docs/plugins/html/gst-plugins-good-plugins-audioiirfilter.html

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  24 <a href="#gst-plugins-good-plugins-audioiirfilter.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#gst-plugins-good-plugins-audioiirfilter.description" class="shortcut">Description</a>
  27                    |
  28                   <a href="#gst-plugins-good-plugins-audioiirfilter.object-hierarchy" class="shortcut">Object Hierarchy</a>
  29                    |
  30                   <a href="#gst-plugins-good-plugins-audioiirfilter.properties" class="shortcut">Properties</a>
  31                    |
  32                   <a href="#gst-plugins-good-plugins-audioiirfilter.signals" class="shortcut">Signals</a>
  33 </td></tr>
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  35 <div class="refentry">
  36 <a name="gst-plugins-good-plugins-audioiirfilter"></a><div class="titlepage"></div>
  37 <div class="refnamediv"><table width="100%"><tr>
  38 <td valign="top">
  39 <h2><span class="refentrytitle"><a name="gst-plugins-good-plugins-audioiirfilter.top_of_page"></a>audioiirfilter</span></h2>
  40 <p>audioiirfilter — Generic audio IIR filter with custom filter kernel</p>
  41 </td>
  42 <td valign="top" align="right"></td>
  43 </tr></table></div>
  44 <div class="refsynopsisdiv">
  45 <a name="gst-plugins-good-plugins-audioiirfilter.synopsis"></a><h2>Synopsis</h2>
  46 <a name="GstAudioIIRFilter"></a><pre class="synopsis">struct              <a class="link" href="gst-plugins-good-plugins-audioiirfilter.html#GstAudioIIRFilter-struct" title="struct GstAudioIIRFilter">GstAudioIIRFilter</a>;
  47 </pre>
  48 </div>
  49 <div class="refsect1">
  50 <a name="gst-plugins-good-plugins-audioiirfilter.object-hierarchy"></a><h2>Object Hierarchy</h2>
  51 <pre class="synopsis">
  52   <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject">GObject</a>
  53    +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html">GstObject</a>
  54          +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html">GstElement</a>
  55                +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-libs/html/GstBaseTransform.html">GstBaseTransform</a>
  56                      +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstaudiofilter.html#GstAudioFilter">GstAudioFilter</a>
  57                            +----GstAudioFXBaseIIRFilter
  58                                  +----GstAudioIIRFilter
  59 </pre>
  60 </div>
  61 <div class="refsect1">
  62 <a name="gst-plugins-good-plugins-audioiirfilter.properties"></a><h2>Properties</h2>
  63 <pre class="synopsis">
  64   "<a class="link" href="gst-plugins-good-plugins-audioiirfilter.html#GstAudioIIRFilter--a" title='The "a" property'>a</a>"                        <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a>*          : Read / Write
  65   "<a class="link" href="gst-plugins-good-plugins-audioiirfilter.html#GstAudioIIRFilter--b" title='The "b" property'>b</a>"                        <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a>*          : Read / Write
  66 </pre>
  67 </div>
  68 <div class="refsect1">
  69 <a name="gst-plugins-good-plugins-audioiirfilter.signals"></a><h2>Signals</h2>
  70 <pre class="synopsis">
  71   "<a class="link" href="gst-plugins-good-plugins-audioiirfilter.html#GstAudioIIRFilter-rate-changed" title='The "rate-changed" signal'>rate-changed</a>"                                   : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a>
  72 </pre>
  73 </div>
  74 <div class="refsect1">
  75 <a name="gst-plugins-good-plugins-audioiirfilter.description"></a><h2>Description</h2>
  76 <p>
  77 audioiirfilter implements a generic audio <a class="ulink" href="http://en.wikipedia.org/wiki/Infinite_impulse_response" target="_top">IIR filter</a>. Before usage the
  78 "a" and "b" properties have to be set to the filter coefficients that
  79 should be used.
