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ffmpeg/libavcodec/vvc_parser.c

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/*
* H.266 / VVC parser
*
* Copyright (C) 2021 Nuo Mi <nuomi2021@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "cbs.h"
#include "cbs_h266.h"
#include "parser.h"
#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
#define IS_IDR(nut) (nut == VVC_IDR_W_RADL || nut == VVC_IDR_N_LP)
#define IS_H266_SLICE(nut) (nut <= VVC_RASL_NUT || (nut >= VVC_IDR_W_RADL && nut <= VVC_GDR_NUT))
typedef struct PuInfo {
const H266RawPPS *pps;
const H266RawSPS *sps;
const H266RawPictureHeader *ph;
const H266RawSlice *slice;
int pic_type;
} PuInfo;
typedef struct AuDetector {
uint8_t prev_layer_id;
int prev_tid0_poc;
int prev_poc;
} AuDetector;
typedef struct VVCParserContext {
ParseContext pc;
CodedBitstreamContext *cbc;
CodedBitstreamFragment picture_unit;
AVPacket au;
AVPacket last_au;
AuDetector au_detector;
int parsed_extradata;
} VVCParserContext;
static const enum AVPixelFormat pix_fmts_8bit[] = {
AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUV420P,
AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P
};
static const enum AVPixelFormat pix_fmts_10bit[] = {
AV_PIX_FMT_GRAY10, AV_PIX_FMT_YUV420P10,
AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10
};
static int get_format(const H266RawSPS *sps)
{
switch (sps->sps_bitdepth_minus8) {
case 0:
return pix_fmts_8bit[sps->sps_chroma_format_idc];
case 2:
return pix_fmts_10bit[sps->sps_chroma_format_idc];
}
return AV_PIX_FMT_NONE;
}
/**
* Find the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or END_NOT_FOUND
*/
static int find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
int buf_size)
{
VVCParserContext *ctx = s->priv_data;
ParseContext *pc = &ctx->pc;
int i;
for (i = 0; i < buf_size; i++) {
int nut, code_len;
pc->state64 = (pc->state64 << 8) | buf[i];
if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
continue;
code_len = ((pc->state64 >> 3 * 8) & 0xFFFFFFFF) == 0x01 ? 4 : 3;
nut = (pc->state64 >> (8 + 3)) & 0x1F;
// 7.4.2.4.3 and 7.4.2.4.4
if ((nut >= VVC_OPI_NUT && nut <= VVC_PREFIX_APS_NUT &&
nut != VVC_PH_NUT) || nut == VVC_AUD_NUT
|| (nut == VVC_PREFIX_SEI_NUT && !pc->frame_start_found)
|| nut == VVC_RSV_NVCL_26 || nut == VVC_UNSPEC_28
|| nut == VVC_UNSPEC_29) {
if (pc->frame_start_found) {
pc->frame_start_found = 0;
return i - (code_len + 2);
}
} else if (nut == VVC_PH_NUT || IS_H266_SLICE(nut)) {
int sh_picture_header_in_slice_header_flag = buf[i] >> 7;
if (nut == VVC_PH_NUT || sh_picture_header_in_slice_header_flag) {
if (!pc->frame_start_found) {
pc->frame_start_found = 1;
} else { // First slice of next frame found
pc->frame_start_found = 0;
return i - (code_len + 2);
}
}
}
}
return END_NOT_FOUND;
}
static int get_pict_type(const CodedBitstreamFragment *pu)
{
int has_p = 0;
for (int i = 0; i < pu->nb_units; i++) {
CodedBitstreamUnit *unit = &pu->units[i];
if (IS_H266_SLICE(unit->type)) {
const H266RawSlice *slice = unit->content;
uint8_t type = slice->header.sh_slice_type;
