ov_time_seek_page_lap

declared in "vorbis/vorbisfile.h";

For seekable streams, ov_time_seek_page_lap seeks to the closest full page preceeding the given time. This variant of ov_time_seek_page also automatically crosslaps the transition from the previous playback position into the new playback position in order to eliminate clicking and boundary discontinuities. Otherwise, usage and behavior is identical to ov_time_seek_page.

ov_time_seek_page_lap is faster than ov_time_seek_lap because it doesn't seek through the last few samples to reach an exact time, but it is also less accurate. This should be used when speed is important, but crosslapping is still desired.

ov_time_seek_page_lap also updates everything needed within the decoder, so you can immediately call ov_read() and get data from the newly seeked to position.

ov_time_seek_page_lap will lap between logical stream links of differing numbers of channels. Any extra channels from the origin of the seek are ignored; playback of these channels simply ends. Extra channels at the destination are lapped from silence. ov_time_seek_page_lap will also lap between logical stream links of differing sample rates. In this case, the sample rates are ignored (no implicit resampling is done to match playback). It is up to the application developer to decide if this behavior makes any sense in a given context; in practical use, these default behaviors perform sensibly.

This function does not work for unseekable streams.

int ov_time_seek_page_lap(OggVorbis_File *vf, double s);

Parameters

vf

Pointer to our already opened and initialized OggVorbis_File structure.

pos

Location to seek to within the file, specified in seconds.

Return Values

• 0 for success
• nonzero indicates failure, described by several error codes:
  • OV_ENOSEEK - Bitstream is not seekable.
  • OV_EINVAL - Invalid argument value; possibly called with an OggVorbis_File structure that isn't open.
  • OV_EREAD - A read from media returned an error.
  • OV_EFAULT - Internal logic fault; indicates a bug or heap/stack corruption.
  • OV_EOF - Indicates stream is at end of file immediately after a seek (making crosslap impossible as there's no preceeding decode state to crosslap).
  • OV_EBADLINK - Invalid stream section supplied to libvorbisfile, or the requested link is corrupt.