Appending AVI

[stephen22]

I'm often editing soundtrack (audio from another file) without altering the video (direct stream copy) - quick and lossless.

Sometimes the audio ends up not exactly the same length as the video. This doesn't seem to matter - until I start concatenating files. Ill-fitting audio in a segment will push the audio of the next segment out of sync.

Is there a simple way of trimming/expanding audio of an AVI file to fit, which doesn't ivolve extracting the audio and editing it in an audio editor?

[videoh]

Don't know about in Vdub, but in Avisynth you have the ++ operator to join clips, doing what you asked for. Nevertheless, it does require decoding/reencoding. I don't know of any tools that can do that in the compressed domain, but let's see what others know about.

[stephen22]

Yes, thanks, in fact I'm looking for a ++ operation in VD - I guess there isn't one.

Suddernly occurred to me - easy to check in File Information which gives the length of both.

[shekh]

Do you know there is option Video->Select range->Cut off audio...
You should enable it to minimize a/v length differences. Other than that, there is nothing to help. Appending large amount of segments will definitely increase sync errors.

[stephen22]

Thanks, no, didn't know that. All 3 boxes seem to be ticked by default, but alas doesn't help with concatenation.