vorbis/doc/vorbisenc/vorbis_encode_setup_vbr.html

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   4 <title>libvorbisenc - function - vorbis_encode_setup_vbr</title>
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  11 <td><p class=tiny>libvorbisenc documentation</p></td>
  12 <td align=right><p class=tiny>libvorbisenc version 1.3.2 - 20101101</p></td>
  13 </tr>
  14 </table>
  15
  16 <h1>vorbis_encode_setup_vbr</h1>
  17
  18 <p><i>declared in "vorbis/vorbisenc.h";</i></p>
  19
  20 <p>This function performs step-one of a three-step variable bitrate
  21 (quality-based) encode setup.  It functions similarly to the one-step
  22 setup performed by <a
  23 href="vorbis_encode_init_vbr.html">vorbis_encode_init_vbr()</a> but
  24 allows an application to make further encode setup tweaks using <a
  25 href="vorbis_encode_ctl.html">vorbis_encode_ctl()</a> before finally
  26 calling <a
  27 href="vorbis_encode_setup_init.html">vorbis_encode_setup_init()</a> to
  28 complete the setup process.
  29
  30 <p>Before this function is called, the <a href="../libvorbis/vorbis_info.html">vorbis_info</a> struct should be initialized by using vorbis_info_init() from the libvorbis API.  After encoding, vorbis_info_clear should be called.
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  36 <pre><b>
  37 extern int vorbis_encode_init_vbr(<a href="../libvorbis/vorbis_info.html">vorbis_info</a> *vi,
  38                               long channels,
  39                               long rate,
  40
  41                               float base_quality);
  42
  43 </b></pre>
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  47
  48 <h3>Parameters</h3>
  49 <dl>
  50 <dt><i>vi</i></dt>
  51 <dd>Pointer to an initialized <a href="../libvorbis/vorbis_info.html">vorbis_info</a> struct.</dd>
  52 <dt><i>channels</i></dt>
  53 <dd>The number of channels to be encoded.</dd>
  54 <dt><i>rate</i></dt>
  55 <dd>The sampling rate of the source audio.</dd>
  56 <dt><i>base_quality</i></dt>
  57 <dd>Desired quality level, currently from -0.1 to 1.0 (lo to hi).</dd>
  58 </dl>
  59
  60
  61 <h3>Return Values</h3>
  62 <blockquote>
  63 <li>
  64 0 for success</li>
  65
  66 <li>less than zero for failure:</li>
  67 <ul>
  68 <li>OV_EFAULT - Internal logic fault; indicates a bug or heap/stack corruption.</li>
  69 <li>OV_EINVAL - Invalid setup request, eg, out of range argument. </li>
  70 <li>OV_EIMPL  - Unimplemented mode; unable to comply with quality level request.</li>
  71 </ul>
  72 </blockquote>
  73 <p>
  74
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  79 <td><p class=tiny>copyright &copy; 2000-2010 Xiph.Org</p></td>
  80 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/index.html">Ogg Vorbis</a></p></td>
  81 </tr><tr>
  82 <td><p class=tiny>libvorbisenc documentation</p></td>
  83 <td align=right><p class=tiny>libvorbisenc version 1.3.2 - 20101101</p></td>
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