AVI's AV not in sync (sometimes)

[SuMo]

OK, I think I've got it figured out, there's no solution for what I understand though.

The sync issue (something I haven't encountered since the beginning of this thread with the ffmpeg adjustments I made) is due to the fact that the mpg stream or does not consist of a GOP structure as defined by the DVD/MPEG2 specs or when skipping starts within a GOP instead of the beginning (what sould always be an I frame). Sync issues will always occur when editing within a GOP (15 frames for PAL /18 frames for NTSC) That's why you (officially) can't edit a MPEG stream that consist of I-B and P frames.
Editing can be done without any problems within an I frame only MPEG stream.
For what I understand, "keyframes" or "keyint(erval)" should preferably be the same as the amount of I frames within 1 GOP (maybe they're even the same, not sure here). Normaly there is 1 I frame in a (PAL) GOP. So lowering the keyframes below 15 in this case doesn't make sence.
All of this makes sence when it comes to these sync issues we're seeing.

[kfhickel]

I use BeyondTV to do my recording and use GB-PVR for playback on the MVP. When I started out I had this same out of sync problem and asked on the BTV forums. The answers I received indicated that most recording is done to a transport stream, but for playback you want a program stream (I think I got that right, it's possible that I flipped them around).

The way I deal with this is that I record everything to an incoming directory, then I weed out the dupes, then I run a batch file that uses VideoRedo to convert everything into a program stream.

Works great. Before the conversion any skipping forward/backwards causes things to get more and more out of sync, but after conversion there's no problems at all.

YMMV.

-Kelly

[zehd]

Kinda sucks that you have to post process the file. That totally throws on-the-fly out the window...

I suppose one could choose a video, start the transcode on the MVP, pause it. Let it finish, and wait for videoredo to do it's thing.... That's really messy though...

[kfhickel]

Kinda sucks that you have to post process the file. That totaly throws on-the-fly out the window...

Well, that's true, but it works for me. I end up post-processing anyway to cut out the commercials, so I do it all all at the same time. Two steps, run the commercial detection part of VideoRedo, then verify all the cuts and batch process the cuts and AV sync at the same time. I tried to use various automatic commercial removal, but none of the tools seemed to work that well, probably because most of what I record is kid's programs and I think it's harder to tell the difference between an animated show and an animated commercial.

-Kelly