1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>scaletempo: GStreamer Good Plugins 1.0 Plugins Reference Manual</title> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="GStreamer Good Plugins 1.0 Plugins Reference Manual"> 8<link rel="up" href="ch01.html" title="gst-plugins-good Elements"> 9<link rel="prev" href="gst-plugins-good-plugins-sbcparse.html" title="sbcparse"> 10<link rel="next" href="gst-plugins-good-plugins-shagadelictv.html" title="shagadelictv"> 11<meta name="generator" content="GTK-Doc V1.28 (XML mode)"> 12<link rel="stylesheet" href="style.css" type="text/css"> 13</head> 14<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 15<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle"> 16<td width="100%" align="left" class="shortcuts"> 17<a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span> 18 <a href="#gst-plugins-good-plugins-scaletempo.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span> 19 <a href="#gst-plugins-good-plugins-scaletempo.object-hierarchy" class="shortcut">Object Hierarchy</a></span><span id="nav_properties"> <span class="dim">|</span> 20 <a href="#gst-plugins-good-plugins-scaletempo.properties" class="shortcut">Properties</a></span> 21</td> 22<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td> 23<td><a accesskey="u" href="ch01.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td> 24<td><a accesskey="p" href="gst-plugins-good-plugins-sbcparse.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td> 25<td><a accesskey="n" href="gst-plugins-good-plugins-shagadelictv.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td> 26</tr></table> 27<div class="refentry"> 28<a name="gst-plugins-good-plugins-scaletempo"></a><div class="titlepage"></div> 29<div class="refnamediv"><table width="100%"><tr> 30<td valign="top"> 31<h2><span class="refentrytitle"><a name="gst-plugins-good-plugins-scaletempo.top_of_page"></a>scaletempo</span></h2> 32<p>scaletempo</p> 33</td> 34<td class="gallery_image" valign="top" align="right"></td> 35</tr></table></div> 36<div class="refsect1"> 37<a name="gst-plugins-good-plugins-scaletempo.properties"></a><h2>Properties</h2> 38<div class="informaltable"><table class="informaltable" border="0"> 39<colgroup> 40<col width="150px" class="properties_type"> 41<col width="300px" class="properties_name"> 42<col width="200px" class="properties_flags"> 43</colgroup> 44<tbody> 45<tr> 46<td class="property_type"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></td> 47<td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--overlap" title="The “overlap” property">overlap</a></td> 48<td class="property_flags">Read / Write</td> 49</tr> 50<tr> 51<td class="property_type"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></td> 52<td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--rate" title="The “rate” property">rate</a></td> 53<td class="property_flags">Read</td> 54</tr> 55<tr> 56<td class="property_type"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a></td> 57<td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--search" title="The “search” property">search</a></td> 58<td class="property_flags">Read / Write</td> 59</tr> 60<tr> 61<td class="property_type"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a></td> 62<td class="property_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--stride" title="The “stride” property">stride</a></td> 63<td class="property_flags">Read / Write</td> 64</tr> 65</tbody> 66</table></div> 67</div> 68<a name="GstScaletempo"></a><div class="refsect1"> 69<a name="gst-plugins-good-plugins-scaletempo.other"></a><h2>Types and Values</h2> 70<div class="informaltable"><table class="informaltable" width="100%" border="0"> 71<colgroup> 72<col width="150px" class="name"> 73<col class="description"> 74</colgroup> 75<tbody><tr> 76<td class="datatype_keyword">struct</td> 77<td class="function_name"><a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo-struct" title="struct GstScaletempo">GstScaletempo</a></td> 78</tr></tbody> 79</table></div> 80</div> 81<div class="refsect1"> 82<a name="gst-plugins-good-plugins-scaletempo.object-hierarchy"></a><h2>Object Hierarchy</h2> 83<pre class="screen"> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject-struct">GObject</a> 84 <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a> 85 <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstObject.html#GstObject-struct">GstObject</a> 86 <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstElement.html#GstElement-struct">GstElement</a> 87 <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransform-struct">GstBaseTransform</a> 88 <span class="lineart">╰──</span> GstScaletempo 89</pre> 90</div> 91<div class="refsect1"> 92<a name="gst-plugins-good-plugins-scaletempo.description"></a><h2>Description</h2> 93<p>Scale tempo while maintaining pitch 94(WSOLA-like technique with cross correlation) 95Inspired by SoundTouch library by Olli Parviainen</p> 96<p>Use Sceletempo to apply playback rates without the chipmunk effect.</p> 97<div class="refsect2"> 98<a name="id-1.2.240.7.4"></a><h3>Example pipelines</h3> 99<p> 100</p> 101<div class="informalexample"> 102 <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> 103 <tbody> 104 <tr> 105 <td class="listing_lines" align="right"><pre>1 1062 1073</pre></td> 108 <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 \ 109 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 \ 110 d<span class="gtkdoc opt">. !</span> queue <span class="gtkdoc opt">!</span> videoconvert <span class="gtkdoc opt">!</span> autovideosink</pre></td> 111 </tr> 112 </tbody> 113 </table> 114</div> 115 116<p> 117OR 118</p> 119<div class="informalexample"> 120 <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> 121 <tbody> 122 <tr> 123 <td class="listing_lines" align="right"><pre>1</pre></td> 124 <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> 125 </tr> 126 </tbody> 127 </table> 128</div> 129 130<p> 131When an application sends a seek event with rate != 1.0, Scaletempo applies 132the rate change by scaling the tempo without scaling the pitch. 