Trimming MPEG2 without reenconding

[pdaldegan]

Hi all,

Is it possible to trim an MPEG2 file into a new file without having to reeconde it? Does it have to be I-frame only? If so, what tool can I use to do it?
The reason I am asking this is because I already have plenty of edits made at Premiere for mpeg4 videos (at a not so great quality) that I want to re-render from higher quality mpeg2 videos. Problem is that the original material is on VHS (no time stamp), so I would have to re-capture it and them trim at the exactly same points as the former mpeg4 clips before replacing them at Premiere (that is not so difficult, because those mpeg4 where also trimmed, at cuts; but in this case they were reencoded). I don't want to reencode the mpeg2 files so there is no "first step loss", and to save time.

Thanks for your help,
Pedro

[snowmoon]

If you are going to re-render you don;t have to physically edit the mpeg-2 first. I don't understand why physical editing of the mpeg-2 would be necessary to re-render them.

I still recommend using MJPEG .avi or very high bitrate i-frame only mpeg-2 since it will contain the highest quality "first step"

[pdaldegan]

Well, I don't want to remake all editing decisions, but simply replace the source clips. Hence, I need the new mpeg2 source clips to be exact matchs of the current mpeg4 source clips, i.e. same in and out points, with 1-frame precision.

Problem is, I can't get this precision while recapturing the material, for it is originally VHS, with no time stamp on it. So, I have to start to recapture a little before the desired in-point, and to stop a little after the desired out-point. Then, I have to trim these fat, in order to match this clip with the mpeg4 source clip.

Rgds,
Pedro

[BJ_M]

vitec dvd tools has a excellent mpeg2 editor with out re-rendering ..
m2edit pro can also do it - but i prefer vitec a lot better ..

wobble mpeg-vcr is another choice

[epo]

Yes, I-frame-only capture at high bitrate and You should be abble to trim without quality loss with TMPGenc or Womble.