DGMPGDec loses sync, VOBs OK

[Inventive Software]

:confused:

This has baffled me for the past week and I cannot figure it out. I recorded a NASCAR race last week with my DVD recorder and have been trying to encode it for when I go back on the train soon. However, after DVD Decrypter demuxing the video and audio, and DGIndex (1.50) indexing the video, and loading the video and audio in AviSynth, they lose sync to the point that the audio is a second or so ahead of the video, and I cannot work out why. I then used DVD Decrypter to copy the VOB files, and opened each one and they were absolutely fine. I'm assuming to solve the issue you'd need a sample of the affected areas. VOB or M2V? And how would I go about this?

[Guest]

Don't demux with DVDDecrypter. Just get all the VOBs into DGIndex together, demux the audio there, and process as per normal using the indicated delay. Then, if you still have sync issues, tell me whether it is a constant offset or if it grows as the movie plays.

[Inventive Software]

Doing it that way it still lost sync. The audio was reported as having no delay, from DVD Decrypter or DGIndex. I'm in the process of indexing the VOBs individually, and seeing what delay (if any) appears.

[Guest]

I'm in the process of indexing the VOBs individually, and seeing what delay (if any) appears. That's pointless. And you did not answer my question about the nature of the desync.

[Inventive Software]

It gets worse the further along the timeline, such that to the end of the race 1 or 2 seconds delay would be needed, whereas for about an hour or 2 into it, none is required. I'm sure it's something to do with either a particular VOB file, or the way it's indexed, because playing (in MPC 6.4.9.0) the VOB files separately (VTS_01_3.VOB and VTS_01_4.VOB for example) don't have any noticable delay. Indexing them separately gave delays of 22ms and 19ms for VTS_01_2 and VTS_01_4 VOBs respectively.

My AviSynth script is this:

#D2V from the VOBs
video=MPEG2Source("NASCAR LifeLock 400.d2v").Bob().SelectOdd().Crop(0,10,-14,-2).BiCubicResize(720,544)

audio=NicMPASource("NASCAR LifeLock 400 Tc0 L2 2ch 48 256 DELAY 0ms.mp2")
complete=AudioDub(video,audio)

#Trim the adverts out
part1=Trim(complete,0,32395)
part2=Trim(complete,32798,57998)
part3=Trim(complete,58532,72057)
part4=Trim(complete,72344,93679)
part5=Trim(complete,94329,109063)
part6=Trim(complete,109382,120731)
part7=Trim(complete,121175,131600)
part8=Trim(complete,132182,176294)
part9=Trim(complete,176742,181368)
part10=Trim(complete,181294,190251)
part11=Trim(complete,190850,200224)
part12=Trim(complete,200579,206995)
part13=Trim(complete,210182,249443)
part14=Trim(complete,249862,275707)

#Combine the parts
trimmed=part1+part2+part3+part4+part5+part6+part7+part8+part9+part10+part11+part12+part13+part14

#Output
Return(trimmed)

On another note, indexing the VOBs separately exhibit no noticable delay when they're in their own AVS scripts, so I have no idea what's going on! :D

[Selur]

shouldn't you use part1++part2 instead of part1+part2 to use aligned splice

[Guest]

Selur is correct.

You should have mentioned in your first post that you were doing trims!

[Inventive Software]

And that will stay with me for the rest of my life! :D