if (type == VVC_SLICE_TYPE_B) {
return AV_PICTURE_TYPE_B;
}
if (type == VVC_SLICE_TYPE_P) {
has_p = 1;
}
}
}
return has_p ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
}
static void set_parser_ctx(AVCodecParserContext *s, AVCodecContext *avctx,
const PuInfo *pu)
{
static const uint8_t h266_sub_width_c[] = {
1, 2, 2, 1
};
static const uint8_t h266_sub_height_c[] = {
1, 2, 1, 1
};
const H266RawSPS *sps = pu->sps;
const H266RawPPS *pps = pu->pps;
const H266RawNALUnitHeader *nal = &pu->slice->header.nal_unit_header;
s->pict_type = pu->pic_type;
s->format = get_format(sps);
s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
s->key_frame = nal->nal_unit_type == VVC_IDR_W_RADL ||
nal->nal_unit_type == VVC_IDR_N_LP ||
nal->nal_unit_type == VVC_CRA_NUT ||
nal->nal_unit_type == VVC_GDR_NUT;
s->coded_width = pps->pps_pic_width_in_luma_samples;
s->coded_height = pps->pps_pic_height_in_luma_samples;
s->width = pps->pps_pic_width_in_luma_samples -
(pps->pps_conf_win_left_offset + pps->pps_conf_win_right_offset) *
h266_sub_width_c[sps->sps_chroma_format_idc];
s->height = pps->pps_pic_height_in_luma_samples -
(pps->pps_conf_win_top_offset + pps->pps_conf_win_bottom_offset) *
h266_sub_height_c[sps->sps_chroma_format_idc];;
avctx->profile = sps->profile_tier_level.general_profile_idc;
avctx->level = sps->profile_tier_level.general_level_idc;
avctx->colorspace = (enum AVColorSpace) sps->vui.vui_matrix_coeffs;
avctx->color_primaries = (enum AVColorPrimaries) sps->vui.vui_colour_primaries;
avctx->color_trc = (enum AVColorTransferCharacteristic) sps->vui.vui_transfer_characteristics;
avctx->color_range =
sps->vui.vui_full_range_flag ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
avctx->has_b_frames = (sps->sps_max_sublayers_minus1 + 1) > 2 ? 2 :
sps->sps_max_sublayers_minus1;
avctx->max_b_frames = sps->sps_max_sublayers_minus1;
if (sps->sps_ptl_dpb_hrd_params_present_flag &&
sps->sps_timing_hrd_params_present_flag) {
int num = sps->sps_general_timing_hrd_parameters.num_units_in_tick;
int den = sps->sps_general_timing_hrd_parameters.time_scale;
if (num != 0 && den != 0)
av_reduce(&avctx->framerate.den, &avctx->framerate.num,
num, den, 1 << 30);
}
}
//8.3.1 Decoding process for picture order count.
//VTM did not follow the spec, and it's much simpler than spec.
//We follow the VTM.
static void get_slice_poc(VVCParserContext *s, int *poc,
const H266RawSPS *sps,
const H266RawPictureHeader *ph,
const H266RawSliceHeader *slice, void *log_ctx)
{
int poc_msb, max_poc_lsb, poc_lsb;
AuDetector *d = &s->au_detector;
max_poc_lsb = 1 << (sps->sps_log2_max_pic_order_cnt_lsb_minus4 + 4);
poc_lsb = ph->ph_pic_order_cnt_lsb;
if (IS_IDR(slice->nal_unit_header.nal_unit_type)) {
if (ph->ph_poc_msb_cycle_present_flag)
poc_msb = ph->ph_poc_msb_cycle_val * max_poc_lsb;
else
poc_msb = 0;
} else {
int prev_poc = d->prev_tid0_poc;
int prev_poc_lsb = prev_poc & (max_poc_lsb - 1);
int prev_poc_msb = prev_poc - prev_poc_lsb;
if (ph->ph_poc_msb_cycle_present_flag) {
poc_msb = ph->ph_poc_msb_cycle_val * max_poc_lsb;
} else {