133 134Scaletempo works by producing audio in constant sized chunks 135(<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 136rate. 137 138Scaletempo then smooths the output by blending the end of one stride with 139the next (<a class="link" href="gst-plugins-good-plugins-scaletempo.html#GstScaletempo--overlap" title="The “overlap” property"><span class="type">“overlap”</span></a>). 140 141Scaletempo smooths the overlap further by searching within the input buffer 142for the best overlap position. Scaletempo uses a statistical cross 143correlation (roughly a dot-product). Scaletempo consumes most of its CPU 144cycles 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 145the algoritm looks. 146</p> 147</div> 148<div class="refsynopsisdiv"> 149<h2>Synopsis</h2> 150<div class="refsect2"> 151<a name="id-1.2.240.7.5.1"></a><h3>Element Information</h3> 152<div class="variablelist"><table border="0" class="variablelist"> 153<colgroup> 154<col align="left" valign="top"> 155<col> 156</colgroup> 157<tbody> 158<tr> 159<td><p><span class="term">plugin</span></p></td> 160<td> 161 <a class="link" href="gst-plugins-good-plugins-plugin-audiofx.html#plugin-audiofx">audiofx</a> 162 </td> 163</tr> 164<tr> 165<td><p><span class="term">author</span></p></td> 166<td>Rov Juvano <rovjuvano@users.sourceforge.net></td> 167</tr> 168<tr> 169<td><p><span class="term">class</span></p></td> 170<td>Filter/Effect/Rate/Audio</td> 171</tr> 172</tbody> 173</table></div> 174</div> 175<hr> 176<div class="refsect2"> 177<a name="id-1.2.240.7.5.2"></a><h3>Element Pads</h3> 178<div class="variablelist"><table border="0" class="variablelist"> 179<colgroup> 180<col align="left" valign="top"> 181<col> 182</colgroup> 183<tbody> 184<tr> 185<td><p><span class="term">name</span></p></td> 186<td>sink</td> 187</tr> 188<tr> 189<td><p><span class="term">direction</span></p></td> 190<td>sink</td> 191</tr> 192<tr> 193<td><p><span class="term">presence</span></p></td> 194<td>always</td> 195</tr> 196<tr> 197<td><p><span class="term">details</span></p></td> 198<td>audio/x-raw, format=(string)F32LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 199</tr> 200<tr> 201<td><p><span class="term"></span></p></td> 202<td> audio/x-raw, format=(string)F64LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 203</tr> 204<tr> 205<td><p><span class="term"></span></p></td> 206<td> audio/x-raw, format=(string)S16LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 207</tr> 208</tbody> 209</table></div> 210<div class="variablelist"><table border="0" class="variablelist"> 211<colgroup> 212<col align="left" valign="top"> 213<col> 214</colgroup> 215<tbody> 216<tr> 217<td><p><span class="term">name</span></p></td> 218<td>src</td> 219</tr> 220<tr> 221<td><p><span class="term">direction</span></p></td> 222<td>source</td> 223</tr> 224<tr> 225<td><p><span class="term">presence</span></p></td> 226<td>always</td> 227</tr> 228<tr> 229<td><p><span class="term">details</span></p></td> 230<td>audio/x-raw, format=(string)F32LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 231</tr> 232<tr> 233<td><p><span class="term"></span></p></td> 234<td> audio/x-raw, format=(string)F64LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 235</tr> 236<tr> 237<td><p><span class="term"></span></p></td> 238<td> audio/x-raw, format=(string)S16LE, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> 239</tr> 240</tbody> 241</table></div> 242</div> 243</div> 244</div> 245<div class="refsect1"> 246<a name="gst-plugins-good-plugins-scaletempo.functions_details"></a><h2>Functions</h2> 247<p></p> 248</div> 249<div class="refsect1"> 250<a name="gst-plugins-good-plugins-scaletempo.other_details"></a><h2>Types and Values</h2> 251<div class="refsect2"> 252<a name="GstScaletempo-struct"></a><h3>struct GstScaletempo</h3> 253<pre class="programlisting">struct GstScaletempo;</pre> 254</div> 255</div> 256<div class="refsect1"> 257<a name="gst-plugins-good-plugins-scaletempo.property-details"></a><h2>Property Details</h2> 258<div class="refsect2"> 259<a name="GstScaletempo--overlap"></a><h3>The <code class="literal">“overlap”</code> property</h3> 260<pre class="programlisting"> “overlap” <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></pre> 261<p>Percentage of stride to overlap.</p> 262<p>Flags: Read / Write</p> 263<p>Allowed values: [0,1]</p> 264<p>Default value: 0.2</p> 265</div> 266<hr> 267<div class="refsect2"> 268<a name="GstScaletempo--rate"></a><h3>The <code class="literal">“rate”</code> property</h3> 269<pre class="programlisting"> “rate” <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a></pre> 270<p>Current playback rate.</p> 271<p>Flags: Read</p> 272<p>Allowed values: [-2.14748e+09,2.14748e+09]</p> 273<p>Default value: 1</p> 274</div> 275<hr> 276<div class="refsect2"> 277<a name="GstScaletempo--search"></a><h3>The <code class="literal">“search”</code> property</h3> 278<pre class="programlisting"> “search” <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a></pre> 279<p>Length in milliseconds to search for best overlap position.</p> 280<p>Flags: Read / Write</p> 281<p>Allowed values: <= 500</p> 282<p>Default value: 14</p> 283</div> 284<hr> 285<div class="refsect2"> 286<a name="GstScaletempo--stride"></a><h3>The <code class="literal">“stride”</code> property</h3> 287<pre class="programlisting"> “stride” <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a></pre> 288<p>Length in milliseconds to output each stride.</p> 289<p>Flags: Read / Write</p> 290<p>Allowed values: [1,5000]</p> 291<p>Default value: 30</p> 292</div> 293</div> 294</div> 295<div class="footer"> 296<hr>Generated by GTK-Doc V1.28</div> 297</body> 298</html>
