1<html> 2 3<head> 4<title>Tremor - 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>Tremor documentation</p></td> 12<td align=right><p class=tiny>Tremor version 1.0 - 20020403</p></td> 13</tr> 14</table> 15 16<H1>Setup/Teardown</h1> <p>In order to decode audio using 17libvorbisidec, a bitstream containing Vorbis audio must be properly 18initialized before decoding and cleared when decoding is finished. 19The simplest possible case is to use <tt>fopen()</tt> to open a Vorbis 20file and then pass the <tt>FILE *</tt> to an <a 21href="ov_open.html">ov_open()</a> call. A successful <a 22href="return.html">return code</a> from <a 23href="ov_open.html">ov_open()</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. </b>Do not</b> call <tt>fclose()</tt> on the 27file; libvorbisidec does this in the <a 28href="ov_clear.html">ov_clear()</a> call. 29 30<p> 31All libvorbisidec initialization and deallocation routines are declared in "ivorbisfile.h". 32<p> 33 34<table border=1 color=black width=50% cellspacing=0 cellpadding=7> 35<tr bgcolor=#cccccc> 36 <td><b>function</b></td> 37 <td><b>purpose</b></td> 38</tr> 39<tr valign=top> 40 <td><a href="ov_open.html">ov_open</a></td> 41 <td>Initializes the Ogg Vorbis bitstream with a pointer to a bitstream and default values. This must be called before other functions in the library may be 42 used.</td> 43</tr> 44<tr valign=top> 45 <td><a href="ov_open_callbacks.html">ov_open_callbacks</a></td> 46 <td>Initializes the Ogg Vorbis bitstream with a pointer to a bitstream, default values, and custom file/bitstream manipulation routines. Used instead of <a href="ov_open.html">ov_open()</a> when working with other than stdio based I/O.</td> 47</tr> 48 49<tr valign=top> 50<td><a href="ov_test.html">ov_test</a></td> 51 52<td>Partially opens a file just far enough to determine if the file 53is an Ogg Vorbis file or not. A successful return indicates that the 54file appears to be an Ogg Vorbis file, but the <a 55href="OggVorbis_File.html">OggVorbis_File</a> struct is not yet fully 56initialized for actual decoding. After a <a href="return.html">successful return</a>, the file 57may be closed using <a href="ov_clear.html">ov_clear()</a> or fully 58opened for decoding using <a 59href="ov_test_open.html">ov_test_open()</a>.<p> This call is intended to 60be used as a less expensive file open test than a full <a 61href="ov_open.html">ov_open()</a>.<p> 62Note that libvorbisidec owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisidec.</td> 63 64</tr> 65<tr valign=top> 66<td><a href="ov_test_callbacks.html">ov_test_callbacks</a></td> 67<td>As above but allowing application-define I/O callbacks.<p> 68Note that libvorbisidec owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisidec.</td> 69 70</tr> 71<tr valign=top> 72<td><a href="ov_test_open.html">ov_test_open</a><td> 73Finish 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> 74</tr> 75<tr valign=top> 76 <td><a href="ov_clear.html">ov_clear</a></td> <td>Closes the 77 bitstream and cleans up loose ends. Must be called when 78 finished with the bitstream. After return, the <a 79 href="OggVorbis_File.html">OggVorbis_File</a> struct is 80 invalid and may not be used before being initialized again 81 before begin reinitialized. 82 83</td> 84</tr> 85</table> 86 87<br><br> 88<hr noshade> 89<table border=0 width=100%> 90<tr valign=top> 91<td><p class=tiny>copyright © 2002 Xiph.org</p></td> 92<td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> 93</tr><tr> 94<td><p class=tiny>Tremor documentation</p></td> 95<td align=right><p class=tiny>Tremor version 1.0 - 20020403</p></td> 96</tr> 97</table> 98 99</body> 100 101</html> 102