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

[James Almer]

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;
 
-- 
2.32.0