[FFmpeg-devel] [PATCH] avcodec/cbs_av1: fix range of values for Mastering Display Color Volume Metadata OBUs

[Mark Thompson]

On 21/03/2019 18:37, James Almer wrote:
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  libavcodec/cbs_av1_syntax_template.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/cbs_av1_syntax_template.c b/libavcodec/cbs_av1_syntax_template.c
> index 48f4fab514..93bba1e5ad 100644
> --- a/libavcodec/cbs_av1_syntax_template.c
> +++ b/libavcodec/cbs_av1_syntax_template.c
> @@ -1637,15 +1637,15 @@ static int FUNC(metadata_hdr_mdcv)(CodedBitstreamContext *ctx, RWContext *rw,
>      int err, i;
>  
>      for (i = 0; i < 3; i++) {
> -        fcs(16, primary_chromaticity_x[i], 0, 50000, 1, i);
> -        fcs(16, primary_chromaticity_y[i], 0, 50000, 1, i);
> +        fbs(16, primary_chromaticity_x[i], 1, i);
> +        fbs(16, primary_chromaticity_y[i], 1, i);
>      }
>  
> -    fc(16, white_point_chromaticity_x, 0, 50000);
> -    fc(16, white_point_chromaticity_y, 0, 50000);
> +    fb(16, white_point_chromaticity_x);
> +    fb(16, white_point_chromaticity_y);
>  
>      fc(32, luminance_max, 1, MAX_UINT_BITS(32));
> -    fc(32, luminance_min, 0, current->luminance_max >> 6);
> +    fc(32, luminance_min, 0, (current->luminance_max << 6) - 1);

<< 6 in uint32_t can overflow.

Given the confusion in the previous value, maybe a comment to explain where the upper bound for min is coming from too?

>  
>      return 0;
>  }
> 
LGTM with that.

Thanks,

- Mark