| [16] | 1 | <html> |
|---|
| 2 | |
|---|
| 3 | <head> |
|---|
| 4 | <title>Vorbisfile - Setup/Teardown</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>Vorbisfile documentation</p></td> |
|---|
| 12 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
|---|
| 13 | </tr> |
|---|
| 14 | </table> |
|---|
| 15 | |
|---|
| 16 | <H1>Setup/Teardown</h1> <p>In order to decode audio using |
|---|
| 17 | libvorbisfile, a bitstream containing Vorbis audio must be properly |
|---|
| 18 | initialized before decoding and cleared when decoding is finished. |
|---|
| 19 | The simplest possible case is to use <a |
|---|
| 20 | href="ov_fopen.html">ov_fopen()</a> to open the file for access, check |
|---|
| 21 | it for Vorbis content, and prepare it for playback. A successful <a |
|---|
| 22 | href="return.html">return code</a> from <a |
|---|
| 23 | href="ov_fopen.html">ov_fopen()</a> indicates the file is ready for use. |
|---|
| 24 | Once the file is no longer needed, <a |
|---|
| 25 | href="ov_clear.html">ov_clear()</a> is used to close the file and |
|---|
| 26 | deallocate decoding resources.<p> |
|---|
| 27 | |
|---|
| 28 | On systems other than Windows<a href="ov_open.html#winfoot">[a]</a>, an |
|---|
| 29 | application may also open a file itself using <tt>fopen()</tt>, then pass the |
|---|
| 30 | <tt>FILE *</tt> to libvorbisfile using <a |
|---|
| 31 | href="ov_open.html">ov_open()</a>. </b>Do not</b> call |
|---|
| 32 | <tt>fclose()</tt> on a file handle successfully submitted to <a |
|---|
| 33 | href="ov_open.html">ov_open()</a>; libvorbisfile does this in the <a |
|---|
| 34 | href="ov_clear.html">ov_clear()</a> call.<p> |
|---|
| 35 | |
|---|
| 36 | An application that requires more setup flexibility may open a data |
|---|
| 37 | stream using <a href="ov_open_callbacks.html">ov_open_callbacks()</a> |
|---|
| 38 | to change default libvorbis behavior or specify non-stdio data access |
|---|
| 39 | mechanisms.<p> |
|---|
| 40 | |
|---|
| 41 | <p> |
|---|
| 42 | All libvorbisfile initialization and deallocation routines are declared in "vorbis/vorbisfile.h". |
|---|
| 43 | <p> |
|---|
| 44 | |
|---|
| 45 | <table border=1 color=black width=50% cellspacing=0 cellpadding=7> |
|---|
| 46 | <tr bgcolor=#cccccc> |
|---|
| 47 | <td><b>function</b></td> |
|---|
| 48 | <td><b>purpose</b></td> |
|---|
| 49 | </tr> |
|---|
| 50 | <tr valign=top> |
|---|
| 51 | <td><a href="ov_fopen.html">ov_fopen</a></td> |
|---|
| 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 |
|---|
| 53 | used.</td> |
|---|
| 54 | </tr> |
|---|
| 55 | <tr valign=top> |
|---|
| 56 | <td><a href="ov_open.html">ov_open</a></td> |
|---|
| 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 |
|---|
| 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> |
|---|
| 59 | </tr> |
|---|
| 60 | <tr valign=top> |
|---|
| 61 | <td><a href="ov_open_callbacks.html">ov_open_callbacks</a></td> |
|---|
| 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> |
|---|
| 63 | </tr> |
|---|
| 64 | |
|---|
| 65 | <tr valign=top> |
|---|
| 66 | <td><a href="ov_test.html">ov_test</a></td> |
|---|
| 67 | |
|---|
| 68 | <td>Partially opens a file just far enough to determine if the file |
|---|
| 69 | is an Ogg Vorbis file or not. A successful return indicates that the |
|---|
| 70 | file appears to be an Ogg Vorbis file, but the <a |
|---|
| 71 | href="OggVorbis_File.html">OggVorbis_File</a> struct is not yet fully |
|---|
| 72 | initialized for actual decoding. After a <a href="return.html">successful return</a>, the file |
|---|
| 73 | may be closed using <a href="ov_clear.html">ov_clear()</a> or fully |
|---|
| 74 | opened for decoding using <a |
|---|
| 75 | href="ov_test_open.html">ov_test_open()</a>.<p> This call is intended to |
|---|
| 76 | be used as a less expensive file open test than a full <a |
|---|
| 77 | href="ov_open.html">ov_open()</a>.<p> |
|---|
| 78 | Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> |
|---|
| 79 | |
|---|
| 80 | </tr> |
|---|
| 81 | <tr valign=top> |
|---|
| 82 | <td><a href="ov_test_callbacks.html">ov_test_callbacks</a></td> |
|---|
| 83 | <td>As above but allowing application-define I/O callbacks.<p> |
|---|
| 84 | Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> |
|---|
| 85 | |
|---|
| 86 | </tr> |
|---|
| 87 | <tr valign=top> |
|---|
| 88 | <td><a href="ov_test_open.html">ov_test_open</a><td> |
|---|
| 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> |
|---|
| 90 | </tr> |
|---|
| 91 | <tr valign=top> |
|---|
| 92 | <td><a href="ov_clear.html">ov_clear</a></td> <td>Closes the |
|---|
| 93 | bitstream and cleans up loose ends. Must be called when |
|---|
| 94 | finished with the bitstream. After return, the <a |
|---|
| 95 | href="OggVorbis_File.html">OggVorbis_File</a> struct is |
|---|
| 96 | invalid and may not be used before being initialized again |
|---|
| 97 | before begin reinitialized. |
|---|
| 98 | |
|---|
| 99 | </td> |
|---|
| 100 | </tr> |
|---|
| 101 | </table> |
|---|
| 102 | |
|---|
| 103 | <br><br> |
|---|
| 104 | <hr noshade> |
|---|
| 105 | |
|---|
| 106 | <table border=0 width=100%> |
|---|
| 107 | <tr valign=top> |
|---|
| 108 | <td><p class=tiny>copyright © 2007 Xiph.org</p></td> |
|---|
| 109 | <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> |
|---|
| 110 | </tr><tr> |
|---|
| 111 | <td><p class=tiny>Vorbisfile documentation</p></td> |
|---|
| 112 | <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> |
|---|
| 113 | </tr> |
|---|
| 114 | </table> |
|---|
| 115 | |
|---|
| 116 | </body> |
|---|
| 117 | |
|---|
| 118 | </html> |
|---|
