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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<a href="#gst-plugins-good-plugins-level.synopsis" class="shortcut">Top</a>
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                  <a href="#gst-plugins-good-plugins-level.description" class="shortcut">Description</a>
                   | 
                  <a href="#gst-plugins-good-plugins-level.object-hierarchy" class="shortcut">Object Hierarchy</a>
                   | 
                  <a href="#gst-plugins-good-plugins-level.properties" class="shortcut">Properties</a>
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<div class="refentry">
<a name="gst-plugins-good-plugins-level"></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-level.top_of_page"></a>level</span></h2>
<p>level — RMS/Peak/Decaying Peak Level messager for audio/raw</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="gst-plugins-good-plugins-level.synopsis"></a><h2>Synopsis</h2>
<a name="GstLevel"></a><pre class="synopsis">struct              <a class="link" href="gst-plugins-good-plugins-level.html#GstLevel-struct" title="struct GstLevel">GstLevel</a>;
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-good-plugins-level.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>
                           +----GstLevel
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-good-plugins-level.properties"></a><h2>Properties</h2>
<pre class="synopsis">
  "<a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--interval" title='The "interval" property'>interval</a>"                 <span class="type">guint64</span>               : Read / Write
  "<a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--message" title='The "message" property'>message</a>"                  <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write
  "<a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--peak-falloff" title='The "peak-falloff" property'>peak-falloff</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-good-plugins-level.html#GstLevel--peak-ttl" title='The "peak-ttl" property'>peak-ttl</a>"                 <span class="type">guint64</span>               : Read / Write
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-good-plugins-level.description"></a><h2>Description</h2>
<p>
Level analyses incoming audio buffers and, if the <a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--message" title='The "message" property'><span class="type">"message"</span></a> property
is <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><span class="type">TRUE</span></a>, generates an element message named
<code class="classname">"level"</code>:
after each interval of time given by the <a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--interval" title='The "interval" property'><span class="type">"interval"</span></a> property.
The message's structure contains these fields:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p>
  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a>
  <code class="classname">"timestamp"</code>:
  the timestamp of the buffer that triggered the message.
  </p></li>
<li class="listitem"><p>
  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a>
  <code class="classname">"stream-time"</code>:
  the stream time of the buffer.
  </p></li>
<li class="listitem"><p>
  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a>
  <code class="classname">"running-time"</code>:
  the running_time of the buffer.
  </p></li>
<li class="listitem"><p>
  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a>
  <code class="classname">"duration"</code>:
  the duration of the buffer.
  </p></li>
<li class="listitem"><p>
  <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a>
  <code class="classname">"endtime"</code>:
  the end time of the buffer that triggered the message as stream time (this
  is deprecated, as it can be calculated from stream-time + duration)
  </p></li>
<li class="listitem"><p>
  <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a> of <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a>
  <code class="classname">"peak"</code>:
  the peak power level in dB for each channel
  </p></li>
<li class="listitem"><p>
  <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a> of <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a>
  <code class="classname">"decay"</code>:
  the decaying peak power level in dB for each channel
  the decaying peak level follows the peak level, but starts dropping
  if no new peak is reached after the time given by
  the <a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--peak-ttl" title='The "peak-ttl" property'>the time to live</a>.
  When the decaying peak level drops, it does so at the decay rate
  as specified by the
  <a class="link" href="gst-plugins-good-plugins-level.html#GstLevel--peak-falloff" title='The "peak-falloff" property'>the peak falloff rate</a>.
  </p></li>
<li class="listitem"><p>
  <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#GValueArray"><span class="type">GValueArray</span></a> of <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a>
  <code class="classname">"rms"</code>:
  the Root Mean Square (or average power) level in dB for each channel
  </p></li>
</ul></div>
<p>
</p>
<p>
</p>
<div class="refsect2">
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<a name="idp12781424"></a><h3>Example application</h3>
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<div class="informalexample">
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        <td class="listing_code"><pre class="programlisting"><span class="comment">/* GStreamer</span>
<span class="comment"> * Copyright (C) 2000,2001,2002,2003,2005</span>
<span class="comment"> *           Thomas Vander Stichele &lt;thomas at apestaart dot org&gt;</span>
<span class="comment"> *</span>
<span class="comment"> * This library is free software; you can redistribute it and/or</span>
<span class="comment"> * modify it under the terms of the GNU Library General Public</span>
<span class="comment"> * License as published by the Free Software Foundation; either</span>
<span class="comment"> * version 2 of the License, or (at your option) any later version.</span>
<span class="comment"> *</span>
<span class="comment"> * This library is distributed in the hope that it will be useful,</span>
<span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU</span>
<span class="comment"> * Library General Public License for more details.</span>
<span class="comment"> *</span>
<span class="comment"> * You should have received a copy of the GNU Library General Public</span>
<span class="comment"> * License along with this library; if not, write to the</span>
<span class="comment"> * Free Software Foundation, Inc., 59 Temple Place - Suite 330,</span>
<span class="comment"> * Boston, MA 02111-1307, USA.</span>
<span class="comment"> */</span>

