*I think* this related to BC_COMPRESSED
cinelerra's internal format. It covers both mjpeg and dv and
I think raw mjpeg and may be raw dv to anything ffmpeg based
now broken ... I have bug logged about mjpeg-only webcam,
but no obvious (for me) solution for a/v recording, I only
found way to record strip of jpegs ... In earlier
cinelerras those conversions were handled by internal
quicktime copy, but this was deleted long ago because it was
buggy, and hard to keep working with updated ffmpeg.
I wonder if user tried another compression
type (say rawdv and not ffmpeg-based) ?