[FFmpeg-devel] [PATCH 2/3] avutil/film_grain_params: add support for H.274 Film Grain Characteristics

[Lynne]

22 Jul 2021, 15:44 by jamrial at gmail.com:

> Used by codecs like H.264, HEVC, and VVC.
>
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> Missing version bump and APIchanges entry.
>
>  libavutil/film_grain_params.h | 89 +++++++++++++++++++++++++++++++++++
>  1 file changed, 89 insertions(+)
>
> diff --git a/libavutil/film_grain_params.h b/libavutil/film_grain_params.h
> index 7629e3a041..7350dfc5b8 100644
> --- a/libavutil/film_grain_params.h
> +++ b/libavutil/film_grain_params.h
> @@ -28,6 +28,11 @@ enum AVFilmGrainParamsType {
>  * The union is valid when interpreted as AVFilmGrainAOMParams (codec.aom)
>  */
>  AV_FILM_GRAIN_PARAMS_AV1,
> +
> +    /**
> +     * The union is valid when interpreted as AVFilmGrainH274Params (codec.h274)
> +     */
> +    AV_FILM_GRAIN_PARAMS_H274,
>  };
>  
>  /**
> @@ -117,6 +122,89 @@ typedef struct AVFilmGrainAOMParams {
>  int limit_output_range;
>  } AVFilmGrainAOMParams;
>  
> +/**
> + * This structure describes how to handle film grain synthesis for codecs using
> + * the ITU-T H.274 Versatile suplemental enhancement information message.
> + *
> + * @note The struct must be allocated as part of AVFilmGrainParams using
> + *       av_film_grain_params_alloc(). Its size is not a part of the public ABI.
> + */
> +typedef struct AVFilmGrainH274Params {
> +    /**
> +     * Specifies the film grain simulation mode.
> +     * 0 = Frequency filtering, 1 = Auto-regression
> +     */
> +    int model_id;
> +
> +    /**
> +     * Specifies the bit depth used for the luma component.
> +     */
> +    int bit_depth_luma;
> +
> +    /**
> +     * Specifies the bit depth used for the chroma components.
> +     */
> +    int bit_depth_chroma;
> +
> +    enum AVColorRange                  color_range;
> +    enum AVColorPrimaries              color_primaries;
> +    enum AVColorTransferCharacteristic color_trc;
> +    enum AVColorSpace                  color_space;
> +
> +    /**
> +     * Specifies the blending mode used to blend the simulated film grain
> +     * with the decoded images.
> +     *
> +     * 0 = Additive, 1 = Multiplicative
> +     */
> +    int blending_mode_id;
> +
> +    /**
> +     * Specifies a scale factor used in the film grain characterization equations.
> +     */
> +    int log2_scale_factor;
> +
> +    /**
> +     * Indicates if the modelling of film grain for a given component is present.
> +     */
> +    int component_model_present[3 /* y, cb, cr */];
> +
> +    /**
> +     * Specifies the number of intensity intervals for which a specific set of
> +     * model values has been estimated, with a range of [1, 256].
> +     */
> +    uint16_t num_intensity_intervals[3 /* y, cb, cr */];
> +
> +    /**
> +     * Specifies the number of model values present for each intensity interval
> +     * in which the film grain has been modelled, with a range of [1, 6].
> +     */
> +    uint8_t num_model_values[3 /* y, cb, cr */];
> +
> +    /**
> +     * Specifies the lower ounds of each intensity interval for whichthe set of
> +     * model values applies for the component.
> +     */
> +    uint8_t intensity_interval_lower_bound[3 /* y, cb, cr */][256 /* intensity interval */];
> +
> +    /**
> +     * Specifies the upper bound of each intensity interval for which the set of
> +     * model values applies for the component.
> +     */
> +    uint8_t intensity_interval_upper_bound[3 /* y, cb, cr */][256 /* intensity interval */];
> +
> +    /**
> +     * Specifies the model values for the component for each intensity interval.
> +     * - When model_id == 0, the following applies:
> +     *     For comp_model_value[y], the range of values is [0, 2^bit_depth_luma - 1]
> +     *     For comp_model_value[cb..cr], the range of values is [0, 2^bit_depth_chroma - 1]
> +     * - Otherwise, the following applies:
> +     *     For comp_model_value[y], the range of values is [-2^(bit_depth_luma - 1), 2^(bit_depth_luma - 1) - 1]
> +     *     For comp_model_value[cb..cr], the range of values is [-2^(bit_depth_chroma - 1), 2^(bit_depth_chroma - 1) - 1]
> +     */
> +    int16_t comp_model_value[3 /* y, cb, cr */][256 /* intensity interval */][6 /* model value */];
> +} AVFilmGrainH274Params;
> +
>  /**
>  * This structure describes how to handle film grain synthesis in video
>  * for specific codecs. Must be present on every frame where film grain is
> @@ -143,6 +231,7 @@ typedef struct AVFilmGrainParams {
>  */
>  union {
>  AVFilmGrainAOMParams aom;
> +        AVFilmGrainH274Params h274;
>  } codec;
>  } AVFilmGrainParams; 
>

Patchset LGTM.