<span class="gtkdoc ppc">#include &lt;string.h&gt;</span>
<span class="gtkdoc ppc">#include &lt;math.h&gt;</span>
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<span class="gtkdoc ppc">#define GLIB_DISABLE_DEPRECATION_WARNINGS</span>
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<span class="gtkdoc ppc">#include &lt;gst/gst.h&gt;</span>

<span class="gtkdoc kwb">static</span> gboolean
<span class="function">message_handler</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 data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>

  <span class="keyword">if</span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">-&gt;</span>type <span class="gtkdoc opt">==</span> GST_MESSAGE_ELEMENT<span class="gtkdoc opt">) {</span>
    <span class="gtkdoc kwb">const</span> GstStructure <span class="gtkdoc opt">*</span>s <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-get-structure">gst_message_get_structure</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">);</span>
    <span class="gtkdoc kwb">const</span> gchar <span class="gtkdoc opt">*</span>name <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#gst-structure-get-name">gst_structure_get_name</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">);</span>

    <span class="keyword">if</span> <span class="gtkdoc opt">(</span><span class="function">strcmp</span> <span class="gtkdoc opt">(</span>name<span class="gtkdoc opt">,</span> <span class="string">&quot;level&quot;</span><span class="gtkdoc opt">) ==</span> <span class="number">0</span><span class="gtkdoc opt">) {</span>
      gint channels<span class="gtkdoc opt">;</span>
      GstClockTime endtime<span class="gtkdoc opt">;</span>
      gdouble rms_dB<span class="gtkdoc opt">,</span> peak_dB<span class="gtkdoc opt">,</span> decay_dB<span class="gtkdoc opt">;</span>
      gdouble rms<span class="gtkdoc opt">;</span>
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      <span class="gtkdoc kwb">const</span> GValue <span class="gtkdoc opt">*</span>array_val<span class="gtkdoc opt">;</span>
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      <span class="gtkdoc kwb">const</span> GValue <span class="gtkdoc opt">*</span>value<span class="gtkdoc opt">;</span>
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      GValueArray <span class="gtkdoc opt">*</span>arr<span class="gtkdoc opt">;</span>
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      gint i<span class="gtkdoc opt">;</span>

