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| <a href="#gst-plugins-good-plugins-audiocheblimit.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#gst-plugins-good-plugins-audiocheblimit.description" class="shortcut">Description</a> |
| | |
| <a href="#gst-plugins-good-plugins-audiocheblimit.object-hierarchy" class="shortcut">Object Hierarchy</a> |
| | |
| <a href="#gst-plugins-good-plugins-audiocheblimit.properties" class="shortcut">Properties</a> |
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| <div class="refentry"> |
| <a name="gst-plugins-good-plugins-audiocheblimit"></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-audiocheblimit.top_of_page"></a>audiocheblimit</span></h2> |
| <p>audiocheblimit — Chebyshev low pass and high pass filter</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsynopsisdiv"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.synopsis"></a><h2>Synopsis</h2> |
| <a name="GstAudioChebLimit"></a><pre class="synopsis">struct <a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit-struct" title="struct GstAudioChebLimit">GstAudioChebLimit</a>; |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.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> |
| +----<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstaudiofilter.html#GstAudioFilter">GstAudioFilter</a> |
| +----GstAudioFXBaseIIRFilter |
| +----GstAudioChebLimit |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.properties"></a><h2>Properties</h2> |
| <pre class="synopsis"> |
| "<a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit--cutoff" title='The "cutoff" property'>cutoff</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gfloat"><span class="type">gfloat</span></a> : Read / Write |
| "<a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit--mode" title='The "mode" property'>mode</a>" <span class="type">GstAudioChebLimitMode</span> : Read / Write |
| "<a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit--poles" title='The "poles" property'>poles</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> : Read / Write |
| "<a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit--ripple" title='The "ripple" property'>ripple</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gfloat"><span class="type">gfloat</span></a> : Read / Write |
| "<a class="link" href="gst-plugins-good-plugins-audiocheblimit.html#GstAudioChebLimit--type" title='The "type" property'>type</a>" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> : Read / Write |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.description"></a><h2>Description</h2> |
| <p> |
| Attenuates all frequencies above the cutoff frequency (low-pass) or all frequencies below the |
| cutoff frequency (high-pass). The number of poles and the ripple parameter control the rolloff. |
| </p> |
| <p> |
| This element has the advantage over the windowed sinc lowpass and highpass filter that it is |
| much faster and produces almost as good results. It's only disadvantages are the highly |
| non-linear phase and the slower rolloff compared to a windowed sinc filter with a large kernel. |
| </p> |
| <p> |
| For type 1 the ripple parameter specifies how much ripple in dB is allowed in the passband, i.e. |
| some frequencies in the passband will be amplified by that value. A higher ripple value will allow |
| a faster rolloff. |
| </p> |
| <p> |
| For type 2 the ripple parameter specifies the stopband attenuation. In the stopband the gain will |
| be at most this value. A lower ripple value will allow a faster rolloff. |
| </p> |
| <p> |
| As a special case, a Chebyshev type 1 filter with no ripple is a Butterworth filter. |
| </p> |
| <p> |
| </p> |
| <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> |
| <h3 class="title">Note</h3> |
| <p> |
| Be warned that a too large number of poles can produce noise. The most poles are possible with |
| a cutoff frequency at a quarter of the sampling rate. |
| </p> |
| </div> |
| <p> |
| </p> |
| <p> |
| </p> |
| <div class="refsect2"> |
| <a name="id-1.2.17.6.8.1"></a><h3>Example launch line</h3> |
| <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">gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> audiotestsrc freq<span class="gtkdoc opt">=</span><span class="number">1500</span> <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audiocheblimit mode<span class="gtkdoc opt">=</span>low<span class="gtkdoc opt">-</span>pass cutoff<span class="gtkdoc opt">=</span><span class="number">1000</span> poles<span class="gtkdoc opt">=</span><span class="number">4</span> <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> alsasink |
| gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> filesrc location<span class="gtkdoc opt">=</span><span class="string">"melo1.ogg"</span> <span class="gtkdoc opt">!</span> oggdemux <span class="gtkdoc opt">!</span> vorbisdec <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audiocheblimit mode<span class="gtkdoc opt">=</span>high<span class="gtkdoc opt">-</span>pass cutoff<span class="gtkdoc opt">=</span><span class="number">400</span> ripple<span class="gtkdoc opt">=</span><span class="number">0.2</span> <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> alsasink |
| gst<span class="gtkdoc opt">-</span>launch<span class="gtkdoc opt">-</span><span class="number">1.0</span> audiotestsrc wave<span class="gtkdoc opt">=</span>white<span class="gtkdoc opt">-</span>noise <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> audiocheblimit mode<span class="gtkdoc opt">=</span>low<span class="gtkdoc opt">-</span>pass cutoff<span class="gtkdoc opt">=</span><span class="number">800</span> type<span class="gtkdoc opt">=</span><span class="number">2</span> <span class="gtkdoc opt">!</span> audioconvert <span class="gtkdoc opt">!</span> alsasink</pre></td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| |
| </div> |
| <p> |
| </p> |
| <div class="refsynopsisdiv"> |
| <h2>Synopsis</h2> |
| <div class="refsect2"> |
| <a name="id-1.2.17.6.9.1"></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>Sebastian Dröge <sebastian.droege@collabora.co.uk></td> |
| </tr> |
| <tr> |
| <td><p><span class="term">class</span></p></td> |
| <td>Filter/Effect/Audio</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="id-1.2.17.6.9.2"></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, F64LE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</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, F64LE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <p> |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.details"></a><h2>Details</h2> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit-struct"></a><h3>struct GstAudioChebLimit</h3> |
| <pre class="programlisting">struct GstAudioChebLimit;</pre> |
| <p> |
| </p> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-good-plugins-audiocheblimit.property-details"></a><h2>Property Details</h2> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit--cutoff"></a><h3>The <code class="literal">"cutoff"</code> property</h3> |
| <pre class="programlisting"> "cutoff" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gfloat"><span class="type">gfloat</span></a> : Read / Write</pre> |
| <p>Cut off frequency (Hz).</p> |
| <p>Allowed values: [0,100000]</p> |
| <p>Default value: 0</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit--mode"></a><h3>The <code class="literal">"mode"</code> property</h3> |
| <pre class="programlisting"> "mode" <span class="type">GstAudioChebLimitMode</span> : Read / Write</pre> |
| <p>Low pass or high pass mode.</p> |
| <p>Default value: Low pass (default)</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit--poles"></a><h3>The <code class="literal">"poles"</code> property</h3> |
| <pre class="programlisting"> "poles" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> : Read / Write</pre> |
| <p>Number of poles to use, will be rounded up to the next even number.</p> |
| <p>Allowed values: [2,32]</p> |
| <p>Default value: 4</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit--ripple"></a><h3>The <code class="literal">"ripple"</code> property</h3> |
| <pre class="programlisting"> "ripple" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gfloat"><span class="type">gfloat</span></a> : Read / Write</pre> |
| <p>Amount of ripple (dB).</p> |
| <p>Allowed values: [0,200]</p> |
| <p>Default value: 0.25</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstAudioChebLimit--type"></a><h3>The <code class="literal">"type"</code> property</h3> |
| <pre class="programlisting"> "type" <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="type">gint</span></a> : Read / Write</pre> |
| <p>Type of the chebychev filter.</p> |
| <p>Allowed values: [1,2]</p> |
| <p>Default value: 1</p> |
| </div> |
| </div> |
| </div> |
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