Audio length do not tally with video

[shans]

Hi,

I wanted to convert one MP4-AVC-AAC video to AVI-Xvid-AC3. I used Avidemux 2.5.4. Opened the source file, saved the audio as PCM-WAV. Brought the same as MainTrack and saved as AC3-Aften 6 CH and video as MPEG4 ASP(xvid). I found the audio length is short to that of the video. But, it is in sync perfectly. Have I done anything wrong. Can any one explain why the audio length vary.

Thanks.

[manono]

Sometimes the audio ends before the video does. Is there 19 seconds of silence at the end, perhaps during the credits or the end part of them?

[shans]

Yes. The audio is absent during the end credits for about 19 seconds. I need not mind as long as the audio is in sync. Anyway, as a matter of interest, I would like to know if any program is available to correct this. On the other hand, if i remove the end where the audio is absent, will it become alright.

Thanks manono

[manono]

Correct what? Nothing's broken. Do you want to make the audio exactly the same length as the video? If so, it's possible. DelayCut can add 19 seconds of silent audio to the end of the AC3 audio.

You could also cut the video, yes, but you can only (easily) cut on keyframes which for XviD's are typically 10 seconds apart. I'd leave it as-is. Up to you, though.

[shans]

Thank you, manono for the explanation. Initially, I thought to make the audio exactly the same length as the video. Now, i will leave as is. In future, if I have problem, will use DelayCut.