From f50382cba60d106440f1ad83396ff7bed586a5ac Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Mon, 26 Feb 2024 14:12:53 +0100 Subject: [PATCH] avcodec/aom_film_grain: implement AFGS1 parsing 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 | 238 ++++++++++++++++++++++++++++++++++++ libavcodec/aom_film_grain.h | 13 ++ 2 files changed, 251 insertions(+) diff --git a/libavcodec/aom_film_grain.c b/libavcodec/aom_film_grain.c index ffcd71b584..e302567ba5 100644 --- a/libavcodec/aom_film_grain.c +++ b/libavcodec/aom_film_grain.c @@ -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 +119,243 @@ 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); + fgp->width = get_bits(gb, 12) << apply_units_log2; + fgp->height = get_bits(gb, 12) << apply_units_log2; + luma_only = get_bits1(gb); + if (luma_only) { + fgp->subsampling_x = fgp->subsampling_y = 0; + } else { + fgp->subsampling_x = get_bits1(gb); + fgp->subsampling_y = get_bits1(gb); + } + + fgp->bit_depth_luma = fgp->bit_depth_chroma = 0; + fgp->color_primaries = AVCOL_PRI_UNSPECIFIED; + fgp->color_trc = AVCOL_TRC_UNSPECIFIED; + fgp->color_space = AVCOL_SPC_UNSPECIFIED; + fgp->color_range = AVCOL_RANGE_UNSPECIFIED; + + vsc_flag = get_bits1(gb); // video_signal_characteristics_flag + if (vsc_flag) { + int cicp_flag; + fgp->bit_depth_luma = get_bits(gb, 3) + 8; + if (!luma_only) + fgp->bit_depth_chroma = fgp->bit_depth_luma; + cicp_flag = get_bits1(gb); + if (cicp_flag) { + fgp->color_primaries = get_bits(gb, 8); + fgp->color_trc = get_bits(gb, 8); + fgp->color_space = get_bits(gb, 8); + fgp->color_range = get_bits1(gb) ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG; + if (fgp->color_primaries > AVCOL_PRI_NB || + fgp->color_primaries == AVCOL_PRI_RESERVED || + fgp->color_primaries == AVCOL_PRI_RESERVED0 || + fgp->color_trc > AVCOL_TRC_NB || + fgp->color_trc == AVCOL_TRC_RESERVED || + fgp->color_trc == AVCOL_TRC_RESERVED0 || + fgp->color_space > AVCOL_SPC_NB || + fgp->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, diff --git a/libavcodec/aom_film_grain.h b/libavcodec/aom_film_grain.h index 5d772bd7d1..1f8c78f657 100644 --- a/libavcodec/aom_film_grain.h +++ b/libavcodec/aom_film_grain.h @@ -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 */