diff options
Diffstat (limited to 'contrib/vorbis/doc/vorbisfile/ov_open.html')
| -rw-r--r-- | contrib/vorbis/doc/vorbisfile/ov_open.html | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/contrib/vorbis/doc/vorbisfile/ov_open.html b/contrib/vorbis/doc/vorbisfile/ov_open.html deleted file mode 100644 index d0311ce..0000000 --- a/contrib/vorbis/doc/vorbisfile/ov_open.html +++ /dev/null @@ -1,183 +0,0 @@ -<html> - -<head> -<title>Vorbisfile - 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>Vorbisfile documentation</p></td> -<td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td> -</tr> -</table> - -<h1>ov_open</h1> - -<p><i>declared in "vorbis/vorbisfile.h";</i></p> - -<p>ov_open is one of three initialization functions used to initialize -an OggVorbis_File structure and prepare a bitstream for playback. - -<p><em><b> WARNING for Windows developers: </b> Do not use ov_open() in -Windows applications; Windows linking places restrictions on -passing <tt>FILE *</tt> handles successfully, and ov_open() runs -afoul of these restrictions <a href="#winfoot">[a]</a>. See the <a -href="ov_open_callbacks.html">ov_open_callbacks() page </a> for -details on using <a -href="ov_open_callbacks.html">ov_open_callbacks()</a> instead. </em> - -<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 libvorbisfile -functions. Once this has been called, the same <a href="OggVorbis_File.html">OggVorbis_File</a> -struct should be passed to all the libvorbisfile functions.<p> - -The <tt>vf</tt> structure initialized using ov_fopen() must eventually -be cleaned using <a href="ov_clear.html">ov_clear()</a>. Once a -<tt>FILE *</tt> handle is passed to ov_open() successfully, the -application MUST NOT <tt>fclose()</tt> or in any other way manipulate -that file handle. Vorbisfile will close the file in <a -href="ov_clear.html">ov_clear()</a>. If the application must be able -to close the <tt>FILE *</tt> handle itself, see <a -href="ov_open_callbacks.html">ov_open_callbacks()</a> with the use of -<tt>OV_CALLBACKS_NOCLOSE</tt>. - -<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 Vorbis. If the call -succeeds but the initialized <tt>vf</tt> structure will not be used, -the application is responsible for calling <a -href="ov_clear.html">ov_clear()</a> to clear the decoder's buffers and -close the file.<p> - -If [and only if] an <tt>ov_open()</tt> call fails, the application -must explicitly <tt>fclose()</tt> the <tt>FILE *</tt> pointer itself. - - -<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 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 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> - -<a name="notes"></a> -<h3>Notes</h3> -<dl> - -<a name="winfoot"></a> -<dt><b>[a] Windows and ov_open()</b><p> - -<dd>Under Windows, stdio file access is implemented in each of many -variants of crt.o, several of which are typically installed on any one -Windows machine. If libvorbisfile and the application using -libvorbisfile are not linked against the exact same -version/variant/build of crt.o (and they usually won't be, especially -using a prebuilt libvorbis DLL), <tt>FILE *</tt> handles cannot be -opened in the application and then passed to vorbisfile to be used -by stdio calls from vorbisfile's different version of CRT. For this -reason, using <a href="ov_open.html">ov_open()</a> under Windows -without careful, expert linking will typically cause a protection -fault. Windows programmers should use <a -href="ov_fopen.html">ov_fopen()</a> (which will only use libvorbis's -crt.o) or <a href="ov_open_callbacks.html">ov_open_callbacks()</a> -(which will only use the application's crt.o) instead.<p> - -This warning only applies to Windows and only applies to <a -href="ov_open.html">ov_open()</a>. It is perfectly safe to use <a -href="ov_open.html">ov_open()</a> on all other platforms.<p> - -For more information, see the following microsoft pages on <a -href="http://msdn2.microsoft.com/en-us/library/abx4dbyh(VS.80).aspx">C -runtime library linking</a> and a specific description of <a -href="http://msdn2.microsoft.com/en-us/library/ms235460(VS.80).aspx">restrictions -on passing CRT objects across DLL boundaries</a>. - -<p> - -<dt><b>[b] Threaded decode</b><p> -<dd>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 libvorbisfile with threads. -<p> - -<dt><b>[c] Mixed media streams</b><p> -<dd> -As of Vorbisfile release 1.2.0, Vorbisfile is able to access the -Vorbis content in mixed-media Ogg streams, not just Vorbis-only -streams. For example, Vorbisfile may be used to open and access the -audio from an Ogg stream consisting of Theora video and Vorbis audio. -Vorbisfile 1.2.0 decodes the first logical audio stream of each -physical stream section.<p> - -<dt><b>[d] Faster testing for Vorbis files</b><p> -<dd><a href="ov_test.html">ov_test()</a> and <a -href="ov_test_callbacks.html">ov_test_callbacks()</a> provide less -computationally expensive ways to test a file for Vorbisness, but -require more setup code.<p> - -</dl> - -<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> |