transcoding mpeg2 -> mpeg2 (was: RE: [mythtv] DVB, (new) recording profiles, and transcoding)

[Edward Wildgoose]

> > I also found:
> > http://mpgtx.sourceforge.net/
> > 
> > Which references: gop-fixup
> > http://mlug.missouri.edu/~markrages/tavi/index.php?page=GopFixup
> That software looks like it has had no activity in the past year.  In any
> case, I don't think changing the header timecodes is difficult (I already
> do this for mpeg4 streams).  I'd prefer to not rely on different programs
> for the transcoder if at all possible, and I have seen nothing so far
> that requires one.

Does it matter if it's unmaintained...  If it works then perhaps it's just finished...?  Presumably the code could be incorporated though rather than using it standalone anyway.

By the way, I did a test transcode of a show into mpeg4.  The sound ends up out of sync as a result.  I was cutting commercials front and back, so I can't rule out that it wasn't caused by this.

There is something slightly wierd about DVB audio it seems.  The sound always starts 1-2 secs behind in myth and then catches up over the next 2-3 secs.  There is some code in avformatdecoder which is adjusting timestamps to try and do the catchup.  However, I assume that mythtranscode is using the myth decoder?  Just not sure why the audio isn't getting sync'd...?

Is there anything else you might suggest to fiddle with?

Thanks

Ed W