File: ffv1_mp3.avi
Command line: ffmpeg -i ffv1_mp3.avi -acodec copy -vcodec flv -b 100 -hq outfile.swf
ffmpeg version: 0.4.9-pre1, build 4718 (CVS checkout from 13.09.2004 ~18:15 CEST)
Compiler: win32; gcc: 3.2.3 (mingw special 20030504-1)

Problem discription: Video is broken (artefacts). Also without -hq switch.
This works fine:

ffmpeg -i ffv1_mp3.avi -acodec copy -vcodec flv -b 100 -hq flv_mp3.avi

And this works fine, too:

ffmpeg -i ffv1_mp3.avi -an -vcodec flv -b 100 -hq flv_no-audio.swf


This does NOT work (artefacts in output video, input avi is working):

ffmpeg -i flv_mp3.avi -acodec copy -vcodec copy flv_mp3.swf

ffmpeg -i ffv1_mp3.avi -acodec mp3 -ab 32 -vcodec flv -b 100 -hq outfile.swf

I could also reproduce this problem with other types of input files (mpg).