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| <div class="refentry"> |
| <a name="gst-plugins-good-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-good-plugins-scaletempo.top_of_page"></a>scaletempo</span></h2> |
| <p>scaletempo</p> |
| </td> |
| <td class="gallery_image" valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-scaletempo.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="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></td> |
| <td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--overlap" title="The “overlap” property">overlap</a></td> |
| <td class="property_flags">Read / Write</td> |
| </tr> |
| <tr> |
| <td class="property_type"><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></td> |
| <td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--rate" title="The “rate” property">rate</a></td> |
| <td class="property_flags">Read</td> |
| </tr> |
| <tr> |
| <td class="property_type"><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint"><span class="type">guint</span></a></td> |
| <td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--search" title="The “search” property">search</a></td> |
| <td class="property_flags">Read / Write</td> |
| </tr> |
| <tr> |
| <td class="property_type"><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint"><span class="type">guint</span></a></td> |
| <td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--stride" title="The “stride” property">stride</a></td> |
| <td class="property_flags">Read / Write</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <a name="GstScaletempo"></a><div class="refsect1"> |
| <a name="gst-plugins-good-plugins-scaletempo.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-good-plugins-scaletempo.html#GstScaletempo-struct" title="struct GstScaletempo">GstScaletempo</a></td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-scaletempo.object-hierarchy"></a><h2>Object Hierarchy</h2> |
| <pre class="screen"> <a href="/usr/share/gtk-doc/html/gobjectgobject-The-Base-Object-Type.html#GObject-struct">GObject</a> |
| <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gobjectgobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a> |
| <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0GstObject.html#GstObject-struct">GstObject</a> |
| <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0GstElement.html#GstElement-struct">GstElement</a> |
| <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0GstBaseTransform.html#GstBaseTransform-struct">GstBaseTransform</a> |
| <span class="lineart">╰──</span> GstScaletempo |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-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> |
| <div class="refsect2"> |
| <a name="id-1.2.227.7.4"></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> videoconvert <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. |
| |
| Scaletempo works by producing audio in constant sized chunks |
| (<a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--stride" title="The “stride” property"><span class="type">“stride”</span></a>) but consuming chunks proportional to the playback |
| rate. |
| |
| Scaletempo then smooths the output by blending the end of one stride with |
| the next (<a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--overlap" title="The “overlap” property"><span class="type">“overlap”</span></a>). |
| |
| 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-good-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> |
| <div class="refsynopsisdiv"> |
| <h2>Synopsis</h2> |
| <div class="refsect2"> |
| <a name="id-1.2.227.7.5.1"></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-good-plugins-plugin-audiofx.html#plugin-audiofx">audiofx</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="id-1.2.227.7.5.2"></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)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)F64LE, 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" 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)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)F64LE, 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> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-scaletempo.functions_details"></a><h2>Functions</h2> |
| <p></p> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-scaletempo.other_details"></a><h2>Types and Values</h2> |
| <div class="refsect2"> |
| <a name="GstScaletempo-struct"></a><h3>struct GstScaletempo</h3> |
| <pre class="programlisting">struct GstScaletempo;</pre> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-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="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></pre> |
| <p>Percentage of stride to overlap.</p> |
| <p>Flags: Read / Write</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="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></pre> |
| <p>Current playback rate.</p> |
| <p>Flags: Read</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="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint"><span class="type">guint</span></a></pre> |
| <p>Length in milliseconds to search for best overlap position.</p> |
| <p>Flags: Read / Write</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="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint"><span class="type">guint</span></a></pre> |
| <p>Length in milliseconds to output each stride.</p> |
| <p>Flags: Read / Write</p> |
| <p>Allowed values: [1,5000]</p> |
| <p>Default value: 30</p> |
| </div> |
| </div> |
| </div> |
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