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> 119