  80 </p>
  81 <p>
  82 The filter coefficients describe the numerator and denominator of the
  83 transfer function.
  84 </p>
  85 <p>
  86 To change the filter coefficients whenever the sampling rate changes the
  87 "rate-changed" signal can be used. This should be done for most
  88 IIR filters as they're depending on the sampling rate.
  89 </p>
  90 <p>
  91 </p>
  92 <div class="refsect2">
  93 <a name="idp6176784"></a><h3>Example application</h3>
  94 <div class="informalexample">
  95   <table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
  96     <tbody>
  97       <tr>
  98         <td class="listing_lines" align="right"><pre>1
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 234 137</pre></td>
 235         <td class="listing_code"><pre class="programlisting"><span class="comment">/* GStreamer</span>
 236 <span class="comment"> * Copyright (C) 2009 Sebastian Droege &lt;sebastian.droege&#64;collabora.co.uk&gt;</span>
 237 <span class="comment"> *</span>
 238 <span class="comment"> * This library is free software; you can redistribute it and/or</span>
 239 <span class="comment"> * modify it under the terms of the GNU Library General Public</span>
 240 <span class="comment"> * License as published by the Free Software Foundation; either</span>
 241 <span class="comment"> * version 2 of the License, or (at your option) any later version.</span>
 242 <span class="comment"> *</span>
 243 <span class="comment"> * This library is distributed in the hope that it will be useful,</span>
 244 <span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
 245 <span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU</span>
 246 <span class="comment"> * Library General Public License for more details.</span>
 247 <span class="comment"> *</span>
 248 <span class="comment"> * You should have received a copy of the GNU Library General Public</span>
 249 <span class="comment"> * License along with this library; if not, write to the</span>
 250 <span class="comment"> * Free Software Foundation, Inc., 59 Temple Place - Suite 330,</span>
 251 <span class="comment"> * Boston, MA 02111-1307, USA.</span>
 252 <span class="comment"> */</span>
 253
 254 <span class="comment">/* This small sample application creates a lowpass IIR filter</span>
 255 <span class="comment"> * and applies it to white noise.</span>
 256 <span class="comment"> * See http://www.dspguide.com/ch19/2.htm for a description</span>
 257 <span class="comment"> * of the IIR filter that is used.</span>
 258 <span class="comment"> */</span>
 259
 260 <span class="gtkdoc ppc">#include &lt;string.h&gt;</span>
 261 <span class="gtkdoc ppc">#include &lt;math.h&gt;</span>
 262
 263 <span class="gtkdoc ppc">#include &lt;gst/gst.h&gt;</span>
 264
 265 <span class="comment">/* Cutoff of 4000 Hz */</span>
 266 <span class="gtkdoc ppc">#define CUTOFF (4000.0)</span>
 267
 268 <span class="gtkdoc kwb">static</span> gboolean
 269 <span class="function">on_message</span> <span class="gtkdoc opt">(</span>GstBus <span class="gtkdoc opt">*</span> bus<span class="gtkdoc opt">,</span> GstMessage <span class="gtkdoc opt">*</span> message<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
 270 <span class="gtkdoc opt">{</span>
 271   GMainLoop <span class="gtkdoc opt">*</span>loop <span class="gtkdoc opt">= (</span>GMainLoop <span class="gtkdoc opt">*)</span> user_data<span class="gtkdoc opt">;</span>
 272
 273   <span class="keyword">switch</span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#GST-MESSAGE-TYPE:CAPS">GST_MESSAGE_TYPE</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">)) {</span>
 274     <span class="keyword">case</span> GST_MESSAGE_ERROR<span class="gtkdoc opt">:</span>
 275       <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Message-Logging.html#g-error">g_error</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Got ERROR&quot;</span><span class="gtkdoc opt">);</span>
 276       <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-quit">g_main_loop_quit</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
 277       <span class="keyword">break</span><span class="gtkdoc opt">;</span>
 278     <span class="keyword">case</span> GST_MESSAGE_WARNING<span class="gtkdoc opt">:</span>
