Audio sync problems

[sircharles]

There are a few movies I've tried encoding, that the audio is off sync with the video. I've tried screwing around with virtual Dub (adding and delaying the audio) to try and fix the problem, but I can't get them to match up.

Has anyone out there had similar problems? And if you did, how did you solve them?

Yet again, any help would be much apreciated, thanks.

[Enchanter]

A few possibilities:
1. Audio is constantly off-synch with the video (from start to end, , which is easily solved by using Virtualdub's Audio Interleave setting.
2. Audio gradually becomes off-synch (where it was perfectly in synch with the video at start of playback). This is usually indicative of the CPU having trouble keeping up with the decoding task set to it.

From what you have written, second possibility is the most likely. Assuming you are running Win2K/XP, run the movie and then press Ctrl-Alt-Del -> Task Manager. Under the CPU Usage bar, is the indicator hovering constantly at 100%? If so, then you need to reencode the video at a lower resolution or bitrate, just so that the CPU can comfortably play the video.

[sircharles]

Yes, on some of the movies, the sound is in sync in the beginning and gradually gets off track, usually by the middle of the film.

However, some of the films are off right from the start. And yes, I've made sure virtual Dub has interleaving on.

I'll try the lower resolution idea, and I'll also try to encode using divx 5.x

Thanks.

[sircharles]

Alright. I used Divx 5.02 Pro to encode Ghostbusters.

I played the movie...the sound was in sync at the beginning, however, about 5 minutes into the movie it was noticably out of sync. Now here's the kicker. The audio (apparently it's normal to have audio problems where it is late) was actually faster than the corresponding video. People were saying their lines before they where moving their mouths. What is going on?!

Some more info, incase it helps: I'm using Rippack v3 beta 15.5

Are there known problems with this program? Has anyone else run into this?

Somebody throw me a line, please

[Enchanter]

A few quick questions then. What is your CPU and its speed? And are you working on PAL or NTSC (do you know whether it is originally-FILM material or not?)?

Edit: I read your other thread. A celeron 1300 should be capable enough of playing the file. That leaves my second question unanswered.

"Some more info, incase it helps: I'm using Rippack v3 beta 15.5 "
Try GordianKnot...

[sircharles]

The Ghostbuster DVD is NTSC.

That's what...23.xxFPS? Where as PAL is 25.00 FPS.

[benedict]

Try this thread (a different forum) for a good explanation of NTSC, PAL, and other formats and how to move between them. It helped me out a lot.