[FFmpeg-devel] Not-very-good timestamps with fragmented mp4 input

[Mika Raento]

I will send a patch that reads the MFRA. It's more a RFC than a patch,
I for example have not yet run the regression suite with it.

    Mika

On 8 October 2014 08:54, Mika Raento <mikie at iki.fi> wrote:
> Hi
>
> I have a number of ISMV files that have discontinuities (missing
> frames between fragments). Using these as input to ffmpeg doesn't work
> very well - the discontinuities are not reflected in the dts or pts,
> e.g., using ffprobe -show_packets. Hence there are audio/video sync
> problems and with large gaps I'm not able to create working HLS
> output.
>
> Ffmpeg does not read the MFRA (fragmentation index), which would
> contain the fragment start times.
>
> I don't know enough to say if the timestamp information might be
> duplicated in the mdat.
>
> Would the solution be to read the MFRA in mov.c?
>
> (there is also an alternate MS-specific uuid atom that contains the
> duration and time data for each moof, but my files don't have those)
>
> Or am I missing something?
>
>     Mika