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 <a name="gst-plugins-base-libs-gstffts32"></a><div class="titlepage"></div>
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 <td valign="top">
 <h2><span class="refentrytitle"><a name="gst-plugins-base-libs-gstffts32.top_of_page"></a>gstffts32</span></h2>
 <p>gstffts32 — FFT functions for signed 32 bit integer samples</p>
 </td>
 <td class="gallery_image" valign="top" align="right"></td>
 </tr></table></div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.functions"></a><h2>Functions</h2>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="functions_return">
 <col class="functions_name">
 </colgroup>
 <tbody>
 <tr>
 <td class="function_type">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="returnvalue">GstFFTS32</span></a> *
 </td>
 <td class="function_name">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()">gst_fft_s32_new</a> <span class="c_punctuation">()</span>
 </td>
 </tr>
 <tr>
 <td class="function_type">
 <span class="returnvalue">void</span>
 </td>
 <td class="function_name">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-fft" title="gst_fft_s32_fft ()">gst_fft_s32_fft</a> <span class="c_punctuation">()</span>
 </td>
 </tr>
 <tr>
 <td class="function_type">
 <span class="returnvalue">void</span>
 </td>
 <td class="function_name">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-inverse-fft" title="gst_fft_s32_inverse_fft ()">gst_fft_s32_inverse_fft</a> <span class="c_punctuation">()</span>
 </td>
 </tr>
 <tr>
 <td class="function_type">
 <span class="returnvalue">void</span>
 </td>
 <td class="function_name">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-window" title="gst_fft_s32_window ()">gst_fft_s32_window</a> <span class="c_punctuation">()</span>
 </td>
 </tr>
 <tr>
 <td class="function_type">
 <span class="returnvalue">void</span>
 </td>
 <td class="function_name">
 <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-free" title="gst_fft_s32_free ()">gst_fft_s32_free</a> <span class="c_punctuation">()</span>
 </td>
 </tr>
 </tbody>
 </table></div>
 </div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.other"></a><h2>Types and Values</h2>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="name">
 <col class="description">
 </colgroup>
 <tbody>
 <tr>
 <td class="datatype_keyword"> </td>
 <td class="function_name"><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32">GstFFTS32</a></td>
 </tr>
 <tr>
 <td class="datatype_keyword">struct</td>
 <td class="function_name"><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32Complex" title="struct GstFFTS32Complex">GstFFTS32Complex</a></td>
 </tr>
 </tbody>
 </table></div>
 </div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.includes"></a><h2>Includes</h2>
 <pre class="synopsis">#include &lt;gst/fft/gstffts32.h&gt;
 </pre>
 </div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.description"></a><h2>Description</h2>
 <p><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> provides a FFT implementation and related functions for
 signed 32 bit integer samples. To use this call <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()"><code class="function">gst_fft_s32_new()</code></a> for
 allocating a <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance with the appropriate parameters and
 then call <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-fft" title="gst_fft_s32_fft ()"><code class="function">gst_fft_s32_fft()</code></a> or <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-inverse-fft" title="gst_fft_s32_inverse_fft ()"><code class="function">gst_fft_s32_inverse_fft()</code></a> to perform the
 FFT or inverse FFT on a buffer of samples.</p>
 <p>After use free the <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance with <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-free" title="gst_fft_s32_free ()"><code class="function">gst_fft_s32_free()</code></a>.</p>
 <p>For the best performance use <a class="link" href="gst-plugins-base-libs-gstfft.html#gst-fft-next-fast-length" title="gst_fft_next_fast_length ()"><code class="function">gst_fft_next_fast_length()</code></a> to get a
 number that is entirely a product of 2, 3 and 5 and use this as the
 <em class="parameter"><code>len</code></em>
  parameter for <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()"><code class="function">gst_fft_s32_new()</code></a>.</p>
 <p>The <em class="parameter"><code>len</code></em>
  parameter specifies the number of samples in the time domain that
 will be processed or generated. The number of samples in the frequency domain
 is <em class="parameter"><code>len</code></em>
 /2 + 1. To get n samples in the frequency domain use 2*n - 2 as <em class="parameter"><code>len</code></em>
 .</p>
 <p>Before performing the FFT on time domain data it usually makes sense
 to apply a window function to it. For this <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-window" title="gst_fft_s32_window ()"><code class="function">gst_fft_s32_window()</code></a> can comfortably
 be used.</p>
 <p>Be aware, that you can't simply run <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-inverse-fft" title="gst_fft_s32_inverse_fft ()"><code class="function">gst_fft_s32_inverse_fft()</code></a> on the
 resulting frequency data of <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-fft" title="gst_fft_s32_fft ()"><code class="function">gst_fft_s32_fft()</code></a> to get the original data back.
