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comparison src/libvorbis-1.3.3/doc/libvorbis/vorbis_analysis.html @ 1:05aa0afa9217
Bring in flac, ogg, vorbis
| author | Chris Cannam |
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| date | Tue, 19 Mar 2013 17:37:49 +0000 |
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| 0:c7265573341e | 1:05aa0afa9217 |
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| 1 <html> | |
| 2 | |
| 3 <head> | |
| 4 <title>libvorbis - function - vorbis_analysis</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>libvorbis documentation</p></td> | |
| 12 <td align=right><p class=tiny>libvorbis version 1.3.2 - 20101101</p></td> | |
| 13 </tr> | |
| 14 </table> | |
| 15 | |
| 16 <h1>vorbis_analysis</h1> | |
| 17 | |
| 18 <p><i>declared in "vorbis/codec.h";</i></p> | |
| 19 | |
| 20 <p>Once the uncompressed audio data has been divided into blocks, this | |
| 21 function is called on each block. It looks up the encoding mode and | |
| 22 dispatches the block to the forward transform provided by that mode. | |
| 23 </p> | |
| 24 <p>When using a basic encoding mode, with no bitrate management, | |
| 25 an ogg_packet pointer can be given, and the coded block is returned | |
| 26 directly through that structure and can be placed in the output stream. | |
| 27 </p> | |
| 28 <p>Otherwise, NULL should be passed for the ogg_packet pointer. In | |
| 29 that case, after the transform has been applied, the block must passed | |
| 30 to vorbis_bitrate_addblock() for further coding. This method works with | |
| 31 both basic and managed encoding modes, so it's recommended for new code. | |
| 32 </p> | |
| 33 | |
| 34 <table border=0 color=black cellspacing=0 cellpadding=7> | |
| 35 <tr bgcolor=#cccccc> | |
| 36 <td> | |
| 37 <pre><b> | |
| 38 extern int vorbis_analysis(vorbis_block *vb,ogg_packet *op); | |
| 39 </b></pre> | |
| 40 </td> | |
| 41 </tr> | |
| 42 </table> | |
| 43 | |
| 44 <h3>Parameters</h3> | |
| 45 <dl> | |
| 46 <dt><i>vb</i></dt> | |
| 47 <dd>Pointer to the vorbis_block to be encoded.</dd> | |
| 48 <dt><i>op</i></dt> | |
| 49 <dd>Optional pointer to an ogg_packet. This is normally NULL, | |
| 50 and the final output is obtained by passing <i>vb</i> though the | |
| 51 vorbis_bitrate_*() interface to perform further refinement. | |
| 52 However, when not using a bitrate managed encoding mode, it | |
| 53 is possible to skip that step by providing an ogg_packet pointer | |
| 54 here, obtaining the compressed data directly.</dd> | |
| 55 </dl> | |
| 56 | |
| 57 | |
| 58 <h3>Return Values</h3> | |
| 59 <ul> | |
| 60 <li>0 for success</li> | |
| 61 <li>negative values for failure: | |
| 62 <ul> | |
| 63 <li>OV_EINVAL - Invalid request; a non-NULL value was passed for <i>op</i> when the encoder is using a bitrate managed mode.</li> | |
| 64 <li>OV_EFAULT - Internal fault; indicates a bug or memory corruption.</li> | |
| 65 <li>OV_EIMPL - Unimplemented; not supported by this version of the library.</li> | |
| 66 </ul> | |
| 67 </li> | |
| 68 </ul> | |
| 69 <p> | |
| 70 | |
| 71 <br><br> | |
| 72 <hr noshade> | |
| 73 <table border=0 width=100%> | |
| 74 <tr valign=top> | |
| 75 <td><p class=tiny>copyright © 2010 Xiph.Org</p></td> | |
| 76 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/index.html">Ogg Vorbis</a></p></td> | |
| 77 </tr><tr> | |
| 78 <td><p class=tiny>libvorbis documentation</p></td> | |
| 79 <td align=right><p class=tiny>libvorbis version 1.3.2 - 20101101</p></td> | |
| 80 </tr> | |
| 81 </table> | |
| 82 | |
| 83 | |
| 84 </body> | |
| 85 | |
| 86 </html> |