 279       <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Got WARNING&quot;</span><span class="gtkdoc opt">);</span>
 280       <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-quit">g_main_loop_quit</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
 281       <span class="keyword">break</span><span class="gtkdoc opt">;</span>
 282     <span class="keyword">case</span> GST_MESSAGE_EOS<span class="gtkdoc opt">:</span>
 283       <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-quit">g_main_loop_quit</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
 284       <span class="keyword">break</span><span class="gtkdoc opt">;</span>
 285     <span class="keyword">default</span><span class="gtkdoc opt">:</span>
 286       <span class="keyword">break</span><span class="gtkdoc opt">;</span>
 287   <span class="gtkdoc opt">}</span>
 288
 289   <span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
 290 <span class="gtkdoc opt">}</span>
 291
 292 <span class="gtkdoc kwb">static void</span>
 293 <span class="function">on_rate_changed</span> <span class="gtkdoc opt">(</span>GstElement <span class="gtkdoc opt">*</span> element<span class="gtkdoc opt">,</span> gint rate<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
 294 <span class="gtkdoc opt">{</span>
 295   GValueArray <span class="gtkdoc opt">*</span>va<span class="gtkdoc opt">;</span>
 296   GValue v <span class="gtkdoc opt">= {</span> <span class="number">0</span><span class="gtkdoc opt">, };</span>
 297   gdouble x<span class="gtkdoc opt">;</span>
 298
 299   <span class="keyword">if</span> <span class="gtkdoc opt">(</span>rate <span class="gtkdoc opt">/</span> <span class="number">2.0</span> <span class="gtkdoc opt">&gt;</span> CUTOFF<span class="gtkdoc opt">)</span>
 300     x <span class="gtkdoc opt">=</span> <span class="function">exp</span> <span class="gtkdoc opt">(-</span><span class="number">2.0</span> <span class="gtkdoc opt">*</span> G_PI <span class="gtkdoc opt">* (</span>CUTOFF <span class="gtkdoc opt">/</span> rate<span class="gtkdoc opt">));</span>
 301   <span class="keyword">else</span>
 302     x <span class="gtkdoc opt">=</span> <span class="number">0.0</span><span class="gtkdoc opt">;</span>
 303
 304   va <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-new">g_value_array_new</a></span> <span class="gtkdoc opt">(</span><span class="number">1</span><span class="gtkdoc opt">);</span>
 305
 306   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#g-value-init">g_value_init</a></span> <span class="gtkdoc opt">(&amp;</span>v<span class="gtkdoc opt">,</span> G_TYPE_DOUBLE<span class="gtkdoc opt">);</span>
 307   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-set-double">g_value_set_double</a></span> <span class="gtkdoc opt">(&amp;</span>v<span class="gtkdoc opt">,</span> <span class="number">1.0</span> <span class="gtkdoc opt">-</span> x<span class="gtkdoc opt">);</span>
 308   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-append">g_value_array_append</a></span> <span class="gtkdoc opt">(</span>va<span class="gtkdoc opt">, &amp;</span>v<span class="gtkdoc opt">);</span>
 309   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#g-value-reset">g_value_reset</a></span> <span class="gtkdoc opt">(&amp;</span>v<span class="gtkdoc opt">);</span>
 310   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-set">g_object_set</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>element<span class="gtkdoc opt">),</span> <span class="string">&quot;a&quot;</span><span class="gtkdoc opt">,</span> va<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 311   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-free">g_value_array_free</a></span> <span class="gtkdoc opt">(</span>va<span class="gtkdoc opt">);</span>
 312
 313   va <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-new">g_value_array_new</a></span> <span class="gtkdoc opt">(</span><span class="number">1</span><span class="gtkdoc opt">);</span>
 314   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-set-double">g_value_set_double</a></span> <span class="gtkdoc opt">(&amp;</span>v<span class="gtkdoc opt">,</span> x<span class="gtkdoc opt">);</span>
