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diff --git a/doc/vorbisfile/decoding.html b/doc/vorbisfile/decoding.html new file mode 100644 index 0000000..f394376 --- /dev/null +++ b/doc/vorbisfile/decoding.html @@ -0,0 +1,92 @@ +<html> + +<head> +<title>Vorbisfile - Decoding</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 1.3.2 - 20101101</p></td> +</tr> +</table> + +<h1>Decoding</h1> + +<p> +All libvorbisfile decoding routines are declared in "vorbis/vorbisfile.h". +<p> + +After <a href="initialization.html">initialization</a>, decoding audio +is as simple as calling <a href="ov_read.html">ov_read()</a> (or the +similar functions <a href="ov_read_float.html">ov_read_float()</a> and +<a href="ov_read_filter.html">ov_read_filter</a>). This function works +similarly to reading from a normal file using <tt>read()</tt>.<p> + +However, a few differences are worth noting: + +<h2>multiple stream links</h2> + +A Vorbis stream may consist of multiple sections (called links) that +encode differing numbers of channels or sample rates. It is vitally +important to pay attention to the link numbers returned by <a +href="ov_read.html">ov_read</a> and handle audio changes that may +occur at link boundaries. Such multi-section files do exist in the +wild and are not merely a specification curiosity. + +<h2>returned data amount</h2> + +<a href="ov_read.html">ov_read</a> does not attempt to completely fill +a large, passed in data buffer; it merely guarantees that the passed +back data does not overflow the passed in buffer size. Large buffers +may be filled by iteratively looping over calls to <a +href="ov_read.html">ov_read</a> (incrementing the buffer pointer) +until the original buffer is filled. + +<h2>file cursor position</h2> + +Vorbis files do not necessarily start at a sample number or time offset +of zero. Do not be surprised if a file begins at a positive offset of +several minutes or hours, such as would happen if a large stream (such +as a concert recording) is chopped into multiple seperate files. + +<p> +<table border=1 color=black width=50% cellspacing=0 cellpadding=7> +<tr bgcolor=#cccccc> + <td><b>function</b></td> + <td><b>purpose</b></td> +</tr> +<tr valign=top> + <td><a href="ov_read.html">ov_read</a></td> + <td>This function makes up the main chunk of a decode loop. It takes an +OggVorbis_File structure, which must have been initialized by a previous +call to <a href="ov_open.html"><tt>ov_open()</tt></a>, <a href="ov_fopen.html"><tt>ov_fopen()</tt></a>, +or <a href="ov_open_callbacks.html"><tt>ov_open_callbacks()</tt></a>.</td> +</tr> +<tr valign=top> + <td><a href="ov_read_float.html">ov_read_float</a></td> + <td>This function decodes to floats instead of integer samples.</td> +</tr> +<tr valign=top> + <td><a href="ov_read_filter.html">ov_read_filter</a></td> + <td>This function works like <a href="ov_read.html">ov_read</a>, but passes the PCM data through the provided filter before converting to integer sample data.</td> +</tr> +</table> + +<br><br> +<hr noshade> +<table border=0 width=100%> +<tr valign=top> +<td><p class=tiny>copyright © 2000-2010 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 1.3.2 - 20101101</p></td> +</tr> +</table> + +</body> + +</html> |