Audio Sync Problems

[Taylor]

OK, I'm converting a Divx movie to SVCD so I can watch it on my TV.

I extracted the audio to a wav file via Virtualdub, and then used TMPGEnc to convert from avi to mpeg. Using source range....

The 1st part (1CD) audio/video sync is fine, but the 2nd CD is all messed up. When I use source range, I just pick an end frame, copy the number, and use it as start fame in the next conversion (or CD).

Anyone have any ideas what I'm doing wrong? Any tips?

[narked]

Try:
http://www.vcdhelp.com/forum/userguides/135552.php

to sort badframes

[Taylor]

I tried the guide. Virtualdub said 0 frames are bad.

[soong]

i got the same problem... i found though there is an errof in the vid stream and it causes the avi itself to get out of sync. However if you pause it and restart or move forward/reverse in the avi, it will "auto correct" and sync up. Vdub reported 0 bad frames... so i'm in the same boat...

[narked]

e-mail me at nathan9909@hotmail.com I can't give a definitive guide but I've dealt with this a number of times over the last few months.

[soong]

I hate to dig this thing back up... but I tried what narked said...and it's not quite working... here are the directions he gave me...

Open avi with virtual dub
1)Go to edit - beginning
2) go to edit - set selection start
3)Now go to the frame where corrupt data starts, go back one frame to the
frame before it starts.Make a note of the frame number e.g. frame 12345
4)Go to edit - set selection end
5)Go to file - save as avi and save selection (direct stream copy on audio
and video)filename e.g. Harry Potter 1.1
6)Now use frame forward button until you find where the corrupt data ends
(ie. no more unexplained rubbish).Make a note of the frame number e.g.12456
7)Set selection start again
8)Calculate length of corrupt data (12456 - 12345=111 frames lost)
9)Calculate time lost(111 frames at 23.976fps = 4.63seconds)
10) go to audio interleaving
11) put in a test figure for the audio skew correction (in the example we
calculated lost video of 4.63seconds so try a value of 4500ms).Because the
sound headers may be 100ms apart looking for keyframes in video to sync to
the audio correction will not be exactly 4630ms.
12)Play the video in virtual dub to check audio correction. If only slightly
out try further corrections of 250ms.
13) when synced go to edit - end
14)set selection end
15)Save avi selection filename e.g. harry potter 1.2
16)you now have 2 avi without corrupt data.close down virtualdub (to make
sure u don't use original wave when you open up next file)and open up first
avi (harry potter 1.1)with virtualdub
17)go to edit - end
18)go to file - append avi segment
19)when prompted open second avi (harry potter 1.2)
20) Now save the whole thing again with new filename


Now I get up to step 10 and 11 and my audio skew is ALWAYS off....I've tried different values and anything near that error, and audio is always too early. Any ideas?

[secretagent]

well two things you can do. I would do the second one first.
1. encode the whole avi in tmpgenc and then cut then mpeg AFTER encoding if the audiio is in synch.
2. If the audio is not in synch open vdub go to audio, check full processing mode then go back to audio and check conversion, then check 44100, 16 bit, hi quality, then stereo. then go to file menu and save this wav and use it as your audio source. you said there were no bad frames so probably your audi is EIGHT bit and vbr which makes it out of synch