      <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/gstreamer-GstStructure.html#gst-structure-get-clock-time">gst_structure_get_clock_time</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">,</span> <span class="string">&quot;endtime&quot;</span><span class="gtkdoc opt">, &amp;</span>endtime<span class="gtkdoc opt">))</span>
        <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;Could not parse endtime&quot;</span><span class="gtkdoc opt">);</span>
      <span class="comment">/* we can get the number of channels as the length of any of the value</span>
<span class="comment">       * lists */</span>
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      array_val <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#gst-structure-get-value">gst_structure_get_value</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">,</span> <span class="string">&quot;rms&quot;</span><span class="gtkdoc opt">);</span>
      arr <span class="gtkdoc opt">= (</span>GValueArray <span class="gtkdoc opt">*)</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-boxed">g_value_get_boxed</a></span> <span class="gtkdoc opt">(</span>array_val<span class="gtkdoc opt">);</span>
      channels <span class="gtkdoc opt">=</span> arr<span class="gtkdoc opt">-&gt;</span>n_values<span class="gtkdoc opt">;</span>
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      <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Warnings-and-Assertions.html#g-print">g_print</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;endtime: %&quot;</span> GST_TIME_FORMAT <span class="string">&quot;, channels: %d</span><span class="gtkdoc esc">\n</span><span class="string">&quot;</span><span class="gtkdoc opt">,</span>
          <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstInfo.html#GST-TIME-ARGS:CAPS">GST_TIME_ARGS</a></span> <span class="gtkdoc opt">(</span>endtime<span class="gtkdoc opt">),</span> channels<span class="gtkdoc opt">);</span>
      <span class="keyword">for</span> <span class="gtkdoc opt">(</span>i <span class="gtkdoc opt">=</span> <span class="number">0</span><span class="gtkdoc opt">;</span> i <span class="gtkdoc opt">&lt;</span> channels<span class="gtkdoc opt">; ++</span>i<span class="gtkdoc opt">) {</span>
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        <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Warnings-and-Assertions.html#g-print">g_print</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;channel %d</span><span class="gtkdoc esc">\n</span><span class="string">&quot;</span><span class="gtkdoc opt">,</span> i<span class="gtkdoc opt">);</span>
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        array_val <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#gst-structure-get-value">gst_structure_get_value</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">,</span> <span class="string">&quot;rms&quot;</span><span class="gtkdoc opt">);</span>
        arr <span class="gtkdoc opt">= (</span>GValueArray <span class="gtkdoc opt">*)</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-boxed">g_value_get_boxed</a></span> <span class="gtkdoc opt">(</span>array_val<span class="gtkdoc opt">);</span>
        value <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-get-nth">g_value_array_get_nth</a></span> <span class="gtkdoc opt">(</span>arr<span class="gtkdoc opt">,</span> i<span class="gtkdoc opt">);</span>
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        rms_dB <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-double">g_value_get_double</a></span> <span class="gtkdoc opt">(</span>value<span class="gtkdoc opt">);</span>
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        array_val <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#gst-structure-get-value">gst_structure_get_value</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">,</span> <span class="string">&quot;peak&quot;</span><span class="gtkdoc opt">);</span>
        arr <span class="gtkdoc opt">= (</span>GValueArray <span class="gtkdoc opt">*)</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-boxed">g_value_get_boxed</a></span> <span class="gtkdoc opt">(</span>array_val<span class="gtkdoc opt">);</span>
        value <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-get-nth">g_value_array_get_nth</a></span> <span class="gtkdoc opt">(</span>arr<span class="gtkdoc opt">,</span> i<span class="gtkdoc opt">);</span>
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        peak_dB <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-double">g_value_get_double</a></span> <span class="gtkdoc opt">(</span>value<span class="gtkdoc opt">);</span>
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        array_val <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstStructure.html#gst-structure-get-value">gst_structure_get_value</a></span> <span class="gtkdoc opt">(</span>s<span class="gtkdoc opt">,</span> <span class="string">&quot;decay&quot;</span><span class="gtkdoc opt">);</span>
        arr <span class="gtkdoc opt">= (</span>GValueArray <span class="gtkdoc opt">*)</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-boxed">g_value_get_boxed</a></span> <span class="gtkdoc opt">(</span>array_val<span class="gtkdoc opt">);</span>
        value <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Value-arrays.html#g-value-array-get-nth">g_value_array_get_nth</a></span> <span class="gtkdoc opt">(</span>arr<span class="gtkdoc opt">,</span> i<span class="gtkdoc opt">);</span>
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Imported Upstream version 0.11.90
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342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 
        decay_dB <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Standard-Parameter-and-Value-Types.html#g-value-get-double">g_value_get_double</a></span> <span class="gtkdoc opt">(</span>value<span class="gtkdoc opt">);</span>
        <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Warnings-and-Assertions.html#g-print">g_print</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;    RMS: %f dB, peak: %f dB, decay: %f dB</span><span class="gtkdoc esc">\n</span><span class="string">&quot;</span><span class="gtkdoc opt">,</span>
            rms_dB<span class="gtkdoc opt">,</span> peak_dB<span class="gtkdoc opt">,</span> decay_dB<span class="gtkdoc opt">);</span>