 The relation between them is iFFT (FFT (x)) = x / nfft where nfft is the
 length of the FFT. This also has to be taken into account when calculation
 the magnitude of the frequency data.</p>
 </div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.functions_details"></a><h2>Functions</h2>
 <div class="refsect2">
 <a name="gst-fft-s32-new"></a><h3>gst_fft_s32_new ()</h3>
 <pre class="programlisting"><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="returnvalue">GstFFTS32</span></a> *
 gst_fft_s32_new (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint"><span class="type">gint</span></a> len</code></em>,
                  <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> inverse</code></em>);</pre>
 <p>This returns a new <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance with the given parameters. It makes
 sense to keep one instance for several calls for speed reasons.</p>
 <p><em class="parameter"><code>len</code></em>
  must be even and to get the best performance a product of
 2, 3 and 5. To get the next number with this characteristics use
 <a class="link" href="gst-plugins-base-libs-gstfft.html#gst-fft-next-fast-length" title="gst_fft_next_fast_length ()"><code class="function">gst_fft_next_fast_length()</code></a>.</p>
 <p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
 <div class="refsect3">
 <a name="gst-fft-s32-new.parameters"></a><h4>Parameters</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="parameters_name">
 <col class="parameters_description">
 <col width="200px" class="parameters_annotations">
 </colgroup>
 <tbody>
 <tr>
 <td class="parameter_name"><p>len</p></td>
 <td class="parameter_description"><p>Length of the FFT in the time domain</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>inverse</p></td>
 <td class="parameter_description"><p><a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance should be used for the inverse FFT</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 </tbody>
 </table></div>
 </div>
 <div class="refsect3">
 <a name="gst-fft-s32-new.returns"></a><h4>Returns</h4>
 <p> a new <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance.</p>
 </div>
 </div>
 <hr>
 <div class="refsect2">
 <a name="gst-fft-s32-fft"></a><h3>gst_fft_s32_fft ()</h3>
 <pre class="programlisting"><span class="returnvalue">void</span>
 gst_fft_s32_fft (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
                  <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint32"><span class="type">gint32</span></a> *timedata</code></em>,
                  <em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32Complex" title="struct GstFFTS32Complex"><span class="type">GstFFTS32Complex</span></a> *freqdata</code></em>);</pre>
 <p>This performs the FFT on <em class="parameter"><code>timedata</code></em>
  and puts the result in <em class="parameter"><code>freqdata</code></em>
 .</p>
 <p><em class="parameter"><code>timedata</code></em>
  must have as many samples as specified with the <em class="parameter"><code>len</code></em>
  parameter while
 allocating the <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance with <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()"><code class="function">gst_fft_s32_new()</code></a>.</p>
 <p><em class="parameter"><code>freqdata</code></em>
  must be large enough to hold <em class="parameter"><code>len</code></em>
 /2 + 1 <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32Complex" title="struct GstFFTS32Complex"><span class="type">GstFFTS32Complex</span></a> frequency
 domain samples.</p>
 <div class="refsect3">
 <a name="gst-fft-s32-fft.parameters"></a><h4>Parameters</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="parameters_name">
 <col class="parameters_description">
 <col width="200px" class="parameters_annotations">
 </colgroup>
 <tbody>
 <tr>
 <td class="parameter_name"><p>self</p></td>
 <td class="parameter_description"><p><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>timedata</p></td>
 <td class="parameter_description"><p>Buffer of the samples in the time domain</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>freqdata</p></td>
 <td class="parameter_description"><p>Target buffer for the samples in the frequency domain</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 </tbody>
 </table></div>
 </div>
 </div>
 <hr>
 <div class="refsect2">
 <a name="gst-fft-s32-inverse-fft"></a><h3>gst_fft_s32_inverse_fft ()</h3>
 <pre class="programlisting"><span class="returnvalue">void</span>
 gst_fft_s32_inverse_fft (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
                          <em class="parameter"><code>const <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32Complex" title="struct GstFFTS32Complex"><span class="type">GstFFTS32Complex</span></a> *freqdata</code></em>,
                          <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint32"><span class="type">gint32</span></a> *timedata</code></em>);</pre>
 <p>This performs the inverse FFT on <em class="parameter"><code>freqdata</code></em>
  and puts the result in <em class="parameter"><code>timedata</code></em>
 .</p>
