[FFmpeg-user] [EXTERNAL] Frame Drops and Audio Sync Issues

[James Board]

 > No one can answer without more data since we don't know what's really inside 
> the avi container and what software you're using to capture (and that's more 
> likely the culprit anyway).

The capture card is a BlackMagic Intensity Pro.  The capture software iscalled MediaExpress: that's proprietary software that comes with it.
I have written programs with libav in the past (not just the command-line ffmpegapplication).  What should I do in order to figure this out?