        <span class="comment">/* converting from dB to normal gives us a value between 0.0 and 1.0 */</span>
        rms <span class="gtkdoc opt">=</span> <span class="function">pow</span> <span class="gtkdoc opt">(</span><span class="number">10</span><span class="gtkdoc opt">,</span> rms_dB <span class="gtkdoc opt">/</span> <span class="number">20</span><span class="gtkdoc opt">);</span>
        <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Warnings-and-Assertions.html#g-print">g_print</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;    normalized rms value: %f</span><span class="gtkdoc esc">\n</span><span class="string">&quot;</span><span class="gtkdoc opt">,</span> rms<span class="gtkdoc opt">);</span>
      <span class="gtkdoc opt">}</span>
    <span class="gtkdoc opt">}</span>
  <span class="gtkdoc opt">}</span>
  <span class="comment">/* we handled the message we want, and ignored the ones we didn't want.</span>
<span class="comment">   * so the core can unref the message for us */</span>
  <span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>

<span class="gtkdoc kwb">int</span>
<span class="function">main</span> <span class="gtkdoc opt">(</span><span class="gtkdoc kwb">int</span> argc<span class="gtkdoc opt">,</span> <span class="gtkdoc kwb">char</span> <span class="gtkdoc opt">*</span>argv<span class="gtkdoc opt">[])</span>
<span class="gtkdoc opt">{</span>
  GstElement <span class="gtkdoc opt">*</span>audiotestsrc<span class="gtkdoc opt">, *</span>audioconvert<span class="gtkdoc opt">, *</span>level<span class="gtkdoc opt">, *</span>fakesink<span class="gtkdoc opt">;</span>
  GstElement <span class="gtkdoc opt">*</span>pipeline<span class="gtkdoc opt">;</span>
  GstCaps <span class="gtkdoc opt">*</span>caps<span class="gtkdoc opt">;</span>
  GstBus <span class="gtkdoc opt">*</span>bus<span class="gtkdoc opt">;</span>
  guint watch_id<span class="gtkdoc opt">;</span>
  GMainLoop <span class="gtkdoc opt">*</span>loop<span class="gtkdoc opt">;</span>

  <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">(&amp;</span>argc<span class="gtkdoc opt">, &amp;</span>argv<span class="gtkdoc opt">);</span>

  caps <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#gst-caps-from-string">gst_caps_from_string</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;audio/x-raw,channels=2&quot;</span><span class="gtkdoc opt">);</span>

  pipeline <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPipeline.html#gst-pipeline-new">gst_pipeline_new</a></span> <span class="gtkdoc opt">(</span>NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">);</span>
  audiotestsrc <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>
  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>audiotestsrc<span class="gtkdoc opt">);</span>
  audioconvert <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>
  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>audioconvert<span class="gtkdoc opt">);</span>
  level <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;level&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>level<span class="gtkdoc opt">);</span>
  fakesink <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;fakesink&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>fakesink<span class="gtkdoc opt">);</span>

  <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> audiotestsrc<span class="gtkdoc opt">,</span> audioconvert<span class="gtkdoc opt">,</span> level<span class="gtkdoc opt">,</span>
      fakesink<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <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">gst_element_link</a></span> <span class="gtkdoc opt">(</span>audiotestsrc<span class="gtkdoc opt">,</span> audioconvert<span class="gtkdoc opt">))</span>
    <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 audiotestsrc and audioconvert&quot;</span><span class="gtkdoc opt">);</span>
  <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-filtered">gst_element_link_filtered</a></span> <span class="gtkdoc opt">(</span>audioconvert<span class="gtkdoc opt">,</span> level<span class="gtkdoc opt">,</span> caps<span class="gtkdoc opt">))</span>
    <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 audioconvert and level&quot;</span><span class="gtkdoc opt">);</span>
  <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">gst_element_link</a></span> <span class="gtkdoc opt">(</span>level<span class="gtkdoc opt">,</span> fakesink<span class="gtkdoc opt">))</span>
    <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 level and fakesink&quot;</span><span class="gtkdoc opt">);</span>

