[FFmpeg-devel] Patch profile/level of existing avc-in-mp4 file

[Måns Rullgård]

Erik Slagter <erik at slagter.name> writes:

> Robert Swain wrote:
>>> Would by any chance be there anybody who has a q&d proglet that exactly
>>> does his? Of course I'll try anything before resorting to re-encoding,
>>> as the source material is no longer available... Any pointer or trick
>>> will also be appreciated.
>> 
>> Maybe MP4Box from GPAC can do it.
>
> Nice suggestion, but I already tried that... I cannot find an option to
> set the profile/level info for an imported stream, nor an option to
> patch it in the ES...

It's the SPS that needs patching.  In an mp4 file you'll find this in
one of the header blocks, not the actual stream.

This reminds me of the time I had to flip the top_field_first bit on
every frame in a bunch of MPEG2 files.  Some "professionals" had got
it wrong...

-- 
M?ns Rullg?rd
mans at mansr.com