@@ -29,6 +29,7 @@
#include "libavutil/imgutils.h"
#include "aom_film_grain.h"
+#include "get_bits.h"
// Common/shared helpers (not dependent on BIT_DEPTH)
static inline int get_random_number(const int bits, unsigned *const state) {
@@ -118,6 +119,241 @@ int ff_aom_apply_film_grain(AVFrame *out, const AVFrame *in,
return AVERROR_INVALIDDATA;
}
+int ff_aom_parse_film_grain_sets(AVFilmGrainAFGS1Params *s,
+ const uint8_t *payload, int payload_size)
+{
+ GetBitContext gbc, *gb = &gbc;
+ AVFilmGrainAOMParams *aom;
+ AVFilmGrainParams *fgp, *ref = NULL;
+ int ret, num_sets, n, i, uv, num_y_coeffs, update_grain, luma_only;
+
+ ret = init_get_bits8(gb, payload, payload_size);
+ if (ret < 0)
+ return ret;
+
+ s->enable = get_bits1(gb);
+ if (!s->enable)
+ return 0;
+
+ skip_bits(gb, 4); // reserved
+ num_sets = get_bits(gb, 3) + 1;
+ for (n = 0; n < num_sets; n++) {
+ int payload_4byte, payload_size, set_idx, apply_units_log2, vsc_flag;
+ int predict_scaling, predict_y_scaling, predict_uv_scaling[2];
+ int payload_bits, start_position;
+
+ start_position = get_bits_count(gb);
+ payload_4byte = get_bits1(gb);
+ payload_size = get_bits(gb, payload_4byte ? 2 : 8);
+ set_idx = get_bits(gb, 3);
+ fgp = &s->sets[set_idx];
+ aom = &fgp->codec.aom;
+
+ fgp->type = get_bits1(gb) ? AV_FILM_GRAIN_PARAMS_AV1 : AV_FILM_GRAIN_PARAMS_NONE;
+ if (!fgp->type)
+ continue;
+
+ fgp->seed = get_bits(gb, 16);
+ update_grain = get_bits1(gb);
+ if (!update_grain)
+ continue;
+
+ apply_units_log2 = get_bits(gb, 4);
+ aom->width = get_bits(gb, 12) << apply_units_log2;
+ aom->height = get_bits(gb, 12) << apply_units_log2;
+ luma_only = get_bits1(gb);
+ if (luma_only) {
+ aom->subx = aom->suby = 0;
+ } else {
+ aom->subx = get_bits1(gb);
+ aom->suby = get_bits1(gb);
+ }
+
+ aom->bit_depth = 0;
+ aom->color_primaries = AVCOL_PRI_UNSPECIFIED;
+ aom->color_trc = AVCOL_TRC_UNSPECIFIED;
+ aom->color_space = AVCOL_SPC_UNSPECIFIED;
+ aom->color_range = AVCOL_RANGE_UNSPECIFIED;
+
+ vsc_flag = get_bits1(gb); // video_signal_characteristics_flag
+ if (vsc_flag) {
+ int cicp_flag;
+ aom->bit_depth = get_bits(gb, 3) + 8;
+ cicp_flag = get_bits1(gb);
+ if (cicp_flag) {
+ aom->color_primaries = get_bits(gb, 8);
+ aom->color_trc = get_bits(gb, 8);
+ aom->color_space = get_bits(gb, 8);
+ aom->color_range = get_bits1(gb) ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
+ if (aom->color_primaries > AVCOL_PRI_NB ||
+ aom->color_primaries == AVCOL_PRI_RESERVED ||
+ aom->color_primaries == AVCOL_PRI_RESERVED0 ||
+ aom->color_trc > AVCOL_TRC_NB ||
+ aom->color_trc == AVCOL_TRC_RESERVED ||
+ aom->color_trc == AVCOL_TRC_RESERVED0 ||
+ aom->color_space > AVCOL_SPC_NB ||
+ aom->color_space == AVCOL_SPC_RESERVED)
+ goto error;
+ }
+ }
+
+ predict_scaling = get_bits1(gb);
+ if (predict_scaling && (!ref || ref == fgp))
+ goto error; // prediction must be from valid, different set
+
+ predict_y_scaling = predict_scaling ? get_bits1(gb) : 0;
+ if (predict_y_scaling) {
+ int y_scale, y_offset, bits_res;
+ y_scale = get_bits(gb, 9) - 256;
+ y_offset = get_bits(gb, 9) - 256;
+ bits_res = get_bits(gb, 3);
+ if (bits_res) {
+ int res[14], pred, granularity;
+ aom->num_y_points = ref->codec.aom.num_y_points;
+ for (i = 0; i < aom->num_y_points; i++)
+ res[i] = get_bits(gb, bits_res);
