[transcode-users] Estimating stream size, without extracting.

[Paul Campbell <transcode@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Hi

I would like to optimize an rip, extract, shrink, multiplex, author burn
process by using named pipes instead of intermediate files.

The problem is that without extracting the audio track i want and the
video stream, I can't figure out how big they are thus calculate the
requant factor for tcrequant.

I can see there are some hints from tcprobe or tcscan, I'm just not sure
if any of them could be used to calculate the stream size accurately.

Totalling up the vobs for a titleset I think, on most mainstream DVDs
would give a fairly accurate size of the main title vob.  However it
could contain a number of audio tracks that I wont need.  So a 7.5Gb VOB
might only extract to 5Gb video and 1/2Gb audio.

Im now thinking along the lines of looking at the duration in tcprobe
and trying to find the bitrates for the tracks I want, and do a little
calculation, but what about variable bit rates?  Can the average
bitrates be trusted?  If not can the bytes per frame * total frames even
work for video?

Thanks for any pointers.

-- 

Paul