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diff --git a/Tremor/doc/ov_open.html b/Tremor/doc/ov_open.html new file mode 100644 index 0000000..654cae8 --- /dev/null +++ b/Tremor/doc/ov_open.html @@ -0,0 +1,115 @@ +<html> + +<head> +<title>Tremor - function - ov_open</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>Tremor documentation</p></td> +<td align=right><p class=tiny>Tremor version 1.0 - 20020403</p></td> +</tr> +</table> + +<h1>ov_open</h1> + +<p><i>declared in "ivorbisfile.h";</i></p> + +<p>This is the main function used to open and initialize an OggVorbis_File +structure. It sets up all the related decoding structure. +<p>The first argument must be a 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). <tt>vf</tt> should be a pointer to the +OggVorbis_File structure--this is used for ALL the externally visible libvorbisidec +functions. Once this has been called, the same <a href="OggVorbis_File.html">OggVorbis_File</a> +struct should be passed to all the libvorbisidec functions. +<p>Also, you should be aware that ov_open(), once successful, takes complete possession of the file resource. After you have opened a file using ov_open(), you MUST close it using <a href="ov_clear.html">ov_clear()</a>, not fclose() or any other function. +<p> +It is often useful to call <tt>ov_open()</tt> +simply to determine whether a given file is a vorbis bitstream. If the +<tt>ov_open()</tt> +call fails, then the file is not recognizable as such. +When you use <tt>ov_open() +</tt>for +this, you should <tt>fclose()</tt> the file pointer if, and only if, the +<tt>ov_open()</tt> +call fails. If it succeeds, you must call <a href="ov_clear.html">ov_clear()</a> to clear +the decoder's buffers and close the file for you.<p> + +(Note that <a href="ov_test.html">ov_test()</a> provides a less expensive way to test a file for Vorbisness.)<p> + +<br><br> +<table border=0 color=black cellspacing=0 cellpadding=7> +<tr bgcolor=#cccccc> + <td> +<pre><b> +int ov_open(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 libvorbisidec +functions. Once this has been called, the same <tt>OggVorbis_File</tt> +struct should be passed to all the libvorbisidec 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 indicates 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 is not 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> +<p>If your decoder is threaded, it is recommended that you NOT call +<tt>ov_open()</tt> +in the main control thread--instead, call <tt>ov_open()</tt> IN your decode/playback +thread. This is important because <tt>ov_open()</tt> may be a fairly time-consuming +call, given that the full structure of the file is determined at this point, +which may require reading large parts of the file under certain circumstances +(determining all the logical bitstreams in one physical bitstream, for +example). See <a href="threads.html">Thread Safety</a> for other information on using libvorbisidec with threads. + + +<br><br> +<hr noshade> +<table border=0 width=100%> +<tr valign=top> +<td><p class=tiny>copyright © 2002 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>Tremor documentation</p></td> +<td align=right><p class=tiny>Tremor version 1.0 - 20020403</p></td> +</tr> +</table> + +</body> + +</html> |