+ granularity = get_bits(gb, 3);
+ for (i = 0; i < aom->num_y_points; i++) {
+ pred = ref->codec.aom.y_points[i][1];
+ pred = ((pred * y_scale + 8) >> 4) + y_offset;
+ pred += (res[i] - (1 << (bits_res - 1))) * granularity;
+ aom->y_points[i][0] = ref->codec.aom.y_points[i][0];
+ aom->y_points[i][1] = av_clip_uint8(pred);
+ }
+ }
+ } else {
+ aom->num_y_points = get_bits(gb, 4);
+ if (aom->num_y_points > 14) {
+ goto error;
+ } else if (aom->num_y_points) {
+ int bits_inc, bits_scaling;
+ int y_value = 0;
+ bits_inc = get_bits(gb, 3) + 1;
+ bits_scaling = get_bits(gb, 2) + 5;
+ for (i = 0; i < aom->num_y_points; i++) {
+ y_value += get_bits(gb, bits_inc);
+ if (y_value > UINT8_MAX)
+ goto error;
+ aom->y_points[i][0] = y_value;
+ aom->y_points[i][1] = get_bits(gb, bits_scaling);
+ }
+ }
+ }
+
+ if (luma_only) {
+ aom->chroma_scaling_from_luma = 0;
+ aom->num_uv_points[0] = aom->num_uv_points[1] = 0;
+ } else {
+ aom->chroma_scaling_from_luma = get_bits1(gb);
+ if (aom->chroma_scaling_from_luma) {
+ aom->num_uv_points[0] = aom->num_uv_points[1] = 0;
+ } else {
+ for (uv = 0; uv < 2; uv++) {
+ predict_uv_scaling[uv] = predict_scaling ? get_bits1(gb) : 0;
+ if (predict_uv_scaling[uv]) {
+ int uv_scale, uv_offset, bits_res;
+ uv_scale = get_bits(gb, 9) - 256;
+ uv_offset = get_bits(gb, 9) - 256;
+ bits_res = get_bits(gb, 3);
+ aom->uv_mult[uv] = ref->codec.aom.uv_mult[uv];
+ aom->uv_mult_luma[uv] = ref->codec.aom.uv_mult_luma[uv];
+ aom->uv_offset[uv] = ref->codec.aom.uv_offset[uv];
+ if (bits_res) {
+ int res[10], pred, granularity;
+ aom->num_uv_points[uv] = ref->codec.aom.num_uv_points[uv];
+ for (i = 0; i < aom->num_uv_points[uv]; i++)
+ res[i] = get_bits(gb, bits_res);
+ granularity = get_bits(gb, 3);
+ for (i = 0; i < aom->num_uv_points[uv]; i++) {
+ pred = ref->codec.aom.uv_points[uv][i][1];
+ pred = ((pred * uv_scale + 8) >> 4) + uv_offset;
+ pred += (res[i] - (1 << (bits_res - 1))) * granularity;
+ aom->uv_points[uv][i][0] = ref->codec.aom.uv_points[uv][i][0];
+ aom->uv_points[uv][i][1] = av_clip_uint8(pred);
+ }
+ }
+ } else {
+ int bits_inc, bits_scaling, uv_offset;
+ int uv_value = 0;
+ aom->num_uv_points[uv] = get_bits(gb, 4);
+ if (aom->num_uv_points[uv] > 10)
+ goto error;
+ bits_inc = get_bits(gb, 3) + 1;
+ bits_scaling = get_bits(gb, 2) + 5;
+ uv_offset = get_bits(gb, 8);
+ for (i = 0; i < aom->num_uv_points[uv]; i++) {
+ uv_value += get_bits(gb, bits_inc);
+ if (uv_value > UINT8_MAX)
+ goto error;
+ aom->uv_points[uv][i][0] = uv_value;
+ aom->uv_points[uv][i][1] = get_bits(gb, bits_scaling) + uv_offset;
+ }
+ }
+ }
+ }
+ }
+
+ aom->scaling_shift = get_bits(gb, 2) + 8;
+ aom->ar_coeff_lag = get_bits(gb, 2);
+ num_y_coeffs = 2 * aom->ar_coeff_lag * (aom->ar_coeff_lag + 1);
+ if (aom->num_y_points) {
+ int ar_bits = get_bits(gb, 2) + 5;
+ for (i = 0; i < num_y_coeffs; i++)
+ aom->ar_coeffs_y[i] = get_bits(gb, ar_bits) - (1 << (ar_bits - 1));
+ }
+ for (uv = 0; uv < 2; uv++) {
+ if (aom->chroma_scaling_from_luma || aom->num_uv_points[uv]) {
+ int ar_bits = get_bits(gb, 2) + 5;
+ for (i = 0; i < num_y_coeffs + !!aom->num_y_points; i++)
+ aom->ar_coeffs_uv[uv][i] = get_bits(gb, ar_bits) - (1 << (ar_bits - 1));
+ }
+ }
+ aom->ar_coeff_shift = get_bits(gb, 2) + 6;
+ aom->grain_scale_shift = get_bits(gb, 2);
