1 <html> 2 3 <head> 4 <title>Vorbisfile - function - ov_crosslap</title> 5 <link rel=stylesheet href="style.css" type="text/css"> 6 </head> 7 8 <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> 9 <table border=0 width=100%> 10 <tr> 11 <td><p class=tiny>Vorbisfile documentation</p></td> 12 <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> 13 </tr> 14 </table> 15 16 <h1>ov_crosslap()</h1> 17 18 <p><i>declared in "vorbis/vorbisfile.h";</i></p> 19 20 <p>ov_crosslap overlaps and blends the boundary at a transition 21 between two separate streams represented by separate <a 22 href="OggVorbis_File.html">OggVorbis_File</a> structures. For lapping 23 transitions due to seeking within a single stream represented by a 24 single <a href="OggVorbis_File.html">OggVorbis_File</a> structure, 25 consider using the lapping versions of the <a 26 href="seeking.html">vorbisfile seeking functions</a> instead. 27 28 <p>ov_crosslap is used between the last (usually ov_read) call on 29 the old stream and the first ov_read from the new stream. Any 30 desired positioning of the new stream must occur before the call to 31 ov_crosslap() as a seek dumps all prior lapping information from a 32 stream's decode state. Crosslapping does not introduce or remove any 33 extraneous samples; positioning works exactly as if ov_crosslap was not 34 called. 35 36 <p>ov_crosslap will lap between streams of differing numbers of 37 channels. Any extra channels from the old stream are ignored; playback 38 of these channels simply ends. Extra channels in the new stream are 39 lapped from silence. ov_crosslap will also lap between streams links 40 of differing sample rates. In this case, the sample rates are ignored 41 (no implicit resampling is done to match playback). It is up to the 42 application developer to decide if this behavior makes any sense in a 43 given context; in practical use, these default behaviors perform 44 sensibly. 45 46 <br><br> 47 <table border=0 color=black cellspacing=0 cellpadding=7> 48 <tr bgcolor=#cccccc> 49 <td> 50 <pre><b> 51 long ov_crosslap(<a href="OggVorbis_File.html">OggVorbis_File</a> *old, <a href="OggVorbis_File.html">OggVorbis_File</a> *new); 52 53 </b></pre> 54 </td> 55 </tr> 56 </table> 57 58 <h3>Parameters</h3> 59 <dl> 60 <dt><i>old</i></dt> 61 <dd>A pointer to the OggVorbis_File structure representing the origin stream from which to transition playback.</dd> 62 63 <dt><i>new</i></dt> 64 <dd>A pointer to the OggVorbis_File structure representing the stream with which playback continues.</dd> 65 </dl> 66 67 68 <h3>Return Values</h3> 69 <blockquote> 70 <dl> 71 <dt>OV_EINVAL</dt> 72 <dd>crosslap called with an OggVorbis_File structure that isn't open.</dd> 73 <dt>OV_EFAULT</dt> 74 <dd>internal error; implies a library bug or external heap corruption.</dd> 75 <dt>OV_EREAD</dt> 76 <dd> A read from media returned an error.</dd> 77 <dt>OV_EOF</dt> 78 <dd>indicates stream <tt>vf2</tt> is at end of file, or that <tt>vf1</tt> is at end of file immediately after a seek (making crosslap impossible as there's no preceding decode state to crosslap).</dd> 79 <dt><i>0</i></dt> 80 <dd>success.</dd> 81 </dl> 82 </blockquote> 83 84 85 86 <br><br> 87 <hr noshade> 88 <table border=0 width=100%> 89 <tr valign=top> 90 <td><p class=tiny>copyright © 2007 Xiph.org</p></td> 91 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> 92 </tr><tr> 93 <td><p class=tiny>Vorbisfile documentation</p></td> 94 <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> 95 </tr> 96 </table> 97 98 </body> 99 100 </html> 101
