[FFmpeg-devel] [PATCH 1/2 v3] lavf/isom: add Dolby Vision sample entry codes for HEVC and H.264

[Jan Ekström]

On Mon, Dec 17, 2018 at 3:47 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>
> 2018-12-17 7:58 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> > On Mon, Dec 17, 2018, 03:02 Carl Eugen Hoyos <ceffmpeg at gmail.com wrote:
> >
> >> 2018-12-17 1:58 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
>
> >> > So as far as it's been possible to test this, that's been done
> >>
> >> Could you point me to a dva1 sample?
> >
> > I have not seen any dolby vision samples with avc in the wild.
> > You can ask Vittorio if he has some as he noted about
> > possibly being able to ask for some before.
>
> The patch is of course ok if Vittorio tested it with his samples.
>
> Thank you, Carl Eugen

Unfortunately I have no idea what samples Vittorio does or does not
possess, he has only mentioned off-hand that he might able to get hold
of some if required. And since you were the one requiring them, I
pointed you towards him.

For myself, I am happy with the following points regarding this:
1. The identifiers are registered at the MPEG-4 RA.
2. There is a proper specification for these mappings that is
seemingly kept up-to-date.
3. The mappings specification specifically notes that the only
difference between the AVC and HEVC identifiers are the semantics
mentioned in ISO/IEC 14496-15. We already have all of the identifiers
specified which these mappings are based upon, so those semantics
should not matter to us (and if they do, we have already broken those
constraints at this point).
4. The mapping specification specifically notes that the given AVC and
HEVC identifiers must also include the standard avcC and hvcC boxes so
that they can be decoded normally without any additional custom code.
5. We have samples for at least one of the four identifiers that
matches points 1 to 4.
6. Android, Chromium, VLC among others have already implemented these
identifiers in the same way.

Now, if you are not happy with these points, then please clearly state
that you are blocking any and all additional identifier additions - no
matter how specified - as long as there are no samples on hand for
them.

Best regards,
Jan