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

[Jan Ekström]

On Mon, Dec 10, 2018 at 12:13 AM Michael Niedermayer
<michael at niedermayer.cc> wrote:
>
> On Fri, Dec 07, 2018 at 07:34:43PM +0200, Jan Ekström wrote:
> > On Wed, Dec 5, 2018 at 7:13 PM Jan Ekström <jeebjp at gmail.com> wrote:
> > >
> > > On Mon, Dec 3, 2018 at 3:19 AM Jan Ekström <jeebjp at gmail.com> wrote:
> > > >
> > > > From: Rodger Combs <rodger.combs at gmail.com>
> > > >
> > > > These are registered identifiers at the MPEG-4 RA, which are
> > > > defined as to be utilized for Dolby Vision AVC/HEVC streams that
> > > > are not correctly presentable by standards-compliant AVC/HEVC players.
> > > >
> > > > According to the Dolby Vision specification for ISOBMFF, these sample
> > > > entry codes are specified to have the standard AVC or HEVC decoder
> > > > configuration box in addition to the Dolby custom DOVIConfigurationBox.
> > > > This is what enables us to decode the streams without custom parsing.
> > > >
> > > > For correct presentation information from the DOVIConfigurationBox
> > > > is required (YCbCr or modified ICtCP, SDR or HDR, base or enhancement
> > > > layer).
> > > > ---
> > >
> > > Gentle Ping?
> > >
> > > Jan
> >
> > Ping^2?
> >
> > And if nobody really cares, I will reverse the comments on the AVC
> > entries (since I seem to have gotten them the wrong way around when
> > adding the comments and commit message late at night) and apply the
> > set tomorrow morning. These additional identifiers and the comment
> > should not be affecting existing FATE samples.
>
> probably ok, if tested and it works
>
> thx

The specification so far has matched reality:
1. Custom MPEG-4 RA registered ID is used
2. Standard AVC or HEVC initialization data box is used (so in that
sense an implementation does not need to implement additional parsing
just to get the streams decoded)
3. Video stream itself contains no metadata, but additional
Dolby-specific box (DOVIConfigurationBox) specified in the
specification contains the actual colorimetry utilized. These custom
identifiers are mostly utilized for profile 5 of Dolby Vision, so we
cannot properly *present* the video without figuring out how ICtCt+PQ
has been mangled for Dolby Vision (which is why at this point I
wouldn't mention tickets being "fixed" by these identifiers).
4. Both VLC and Chromium added and utilize these same identifiers, as
I've posted links to them before in previous versions of this patch
set.

So as far as it's been possible to test this, that's been done and
we're just implementing things according to the specification - which
is how other projects seem to have done it as well.

Jan