[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 11:02 PM Jan Ekström <jeebjp at gmail.com> wrote:
>
> On Mon, Dec 17, 2018 at 10:57 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> >
> > 2018-12-17 21:52 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> > > On Mon, Dec 17, 2018 at 10:49 PM Carl Eugen Hoyos <ceffmpeg at gmail.com>
> > > wrote:
> > >>
> > >> 2018-12-17 21:30 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> > >> > On Mon, Dec 17, 2018 at 10:23 PM Carl Eugen Hoyos <ceffmpeg at gmail.com>
> > >> > wrote:
> > >> >>
> > >> >> 2018-12-17 21:17 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> > >> >> > 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.
> > >> >>
> > >> >> I thought we had samples?
> > >> >>
> > >> >> Anyway, please mention ticket #7347.
> > >> >
> > >> > The sample last linked in that ticket was supposedly MPEG-TS for the
> > >> > other HEVC identifier, not ISOBMFF.
> > >>
> > >> Why do you think so? Which sample did you test?
> > >>
> > >
> > > From #7347
> > >> Dobly Vision transport stream with codec tag "dvhe" can be found under:
> > >> http://4kmedia.org/tag/dolby-vision/
> > >
> > > The site also notes that it's supposed to be a transport stream. I did
> > > not look further.
> >
> > Then please allow me to once again suggest testing (at least if
> > you trust neither me nor Igor).
> >
> > Carl Eugen
>
> That was a quote FROM Igor's post
> (https://trac.ffmpeg.org/ticket/7347#comment:12). If he and the site
> mentioned it wrong then please just note that.
>
> Jan

OK, so it is ISOBMFF and not MPEG-TS unlike Igor and the site noted.
Thank you, now there is a sample.

I think this is the sample that Rodger coded this patch set originally
against when we were hacking on this stuff around mpv.

Jan