1 <html> 2 3 <head> 4 <title>libvorbisenc - function - vorbis_encode_setup_vbr</title> 5 <link rel=stylesheet href="style.css" type="text/css"> 6 </head> 7 8 <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> 9 <table border=0 width=100%> 10 <tr> 11 <td><p class=tiny>libvorbisenc documentation</p></td> 12 <td align=right><p class=tiny>libvorbisenc release 1.1 - 20040709</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="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. 31 <p> 32 <br><br> 33 <table border=0 color=black cellspacing=0 cellpadding=7> 34 <tr bgcolor=#cccccc> 35 <td> 36 <pre><b> 37 extern int vorbis_encode_init_vbr(<a href="vorbis_info.html">vorbis_info</a> *vi, 38 long channels, 39 long rate, 40 41 float base_quality); 42 43 </b></pre> 44 </td> 45 </tr> 46 </table> 47 48 <h3>Parameters</h3> 49 <dl> 50 <dt><i>vi</i></dt> 51 <dd>Pointer to an initialized <a href="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 75 <br><br> 76 <hr noshade> 77 <table border=0 width=100%> 78 <tr valign=top> 79 <td><p class=tiny>copyright © 2004 xiph.org</p></td> 80 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/index.html">Ogg Vorbis</a><br><a href="mailto:team (a] vorbis.org">team (a] vorbis.org</a></p></td> 81 </tr><tr> 82 <td><p class=tiny>libvorbisenc documentation</p></td> 83 <td align=right><p class=tiny>libvorbisenc release 1.1 - 20040709</p></td> 84 </tr> 85 </table> 86 87 88 </body> 89 90 </html> 91
