Vorbis dev - Mar 2007 - Finding the size of a vorbis stream

Hello,

I am trying to make an OGG Vorbis player for my cell phone. I have
ported J-Ogg to J2ME, and it is decoding files in non-realtime. The
problem is that I need to convert the OGG into a WAVE stream, which
needs the size of the data in the header which has to be read before the
OGG is fully decoded. So my question is, is there any way to find the
size of the resulting PCM data before decoding all of it?

Thanks,
Trent

On Thu, Mar 22, 2007 at 08:18:41PM -0600, Trent Gamblin wrote:
> [...] So my question is, is there any way to find the
> size of the resulting PCM data before decoding all of it?
If you're using libvorbisfile (or a java equivalent, I guess) you can 
just call ov_pcm_total and multiply by the number of channels and the
number of bytes per channel (2 and 2 for most files)
 
http://xiph.org/vorbis/doc/vorbisfile/ov_pcm_total.html

If not, you can try and port the code. In rough, you read the granulepos 
of the first and last pages. Subtract the two and that's the number of 
samples (modulo chaining, holes, and files with lead-in).

HTH,
 -r