Audio Sync problem

[JoeCurry]

Right

I converted anNTSC Film/avi (23.96) to a 25fps Mpg, however i converted the audio seperately (via virtualdub) to a Wav file. Coming to completion the audio and video are way out of sync.
Should i have seperated the audio file AFTER i converted the original avi to PAL format OR before i convert it?

[Questor]

I am pretty new to this, but I was having a similar problem to you, I will try to help you best I can. Because you are converting from 23.976 to 25fps, the movie will be shorter, so the audio track will be too long for it, thus going out of synch.
Im no expert, but Ive succesfully downloaded a 23.976 movie, converted it to 25fps and burnt to DVD, and it plays perfectly smooth and the audio is in synch.

I need a bit more info about what your trying to do.
have you downloaded a movie that you want to put onto DVD or VCD?
are you using TMPGEnc for the converting?

[JoeCurry]

ive started again i think there wa a problem with one of the files, will let you know how i get on, thanks!

[antoniosgubba]

I do this all the time...I find 25fps plays much smoother than 23.976.

First extract the audio to WAV with virtualdub (full processing, no compression, convert to 44100)

Then convert the video to 25fps with virtualdub (NO audio, direct stream copy on the video)

Then you need to timestretch the audio to match the video...I find Goldwave does a great job of this....multiply the original audio time in seconds by 0.95904 to get the new time to stretch to.

Then just use the resultant audio and video as the sources in TMPGenc, using the PAL settings and none of the other stuff like 3:2 pulldown etc.

[Questor]

antoniosgubba - Ive read some of your other posts about this method you are using, It sounds really good, but I can't get virtual dub to export my audio in "full processing mode". i get an error - "acm failed to suggest audio decompression format".

ive only burnt a couple of succesful DVDs and its because they were already 25fps movies. The ntsc ones just give me coasters

I have Ac3 installed (nimo pack), and the movie will play in media player with audio ok, but virtual dub doesent seem to recognize the Ac3 . Do you know what I'm doing wrong. ?
btw, what version of Virtualdub are you using ?

Another point, the Ac3audio.ax file (in windows system32 folder) will cause my mp3 songs to play funny, so I have to move it to a temp folder if I want to listen to my music, and then move it back when I'm encoding etc..

[M.AD]

I dont know what happened, but I was having real trouble with AVIs. I had the Nimo codec pack, but then I changed many things at once and then I got much further encoding results than before. One thing I changed was codecs - I uninstalled Nimo and used k-lite codec pack. Maybe this can help

[antoniosgubba]

Hi Questor....

If you get the "acm failed to blah blah blah" error message in virtualdub then the movie has AC3 sound....which requires a slightly different approach.

I just use the regular version of virtualdub...I find it the most reliable.

First thing you should do before doing any extracting of audio etc is to open the movie with regular virtualdub and click file/file information. Look what it says next to audio stream/compression...if it says "unknown (tag 2000)" or similar then it is AC3 sound.

If it DOES have AC3 sound then my method is basically the same except for one difference....you do NOT extract the audio with virtualdub at all...what you do is load the entire movie avi into Goldwave then just select file/save as, and it will convert the audio to conventional WAV audio which you can then load back into Goldwave for time stretching as I've previously explained how to (its called "time warp" in Goldwave).

I think you can probably do the audio extracting and time warping all in one go, but I prefer to do it separately to keep it simpler.

I don't think everyone agrees with my method, but I've tried everything and I find converting my 23.976 movies to 25fps with this method produces silky smooth SVCDs (I'm sure the same principle aplies if making DVDs too...I have no DVD burner though )

[M.AD]

Joe, would the AVI happen to be Xvid? I am having trouble encoding Xvid files with audio in sync...