 315   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-append">g_value_array_append</a></span> <span class="gtkdoc opt">(</span>va<span class="gtkdoc opt">, &amp;</span>v<span class="gtkdoc opt">);</span>
 316   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#g-value-reset">g_value_reset</a></span> <span class="gtkdoc opt">(&amp;</span>v<span class="gtkdoc opt">);</span>
 317   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-set">g_object_set</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>element<span class="gtkdoc opt">),</span> <span class="string">&quot;b&quot;</span><span class="gtkdoc opt">,</span> va<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 318   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-free">g_value_array_free</a></span> <span class="gtkdoc opt">(</span>va<span class="gtkdoc opt">);</span>
 319 <span class="gtkdoc opt">}</span>
 320
 321 gint
 322 <span class="function">main</span> <span class="gtkdoc opt">(</span>gint argc<span class="gtkdoc opt">,</span> gchar <span class="gtkdoc opt">*</span> argv<span class="gtkdoc opt">[])</span>
 323 <span class="gtkdoc opt">{</span>
 324   GstElement <span class="gtkdoc opt">*</span>pipeline<span class="gtkdoc opt">, *</span>src<span class="gtkdoc opt">, *</span>filter<span class="gtkdoc opt">, *</span>conv<span class="gtkdoc opt">, *</span>sink<span class="gtkdoc opt">;</span>
 325   GstBus <span class="gtkdoc opt">*</span>bus<span class="gtkdoc opt">;</span>
 326   GMainLoop <span class="gtkdoc opt">*</span>loop<span class="gtkdoc opt">;</span>
 327
 328   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-Gst.html#gst-init">gst_init</a></span> <span class="gtkdoc opt">(</span>NULL<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 329
 330   pipeline <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;pipeline&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 331
 332   src <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;audiotestsrc&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 333   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-set">g_object_set</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>src<span class="gtkdoc opt">),</span> <span class="string">&quot;wave&quot;</span><span class="gtkdoc opt">,</span> <span class="number">5</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 334
 335   filter <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;audioiirfilter&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 336   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#g-signal-connect">g_signal_connect</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>filter<span class="gtkdoc opt">),</span> <span class="string">&quot;rate-changed&quot;</span><span class="gtkdoc opt">,</span>
 337       <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Closures.html#G-CALLBACK:CAPS">G_CALLBACK</a></span> <span class="gtkdoc opt">(</span>on_rate_changed<span class="gtkdoc opt">),</span> NULL<span class="gtkdoc opt">);</span>
 338
 339   conv <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;audioconvert&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 340
 341   sink <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;autoaudiosink&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 342   <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Warnings-and-Assertions.html#g-return-val-if-fail">g_return_val_if_fail</a></span> <span class="gtkdoc opt">(</span>sink <span class="gtkdoc opt">!=</span> NULL<span class="gtkdoc opt">, -</span><span class="number">1</span><span class="gtkdoc opt">);</span>
 343
 344   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBin.html#gst-bin-add-many">gst_bin_add_many</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_BIN</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">),</span> src<span class="gtkdoc opt">,</span> filter<span class="gtkdoc opt">,</span> conv<span class="gtkdoc opt">,</span> sink<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
 345   <span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#gst-element-link-many">gst_element_link_many</a></span> <span class="gtkdoc opt">(</span>src<span class="gtkdoc opt">,</span> filter<span class="gtkdoc opt">,</span> conv<span class="gtkdoc opt">,</span> sink<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">)) {</span>
