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| 3 | <head> |
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| 4 | <title>Vorbisfile - Setup/Teardown</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>Setup/Teardown</h1> <p>In order to decode audio using |
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| 17 | libvorbisfile, a bitstream containing Vorbis audio must be properly |
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| 18 | initialized before decoding and cleared when decoding is finished. |
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| 19 | The simplest possible case is to use <a |
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| 20 | href="ov_fopen.html">ov_fopen()</a> to open the file for access, check |
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| 21 | it for Vorbis content, and prepare it for playback. A successful <a |
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| 22 | href="return.html">return code</a> from <a |
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| 23 | href="ov_fopen.html">ov_fopen()</a> indicates the file is ready for use. |
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| 24 | Once the file is no longer needed, <a |
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| 25 | href="ov_clear.html">ov_clear()</a> is used to close the file and |
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| 26 | deallocate decoding resources.<p> |
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| 27 | |
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| 28 | On systems other than Windows<a href="ov_open.html#winfoot">[a]</a>, an |
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| 29 | application may also open a file itself using <tt>fopen()</tt>, then pass the |
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| 30 | <tt>FILE *</tt> to libvorbisfile using <a |
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| 31 | href="ov_open.html">ov_open()</a>. </b>Do not</b> call |
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| 32 | <tt>fclose()</tt> on a file handle successfully submitted to <a |
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| 33 | href="ov_open.html">ov_open()</a>; libvorbisfile does this in the <a |
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| 34 | href="ov_clear.html">ov_clear()</a> call.<p> |
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| 35 | |
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| 36 | An application that requires more setup flexibility may open a data |
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| 37 | stream using <a href="ov_open_callbacks.html">ov_open_callbacks()</a> |
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| 38 | to change default libvorbis behavior or specify non-stdio data access |
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| 39 | mechanisms.<p> |
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| 40 | |
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| 41 | <p> |
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| 42 | All libvorbisfile initialization and deallocation routines are declared in "vorbis/vorbisfile.h". |
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| 43 | <p> |
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| 44 | |
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| 45 | <table border=1 color=black width=50% cellspacing=0 cellpadding=7> |
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| 46 | <tr bgcolor=#cccccc> |
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| 47 | <td><b>function</b></td> |
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| 48 | <td><b>purpose</b></td> |
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| 49 | </tr> |
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| 50 | <tr valign=top> |
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| 51 | <td><a href="ov_fopen.html">ov_fopen</a></td> |
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| 52 | <td>Opens a file and initializes the Ogg Vorbis bitstream with default values. This must be called before other functions in the library may be |
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| 53 | used.</td> |
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| 54 | </tr> |
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| 55 | <tr valign=top> |
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| 56 | <td><a href="ov_open.html">ov_open</a></td> |
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| 57 | <td>Initializes the Ogg Vorbis bitstream with default values from a passed in file handle. This must be called before other functions in the library may be |
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| 58 | used. <a href="#winfoot"><em>Do not use this call under Windows [a];</em></a> Use <a href="ov_fopen.html">ov_fopen()</a> or <a href="ov_open_callbacks.html">ov_open_callbacks()</a> instead.</td> |
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| 59 | </tr> |
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| 60 | <tr valign=top> |
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| 61 | <td><a href="ov_open_callbacks.html">ov_open_callbacks</a></td> |
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| 62 | <td>Initializes the Ogg Vorbis bitstream from a file handle and custom file/bitstream manipulation routines. Used instead of <a href="ov_open.html">ov_open()</a> or <a href="ov_fopen.html">ov_fopen()</a> when altering or replacing libvorbis's default stdio I/O behavior, or when a bitstream must be initialized from a <tt>FILE *</tt> under Windows.</td> |
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| 63 | </tr> |
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| 64 | |
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| 65 | <tr valign=top> |
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| 66 | <td><a href="ov_test.html">ov_test</a></td> |
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| 67 | |
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| 68 | <td>Partially opens a file just far enough to determine if the file |
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| 69 | is an Ogg Vorbis file or not. A successful return indicates that the |
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| 70 | file appears to be an Ogg Vorbis file, but the <a |
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| 71 | href="OggVorbis_File.html">OggVorbis_File</a> struct is not yet fully |
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| 72 | initialized for actual decoding. After a <a href="return.html">successful return</a>, the file |
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| 73 | may be closed using <a href="ov_clear.html">ov_clear()</a> or fully |
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| 74 | opened for decoding using <a |
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| 75 | href="ov_test_open.html">ov_test_open()</a>.<p> This call is intended to |
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| 76 | be used as a less expensive file open test than a full <a |
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| 77 | href="ov_open.html">ov_open()</a>.<p> |
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| 78 | Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> |
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| 79 | |
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| 80 | </tr> |
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| 81 | <tr valign=top> |
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| 82 | <td><a href="ov_test_callbacks.html">ov_test_callbacks</a></td> |
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| 83 | <td>As above but allowing application-define I/O callbacks.<p> |
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| 84 | Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> |
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| 85 | |
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| 86 | </tr> |
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| 87 | <tr valign=top> |
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| 88 | <td><a href="ov_test_open.html">ov_test_open</a><td> |
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| 89 | Finish opening a file after a successful call to <a href="ov_test.html">ov_test()</a> or <a href="ov_test_callbacks.html">ov_test_callbacks()</a>.</td> |
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| 90 | </tr> |
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| 91 | <tr valign=top> |
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| 92 | <td><a href="ov_clear.html">ov_clear</a></td> <td>Closes the |
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| 93 | bitstream and cleans up loose ends. Must be called when |
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| 94 | finished with the bitstream. After return, the <a |
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| 95 | href="OggVorbis_File.html">OggVorbis_File</a> struct is |
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| 96 | invalid and may not be used before being initialized again |
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| 97 | before begin reinitialized. |
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| 98 | |
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| 99 | </td> |
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| 100 | </tr> |
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| 101 | </table> |
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| 102 | |
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| 103 | <br><br> |
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| 104 | <hr noshade> |
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| 105 | |
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| 106 | <table border=0 width=100%> |
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| 107 | <tr valign=top> |
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| 108 | <td><p class=tiny>copyright © 2007 Xiph.org</p></td> |
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| 109 | <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> |
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| 110 | </tr><tr> |
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| 111 | <td><p class=tiny>Vorbisfile documentation</p></td> |
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| 112 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
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| 113 | </tr> |
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| 114 | </table> |
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| 115 | |
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| 116 | </body> |
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| 117 | |
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| 118 | </html> |
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