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

[Thomas Worth]

On Fri, Oct 26, 2012 at 7:20 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>> While all of the packets in this remux are even-sized, the entire
>> thing is out of alignment file position wise, apparently due to
>> something in the header winding up odd sized.. but no matter, it
>> seems to play.  The primary difference is that the muxing rate is
>> much longer than what ffmpeg generates.  For instance, ffmpeg makes:
>>
>> VaaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaaVaVaaVaVaaVaVaaVaVaaVaaVaVaaVa
>>
>> etc. while the Quicktime Pro remux (and other "real" ProRes files)
>> look more like:
>>
>> aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaVVVVVVVVVVVVVVVaaaaaaaaaaaaaaaaaaaaaaaaVVVVVVVVVVVVVVVaaaaaaaaaaaaaaaaaaaaaaaaVVVVVVVVVVVVVVVaaaaaaaaaaaaaaaaaaaaaaaaVVVVVVVVVVVVVVV
>>
>> At this point I'm feeling confident that it's a general performance
>> issue with the very tight mux ffmpeg is doing, AND almost certainly
>> exacerbated by the odd frame lengths in most situations which helps
>> explain why the behavior is so erratic.
>>
>> So my next question, is there any way to tell ffmpeg to mux/re-mux
>> with larger runs, to see if this greatly improves the reliability of
>> playback, or is this hard-coded into the muxer (in which case, is
>
> see -chunk_duration and -chunk_size

Michael, could these options be used in lieu of the asetnsamples
filter? In other words, could the same mux behavior be achieved only
by using the -chunk_duration and -chunk_size options?