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| 3 | <head> |
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| 4 | <title>Vorbisfile - function - ov_test</title> |
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| 5 | <link rel=stylesheet href="style.css" type="text/css"> |
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| 6 | </head> |
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| 7 | |
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| 8 | <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> |
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| 9 | <table border=0 width=100%> |
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| 10 | <tr> |
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| 11 | <td><p class=tiny>Vorbisfile documentation</p></td> |
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| 12 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
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| 13 | </tr> |
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| 14 | </table> |
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| 15 | |
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| 16 | <h1>ov_test</h1> |
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| 17 | |
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| 18 | <p><i>declared in "vorbis/vorbisfile.h";</i></p> |
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| 19 | |
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| 20 | <p> |
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| 21 | This partially opens a vorbis file to test for Vorbis-ness. It loads |
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| 22 | the headers for the first chain and tests for seekability (but does not seek). |
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| 23 | Use <a href="ov_test_open.html">ov_test_open()</a> to finish opening the file |
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| 24 | or <a href="ov_clear.html">ov_clear</a> to close/free it. |
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| 25 | <p> |
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| 26 | |
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| 27 | <p><em><b> WARNING for Windows developers: </b> Do not use ov_test() |
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| 28 | in Windows applications; Windows linking places restrictions on |
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| 29 | passing <tt>FILE *</tt> handles successfully, and ov_test() runs afoul |
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| 30 | of these restrictions <a href="#winfoot">[a]</a> in exactly the same |
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| 31 | way as <a href="ov_open.html">ov_open()</a>. See the <a |
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| 32 | href="ov_test_callbacks.html">ov_test_callbacks() page </a> for |
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| 33 | details on using <a |
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| 34 | href="ov_test_callbacks.html">ov_test_callbacks()</a> instead. </em> |
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| 35 | <p> |
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| 36 | |
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| 37 | <table border=0 color=black cellspacing=0 cellpadding=7> |
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| 38 | <tr bgcolor=#cccccc> |
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| 39 | <td> |
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| 40 | <pre><b> |
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| 41 | int ov_test(FILE *f,<a href="OggVorbis_File.html">OggVorbis_File</a> *vf,char *initial,long ibytes); |
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| 42 | </b></pre> |
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| 43 | </td> |
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| 44 | </tr> |
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| 45 | </table> |
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| 46 | |
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| 47 | <h3>Parameters</h3> |
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| 48 | <dl> |
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| 49 | <dt><i>f</i></dt> |
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| 50 | <dd>File pointer to an already opened file |
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| 51 | or pipe (it need not be seekable--though this obviously restricts what |
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| 52 | can be done with the bitstream).</dd> |
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| 53 | <dt><i>vf</i></dt> |
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| 54 | <dd>A pointer to the OggVorbis_File structure--this is used for ALL the externally visible libvorbisfile |
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| 55 | functions. Once this has been called, the same <tt>OggVorbis_File</tt> |
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| 56 | struct should be passed to all the libvorbisfile functions.</dd> |
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| 57 | <dt><i>initial</i></dt> |
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| 58 | <dd>Typically set to NULL. This parameter is useful if some data has already been |
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| 59 | read from the file and the stream is not seekable. It is used in conjunction with <tt>ibytes</tt>. In this case, <tt>initial</tt> |
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| 60 | should be a pointer to a buffer containing the data read.</dd> |
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| 61 | <dt><i>ibytes</i></dt> |
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| 62 | <dd>Typically set to 0. This parameter is useful if some data has already been |
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| 63 | read from the file and the stream is not seekable. In this case, <tt>ibytes</tt> |
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| 64 | should contain the length (in bytes) of the buffer. Used together with <tt>initial</tt></dd> |
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| 65 | </dl> |
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| 66 | |
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| 67 | |
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| 68 | <h3>Return Values</h3> |
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| 69 | <blockquote> |
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| 70 | <li>0 for success</li> |
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| 71 | |
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| 72 | <li>less than zero for failure:</li> |
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| 73 | <ul> |
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| 74 | <li>OV_EREAD - A read from media returned an error.</li> |
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| 75 | <li>OV_ENOTVORBIS - Bitstream contains no Vorbis data.</li> |
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| 76 | <li>OV_EVERSION - Vorbis version mismatch.</li> |
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| 77 | <li>OV_EBADHEADER - Invalid Vorbis bitstream header.</li> |
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| 78 | <li>OV_EFAULT - Internal logic fault; indicates a bug or heap/stack corruption.</li> |
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| 79 | </ul> |
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| 80 | </blockquote> |
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| 81 | <p> |
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| 82 | |
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| 83 | <h3>Notes</h3> |
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| 84 | |
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| 85 | All the <a href="ov_open.html#notes">notes from ov_open()</a> apply to ov_test(). |
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| 86 | |
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| 87 | <br><br> |
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| 88 | <hr noshade> |
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| 89 | <table border=0 width=100%> |
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| 90 | <tr valign=top> |
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| 91 | <td><p class=tiny>copyright © 2007 Xiph.org</p></td> |
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| 92 | <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> |
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| 93 | </tr><tr> |
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| 94 | <td><p class=tiny>Vorbisfile documentation</p></td> |
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| 95 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
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| 96 | </tr> |
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| 97 | </table> |
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| 98 | |
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| 99 | </body> |
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| 100 | |
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| 101 | </html> |
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