[FFmpeg-user] ProRes Quicktimes with audio not playing back reliably

[Tim Nicholson]

On 25/10/12 00:05, Bob Maple wrote:
> More tests today including FCP (more on that later) but I think we might
> have a winner!
> 
> Last month when I originally brought all this up Roger Pack suggested
> using the 'asetnsamples' filter to get ffmpeg to do a longer mux
> sequence, and I just sort of missed it while we chased other things.
> 
> Well, today I went back through the whole thread and caught his message
> and did some more playing.  Indeed, asetnsamples does the trick in
> allowing me to make a much longer mux sequence.
> 

Good news.

> [..]
> 
> Unfortunately, I haven't been able to figure out what it is about
> certain ProRes files that causes FCP to throw up the optimization
> warning on import.
> 
> Both my aligned AND unaligned tighly-muxed test files imported with no
> warnings... yet a different unaligned one DID throw the warning, and I
> don't really see what the big difference is.  The one that threw the
> warning actually had, as a percentage, fewer unaligned/uneven-sized
> packets than the other one that didn't, both files were an even number
> of bytes total... so, still not really sure what FCP scans for to
> complain about.  Oh well.


I have done comparisons between genuine ProRes and ffmpeg, and for the
same uncompressed source material the resultant file sizes have been
noticeably different. A 1 sec QT prores was 77M, but ffmpeg's were 76M
for prores and 79M for prores_kostya! Incidentally only prores_kostya
"supports" interlaced, and sets the stream flags accordingly.

> [...]


-- 
Tim