[Vorbis-dev] Is it possible to seek different Ogg Vorbis encoded packets from the File?

[Gregory Maxwell]

On Thu, Oct 22, 2009 at 8:40 PM, Niranjan Udipi <ucniranjan at gmail.com> wrote:
> Thank you very much for the detailed description. I request you to elaborate
> what is 'fine-grained parallelism' in Tremor, with an example.
>
> Another thought is to split the OggVorbis encoded data in to four nearly
> equal PCM length parts, once all the Headers have been decoded. Then, decode
> each part separately in a new thread. In this case, only at the beginning
> and end of the divided data parts, i.e. the first and last packets need the
> previous and next packet respectively, for decoding. Please comment on this
> idea. Please suggest me what functions I will have to use, to implement this
> scheme.

Refer to section 4.3.8 of the Vorbis specification:
http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-790004.3.8

The vorbis frames represent overlapping portions of audio.

You could decode the frames in parallel but must then sum the
overlapping parts. This will require fairly extensive modification to
the decoder. I do not believe that anyone here has investigated making
this change so you would need to determine the best approach yourself.