Yet another audiosync problem (exhausted ideas)

[Spire]

Guys,
I know you have seen many problems like the following on the forum, and frankly you must be getting fed up with all of them, but hey, we have all been there and I am hopeing that somebody had provide some help to the following problem:

I have ripped a DVD (007: World is not Enough) to Hard Disk (It comes in 7 or 8 640M files). I have extracted the Audio to WAV (PCM, Stereo, 48000) using ac3Dec. Also, I used FlaskMPEG to generate the DIVX file (using DIVX - codec, 23.97fps). I have verified that the there is no offset between my wav generated and AVI (however there is a little extra blank audio on the end of the WAV, about 2 seconds worth). However, when I use VirtualDub to create the final file (either split into 2 CD portions or one full), I get significant audio streching, it can be off by as much as 3 or 4 seconds about 20 minutes into the movie.
I am going to try AVInfo tonight (though it will probably take many tries to get it perfect), however I do not know why this problem is generated, I specified for the video frame rate to remain as in AVI.

Any Advice would greatly appreciated, I hope that I have given all of the appropriate inforation.

Thanks,

-- S

[tungsten]

hi there!

i am having some trouble with audio sync as well so i understand your frustration! but hey... don't give up! i guess AVI Info should do the trick for you, but make sure you read Nicky's guide on Audio Sync (i believe Nicky is the creator of AVI Info). I've pasted the url for you in case you don't know where to find it.

I wish you the best of luck!

http://www.digital-digest.com/nickyguides/audio-synch.htm

[Spire]

Thanks for the reply tungsten,

I was already following nicky's guide . I happen to have them all compiled into one large PDF (makes it nice and searchable), that was the guide I was going to follow regarding AVInfo.

I still don't quite understand how the audio gets to be 20+ seconds off by the end of the film when the inputs are both exactly the same length...

If anyone has an idea of something I did wrong in the creation, I welcome suggestions,

thanks again,

-- S
--

[omarh]

Can you try using the graphedit method of extracting the audio and see if it comes out longer than the video too?

That is so strange....i don't know why the audio portion is coming out longer than the video..hm

Unless flask is screwing something up...i don't use flask anymore. I use dvd2avi and virtual dub...its not the easiest method but it seems to work really well. i don't have audio sync problems anymore.

[Spire]

The audio does not come out longer. After the extraction the video and the audio are the exact same length, however, when virtualdub combines the two, the audio winds up stretched longer.

-- S

[tungsten]

hey Spire! You think your problem is a mind teaser? Check mine out!

i've encoded a divx movie (1300bits, 640x512, 25fps) with ac3 sound (dolby 2.0, 48khz, 256kbit/s) using Nandub and 2 pass encoding with the 3.11 Alpha codec. The sync is quite weird! it seems to be lost in 3 different parts of the movie (start-middle-end) but, when that happens, the sound ALWAYS comes before and with the same offset. now, for the really strange part...:: when the movie is played from start-to-end, the sync is lost as mentioned above. Now, at any point in the movie, pause and skip back to previous scenes where sound and video seemed to be out of sync... they now play perfectly synced! cool huh? Ripping was done with SmartRipper, DVD2AVI + VFAPI conv. for the fake avi, and sound extraction with Graph Edit. All divx parametrs set according to nicky's guide. The previous movie i made using the same progs but pcm sound didn't seem to have those problems...

oh! the "effect" is the same on any player i've played the movie on (radlight, playa and media player)! so it shouldn't be a player problem.

you like????? It is also posted as a separate thread but no one has replied! hehe...

[omarh]

I haven't had any serious sync problems with the audio since I started using mp3 for sound, and virtual dub, instead of flask...

hmm, the other thing, is i notice if i had post proccessing at too high a level, i'd easily lose sync all the time. i put it down to 0 (minimum) and i stopped losing sync. what kind of CPU's do you have and what post processing level are you running at ?

also in the properties for the renderer, mine shows jitter and sync offset. what does it show there for you??? mine is usually 0 or some small number...but if i seek through the movie, it skyrockets for a bit..