Audio Sync Issues

[mujahid7ia]

Have a avi file that's XVID and AC3. Whenever I try to extract teh ac3 using VirtualDubMod, the audio file is out of sync. I checked for bad frames using VDUB MP3-Freeze but it did not find any. What is causing this then? The file plays perfectly with the original avi file, but when i play AVI video + AC3 extracted audio = out of sync !

File specs.:
File : 698 MB (698 MB), duration: 1:07:07, type: AVI, 1 audio stream(s), quality: 71 %
Video : 514 MB, 1070 Kbps, 25.0 fps, 640*272 (2.21:1), XVID = XVID Mpeg-4, Supported
Audio : 184 MB, 384 Kbps, 48000 Hz, 5 channels, 0x2000 = AC3 DVM, Supported

Thanks alot.

[zero_net]

extract uncompressed 44100hz 16bit

[Craig Tucker]

Are you extracting it using direct stream copy. What is your ultimate goal with this file.

[mujahid7ia]

extract uncompressed 44100hz 16bit

As a WAV, right? Thanks, i'll try that.

Are you extracting it using direct stream copy. What is your ultimate goal with this file.

Yes, i am. My ultimate goal is to convert it to a standard compliant VCD MPEG1 file. The audio will be converted with besweet into a stereo wave.

Thanks for your help.

[Craig Tucker]

OK, this is how I do it, if you find you are still having problems.

1. Save the wav file out using direct stream copy (I use regular virtual dub)
2. Rename the wav file to *.ac3 and run it through ac3fix to repair the file header
3. Convert the ac3 file to wav using headac3he.
4. Encode with tmpgenc using the wav file as your audio source.

[mujahid7ia]

Well, for some reason ac3fix didn't work for me, when I pressed process in the GUI it did not do anything.

But after following step 1, Craig Tucker, the ac3 (w/ wav ext) played in sync w/ the video AVI. In a few hours maybe I'll try to convert it w/ tmpgenc. (after using besweet to convert that ac3)

I've never tried headac3he, and am pretty comfortable with besweet.

Thanks a alot!

[mujahid7ia]

besweet outputted a wav that was out of sync, maybe it's causing the problem. The ac3 was perfect i think.
I'll try headac3he

[mujahid7ia]

Well, the headac3he RAR from both the official site and digital-digest is corrupt... I'll check the tools section for other AC3 converters.

[mujahid7ia]

I used px3convert from teh Tools section, it created a wav that's in sync. However, it remains to be seen if the resulting MPEG will be in sync (but I don't think that's where the problem lies).

[Craig Tucker]

Well, for some reason ac3fix didn't work for me, when I pressed process in the GUI it did not do anything.

The file you are going to repair has to be in the same folder as the ac3fix program file.

[mujahid7ia]

Same folder? Oops!
Well the MPEG is in sync, I think my problem is solved. I'll post if I find another problem. Thanks everyone for your help.