Splitstream Survey

[joe666boxer@y...]

--- In ExtractStream@y..., Dale Reed <daler@n...> wrote:
> When the tivo records a movie, its getting the mpeg encoded
> audio and video from two seperate sources (chips) at the rate
> you have defined them to be recorded. It stores these intertwined
> in the tystream file. To show the program, it simply reads the
> tystream file back out, sending the audio to the audio player
> and the video to the video player. Because its sending the streams
> simultaneously to each chip from the same source, they stay in
> sync.
> 

I'm convinced there is more to it than that. There are PES packets
inside the stream that have very accurate time stamps (that's what
splitstream uses to display the time). Charlie recently posted the PES
timestamp format and I've played around with it. The audio and video
in a single chunk can be off by up to 450 ms (very noticable), but
there is never any sync problems on the Tivo playback. That suggests
the tivo is using these timestamps to do the sync.



> The initial work done with tympeg has never had a sync issue.
> It just doesn't fully process the full (raw) tystream file
> all the time. Tympeg is the first (AFAIK) program that is
> trying to solve the sync issue by acting like the tivo does
> (without splitting the audio/video to seperate files and then
> re-constructing them).
> 

I wish I could look at the source and see how you dealt with the PES
packets :->

Thanks
Joe