+ for (uv = 0; uv < 2; uv++) {
+ if (aom->num_uv_points[uv] && !predict_uv_scaling[uv]) {
+ aom->uv_mult[uv] = get_bits(gb, 8) - 128;
+ aom->uv_mult_luma[uv] = get_bits(gb, 8) - 128;
+ aom->uv_offset[uv] = get_bits(gb, 9) - 256;
+ }
+ }
+ aom->overlap_flag = get_bits1(gb);
+ aom->limit_output_range = get_bits1(gb);
+
+ // use first set as reference only if it was fully transmitted
+ if (n == 0)
+ ref = fgp;
+
+ payload_bits = get_bits_count(gb) - start_position;
+ if (payload_bits > payload_size * 8)
+ goto error;
+ skip_bits(gb, payload_size * 8 - payload_bits);
+ }
+ return 0;
+
+error:
+ memset(s, 0, sizeof(*s));
+ return AVERROR_INVALIDDATA;
+}
+
+int ff_aom_attach_film_grain_sets(const AVFilmGrainAFGS1Params *s, AVFrame *frame)
+{
+ AVFilmGrainParams *fgp;
+ if (!s->enable)
+ return 0;
+
+ for (int i = 0; i < FF_ARRAY_ELEMS(s->sets); i++) {
+ if (s->sets[i].type != AV_FILM_GRAIN_PARAMS_AV1)
+ continue;
+ fgp = av_film_grain_params_create_side_data(frame);
+ if (!fgp)
+ return AVERROR(ENOMEM);
+ memcpy(fgp, &s->sets[i], sizeof(*fgp));
+ }
+
+ return 0;
+}
+
// Taken from the AV1 spec. Range is [-2048, 2047], mean is 0 and stddev is 512
static const int16_t gaussian_sequence[2048] = {
56, 568, -180, 172, 124, -84, 172, -64, -900, 24, 820,
@@ -30,9 +30,22 @@
#include "libavutil/film_grain_params.h"
+typedef struct AVFilmGrainAFGS1Params {
+ int enable;
+ AVFilmGrainParams sets[8];
+} AVFilmGrainAFGS1Params;
+
// Synthesizes film grain on top of `in` and stores the result to `out`. `out`
// must already have been allocated and set to the same size and format as `in`.
int ff_aom_apply_film_grain(AVFrame *out, const AVFrame *in,
const AVFilmGrainParams *params);
+// Parse AFGS1 parameter sets from an ITU-T T.35 payload. Returns 0 on success,
+// or a negative error code.
+int ff_aom_parse_film_grain_sets(AVFilmGrainAFGS1Params *s,
+ const uint8_t *payload, int payload_size);
+
+// Attach all valid film grain param sets to `frame`.
+int ff_aom_attach_film_grain_sets(const AVFilmGrainAFGS1Params *s, AVFrame *frame);
+
#endif /* AVCODEC_AOM_FILM_GRAIN_H */
From: Niklas Haas <git@haasn.dev> Based on the AOMedia Film Grain Synthesis 1 (AFGS1) spec: https://aomediacodec.github.io/afgs1-spec/ The parsing has been changed substantially relative to the AV1 film grain OBU. In particular: 1. There is the possibility of maintaining multiple independent film grain parameter sets, and decoders/players are recommended to pick the one most appropriate for the intended display resolution. This could also be used to e.g. switch between different grain profiles without having to re-signal the appropriate coefficients. 2. Supporting this, it's possible to *predict* the grain coefficients from previously signalled parameter sets, transmitting only the residual. 3. When not predicting, the parameter sets are now stored as a series of increments, rather than being directly transmitted. 4. There are several new AFGS1-exclusive fields. I placed this parser in its own file, rather than h2645_sei.c, since nothing in the generic AFGS1 film grain payload is specific to T.35, and to compartmentalize the code base. --- libavcodec/aom_film_grain.c | 236 ++++++++++++++++++++++++++++++++++++ libavcodec/aom_film_grain.h | 13 ++ 2 files changed, 249 insertions(+)