[FFmpeg-devel] [PATCH v2 1/2] libavutil/dovi_meta: Add nlq_pivots to AVDOVIDataMapping

[Andreas Rheinhardt]

quietvoid:
> The NLQ pivots are not documented but should be present
> in the header for profile 7 RPU format.
> It has been verified using Dolby's verification toolkit.
> 
> Also implemented the parsing in libavcodec/dovi_rpu.c.
> And added the info to ffprobe and showinfo.
> 
> Signed-off-by: quietvoid <tcChlisop0 at gmail.com>
> ---
>  fftools/ffprobe.c         | 4 ++++
>  libavcodec/dovi_rpu.c     | 7 +++++++
>  libavfilter/vf_showinfo.c | 8 ++++++++
>  libavutil/dovi_meta.h     | 1 +
>  4 files changed, 20 insertions(+)
> 
> diff --git a/fftools/ffprobe.c b/fftools/ffprobe.c
> index 4e2fdbaec8..bc4f7ec0a1 100644
> --- a/fftools/ffprobe.c
> +++ b/fftools/ffprobe.c
> @@ -2001,6 +2001,10 @@ static void print_dovi_metadata(WriterContext *w, const AVDOVIMetadata *dovi)
>              break;
>          }
>  
> +        if (mapping->nlq_method_idc != AV_DOVI_NLQ_NONE) {
> +            print_list_fmt("nlq_pivots", "%"PRIu16, 2, mapping->nlq_pivots[idx]);
> +        }
> +
>          print_int("num_x_partitions",          mapping->num_x_partitions);
>          print_int("num_y_partitions",          mapping->num_y_partitions);
>  
> diff --git a/libavcodec/dovi_rpu.c b/libavcodec/dovi_rpu.c
> index a87562c8a3..17837eb845 100644
> --- a/libavcodec/dovi_rpu.c
> +++ b/libavcodec/dovi_rpu.c
> @@ -315,7 +315,14 @@ int ff_dovi_rpu_parse(DOVIContext *s, const uint8_t *rpu, size_t rpu_size)
>          }
>  
>          if (use_nlq) {
> +            int nlq_pivot = 0;
>              vdr->mapping.nlq_method_idc = get_bits(gb, 3);
> +
> +            for (int i = 0; i < 2; i++) {
> +                nlq_pivot += get_bits(gb, hdr->bl_bit_depth);
> +                vdr->mapping.nlq_pivots[i] = av_clip_uint16(nlq_pivot);
> +            }
> +
>              /**
>               * The patent mentions another legal value, NLQ_MU_LAW, but it's
>               * not documented anywhere how to parse or apply that type of NLQ.
> diff --git a/libavfilter/vf_showinfo.c b/libavfilter/vf_showinfo.c
> index 6efcafce28..f8c04fb2fa 100644
> --- a/libavfilter/vf_showinfo.c
> +++ b/libavfilter/vf_showinfo.c
> @@ -535,6 +535,14 @@ static void dump_dovi_metadata(AVFilterContext *ctx, const AVFrameSideData *sd)
>      av_log(ctx, AV_LOG_INFO, "mapping_color_space=%"PRIu8"; ", mapping->mapping_color_space);
>      av_log(ctx, AV_LOG_INFO, "mapping_chroma_format_idc=%"PRIu8"; ", mapping->mapping_chroma_format_idc);
>      av_log(ctx, AV_LOG_INFO, "nlq_method_idc=%d; ", (int) mapping->nlq_method_idc);
> +
> +    if (mapping->nlq_method_idc != AV_DOVI_NLQ_NONE) {
> +        av_log(ctx, AV_LOG_INFO, "nlq_pivots={ ");
> +        for (int i = 0; i < 2; i++)
> +            av_log(ctx, AV_LOG_INFO, "%"PRIu16" ", mapping->nlq_pivots[i]);
> +        av_log(ctx, AV_LOG_INFO, "}; ");

Don't use four calls to av_log for something that is so simple. Besides
having higher overhead and binary size it also adds the risk that these
av_logs are disturbed by another av_log in the middle, breaking the
output (at least with the default log callback).
(The same btw applies to other av_logs in this very function. Is it
actually intended for this to be one big line?)

> +    }
> +
>      av_log(ctx, AV_LOG_INFO, "num_x_partitions=%"PRIu32"; ", mapping->num_x_partitions);
>      av_log(ctx, AV_LOG_INFO, "num_y_partitions=%"PRIu32"\n", mapping->num_y_partitions);
>  
> diff --git a/libavutil/dovi_meta.h b/libavutil/dovi_meta.h
> index 3d11e02bff..6afc7b055a 100644
> --- a/libavutil/dovi_meta.h
> +++ b/libavutil/dovi_meta.h
> @@ -147,6 +147,7 @@ typedef struct AVDOVIDataMapping {
>      uint32_t num_x_partitions;
>      uint32_t num_y_partitions;
>      AVDOVINLQParams nlq[3]; /* per component */
> +    uint16_t nlq_pivots[2]; /* nlq_pred_pivot_value */
>  } AVDOVIDataMapping;
>  
>  /**