[FFmpeg-devel] [PATCH] [MXF] - Add jpeg2000 subdescriptor in MXF file (V2).

[Pierre-Anthony Lemieux]

av_pix_fmt_count_planes() in

On Thu, Dec 21, 2023 at 3:11 AM Tomas Härdin <git at haerdin.se> wrote:
>
> ons 2023-12-20 klockan 18:04 +0100 skrev Cédric Le Barz:
> > Le 19/12/2023 à 14:36, Tomas Härdin a écrit :
> > > > +    for ( comp = 0; comp < component_count; comp++ ) {
> > > > +        avio_write(pb, &sc->j2k_info.j2k_comp_desc[3*comp] , 3);
> > > > +    }
> > > Looks like this could be simplified to just
> > >
> > >    avio_write(pb, sc->j2k_info.j2k_comp_desc, 3*component_count);
> > >
> > > > +    if (j2k_ncomponents != component_count) {
> > > > +        av_log(s, AV_LOG_ERROR, "Incoherence about components
> > > > image
> > > > number.\n");
> > > > +    }
> > > I again feel this should be a hard error
> > >
> > > > +    for (comp = 0; comp < j2k_ncomponents; comp++) {
> > > > +        sc->j2k_info.j2k_comp_desc[comp*j2k_ncomponents] =
> > > > bytestream2_get_byteu(&g);   // Bitdepth for each component
> > > > +        sc->j2k_info.j2k_comp_desc[comp*j2k_ncomponents+1] =
> > > > bytestream2_get_byteu(&g); // Horizontal sampling for each
> > > > component
> > > > +        sc->j2k_info.j2k_comp_desc[comp*j2k_ncomponents+2] =
> > > > bytestream2_get_byteu(&g); // Vertical sampling for each
> > > > component
> > > > +    }
> > > Could be simplified to a single avio_read()
> > >
> > > /Tomas
> > > _______________________________________________
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> >
> > Here is the new version of the patch taken into account your remarks.
>
> Looks OK. Does this also work with RGB(A)? Seems to not be hardcoded
> for YUV at least. Higher bitdepths would also be nice, I've been
> working with lossless RGB48 J2K. Doesn't necessarily need to hold up
> this patch, just curious.

av_pix_fmt_count_planes() in mxf_write_jpeg2000_subdesc() will not
work for RGB(A) since the number of planes will not be equal to the
number of J2K components.

See https://trac.ffmpeg.org/ticket/11267

>
> /Tomas
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