Muxed video slowly goes out of sync.

[paros]

I have taken an uncompressed AVI file and attempted to mux it with an uncompressed wave file. They are both completely IDENTICAL in length (see below). The resulting video after muxing is synced with the sound at the beginning and slowly becomes unsynced more and more as time passes during playback.

I have been having this problem on this computer for over a year now. I have tried two seperate programs, GraphEdit and AVImux and niether of these solves the issue. I will attempt to give every amount of information about the files. Hopefully this info might help you.

File Name: "tristan_vidstr.avi"
File Size: 1.96 GB
Playback Length: 5 min 41.893 sec
Vid resol: 640x480
kbps: 49397
FPS: 14.896
Qf: 10.794
Codec Info:
IYUV
Planar YUV format (8-bpp Y plane, followed by 8-bpp 2?2 U and V planes)
Multipart OpenDML AVI (2 parts)
(5093 frames in first part, 0 frames follow)
=========================
File Name: "tristan_snd690.wav"
File Size: 32,052 KB
Playback Length: 5 min 41.893 sec
kbps: 768
bitrate: 48000 Hz, 1 Channel
Codec Info: PCM audio

Thanks for your help!

[Soopafresh]

Yup, that's a tough one...

There are several instructional guides about that problem in particular here on Videohelp.com. I wish I kept the links handy. I recall 2 issues being responsible - The sampling rate really ISN'T 48000hz, so by the end of the movie, the difference becomes quite noticeable. The other culprit (and mind you, I can't remember what I ate for lunch) I believe was due to a faulty Quartz.dll file.

[paros]

Okay. It is indeed an issue with the sound as you said. I have discovered a way to solve this that is much easier than any of the methods given by the Guides or Tutorials here.

Essentially, you must shrink or expand the AUDIO STREAM so that they are synched at the end. The fastest way to do this is to use CoolEdit, and perform a Time Stretch, with the option of "Preserve neither". Now mux the two streams togethor and it works like a charm. I suggest AVImux.exe

The Guides/Tutorials are going to have you perform weird math operations on the bit rate. This is nonintuitive and innacurate to calculate. Its much easier to use Frameshots or VirtualDub to find a spot at the end of the video down to the 1000ths of a second. CoolEdit gives you the time stamp on wav files to 1000ths of a second. Just shrink or expand the audio stream so that these two events line up. Stop worrying about bit rates and other nonsense.

(I experimented with manipulating the Frames-per-second on the video stream instead. This did not work at all.)