if ((poc_lsb < prev_poc_lsb) && ((prev_poc_lsb - poc_lsb) >=
(max_poc_lsb / 2)))
poc_msb = prev_poc_msb + (unsigned)max_poc_lsb;
else if ((poc_lsb > prev_poc_lsb) && ((poc_lsb - prev_poc_lsb) >
(max_poc_lsb / 2)))
poc_msb = prev_poc_msb - (unsigned)max_poc_lsb;
else
poc_msb = prev_poc_msb;
}
}
*poc = poc_msb + poc_lsb;
}
static void au_detector_init(AuDetector *d)
{
d->prev_layer_id = UINT8_MAX;
d->prev_poc = INT_MAX;
d->prev_tid0_poc = INT_MAX;
}
static int is_au_start(VVCParserContext *s, const PuInfo *pu, void *log_ctx)
{
//7.4.2.4.3
AuDetector *d = &s->au_detector;
const H266RawSPS *sps = pu->sps;
const H266RawNALUnitHeader *nal = &pu->slice->header.nal_unit_header;
const H266RawPictureHeader *ph = pu->ph;
const H266RawSlice *slice = pu->slice;
int ret, poc, nut;
get_slice_poc(s, &poc, sps, ph, &slice->header, log_ctx);
ret = (nal->nuh_layer_id <= d->prev_layer_id) || (poc != d->prev_poc);
nut = nal->nal_unit_type;
d->prev_layer_id = nal->nuh_layer_id;
d->prev_poc = poc;
if (nal->nuh_temporal_id_plus1 == 1 &&
!ph->ph_non_ref_pic_flag && nut != VVC_RADL_NUT
&& nut != VVC_RASL_NUT) {
d->prev_tid0_poc = poc;
}
return ret;
}
static int get_pu_info(PuInfo *info, const CodedBitstreamH266Context *h266,
const CodedBitstreamFragment *pu, void *logctx)
{
const H266RawNALUnitHeader *nal;
int ret;
memset(info, 0, sizeof(*info));
for (int i = 0; i < pu->nb_units; i++) {
nal = pu->units[i].content;
if (!nal)
continue;
if ( nal->nal_unit_type == VVC_PH_NUT ) {
const H266RawPH *ph = pu->units[i].content;
info->ph = &ph->ph_picture_header;
} else if (IS_H266_SLICE(nal->nal_unit_type)) {
info->slice = pu->units[i].content;
if (info->slice->header.sh_picture_header_in_slice_header_flag)
info->ph = &info->slice->header.sh_picture_header;
if (!info->ph) {
av_log(logctx, AV_LOG_ERROR,
"can't find picture header in picture unit.\n");
ret = AVERROR_INVALIDDATA;
goto error;
}
break;
}
}
if (!info->slice) {
av_log(logctx, AV_LOG_ERROR, "can't find slice in picture unit.\n");
ret = AVERROR_INVALIDDATA;
goto error;
}
info->pps = h266->pps[info->ph->ph_pic_parameter_set_id];
if (!info->pps) {
av_log(logctx, AV_LOG_ERROR, "PPS id %d is not avaliable.\n",
info->ph->ph_pic_parameter_set_id);
ret = AVERROR_INVALIDDATA;
goto error;
}
info->sps = h266->sps[info->pps->pps_seq_parameter_set_id];
if (!info->sps) {
av_log(logctx, AV_LOG_ERROR, "SPS id %d is not avaliable.\n",
info->pps->pps_seq_parameter_set_id);
ret = AVERROR_INVALIDDATA;
goto error;
}
info->pic_type = get_pict_type(pu);
return 0;
error:
memset(info, 0, sizeof(*info));
return ret;
}
static int append_au(AVPacket *pkt, const uint8_t *buf, int buf_size)
{
int offset = pkt->size;
int ret;
if ((ret = av_grow_packet(pkt, buf_size)) < 0)
goto end;
memcpy(pkt->data + offset, buf, buf_size);
end:
return ret;
}
/**
* Parse NAL units of found picture and decode some basic information.
*
* @param s parser context.
* @param avctx codec context.
* @param buf buffer with field/frame data.
* @param buf_size size of the buffer.
* @return < 0 for error, == 0 for a complete au, > 0 is not a completed au.
