<html> <head> <title>Vorbisfile - function - ov_test</title> <link rel=stylesheet href="style.css" type="text/css"> </head> <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> <table border=0 width=100%> <tr> <td><p class=tiny>Vorbisfile documentation</p></td> <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> </tr> </table> <h1>ov_test</h1> <p><i>declared in "vorbis/vorbisfile.h";</i></p> <p> This partially opens a vorbis file to test for Vorbis-ness. It loads the headers for the first chain and tests for seekability (but does not seek). Use <a href="ov_test_open.html">ov_test_open()</a> to finish opening the file or <a href="ov_clear.html">ov_clear</a> to close/free it. <p> <p><em><b> WARNING for Windows developers: </b> Do not use ov_test() in Windows applications; Windows linking places restrictions on passing <tt>FILE *</tt> handles successfully, and ov_test() runs afoul of these restrictions <a href="#winfoot">[a]</a> in exactly the same way as <a href="ov_open.html">ov_open()</a>. See the <a href="ov_test_callbacks.html">ov_test_callbacks() page </a> for details on using <a href="ov_test_callbacks.html">ov_test_callbacks()</a> instead. </em> <p> <table border=0 color=black cellspacing=0 cellpadding=7> <tr bgcolor=#cccccc> <td> <pre><b> int ov_test(FILE *f,<a href="OggVorbis_File.html">OggVorbis_File</a> *vf,char *initial,long ibytes); </b></pre> </td> </tr> </table> <h3>Parameters</h3> <dl> <dt><i>f</i></dt> <dd>File pointer to an already opened file or pipe (it need not be seekable--though this obviously restricts what can be done with the bitstream).</dd> <dt><i>vf</i></dt> <dd>A pointer to the OggVorbis_File structure--this is used for ALL the externally visible libvorbisfile functions. Once this has been called, the same <tt>OggVorbis_File</tt> struct should be passed to all the libvorbisfile functions.</dd> <dt><i>initial</i></dt> <dd>Typically set to NULL. This parameter is useful if some data has already been read from the file and the stream is not seekable. It is used in conjunction with <tt>ibytes</tt>. In this case, <tt>initial</tt> should be a pointer to a buffer containing the data read.</dd> <dt><i>ibytes</i></dt> <dd>Typically set to 0. This parameter is useful if some data has already been read from the file and the stream is not seekable. In this case, <tt>ibytes</tt> should contain the length (in bytes) of the buffer. Used together with <tt>initial</tt></dd> </dl> <h3>Return Values</h3> <blockquote> <li>0 for success</li> <li>less than zero for failure:</li> <ul> <li>OV_EREAD - A read from media returned an error.</li> <li>OV_ENOTVORBIS - Bitstream contains no Vorbis data.</li> <li>OV_EVERSION - Vorbis version mismatch.</li> <li>OV_EBADHEADER - Invalid Vorbis bitstream header.</li> <li>OV_EFAULT - Internal logic fault; indicates a bug or heap/stack corruption.</li> </ul> </blockquote> <p> <h3>Notes</h3> All the <a href="ov_open.html#notes">notes from ov_open()</a> apply to ov_test(). <br><br> <hr noshade> <table border=0 width=100%> <tr valign=top> <td><p class=tiny>copyright © 2007 Xiph.org</p></td> <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> </tr><tr> <td><p class=tiny>Vorbisfile documentation</p></td> <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> </tr> </table> </body> </html>