a Newbie with Video-Audio Sync Issue

[numbaz]

Steps I have followed so far... (Video Converting)


My source avi's framerate is 23.976fps, with 5.1ch AC3.

1. Joined two avi files using Nandub (Video1.avi, Video2.avi) to create a single avi file (Video3.avi)

2. Extracted audio as Wav file (Audio.wav) from Video3.avi using Virtualdubmod, Fixed it with Besliced (Audio_Fixed01.ac3)

3. Wrote an Avisynth script, and Using QuEnc, Converted Video3.avi file to Mpeg-2 (Video3.m2v)

4. Using DGpulldown, converted Video3.m2v's framerate to 29.97fps

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Audio gradually goes out of sync as the video plays,
and I understand that.

So I'm trying to fix the Audio_Fixed01.ac3 file to match 29.97fps video using Besweet (actually using Belight).
Output setting is to AC3, putting checkmark to "Convert Frame Rate 23.976 to 29.970 fps" in Advanced Settings.

The Problem is..

It results in producing a new file "Audio_Fixed01-new.ac3" with 0 KB!


What am I doing wrong?

[neuron2]

DGPulldown does not change the duration of the video, so you shouldn't have to change the audio. Check the durations of the M2V and processed audio files against the original duration.

[numbaz]

Oh.. It doesn't change the video length?
hmmm...Ok, got it.

Length
Video3.m2v 02;12;26;23
Audio_Fixed01.ac3 02;12;26;17

The difference is six frames.

So, that means while Extracting the audio, the duration is shrunken by 6 frames legth?
Then what am I supposed to do to stretch, or elongate the audio by 6 frames legth?

This happened when I was working on the other project. (Also wasn't able to fix the problem then)
Why the shrinkage?

[neuron2]

Don't worry about it. Get the alignment right at the start and don't worry about the end.

Is the audio duration the same before and after "fixing"?

[numbaz]

OK, I finally GOT IT!!

I thought the sync was perfect at the begining part of the video,
and then the gradual desync was happening, but I was wrong!

I carefully re-adjusted the sync based on the end part of the video,
and checked the begining part, and guess what, It was totally in sync. Yupee!

It was My bad after all..

Thank you, neuron2!

[numbaz]

I was able to adjust the other project's desync problem as well. Thnx