 346     <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Message-Logging.html#g-error">g_error</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Failed to link elements&quot;</span><span class="gtkdoc opt">);</span>
 347     <span class="keyword">return</span> <span class="gtkdoc opt">-</span><span class="number">2</span><span class="gtkdoc opt">;</span>
 348   <span class="gtkdoc opt">}</span>
 349
 350   loop <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-new">g_main_loop_new</a></span> <span class="gtkdoc opt">(</span>NULL<span class="gtkdoc opt">,</span> FALSE<span class="gtkdoc opt">);</span>
 351
 352   bus <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPipeline.html#gst-pipeline-get-bus">gst_pipeline_get_bus</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_PIPELINE</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">));</span>
 353   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBus.html#gst-bus-add-signal-watch">gst_bus_add_signal_watch</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">);</span>
 354   <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#g-signal-connect">g_signal_connect</a></span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#G-OBJECT:CAPS">G_OBJECT</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">),</span> <span class="string">&quot;message&quot;</span><span class="gtkdoc opt">,</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Closures.html#G-CALLBACK:CAPS">G_CALLBACK</a></span> <span class="gtkdoc opt">(</span>on_message<span class="gtkdoc opt">),</span> loop<span class="gtkdoc opt">);</span>
 355   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_OBJECT</span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">));</span>
 356
 357   <span class="keyword">if</span> <span class="gtkdoc opt">(</span><span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span>
 358           GST_STATE_PLAYING<span class="gtkdoc opt">) ==</span> GST_STATE_CHANGE_FAILURE<span class="gtkdoc opt">) {</span>
 359     <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Message-Logging.html#g-error">g_error</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Failed to go into PLAYING state&quot;</span><span class="gtkdoc opt">);</span>
 360     <span class="keyword">return</span> <span class="gtkdoc opt">-</span><span class="number">3</span><span class="gtkdoc opt">;</span>
 361   <span class="gtkdoc opt">}</span>
 362
 363   <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-run">g_main_loop_run</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
 364
 365   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span> GST_STATE_NULL<span class="gtkdoc opt">);</span>
 366
 367   <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-main-loop-unref">g_main_loop_unref</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
 368   <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">);</span>
 369
 370   <span class="keyword">return</span> <span class="number">0</span><span class="gtkdoc opt">;</span>
 371 <span class="gtkdoc opt">}</span></pre></td>
 372       </tr>
 373     </tbody>
 374   </table>
 375 </div>
 376
 377 </div>
 378 <p>
 379 </p>
 380 <div class="refsynopsisdiv">
 381 <h2>Synopsis</h2>
 382 <div class="refsect2">
 383 <a name="idp9054496"></a><h3>Element Information</h3>
 384 <div class="variablelist"><table border="0">
 385 <col align="left" valign="top">
 386 <tbody>
 387 <tr>
 388 <td><p><span class="term">plugin</span></p></td>
 389 <td>
 390             <a class="link" href="gst-plugins-good-plugins-plugin-audiofx.html#plugin-audiofx">audiofx</a>
 391           </td>
 392 </tr>
 393 <tr>
 394 <td><p><span class="term">author</span></p></td>
 395 <td>Sebastian Dröge &lt;sebastian.droege@collabora.co.uk&gt;</td>
 396 </tr>
 397 <tr>
 398 <td><p><span class="term">class</span></p></td>
 399 <td>Filter/Effect/Audio</td>
 400 </tr>
 401 </tbody>
 402 </table></div>
 403 </div>
 404 <hr>
 405 <div class="refsect2">
 406 <a name="idp5826368"></a><h3>Element Pads</h3>
 407 <div class="variablelist"><table border="0">
 408 <col align="left" valign="top">
 409 <tbody>
 410 <tr>
