video length is not equal to audio length exactly

[anzhu]

My movie is in NTSC but the frame rate is 23.97 acctually. Use DVDx 2.2 to extract video and audio seperately (due to DVDx audio problem).

audio length is 02:25:03 but the video length looks 02:25:06. (Acctually I wasn't able to get the whole video stream becuse DVDx stopped at the end of audio. So acctual length of video I got is 02:25:03, but it missed a few seconds.)

The difference is very slight but it causes noticable a/v async problem. Compared to the time length is DVD player, the audio length is correct exactly.

At the beginning of movie, a/v is synced well. So I guess video fram rate gets slowed down gradually.

I know I may solve async problem in virtualDub by adjusting frame rate a little. But still currious why the lengths don't match.

[drewson99]

I think the simplest way to solve your problem is instead of adjusting the frame rate, strip the wav, then trim the difference (3 seconds i believe you wrote) from the end of your video file.

if it is in synch at the start but not at the end, then it sounds like it is missing 3 seconds at the very end, for which this will solve your problem (i am assuming it is a movie, you will lose 3 seconds of the very end of the credits)

i have had similar probs, can anyone confirm this method?

[anzhu]

I got some clue but not sure.

I guess my movie's frame rate is 23.976 instead of 23.97. The total movie time is 8704 seconds. So I get the video delay 8704*(23.976-23.97)/23.97 = 2.178 seconds.

Anybody can confirm it for me?

If it's true, this problem should only happen to pseudo NTSC movies (23.97 rate).

BTW, the frame rate is set up by DVDx or Divx codec? I'm using Divx basic 5.03.