That may be a limitation of Avidemux or it may be an incorrect setting on my behalf, but either way it doesn't match Paul's comments about both VideoRedo and Avidemux producing cleaner cuts. It looks as if Avidemux doesn't generate a new P-frame and sufficient I-frames to last until the next P-frame in the original video, as VideoRedo does.

I'm wondering if I'm doing something wrong because if I make a cut which is not on a P-frame boundary, I get a warning message that the join will be corrupted - and indeed the picture does dissolve into macroblocks for a couple of frames at the join. Video Redo and Avidemux fall into this latter category of video editors.' With frame-based editors, you can make much cleaner edits. Thus, if the broadcast image fades to a commercial that does not occur at a reference frame, you can still make precise cuts, eliminating the 'flash' of the last fraction of a second of an advertisement that precedes your cut point. He talks about time-based editors having to restrict cuts to the nearest full P-frame, and says 'Now, with frame-based editors, you can make your edits on any frame of the video. I was reading Paul Arnote's article about using Avidemux as a Linux alternative to VideoRedo on Windows, for editing out continuity announcements, trailers and commercials from an off-air video recording.

Avidemux linux