Searching for an MPEG2 editing tool

[mbriody]

I have a load of MPEG2 clips extracted from my TiVo. I need to reduce the bitrate from 8Mb/sec down to about 2.5 and also correct a slight audio sync problem which they all seem to suffer from (it seems to have been on the source broadcast).

I am currently trying to use the 'audio gap correct' function within TMpegEnc Plus on an extract of one of the clips. The problem is that I am having to use a trial and error method of setting an audio gap correct value of several ms, muxing the extract with this offset out to an MPEG file and then playing it back in Winamp and trying to figure out if it is any better.

I have been round this loop many times now and I still am no closer - I'm not even sure if I need a positive or negative value.

Is there an MPEG editing tool where I can shift the audio track forward or backwards and immediately preview the result (with audio, obviously) without having to mux?

[wolleric]

you can use virtualdub. open your mpeg2 file, goto streams/stream list, right click on your audio track, choose interleaving and set a delay value (pos oder neg).
as for the delay, you can scan your clip for a scene like a door slamming or so and get the delay with a stop watch. this is of course a very rough method and is useless if the delay isn't constant throughout the movie (in which case the sampling rate should be wrong).
another way is to take the exact length of both video (divide file/file information/frames by fps) and audio (again, under streams/stream list) and delay the audio by that difference.

[Soopafresh]

The easiest way (I've found) is to play the mpeg file in MediaPlayerClassic. As the file is playing, right click on the video, and choose

audio-->options-->audio time shift(ms)

enter a number between -1000 and 1000 and watch if the sync gets better or worse. 90% of the time the sync is in this 2 second window. Refine the sync by 200 ms increments, then 100ms increments, and pretty soon you'll find it.

[reboot]

Demux in PVAStrumento, check the option to write a Cuttermaran .info file, and use cuttermaran to edit.
Author the finished elementary streams, and use DVDShrink if necessary.
The other option is to re-encode the whole bunch to a lower bitrate, which seems a waste of time.