I'm using avidemux 2.5.4 which comes with Ubuntu 11.10's package repositories.
I have some AVI files from my camera that are identified as:
$ file *
SDC10806.AVI: RIFF (little-endian) data, AVI, 800 x 592, 20.00 fps, video: XviD, audio: ADPCM (mono, 22050 Hz)
The files play fine with the default video player (Totem) and have sound. You can download these files at http://www.mediafire.com/?jkyj3zbk634ya6m
However, once I open the files in avidemux and then save it right away (Copy), I get a strange output file:
yang@yang-latitude-13:~/Videos$ file *
A.avi: RIFF (little-endian) data, AVI, 800 x 592, video: XviD, audio: ADPCM (mono, 22050 Hz)
This output file no longer plays in Totem, though it can still play using VLC (known to play anything you throw at it). However it also has no sound (despite the audio information).
(In case it makes a difference: my ultimate goal is to just concatenate two of these AVIs from my camera together with minimal re-encoding or quality loss.)
Any idea why this might be happening? Thanks in advance for any help.