/usr/share/gtk-doc/html/gst-plugins-base-libs-0.10/gst-plugins-base-libs-gstffts32.html is in gstreamer0.10-plugins-base-doc 0.10.36-1ubuntu0.2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>gstffts32</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.76.1">
<link rel="home" href="index.html" title="GStreamer Base Plugins 0.10 Library Reference Manual">
<link rel="up" href="gstreamer-ffft.html" title="FFT Library">
<link rel="prev" href="gst-plugins-base-libs-gstffts16.html" title="gstffts16">
<link rel="next" href="gst-plugins-base-libs-gstfftf32.html" title="gstfftf32">
<meta name="generator" content="GTK-Doc V1.18 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2">
<tr valign="middle">
<td><a accesskey="p" href="gst-plugins-base-libs-gstffts16.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="gstreamer-ffft.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">GStreamer Base Plugins 0.10 Library Reference Manual</th>
<td><a accesskey="n" href="gst-plugins-base-libs-gstfftf32.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr>
<tr><td colspan="5" class="shortcuts">
<a href="#gst-plugins-base-libs-gstffts32.synopsis" class="shortcut">Top</a>
|
<a href="#gst-plugins-base-libs-gstffts32.description" class="shortcut">Description</a>
</td></tr>
</table>
<div class="refentry">
<a name="gst-plugins-base-libs-gstffts32"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<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 valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="gst-plugins-base-libs-gstffts32.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">
#include <gst/fft/gstffts32.h>
struct <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32">GstFFTS32</a>;
struct <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32Complex" title="struct GstFFTS32Complex">GstFFTS32Complex</a>;
<a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="returnvalue">GstFFTS32</span></a> * <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-new" title="gst_fft_s32_new ()">gst_fft_s32_new</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> len</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> inverse</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-fft" title="gst_fft_s32_fft ()">gst_fft_s32_fft</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
<em class="parameter"><code>const <span class="type">gint32</span> *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>);
<span class="returnvalue">void</span> <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> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct 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><span class="type">gint32</span> *timedata</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-window" title="gst_fft_s32_window ()">gst_fft_s32_window</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
<em class="parameter"><code><span class="type">gint32</span> *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>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-base-libs-gstffts32.html#gst-fft-s32-free" title="gst_fft_s32_free ()">gst_fft_s32_free</a> (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>);
</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="struct 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="struct 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="struct 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.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GstFFTS32"></a><h3>struct GstFFTS32</h3>
<pre class="programlisting">struct GstFFTS32 {
};
</pre>
<p>
Instance structure for <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a>.
</p>
</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="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><span class="type">gint32</span> <em class="structfield"><code><a name="GstFFTS32Complex.r"></a>r</code></em>;</span></p></td>
<td>Real part</td>
</tr>
<tr>
<td><p><span class="term"><span class="type">gint32</span> <em class="structfield"><code><a name="GstFFTS32Complex.i"></a>i</code></em>;</span></p></td>
<td>Imaginary part</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<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="struct GstFFTS32"><span class="returnvalue">GstFFTS32</span></a> * gst_fft_s32_new (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> len</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-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="struct 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>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>len</code></em> :</span></p></td>
<td>Length of the FFT in the time domain</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>inverse</code></em> :</span></p></td>
<td>
<a href="/usr/share/gtk-doc/html/glib/glib-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="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance should be used for the inverse FFT</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>a new <a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance.</td>
</tr>
</tbody>
</table></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="struct GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
<em class="parameter"><code>const <span class="type">gint32</span> *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="struct 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="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>self</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>timedata</code></em> :</span></p></td>
<td>Buffer of the samples in the time domain</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>freqdata</code></em> :</span></p></td>
<td>Target buffer for the samples in the frequency domain</td>
</tr>
</tbody>
</table></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="struct 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><span class="type">gint32</span> *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="struct 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="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>self</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>freqdata</code></em> :</span></p></td>
<td>Buffer of the samples in the frequency domain</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>timedata</code></em> :</span></p></td>
<td>Target buffer for the samples in the time domain</td>
</tr>
</tbody>
</table></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="struct GstFFTS32"><span class="type">GstFFTS32</span></a> *self</code></em>,
<em class="parameter"><code><span class="type">gint32</span> *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="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>self</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>timedata</code></em> :</span></p></td>
<td>Time domain samples</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>window</code></em> :</span></p></td>
<td>Window function to apply</td>
</tr>
</tbody>
</table></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="struct 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="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>self</code></em> :</span></p></td>
<td>
<a class="link" href="gst-plugins-base-libs-gstffts32.html#GstFFTS32" title="struct GstFFTS32"><span class="type">GstFFTS32</span></a> instance for this call</td>
</tr></tbody>
</table></div>
</div>
</div>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.18</div>
</body>
</html>
|