Hello

I know next to nothing about video editing, and need to extract a segment from an MPEG4 video that, according to VLC, has the following features:

Audio: MPEG AAC (mp4a) @ 44100Hz
Video: H264 - MPEG-4 AVC (part 10)(avc1)
I first tried with VirtualDub 1.9.11, but I get an error when opening the file: "The file ... is of an unknown or unsupported file type."

Next, I tried with AVIDemux 2.5.5, but when playing the segment in VLC, the video plays a bit faster than the original, and some cracking noises can be heard in the audio.

I don't know if it means anything, but the codec infos as returned by VLC are a bit different between the full original file and the short segment I build with AVIDemux:

http://img14.imageshack.us/img14/7738/avidemuxfullpart.jpg

Does someone know the cause for this problem, and a possible solution, whether with AVIDemux, VirtualDub, or any other Windows application?

And for my education, if there's a good newbie-accessible primer about audio/video that explains what the main issues are when playing/editing/converting files, I'm interested.

Thank you.