[FFmpeg-devel] [PATCH v5] pngdec: expose gAMA and cHRM chunks as side/meta data

[Rostislav Pehlivanov]

On 9 November 2017 at 02:44, James Almer <jamrial at gmail.com> wrote:

> On 11/8/2017 11:32 PM, Rostislav Pehlivanov wrote:
> > Signed-off-by: Rostislav Pehlivanov <atomnuker at gmail.com>
> > ---
> >  libavcodec/pngdec.c | 39 ++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 38 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
> > index 0d6612ccca..0a9a248ee7 100644
> > --- a/libavcodec/pngdec.c
> > +++ b/libavcodec/pngdec.c
> > @@ -25,6 +25,7 @@
> >  #include "libavutil/bprint.h"
> >  #include "libavutil/imgutils.h"
> >  #include "libavutil/stereo3d.h"
> > +#include "libavutil/mastering_display_metadata.h"
> >
> >  #include "avcodec.h"
> >  #include "bytestream.h"
> > @@ -1165,7 +1166,7 @@ static int decode_frame_common(AVCodecContext
> *avctx, PNGDecContext *s,
> >      AVDictionary **metadatap = NULL;
> >      uint32_t tag, length;
> >      int decode_next_dat = 0;
> > -    int ret;
> > +    int i, ret;
> >
> >      for (;;) {
> >          length = bytestream2_get_bytes_left(&s->gb);
> > @@ -1287,6 +1288,42 @@ static int decode_frame_common(AVCodecContext
> *avctx, PNGDecContext *s,
> >                  goto fail;
> >              break;
> >          }
> > +        case MKTAG('c', 'H', 'R', 'M'): {
> > +            AVMasteringDisplayMetadata *mdm =
> av_mastering_display_metadata_create_side_data(p);
> > +            if (!mdm) {
> > +                ret = AVERROR(ENOMEM);
> > +                goto fail;
> > +            }
> > +
> > +            mdm->white_point[0] = av_make_q(bytestream2_get_be32(&s->gb),
> 100000);
> > +            mdm->white_point[1] = av_make_q(bytestream2_get_be32(&s->gb),
> 100000);
> > +
> > +            /* RGB Primaries */
> > +            for (i = 0; i < 3; i++) {
> > +                mdm->display_primaries[i][0] =
> av_make_q(bytestream2_get_be32(&s->gb), 100000);
> > +                mdm->display_primaries[i][1] =
> av_make_q(bytestream2_get_be32(&s->gb), 100000);
> > +            }
> > +
> > +            mdm->has_primaries = 1;
> > +            bytestream2_skip(&s->gb, 4); /* crc */
> > +            break;
> > +        }
> > +        case MKTAG('g', 'A', 'M', 'A'): {
> > +            AVBPrint bp;
> > +            char *gamma_str;
> > +            int num = bytestream2_get_be32(&s->gb);
> > +
> > +            av_bprint_init(&bp, 0, -1);
> > +            av_bprintf(&bp, "%i/%i", num, 100000);
> > +            av_bprint_finalize(&bp, (char **)&gamma_str);
>
> No need for a cast if gamma_str is already char*
>
> > +            if (!gamma_str)
> > +                return AVERROR(ENOMEM);
> > +
> > +            av_dict_set(&p->metadata, "gamma", gamma_str, 0);
>
> Add the AV_DICT_DONT_STRDUP_VAL flag, otherwise gamma_str will leak.
>
> > +
> > +            bytestream2_skip(&s->gb, 4); /* crc */
> > +            break;
> > +        }
> >          case MKTAG('I', 'E', 'N', 'D'):
> >              if (!(s->pic_state & PNG_ALLIMAGE))
> >                  av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
> >
>
> LGTM aside from the above.
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>

Pushed with your suggestions

Thanks