cannam@86: <html> cannam@86: cannam@86: <head> cannam@86: <title>Vorbisfile - Setup/Teardown</title> cannam@86: <link rel=stylesheet href="style.css" type="text/css"> cannam@86: </head> cannam@86: cannam@86: <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> cannam@86: <table border=0 width=100%> cannam@86: <tr> cannam@86: <td><p class=tiny>Vorbisfile documentation</p></td> cannam@86: <td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td> cannam@86: </tr> cannam@86: </table> cannam@86: cannam@86: <H1>Setup/Teardown</h1> <p>In order to decode audio using cannam@86: libvorbisfile, a bitstream containing Vorbis audio must be properly cannam@86: initialized before decoding and cleared when decoding is finished. cannam@86: The simplest possible case is to use <a cannam@86: href="ov_fopen.html">ov_fopen()</a> to open the file for access, check cannam@86: it for Vorbis content, and prepare it for playback. A successful <a cannam@86: href="../libvorbis/return.html">return code</a> from <a cannam@86: href="ov_fopen.html">ov_fopen()</a> indicates the file is ready for use. cannam@86: Once the file is no longer needed, <a cannam@86: href="ov_clear.html">ov_clear()</a> is used to close the file and cannam@86: deallocate decoding resources.<p> cannam@86: cannam@86: On systems other than Windows<a href="ov_open.html#winfoot">[a]</a>, an cannam@86: application may also open a file itself using <tt>fopen()</tt>, then pass the cannam@86: <tt>FILE *</tt> to libvorbisfile using <a cannam@86: href="ov_open.html">ov_open()</a>. </b>Do not</b> call cannam@86: <tt>fclose()</tt> on a file handle successfully submitted to <a cannam@86: href="ov_open.html">ov_open()</a>; libvorbisfile does this in the <a cannam@86: href="ov_clear.html">ov_clear()</a> call.<p> cannam@86: cannam@86: An application that requires more setup flexibility may open a data cannam@86: stream using <a href="ov_open_callbacks.html">ov_open_callbacks()</a> cannam@86: to change default libvorbis behavior or specify non-stdio data access cannam@86: mechanisms.<p> cannam@86: cannam@86: <p> cannam@86: All libvorbisfile initialization and deallocation routines are declared in "vorbis/vorbisfile.h". cannam@86: <p> cannam@86: cannam@86: <table border=1 color=black width=50% cellspacing=0 cellpadding=7> cannam@86: <tr bgcolor=#cccccc> cannam@86: <td><b>function</b></td> cannam@86: <td><b>purpose</b></td> cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_fopen.html">ov_fopen</a></td> cannam@86: <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 cannam@86: used.</td> cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_open.html">ov_open</a></td> cannam@86: <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 cannam@86: 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> cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_open_callbacks.html">ov_open_callbacks</a></td> cannam@86: <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> cannam@86: </tr> cannam@86: cannam@86: <tr valign=top> cannam@86: <td><a href="ov_test.html">ov_test</a></td> cannam@86: cannam@86: <td>Partially opens a file just far enough to determine if the file cannam@86: is an Ogg Vorbis file or not. A successful return indicates that the cannam@86: file appears to be an Ogg Vorbis file, but the <a cannam@86: href="OggVorbis_File.html">OggVorbis_File</a> struct is not yet fully cannam@86: initialized for actual decoding. After a <a href="../libvorbis/return.html">successful return</a>, the file cannam@86: may be closed using <a href="ov_clear.html">ov_clear()</a> or fully cannam@86: opened for decoding using <a cannam@86: href="ov_test_open.html">ov_test_open()</a>.<p> This call is intended to cannam@86: be used as a less expensive file open test than a full <a cannam@86: href="ov_open.html">ov_open()</a>.<p> cannam@86: Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> cannam@86: cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_test_callbacks.html">ov_test_callbacks</a></td> cannam@86: <td>As above but allowing application-define I/O callbacks.<p> cannam@86: Note that libvorbisfile owns the passed in file resource is it returns success; do not <tt>fclose()</tt> files owned by libvorbisfile.</td> cannam@86: cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_test_open.html">ov_test_open</a><td> cannam@86: 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> cannam@86: </tr> cannam@86: <tr valign=top> cannam@86: <td><a href="ov_clear.html">ov_clear</a></td> <td>Closes the cannam@86: bitstream and cleans up loose ends. Must be called when cannam@86: finished with the bitstream. After return, the <a cannam@86: href="OggVorbis_File.html">OggVorbis_File</a> struct is cannam@86: invalid and may not be used before being initialized again cannam@86: before begin reinitialized. cannam@86: cannam@86: </td> cannam@86: </tr> cannam@86: </table> cannam@86: cannam@86: <br><br> cannam@86: <hr noshade> cannam@86: cannam@86: <table border=0 width=100%> cannam@86: <tr valign=top> cannam@86: <td><p class=tiny>copyright © 2000-2010 Xiph.Org</p></td> cannam@86: <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> cannam@86: </tr><tr> cannam@86: <td><p class=tiny>Vorbisfile documentation</p></td> cannam@86: <td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td> cannam@86: </tr> cannam@86: </table> cannam@86: cannam@86: </body> cannam@86: cannam@86: </html>