[FFmpeg-user] concat - C needs to go before B - How?

[Mark Filipak]

Gyan, Paul, Devin, Jim, anyone. Help!

You folks have been following my trim+concat adventure. I think I may have found the problem, not 
just for me. It's a general problem.

"N" signifies one frame time. All times are relative to ptsA.

__DTS__  _PTS__
ptsA-2N  ptsA    I-frame with DTS-to-PTS=2N <- call this frame "A"
ptsA-N   ptsA-N  B-frame with DTS-to-PTS=0  <- call this frame "B"
--- join here ---
ptsA-2N  ptsA+N  I-frame with DTS-to-PTS=3N <- call this frame "C"

You see, dtsC is before dtsB, so C needs to go before B. That's not happening.

I don't know of a way to force C to be before B in order to test whether that fixes the glitch. Do you?

Aside: Is it okay if dtsC==dtsA?

--Mark.