  <span class="comment">/* make sure we'll get messages */</span>
  <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>level<span class="gtkdoc opt">),</span> <span class="string">&quot;message&quot;</span><span class="gtkdoc opt">,</span> TRUE<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <span class="comment">/* run synced and not as fast as we can */</span>
  <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>fakesink<span class="gtkdoc opt">),</span> <span class="string">&quot;sync&quot;</span><span class="gtkdoc opt">,</span> TRUE<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>

  bus <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#gst-element-get-bus">gst_element_get_bus</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">);</span>
  watch_id <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBus.html#gst-bus-add-watch">gst_bus_add_watch</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">,</span> message_handler<span class="gtkdoc opt">,</span> NULL<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> GST_STATE_PLAYING<span class="gtkdoc opt">);</span>

  <span class="comment">/* we need to run a GLib main loop to get the messages */</span>
  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>
  <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>

  <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html#g-source-remove">g_source_remove</a></span> <span class="gtkdoc opt">(</span>watch_id<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-unref">g_main_loop_unref</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
  <span class="keyword">return</span> <span class="number">0</span><span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span></pre></td>
      </tr>
    </tbody>
  </table>
</div>

</div>
<p>
</p>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<div class="refsect2">
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Imported Upstream version 1.0.8  
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<a name="idp14809568"></a><h3>Element Information</h3>
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<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-good-plugins-plugin-level.html#plugin-level">level</a>
          </td>
</tr>
<tr>
<td><p><span class="term">author</span></p></td>
<td>Thomas Vander Stichele &lt;thomas at apestaart dot org&gt;</td>
</tr>
<tr>
<td><p><span class="term">class</span></p></td>
<td>Filter/Analyzer/Audio</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
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Imported Upstream version 1.0.8  
Sebastian Dröge committed
443 
<a name="idp12208672"></a><h3>Element Pads</h3>
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<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>
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Imported Upstream version 1.0.6  
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461 
<td>audio/x-raw, format=(string){ S8, S16LE, S32LE, F32LE, F64LE }, layout=(string)interleaved, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td>
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Imported Upstream version 0.11.90
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462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 
</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>
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Imported Upstream version 1.0.6  
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482 
<td>audio/x-raw, format=(string){ S8, S16LE, S32LE, F32LE, F64LE }, layout=(string)interleaved, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]</td>
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Imported Upstream version 0.11.90
Olivier Naudan committed
483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 
</tr>
</tbody>
</table></div>
</div>
</div>
<p>
</p>
</div>
<div class="refsect1">
<a name="gst-plugins-good-plugins-level.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GstLevel-struct"></a><h3>struct GstLevel</h3>
<pre class="programlisting">struct GstLevel;</pre>
<p>
Opaque data structure.
</p>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-good-plugins-level.property-details"></a><h2>Property Details</h2>
<div class="refsect2">
<a name="GstLevel--interval"></a><h3>The <code class="literal">"interval"</code> property</h3>
<pre class="programlisting">  "interval"                 <span class="type">guint64</span>               : Read / Write</pre>
<p>Interval of time between message posts (in nanoseconds).</p>
<p>Allowed values: &gt;= 1</p>
<p>Default value: 100000000</p>
</div>
<hr>
<div class="refsect2">
<a name="GstLevel--message"></a><h3>The <code class="literal">"message"</code> property</h3>
<pre class="programlisting">  "message"                  <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a>              : Read / Write</pre>
<p>Post a level message for each passed interval.</p>
<p>Default value: TRUE</p>
</div>
<hr>
<div class="refsect2">
<a name="GstLevel--peak-falloff"></a><h3>The <code class="literal">"peak-falloff"</code> property</h3>
<pre class="programlisting">  "peak-falloff"             <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a>               : Read / Write</pre>
<p>Decay rate of decay peak after TTL (in dB/sec).</p>
<p>Allowed values: &gt;= 0</p>
<p>Default value: 10</p>
</div>
<hr>
<div class="refsect2">
<a name="GstLevel--peak-ttl"></a><h3>The <code class="literal">"peak-ttl"</code> property</h3>
<pre class="programlisting">  "peak-ttl"                 <span class="type">guint64</span>               : Read / Write</pre>
<p>Time To Live of decay peak before it falls back (in nanoseconds).</p>
<p>Default value: 300000000</p>
</div>
</div>
</div>
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