 <p><em class="parameter"><code>freqdata</code></em>
  must have <em class="parameter"><code>len</code></em>
 /2 + 1 samples, where <em class="parameter"><code>len</code></em>
  is the parameter specified
 while allocating the <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance with <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()"><code class="function">gst_fft_s32_new()</code></a>.</p>
 <p><em class="parameter"><code>timedata</code></em>
  must be large enough to hold <em class="parameter"><code>len</code></em>
  time domain samples.</p>
 <div class="refsect3">
 <a name="gst-fft-s32-inverse-fft.parameters"></a><h4>Parameters</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="parameters_name">
 <col class="parameters_description">
 <col width="200px" class="parameters_annotations">
 </colgroup>
 <tbody>
 <tr>
 <td class="parameter_name"><p>self</p></td>
 <td class="parameter_description"><p><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>freqdata</p></td>
 <td class="parameter_description"><p>Buffer of the samples in the frequency domain</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>timedata</p></td>
 <td class="parameter_description"><p>Target buffer for the samples in the time domain</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 </tbody>
 </table></div>
 </div>
 </div>
 <hr>
 <div class="refsect2">
 <a name="gst-fft-s32-window"></a><h3>gst_fft_s32_window ()</h3>
 <pre class="programlisting"><span class="returnvalue">void</span>
 gst_fft_s32_window (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
                     <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint32"><span class="type">gint32</span></a> *timedata</code></em>,
                     <em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstfft.html#GstFFTWindow" title="enum GstFFTWindow"><span class="type">GstFFTWindow</span></a> window</code></em>);</pre>
 <p>This calls the window function <em class="parameter"><code>window</code></em>
  on the <em class="parameter"><code>timedata</code></em>
  sample buffer.</p>
 <div class="refsect3">
 <a name="gst-fft-s32-window.parameters"></a><h4>Parameters</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="parameters_name">
 <col class="parameters_description">
 <col width="200px" class="parameters_annotations">
 </colgroup>
 <tbody>
 <tr>
 <td class="parameter_name"><p>self</p></td>
 <td class="parameter_description"><p><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>timedata</p></td>
 <td class="parameter_description"><p>Time domain samples</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 <tr>
 <td class="parameter_name"><p>window</p></td>
 <td class="parameter_description"><p>Window function to apply</p></td>
 <td class="parameter_annotations"> </td>
 </tr>
 </tbody>
 </table></div>
 </div>
 </div>
 <hr>
 <div class="refsect2">
 <a name="gst-fft-s32-free"></a><h3>gst_fft_s32_free ()</h3>
 <pre class="programlisting"><span class="returnvalue">void</span>
 gst_fft_s32_free (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>);</pre>
 <p>This frees the memory allocated for <em class="parameter"><code>self</code></em>
 .</p>
 <div class="refsect3">
 <a name="gst-fft-s32-free.parameters"></a><h4>Parameters</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="150px" class="parameters_name">
 <col class="parameters_description">
 <col width="200px" class="parameters_annotations">
 </colgroup>
 <tbody><tr>
 <td class="parameter_name"><p>self</p></td>
 <td class="parameter_description"><p><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</p></td>
 <td class="parameter_annotations"> </td>
 </tr></tbody>
 </table></div>
 </div>
 </div>
 </div>
 <div class="refsect1">
 <a name="gst-plugins-base-libs-gstffts32.other_details"></a><h2>Types and Values</h2>
 <div class="refsect2">
 <a name="GstFFTS32"></a><h3>GstFFTS32</h3>
 <pre class="programlisting">typedef struct _GstFFTS32 GstFFTS32;</pre>
 </div>
 <hr>
 <div class="refsect2">
 <a name="GstFFTS32Complex"></a><h3>struct GstFFTS32Complex</h3>
 <pre class="programlisting">struct GstFFTS32Complex {
   gint32 r;
   gint32 i;
 };
 </pre>
 <p>Data type for complex numbers composed of
 signed 32 bit integers.</p>
 <div class="refsect3">
 <a name="GstFFTS32Complex.members"></a><h4>Members</h4>
 <div class="informaltable"><table class="informaltable" width="100%" border="0">
 <colgroup>
 <col width="300px" class="struct_members_name">
 <col class="struct_members_description">
 <col width="200px" class="struct_members_annotations">
 </colgroup>
 <tbody>
 <tr>
 <td class="struct_member_name"><p><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint32"><span class="type">gint32</span></a> <em class="structfield"><code><a name="GstFFTS32Complex.r"></a>r</code></em>;</p></td>
 <td class="struct_member_description"><p>Real part</p></td>
 <td class="struct_member_annotations"> </td>
 </tr>
 <tr>
 <td class="struct_member_name"><p><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gint32"><span class="type">gint32</span></a> <em class="structfield"><code><a name="GstFFTS32Complex.i"></a>i</code></em>;</p></td>
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