[FFmpeg-user] mp4 concatenation (muxer) problems -- invalid output?

[John Hawkinson]

> >> The "video" was encoded by a hardware encoder, the "held frame" by
> >> x264, you cannot concatenate them.
> > When you say "cannot concatenate" do you mean with "-c copy" or not at all?
> Didn't you try without -c copy?

Yes, I tried both ways, and both produced invalid output.  I'm not sure
if one of these ought to be working.

> You cannot use the concat demuxer if the streams are not "compatible".

I understand this. What I don't really understand is how to tell if they
are compatible, and what exactly compatible means. It seems like
I ought to be able to repeat a frame from a video in a fashion that is
"compatible" with that video, but I don't seem to be having much success.

(It's especially frustrating because I believe I've gotten this to work
in the past, but maybe the camera's "black magic" was different? Not sure
really what is different here.)

Can you suggest a better approach to acheive either this sub-goal
or the larger goal of stitching together videos that have short gaps
without processor-intensive work?

Thanks.

--jhawk at mit.edu
  John Hawkinson