class="literal">“dithering”</code> property</h3>
<pre class="programlisting"> “dithering” <a href="../html/gst-plugins-base-libs-GstAudioQuantize.html#GstAudioDitherMethod"><span class="type">GstAudioDitherMethod</span></a></pre>
<p>Selects between different dithering methods.</p>
<p>Flags: Read / Write</p>
<p>Default value: GST_AUDIO_DITHER_TPDF</p>
</div>
<hr>
<div class="refsect2">
<a name="GstAudioConvert--noise-shaping"></a><h3>The <code class="literal">“noise-shaping”</code> property</h3>
<pre class="programlisting"> “noise-shaping” <a href="../html/gst-plugins-base-libs-GstAudioQuantize.html#GstAudioNoiseShapingMethod"><span class="type">GstAudioNoiseShapingMethod</span></a></pre>
<p>Selects between different noise shaping methods.</p>
<p>Flags: Read / Write</p>
<p>Default value: GST_AUDIO_NOISE_SHAPING_NONE</p>
</div>
<hr>
<div class="refsect2">
<a name="GstAudioConvert--mix-matrix"></a><h3>The <code class="literal">“mix-matrix”</code> property</h3>
<pre class="programlisting"> “mix-matrix” <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstControlSource.html#GstValueArray"><span class="type">GstValueArray</span></a></pre>
<p>Transformation matrix for input/output channels.</p>
<p>Flags: Read / Write</p>
</div>
</div>
</div>
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