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

[Mika Raento]

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