*/
static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
int buf_size, AVCodecContext *avctx)
{
VVCParserContext *ctx = s->priv_data;
const CodedBitstreamH266Context *h266 = ctx->cbc->priv_data;
CodedBitstreamFragment *pu = &ctx->picture_unit;
int ret;
PuInfo info;
if (!buf_size) {
if (ctx->au.size) {
av_packet_move_ref(&ctx->last_au, &ctx->au);
return 0;
}
return 1;
}
if ((ret = ff_cbs_read(ctx->cbc, pu, buf, buf_size)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Failed to parse picture unit.\n");
goto end;
}
if ((ret = get_pu_info(&info, h266, pu, avctx)) < 0)
goto end;
if (append_au(&ctx->au, buf, buf_size) < 0) {
ret = AVERROR(ENOMEM);
goto end;
}
if (is_au_start(ctx, &info, avctx)) {
set_parser_ctx(s, avctx, &info);
av_packet_move_ref(&ctx->last_au, &ctx->au);
} else {
ret = 1; //not a completed au
}
end:
ff_cbs_fragment_reset(pu);
return ret;
}
/**
* Combine PU to AU
*
* @param s parser context.
* @param avctx codec context.
* @param buf buffer to a PU.
* @param buf_size size of the buffer.
* @return < 0 for error, == 0 a complete au, > 0 not a completed au.
*/
static int combine_au(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **buf, int *buf_size)
{
VVCParserContext *ctx = s->priv_data;
int ret;
ctx->cbc->log_ctx = avctx;
av_packet_unref(&ctx->last_au);
ret = parse_nal_units(s, *buf, *buf_size, avctx);
if (ret == 0) {
if (ctx->last_au.size) {
*buf = ctx->last_au.data;
*buf_size = ctx->last_au.size;
} else {
ret = 1; //no output
}
}
ctx->cbc->log_ctx = NULL;
return ret;
}
static int vvc_parser_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
int next, ret;
VVCParserContext *ctx = s->priv_data;
ParseContext *pc = &ctx->pc;
CodedBitstreamFragment *pu = &ctx->picture_unit;
int is_dummy_buf = !buf_size;
int flush = !buf_size;
const uint8_t *dummy_buf = buf;
*poutbuf = NULL;
*poutbuf_size = 0;
if (avctx->extradata_size && !ctx->parsed_extradata) {
ctx->parsed_extradata = 1;
ret = ff_cbs_read_extradata_from_codec(ctx->cbc, pu, avctx);
if (ret < 0)
av_log(avctx, AV_LOG_WARNING, "Failed to parse extradata.\n");
ff_cbs_fragment_reset(pu);
}
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = find_frame_end(s, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0)
return buf_size;
}
is_dummy_buf &= (dummy_buf == buf);
if (!is_dummy_buf) {
ret = combine_au(s, avctx, &buf, &buf_size);
if (ret > 0 && flush) {
buf_size = 0;
ret = combine_au(s, avctx, &buf, &buf_size);
}
if (ret != 0)
return next;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
static const CodedBitstreamUnitType decompose_unit_types[] = {
VVC_TRAIL_NUT,
VVC_STSA_NUT,
VVC_RADL_NUT,
VVC_RASL_NUT,
VVC_IDR_W_RADL,
VVC_IDR_N_LP,
VVC_CRA_NUT,
VVC_GDR_NUT,
VVC_VPS_NUT,
VVC_SPS_NUT,
VVC_PPS_NUT,
VVC_PH_NUT,
VVC_AUD_NUT,
};
static av_cold int vvc_parser_init(AVCodecParserContext *s)
{
VVCParserContext *ctx = s->priv_data;
int ret;
ret = ff_cbs_init(&ctx->cbc, AV_CODEC_ID_VVC, NULL);
if (ret < 0)
return ret;
au_detector_init(&ctx->au_detector);
ctx->cbc->decompose_unit_types = decompose_unit_types;
ctx->cbc->nb_decompose_unit_types = FF_ARRAY_ELEMS(decompose_unit_types);
return ret;
}
static av_cold void vvc_parser_close(AVCodecParserContext *s)
{
VVCParserContext *ctx = s->priv_data;
av_packet_unref(&ctx->au);
av_packet_unref(&ctx->last_au);
ff_cbs_fragment_free(&ctx->picture_unit);
ff_cbs_close(&ctx->cbc);
av_freep(&ctx->pc.buffer);
}
const AVCodecParser ff_vvc_parser = {
.codec_ids = { AV_CODEC_ID_VVC },
.priv_data_size = sizeof(VVCParserContext),
.parser_init = vvc_parser_init,
.parser_close = vvc_parser_close,
.parser_parse = vvc_parser_parse,
};
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