 411 <td><p><span class="term">name</span></p></td>
 412 <td>sink</td>
 413 </tr>
 414 <tr>
 415 <td><p><span class="term">direction</span></p></td>
 416 <td>sink</td>
 417 </tr>
 418 <tr>
 419 <td><p><span class="term">presence</span></p></td>
 420 <td>always</td>
 421 </tr>
 422 <tr>
 423 <td><p><span class="term">details</span></p></td>
 424 <td>audio/x-raw-float, width=(int){ 32, 64 }, endianness=(int)1234, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td>
 425 </tr>
 426 </tbody>
 427 </table></div>
 428 <div class="variablelist"><table border="0">
 429 <col align="left" valign="top">
 430 <tbody>
 431 <tr>
 432 <td><p><span class="term">name</span></p></td>
 433 <td>src</td>
 434 </tr>
 435 <tr>
 436 <td><p><span class="term">direction</span></p></td>
 437 <td>source</td>
 438 </tr>
 439 <tr>
 440 <td><p><span class="term">presence</span></p></td>
 441 <td>always</td>
 442 </tr>
 443 <tr>
 444 <td><p><span class="term">details</span></p></td>
 445 <td>audio/x-raw-float, width=(int){ 32, 64 }, endianness=(int)1234, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td>
 446 </tr>
 447 </tbody>
 448 </table></div>
 449 </div>
 450 </div>
 451 <p>
 452 </p>
 453 </div>
 454 <div class="refsect1">
 455 <a name="gst-plugins-good-plugins-audioiirfilter.details"></a><h2>Details</h2>
 456 <div class="refsect2">
 457 <a name="GstAudioIIRFilter-struct"></a><h3>struct GstAudioIIRFilter</h3>
 458 <pre class="programlisting">struct GstAudioIIRFilter;</pre>
 459 <p>
 460 Opaque data structure.
 461 </p>
 462 </div>
 463 </div>
 464 <div class="refsect1">
 465 <a name="gst-plugins-good-plugins-audioiirfilter.property-details"></a><h2>Property Details</h2>
 466 <div class="refsect2">
 467 <a name="GstAudioIIRFilter--a"></a><h3>The <code class="literal">"a"</code> property</h3>
 468 <pre class="programlisting">  "a"                        <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a>*          : Read / Write</pre>
 469 <p>Filter coefficients (numerator of transfer function).</p>
 470 </div>
 471 <hr>
 472 <div class="refsect2">
 473 <a name="GstAudioIIRFilter--b"></a><h3>The <code class="literal">"b"</code> property</h3>
 474 <pre class="programlisting">  "b"                        <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a>*          : Read / Write</pre>
 475 <p>Filter coefficients (denominator of transfer function).</p>
 476 </div>
 477 </div>
 478 <div class="refsect1">
 479 <a name="gst-plugins-good-plugins-audioiirfilter.signal-details"></a><h2>Signal Details</h2>
 480 <div class="refsect2">
 481 <a name="GstAudioIIRFilter-rate-changed"></a><h3>The <code class="literal">"rate-changed"</code> signal</h3>
 482 <pre class="programlisting"><span class="returnvalue">void</span>                user_function                      (<a class="link" href="gst-plugins-good-plugins-audioiirfilter.html#GstAudioIIRFilter"><span class="type">GstAudioIIRFilter</span></a> *filter,
 483                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a>               rate,
 484                                                         <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>           user_data)      : <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Signals.html#G-SIGNAL-RUN-LAST:CAPS"><code class="literal">Run Last</code></a></pre>
 485 <p>
 486 Will be emitted when the sampling rate changes. The callbacks
 487 will be called from the streaming thread and processing will
 488 stop until the event is handled.
 489 </p>
 490 <div class="variablelist"><table border="0">
 491 <col align="left" valign="top">
 492 <tbody>
 493 <tr>
 494 <td><p><span class="term"><em class="parameter"><code>filter</code></em> :</span></p></td>
 495 <td>the filter on which the signal is emitted</td>
 496 </tr>
 497 <tr>
 498 <td><p><span class="term"><em class="parameter"><code>rate</code></em> :</span></p></td>
 499 <td>the new sampling rate</td>
 500 </tr>
 501 <tr>
 502 <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td>
 503 <td>user data set when the signal handler was connected.</td>
 504 </tr>
 505 </tbody>
 506 </table></div>
 507 </div>
 508 </div>
 509 </div>
 510 <div class="footer">
 511 <hr>
 512           Generated by GTK-Doc V1.18</div>
 513 </body>
 514 </html>