[FFmpeg-devel] [PATCH 1/2] avformat/mov: Rework the AVIF parser to handle multiple items

[James Zern]

On Fri, Jul 22, 2022 at 11:21 AM Vignesh Venkatasubramanian
<vigneshv-at-google.com at ffmpeg.org> wrote:
>
> On Wed, Jul 13, 2022 at 9:12 AM Vignesh Venkatasubramanian
> <vigneshv at google.com> wrote:
> >
> > On Mon, Jul 11, 2022 at 3:25 PM James Zern
> > <jzern-at-google.com at ffmpeg.org> wrote:
> > >
> > > On Thu, Jun 30, 2022 at 2:04 PM Vignesh Venkatasubramanian
> > > <vigneshv-at-google.com at ffmpeg.org> wrote:
> > > >
> > > > Stores the item ids of all the items found in the file and
> > > > processes the primary item at the end of the meta box. This patch
> > > > does not change any behavior. It sets up the code for parsing
> > > > alpha channel (and possibly images with 'grid') in follow up
> > > > patches.
> > > >
> > > > Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
> > > > ---
> > > >  libavformat/isom.h |   4 ++
> > > >  libavformat/mov.c  | 148 ++++++++++++++++++++++++++++-----------------
> > > >  2 files changed, 97 insertions(+), 55 deletions(-)
> > > >
> > > > [...]
> > >
> > > @@ -4692,9 +4755,25 @@ static int mov_read_meta(MOVContext *c,
> > > AVIOContext *pb, MOVAtom atom)
> > >          tag = avio_rl32(pb);
> > >          atom.size -= 4;
> > >          if (tag == MKTAG('h','d','l','r')) {
> > > +            int ret;
> > >              avio_seek(pb, -8, SEEK_CUR);
> > >              atom.size += 8;
> > > -            return mov_read_default(c, pb, atom);
> > > +            ret = mov_read_default(c, pb, atom);
> > > +            if (ret < 0)
> > >
> > > In some other cases these two lines are combined, if ((ret = ...
> > >
> >
> > Done.
> >
> > > +                return ret;
> > > +            if (c->is_still_picture_avif) {
> > > +                int ret;
> > > +                // Add a stream for the YUV planes (primary item).
> > > +                ret = avif_add_stream(c, c->primary_item_id);
> > > +                if (ret)
> > >
> > > This could be updated too and use '< 0' to match other code.
> > >
> >
> > Done.
> >
> > > +                    return ret;
> > > +                // For still AVIF images, the meta box contains all the
> > > +                // necessary information that would generally be
> > > provided by the
> > > +                // moov box. So simply mark that we have found the moov box so
> > > +                // that parsing can continue.
> > > +                c->found_moov = 1;
> > > +            }
> > > +            return ret;
> > >          }
> > > _______________________________________________
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> > >
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> >
> >
> >
> > --
> > Vignesh
>
> Any further comments on this one?
>
> Please note that i have abandoned the second patch in this list. But
> this one is still up for merging.
>

This looks like it needs to be rebased. I'll take a look after that.