[FFmpeg-devel] [PATCH v1 03/19] avcodec/vvc/sei: add decode_film_grain_characteristics

toqsxw at gmail.com toqsxw at gmail.com
Tue Apr 1 20:16:00 EEST 2025


From: Wu Jianhua <toqsxw at outlook.com>

Signed-off-by: Wu Jianhua <toqsxw at outlook.com>
---
 libavcodec/vvc/sei.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/libavcodec/vvc/sei.c b/libavcodec/vvc/sei.c
index 2842862a36..365f815950 100644
--- a/libavcodec/vvc/sei.c
+++ b/libavcodec/vvc/sei.c
@@ -24,15 +24,81 @@
 #include "dec.h"
 #include "libavutil/refstruct.h"
 
+static int decode_film_grain_characteristics(H2645SEIFilmGrainCharacteristics *h, const SEIRawFilmGrainCharacteristics *s, const VVCFrameContext *fc)
+{
+    const VVCSPS *sps = fc->ps.sps;
+
+    h->present = !s->fg_characteristics_cancel_flag;
+    if (h->present) {
+        h->model_id                                 = s->fg_model_id;
+        h->separate_colour_description_present_flag = s->fg_separate_colour_description_present_flag;
+        if (h->separate_colour_description_present_flag) {
+            h->bit_depth_luma           =  s->fg_bit_depth_luma_minus8 + 8;
+            h->bit_depth_chroma         =  s->fg_bit_depth_chroma_minus8 + 8;
+            h->full_range               =  s->fg_full_range_flag;
+            h->color_primaries          =  s->fg_colour_primaries;
+            h->transfer_characteristics =  s->fg_transfer_characteristics;
+            h->matrix_coeffs            =  s->fg_matrix_coeffs;
+        }  else {
+            if (!sps) {
+                av_log(fc->log_ctx, AV_LOG_ERROR,
+                    "No active SPS for film_grain_characteristics.\n");
+                return AVERROR_INVALIDDATA;
+            }
+            h->bit_depth_luma           = sps->bit_depth;
+            h->bit_depth_chroma         = sps->bit_depth;
+            h->full_range               = sps->r->vui.vui_full_range_flag;
+            h->color_primaries          = sps->r->vui.vui_colour_primaries;
+            h->transfer_characteristics = sps->r->vui.vui_transfer_characteristics;
+            h->matrix_coeffs            = sps->r->vui.vui_matrix_coeffs ;
+        }
+
+        h->blending_mode_id  =  s->fg_blending_mode_id;
+        h->log2_scale_factor =  s->fg_log2_scale_factor;
+
+        for (int c = 0; c < 3; c++) {
+            h->comp_model_present_flag[c] = s->fg_comp_model_present_flag[c];
+            if (h->comp_model_present_flag[c]) {
+                h->num_intensity_intervals[c] = s->fg_num_intensity_intervals_minus1[c] + 1;
+                h->num_model_values[c]        = s->fg_num_model_values_minus1[c] + 1;
+
+                if (h->num_model_values[c] > 6)
+                    return AVERROR_INVALIDDATA;
+
+                for (int i = 0; i < h->num_intensity_intervals[c]; i++) {
+                    h->intensity_interval_lower_bound[c][i] = s->fg_intensity_interval_lower_bound[c][i];
+                    h->intensity_interval_upper_bound[c][i] = s->fg_intensity_interval_upper_bound[c][i];
+                    for (int j = 0; j < h->num_model_values[c]; j++)
+                        h->comp_model_value[c][i][j] = s->fg_comp_model_value[c][i][j];
+                }
+            }
+        }
+
+        h->persistence_flag = s->fg_characteristics_persistence_flag;
+    }
+
+    return 0;
+}
+
 int ff_vvc_sei_decode(VVCSEI *s, const H266RawSEI *sei, const struct VVCFrameContext *fc)
 {
+    H2645SEI *c  = &s->common;
+
     if (!sei)
         return AVERROR_INVALIDDATA;
 
     for (int i = 0; i < sei->message_list.nb_messages; i++) {
         SEIRawMessage *message = &sei->message_list.messages[i];
+        void *payload          = message->payload;
 
         switch (message->payload_type) {
+        case SEI_TYPE_FILM_GRAIN_CHARACTERISTICS:
+            av_refstruct_unref(&c->film_grain_characteristics);
+            c->film_grain_characteristics = av_refstruct_allocz(sizeof(*c->film_grain_characteristics));
+            if (!c->film_grain_characteristics)
+                return AVERROR(ENOMEM);
+            return decode_film_grain_characteristics(c->film_grain_characteristics, payload, fc);
+
         default:
             av_log(fc->log_ctx, AV_LOG_DEBUG, "Skipped %s SEI %d\n",
                 sei->nal_unit_header.nal_unit_type == VVC_PREFIX_SEI_NUT ?
-- 
2.44.0.windows.1



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