Audio-Video synchronization error in recorded .mov file

[bobby_yan]

I have recorded .mov file form rtsp://202.38.70.248/2003sjh/20030901.mov using MovRecorder 1.3. The audio is ahead of video in the recorded file. The amount of advanced time is negligible at the beginning of the file, but increases gradually as we go forward, and reaches the maximum at the tail of the file. The stream on the Internet has no such a sync error.

I also observe the fps (Frames Per Second) of the file by Quicktime 7.2. When playing the rtsp stream directly on the Internet with enough bandwidth, the fps is roughly 25.00, while the fps becomes 24 in the recorded file. Moreover, with VLC, we can see in the recorded file the video is longer than the audio, whose lengths are 1:09:25 and 1:06:48, respectively. I guess the change of the fps is the causation.

Is there any possible solution to this? Maybe modifying the fps of the recorded file is one, but I don’t know how. Thank you.