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| <a href="#gst-plugins-bad-plugins-scaletempo.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#gst-plugins-bad-plugins-scaletempo.description" class="shortcut">Description</a> |
| | |
| <a href="#gst-plugins-bad-plugins-scaletempo.object-hierarchy" class="shortcut">Object Hierarchy</a> |
| | |
| <a href="#gst-plugins-bad-plugins-scaletempo.properties" class="shortcut">Properties</a> |
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| <div class="refentry"> |
| <a name="gst-plugins-bad-plugins-scaletempo"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="gst-plugins-bad-plugins-scaletempo.top_of_page"></a>scaletempo</span></h2> |
| <p>scaletempo — Sync audio tempo with playback rate</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsynopsisdiv"> |
| <a name="gst-plugins-bad-plugins-scaletempo.synopsis"></a><h2>Synopsis</h2> |
| <a name="GstScaletempo"></a><pre class="synopsis">struct <a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo-struct" title="struct GstScaletempo">GstScaletempo</a>; |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-plugins-scaletempo.object-hierarchy"></a><h2>Object Hierarchy</h2> |
| <pre class="synopsis"> |
| <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject">GObject</a> |
| +----<a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a> |
| +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html">GstObject</a> |
| +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html">GstElement</a> |
| +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-libs/html/GstBaseTransform.html">GstBaseTransform</a> |
| +----GstScaletempo |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-plugins-scaletempo.properties"></a><h2>Properties</h2> |
| <pre class="synopsis"> |
| "<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--overlap" title='The "overlap" property'>overlap</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read / Write |
| "<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--rate" title='The "rate" property'>rate</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read |
| "<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--search" title='The "search" property'>search</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> : Read / Write |
| "<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--stride" title='The "stride" property'>stride</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> : Read / Write |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-plugins-scaletempo.description"></a><h2>Description</h2> |
| <p> |
| Scale tempo while maintaining pitch |
| (WSOLA-like technique with cross correlation) |
| Inspired by SoundTouch library by Olli Parviainen |
| </p> |
| <p> |
| Use Sceletempo to apply playback rates without the chipmunk effect. |
| </p> |
| <p> |
| </p> |
| <div class="refsect2"> |
| <a name="idp18114816"></a><h3>Example pipelines</h3> |
| <p> |
| </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</pre></td> |
| <td class="listing_code"><pre class="programlisting">filesrc location<span class="gtkdoc opt">=</span>media<span class="gtkdoc opt">.</span>ext <span class="gtkdoc opt">!</span> decodebin name<span class="gtkdoc opt">=</span>d \ |
| d<span class="gtkdoc opt">. !</span> queue <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audioresample <span class="gtkdoc opt">!</span> scaletempo <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audioresample <span class="gtkdoc opt">!</span> autoaudiosink \ |
| d<span class="gtkdoc opt">. !</span> queue <span class="gtkdoc opt">!</span> ffmpegcolorspace <span class="gtkdoc opt">!</span> autovideosink</pre></td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| |
| <p> |
| OR |
| </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">playbin uri<span class="gtkdoc opt">=...</span> audio_sink<span class="gtkdoc opt">=</span><span class="string">"scaletempo ! audioconvert ! audioresample ! autoaudiosink"</span></pre></td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| |
| <p> |
| When an application sends a seek event with rate != 1.0, Scaletempo applies |
| the rate change by scaling the tempo without scaling the pitch. |
| </p> |
| <p> |
| Scaletempo works by producing audio in constant sized chunks |
| (<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--stride" title='The "stride" property'><span class="type">"stride"</span></a>) but consuming chunks proportional to the playback |
| rate. |
| </p> |
| <p> |
| Scaletempo then smooths the output by blending the end of one stride with |
| the next (<a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--overlap" title='The "overlap" property'><span class="type">"overlap"</span></a>). |
| </p> |
| <p> |
| Scaletempo smooths the overlap further by searching within the input buffer |
| for the best overlap position. Scaletempo uses a statistical cross |
| correlation (roughly a dot-product). Scaletempo consumes most of its CPU |
| cycles here. One can use the <a class="link" href="gst-plugins-bad-plugins-scaletempo.html#GstScaletempo--search" title='The "search" property'><span class="type">"search"</span></a> propery to tune how far |
| the algoritm looks. |
| </p> |
| </div> |
| <p> |
| </p> |
| <div class="refsynopsisdiv"> |
| <h2>Synopsis</h2> |
| <div class="refsect2"> |
| <a name="idp16152016"></a><h3>Element Information</h3> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term">plugin</span></p></td> |
| <td> |
| <a class="link" href="gst-plugins-bad-plugins-plugin-scaletempo.html#plugin-scaletempo">scaletempo</a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term">author</span></p></td> |
| <td>Rov Juvano <rovjuvano@users.sourceforge.net></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">class</span></p></td> |
| <td>Filter/Effect/Rate</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="idp17878848"></a><h3>Element Pads</h3> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <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)F32LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"></span></p></td> |
| <td> audio/x-raw, format=(string)S16LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td> |
| </tr> |
| </tbody> |
| </table></div> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <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)F32LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"></span></p></td> |
| <td> audio/x-raw, format=(string)S16LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <p> |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-plugins-scaletempo.details"></a><h2>Details</h2> |
| <div class="refsect2"> |
| <a name="GstScaletempo-struct"></a><h3>struct GstScaletempo</h3> |
| <pre class="programlisting">struct GstScaletempo;</pre> |
| <p> |
| </p> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-plugins-scaletempo.property-details"></a><h2>Property Details</h2> |
| <div class="refsect2"> |
| <a name="GstScaletempo--overlap"></a><h3>The <code class="literal">"overlap"</code> property</h3> |
| <pre class="programlisting"> "overlap" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read / Write</pre> |
| <p>Percentage of stride to overlap.</p> |
| <p>Allowed values: [0,1]</p> |
| <p>Default value: 0.2</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstScaletempo--rate"></a><h3>The <code class="literal">"rate"</code> property</h3> |
| <pre class="programlisting"> "rate" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> : Read</pre> |
| <p>Current playback rate.</p> |
| <p>Allowed values: [-2.14748e+09,2.14748e+09]</p> |
| <p>Default value: 1</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstScaletempo--search"></a><h3>The <code class="literal">"search"</code> property</h3> |
| <pre class="programlisting"> "search" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> : Read / Write</pre> |
| <p>Length in milliseconds to search for best overlap position.</p> |
| <p>Allowed values: <= 500</p> |
| <p>Default value: 14</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstScaletempo--stride"></a><h3>The <code class="literal">"stride"</code> property</h3> |
| <pre class="programlisting"> "stride" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> : Read / Write</pre> |
| <p>Length in milliseconds to output each stride.</p> |
| <p>Allowed values: [1,5000]</p> |
| <p>Default value: 30</p> |
| </div> |
| </div> |
| </div> |
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