| [16] | 1 | <html> |
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| 2 | |
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| 3 | <head> |
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| 4 | <title>Vorbisfile - datatype - OggVorbis_File</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>OggVorbis_File</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 | The OggVorbis_File structure defines an Ogg Vorbis file. |
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| 22 | <p> |
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| 23 | |
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| 24 | This structure is used in all libvorbisfile routines. Before it can |
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| 25 | be used, it must be initialized by <a |
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| 26 | href="ov_open.html">ov_open()</a>, <a |
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| 27 | href="ov_fopen.html">ov_fopen()</a>, or <a |
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| 28 | href="ov_open_callbacks.html">ov_open_callbacks()</a>. <em>Important |
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| 29 | Note:</em> The use of <a href="ov_open.html">ov_open()</a> is |
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| 30 | discouraged under Windows due to a peculiarity of Windows linking |
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| 31 | convention; use <a href="ov_fopen.html">ov_fopen()</a> or <a |
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| 32 | href="ov_open_callbacks.html">ov_open_callbacks()</a> instead. This |
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| 33 | caution only applies to Windows; use of <a |
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| 34 | href="ov_open.html">ov_open()</a> is appropriate for all other |
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| 35 | platforms. See the <a href="ov_open.html">ov_open()</a> page for more |
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| 36 | information. |
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| 37 | |
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| 38 | <p> |
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| 39 | After use, the OggVorbis_File structure must be deallocated with a |
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| 40 | call to <a href="ov_clear.html">ov_clear()</a>. |
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| 41 | |
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| 42 | <p> |
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| 43 | Note that once a file handle is passed to a successful <a |
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| 44 | href="ov_open.html">ov_open()</a> call, the handle is owned by |
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| 45 | libvorbisfile and will be closed by libvorbisfile later during the |
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| 46 | call to <a href="ov_clear.html">ov_clear()</a>. The handle should not |
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| 47 | be used or closed outside of the libvorbisfile API. Similarly, files |
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| 48 | opened by <a href="ov_fopen.html">ov_fopen()</a> will also be closed |
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| 49 | internally by vorbisfile in <a href="ov_clear.html">ov_clear()</a>.<p> |
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| 50 | |
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| 51 | <a href="ov_open_callbacks.html">ov_open_callbacks()</a> allows the |
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| 52 | application to choose whether libvorbisfile will or will not close the |
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| 53 | handle in <a href="ov_clear.html">ov_clear()</a>; see the <a |
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| 54 | href="ov_open_callbacks.html">ov_open_callbacks()</a> page for more information.<p> |
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| 55 | |
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| 56 | If a call to <a href="ov_open.html">ov_open()</a> or <a |
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| 57 | href="ov_open_callbacks.html">ov_open_callbacks()</a> <b>fails</b>, |
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| 58 | libvorbisfile does <b>not</b> assume ownership of the handle and the |
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| 59 | application is expected to close it if necessary. A failed <a |
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| 60 | href="ov_fopen.html">ov_fopen()</a> call will internally close the |
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| 61 | file handle if the open process fails.<p> |
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| 62 | |
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| 63 | <br><br> |
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| 64 | <table border=0 width=100% color=black cellspacing=0 cellpadding=7> |
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| 65 | <tr bgcolor=#cccccc> |
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| 66 | <td> |
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| 67 | <pre><b>typedef struct { |
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| 68 | void *datasource; /* Pointer to a FILE *, etc. */ |
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| 69 | int seekable; |
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| 70 | ogg_int64_t offset; |
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| 71 | ogg_int64_t end; |
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| 72 | ogg_sync_state oy; |
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| 73 | |
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| 74 | /* If the FILE handle isn't seekable (eg, a pipe), only the current |
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| 75 | stream appears */ |
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| 76 | int links; |
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| 77 | ogg_int64_t *offsets; |
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| 78 | ogg_int64_t *dataoffsets; |
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| 79 | long *serialnos; |
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| 80 | ogg_int64_t *pcmlengths; |
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| 81 | vorbis_info *vi; |
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| 82 | vorbis_comment *vc; |
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| 83 | |
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| 84 | /* Decoding working state local storage */ |
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| 85 | ogg_int64_t pcm_offset; |
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| 86 | int ready_state; |
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| 87 | long current_serialno; |
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| 88 | int current_link; |
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| 89 | |
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| 90 | ogg_int64_t bittrack; |
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| 91 | ogg_int64_t samptrack; |
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| 92 | |
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| 93 | ogg_stream_state os; /* take physical pages, weld into a logical |
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| 94 | stream of packets */ |
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| 95 | vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */ |
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| 96 | vorbis_block vb; /* local working space for packet->PCM decode */ |
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| 97 | |
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| 98 | <a href="ov_callbacks.html">ov_callbacks</a> callbacks; |
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| 99 | |
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| 100 | } OggVorbis_File;</b></pre> |
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| 101 | </td> |
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| 102 | </tr> |
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| 103 | </table> |
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| 104 | |
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| 105 | <h3>Relevant Struct Members</h3> |
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| 106 | <dl> |
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| 107 | <dt><i>datasource</i></dt> |
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| 108 | |
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| 109 | <dd>Pointer to file or other ogg source. When using stdio based |
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| 110 | file/stream access, this field contains a <tt>FILE</tt> pointer. When using |
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| 111 | custom IO via callbacks, libvorbisfile treats this void pointer as a |
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| 112 | black box only to be passed to the callback routines provided by the |
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| 113 | application.</dd> |
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| 114 | |
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| 115 | <dt><i>seekable</i></dt> |
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| 116 | <dd>Read-only int indicating whether file is seekable. E.g., a physical file is seekable, a pipe isn't.</dd> |
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| 117 | <dt><i>links</i></dt> |
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| 118 | <dd>Read-only int indicating the number of logical bitstreams within the physical bitstream.</dd> |
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| 119 | <dt><i>ov_callbacks</i></dt> |
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| 120 | <dd>Collection of file manipulation routines to be used on this data source. When using stdio/FILE access via <a href="ov_open.html">ov_open()</a>, the callbacks will be filled in with stdio calls or wrappers to stdio calls.</dd> |
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| 121 | </dl> |
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| 122 | |
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| 123 | <br><br> |
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| 124 | <hr noshade> |
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| 125 | <table border=0 width=100%> |
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| 126 | <tr valign=top> |
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| 127 | <td><p class=tiny>copyright © 2007 Xiph.org</p></td> |
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| 128 | <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> |
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| 129 | </tr><tr> |
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| 130 | <td><p class=tiny>Vorbisfile documentation</p></td> |
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| 131 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
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| 132 | </tr> |
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| 133 | </table> |
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| 134 | |
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| 135 | </body> |
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| 136 | |
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| 137 | </html> |
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