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 17libvorbisfile, a bitstream containing Vorbis audio must be properly 18initialized before decoding and cleared when decoding is finished. 19The simplest possible case is to use <a 20href="ov_fopen.html">ov_fopen()</a> to open the file for access, check 21it for Vorbis content, and prepare it for playback. A successful <a 22href="return.html">return code</a> from <a 23href="ov_fopen.html">ov_fopen()</a> indicates the file is ready for use. 24Once the file is no longer needed, <a 25href="ov_clear.html">ov_clear()</a> is used to close the file and 26deallocate decoding resources.<p> 27 28On systems other than Windows<a href="ov_open.html#winfoot">[a]</a>, an 29application may also open a file itself using <tt>fopen()</tt>, then pass the 30<tt>FILE *</tt> to libvorbisfile using <a 31href="ov_open.html">ov_open()</a>. </b>Do not</b> call 32<tt>fclose()</tt> on a file handle successfully submitted to <a 33href="ov_open.html">ov_open()</a>; libvorbisfile does this in the <a 34href="ov_clear.html">ov_clear()</a> call.<p> 35 36An application that requires more setup flexibility may open a data 37stream using <a href="ov_open_callbacks.html">ov_open_callbacks()</a> 38to change default libvorbis behavior or specify non-stdio data access 39mechanisms.<p> 40 41<p> 42All 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 69is an Ogg Vorbis file or not. A successful return indicates that the 70file appears to be an Ogg Vorbis file, but the <a 71href="OggVorbis_File.html">OggVorbis_File</a> struct is not yet fully 72initialized for actual decoding. After a <a href="return.html">successful return</a>, the file 73may be closed using <a href="ov_clear.html">ov_clear()</a> or fully 74opened for decoding using <a 75href="ov_test_open.html">ov_test_open()</a>.<p> This call is intended to 76be used as a less expensive file open test than a full <a 77href="ov_open.html">ov_open()</a>.<p> 78Note 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> 84Note 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> 89Finish 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