mp4 sound out of synch

[harrypickle]

I have converted some vts video files to mp4 to view on my phone, the quality is great but the sound is out of synch with the video why is this and can i rectify it.

[redwudz]

Do you mean DVD video to MP4? What codec/format of MP4? There are quite a few. What software and methods did you use?

There are several ways a video file can get out of sync with the audio.

Does the audio have the same sync error the full length of the video? If so, you can apply an audio offset with VirtualDub to bring it back in line.

If the audio sync gradually gets worse as the video plays, the audio and video may be different lengths. Did you do any framerate conversions such as PAL<>NTSC? Framerate conversion can cause that. You may be able to see the lengths of both in VirtualDub.

It doesn't apply in this case, but using VBR audio can cause sync problems when encoded to different formats.

Bad cuts/joins can also cause sync loss. As can corrupted or missing frames.

If you can determine where in your process that the sync error occurred, then you may be able to prevent the problem in the future.

[harrypickle]

I used shrink then imtoo mpeg encoder to convert to mp4, the movie isn't out of sync when played on my pc only when i play it on my phone so maybe its the phone thats the problem.

[redwudz]

That's possible, but you might try some short clips with a few different converters. SUPER might be worth trying. Some audio formats that use VBR audio may cause problems. Drop your MP4 into Gspot 2.60 and look for the VBR indicator in the audio section. If so, try it with CBR audio instead.