1 <html> 2 3 <head> 4 <title>Vorbisfile - function - ov_pcm_seek_page_lap</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_pcm_seek_page_lap</h1> 17 18 <p><i>declared in "vorbis/vorbisfile.h";</i></p> 19 20 <p>Seeks to the closest page preceding the specified location (in pcm 21 samples) within the physical bitstream. This variant of <a 22 href="ov_pcm_seek_page.html">ov_pcm_seek_page</a> also automatically 23 crosslaps the transition from the previous playback position into the 24 new playback position in order to eliminate clicking and boundary 25 discontinuities. Otherwise, usage and behavior is identical to <a 26 href="ov_pcm_seek_page.html">ov_pcm_seek_page</a>. 27 28 <p>This function is faster than <a 29 href="ov_pcm_seek_lap.html">ov_pcm_seek_lap</a> because the function 30 can begin decoding at a page boundary rather than seeking through any 31 remaining samples before the specified location. However, it is less 32 accurate. 33 34 <p>ov_pcm_seek_page_lap also updates everything needed within the 35 decoder, so you can immediately call <a 36 href="ov_read.html">ov_read()</a> and get data from the newly seeked 37 to position. 38 39 <p>ov_pcm_seek_page_lap will lap between logical stream links of 40 differing numbers of channels. Any extra channels from the origin of 41 the seek are ignored; playback of these channels simply ends. Extra 42 channels at the destination are lapped from silence. 43 ov_pcm_seek_page_lap will also lap between logical stream links of 44 differing sample rates. In this case, the sample rates are ignored 45 (no implicit resampling is done to match playback). It is up to the 46 application developer to decide if this behavior makes any sense in a 47 given context; in practical use, these default behaviors perform 48 sensibly. 49 50 <p>This function only works for seekable streams. 51 52 <br><br> 53 <table border=0 color=black cellspacing=0 cellpadding=7> 54 <tr bgcolor=#cccccc> 55 <td> 56 <pre><b> 57 int ov_pcm_seek_page_lap(OggVorbis_File *vf,ogg_int64_t pos); 58 </b></pre> 59 </td> 60 </tr> 61 </table> 62 63 <h3>Parameters</h3> 64 <dl> 65 <dt><i>vf</i></dt> 66 <dd>A pointer to the OggVorbis_File structure--this is used for ALL the externally visible libvorbisfile 67 functions.</dd> 68 <dt><i>pos</i></dt> 69 <dd>Position in pcm samples to seek to in the bitstream.</dd> 70 </dl> 71 72 73 <h3>Return Values</h3> 74 <blockquote> 75 <ul> 76 <li>0 for success</li> 77 78 <li> 79 nonzero indicates failure, described by several error codes: 80 <ul> 81 <li>OV_ENOSEEK - Bitstream is not seekable. 82 </li> 83 <li>OV_EINVAL - Invalid argument value; possibly called with an OggVorbis_File structure that isn't open. 84 </li> 85 <li>OV_EREAD - A read from media returned an error. 86 </li> 87 <li>OV_EFAULT - Internal logic fault; indicates a bug or heap/stack 88 corruption. 89 </li> 90 <li>OV_EOF - Indicates stream is at end of file immediately after a seek 91 (making crosslap impossible as there's no preceeding decode state to crosslap). 92 </li> 93 <li>OV_EBADLINK - Invalid stream section supplied to libvorbisfile, or the requested link is corrupt. 94 </li> 95 </ul></li> 96 </ul></blockquote> 97 98 <br><br> 99 <hr noshade> 100 <table border=0 width=100%> 101 <tr valign=top> 102 <td><p class=tiny>copyright © 2007 Xiph.org</p></td> 103 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td> 104 </tr><tr> 105 <td><p class=tiny>Vorbisfile documentation</p></td> 106 <td align=right><p class=tiny>vorbisfile version 1.2.0 - 20070723</p></td> 107 </tr> 108 </table> 109 110 </body> 111 112 </html> 113
