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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-21 10:55:51 +02:00
FFmpeg/libavcodec/h264_parser.c
Anton Khirnov e930b834a9 lavf: use AV_CODEC_PROP_FIELDS where appropriate
H.264 and mpeg12 parsers need to be adjusted at the same time to stop
using the value of AVCodecContext.ticks_per_frame, because it is not set
correctly unless the codec has been opened. Previously this would result
in both the parser and lavf seeing the same incorrect value, which would
cancel out.
Updating lavf and not the parsers would result in correct value in lavf,
but the wrong one in parsers, which would break some tests.
2023-05-15 10:31:55 +02:00

696 lines
25 KiB
C

/*
* H.26L/H.264/AVC/JVT/14496-10/... parser
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* 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
*/
/**
* @file
* H.264 / AVC / MPEG-4 part10 parser.
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#define UNCHECKED_BITSTREAM_READER 1
#include <stdint.h>
#include "libavutil/avutil.h"
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/pixfmt.h"
#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "h264.h"
#include "h264dsp.h"
#include "h264_parse.h"
#include "h264_sei.h"
#include "h264_ps.h"
#include "h2645_parse.h"
#include "h264data.h"
#include "mpegutils.h"
#include "parser.h"
#include "startcode.h"
typedef struct H264ParseContext {
ParseContext pc;
H264ParamSets ps;
H264DSPContext h264dsp;
H264POCContext poc;
H264SEIContext sei;
int is_avc;
int nal_length_size;
int got_first;
int picture_structure;
uint8_t parse_history[6];
int parse_history_count;
int parse_last_mb;
int64_t reference_dts;
int last_frame_num, last_picture_structure;
} H264ParseContext;
static int find_start_code(const uint8_t *buf, int buf_size,
int buf_index, int next_avc)
{
uint32_t state = -1;
buf_index = avpriv_find_start_code(buf + buf_index, buf + next_avc + 1, &state) - buf - 1;
return FFMIN(buf_index, buf_size);
}
static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf,
int buf_size, void *logctx)
{
int i, j;
uint32_t state;
ParseContext *pc = &p->pc;
int next_avc = p->is_avc ? 0 : buf_size;
// mb_addr= pc->mb_addr - 1;
state = pc->state;
if (state > 13)
state = 7;
if (p->is_avc && !p->nal_length_size)
av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n");
for (i = 0; i < buf_size; i++) {
if (i >= next_avc) {
int64_t nalsize = 0;
i = next_avc;
for (j = 0; j < p->nal_length_size; j++)
nalsize = (nalsize << 8) | buf[i++];
if (!nalsize || nalsize > buf_size - i) {
av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal size %"PRId64" "
"remaining %d\n", nalsize, buf_size - i);
return buf_size;
}
next_avc = i + nalsize;
state = 5;
}
if (state == 7) {
i += p->h264dsp.startcode_find_candidate(buf + i, next_avc - i);
if (i < next_avc)
state = 2;
} else if (state <= 2) {
if (buf[i] == 1)
state ^= 5; // 2->7, 1->4, 0->5
else if (buf[i])
state = 7;
else
state >>= 1; // 2->1, 1->0, 0->0
} else if (state <= 5) {
int nalu_type = buf[i] & 0x1F;
if (nalu_type == H264_NAL_SEI || nalu_type == H264_NAL_SPS ||
nalu_type == H264_NAL_PPS || nalu_type == H264_NAL_AUD) {
if (pc->frame_start_found) {
i++;
goto found;
}
} else if (nalu_type == H264_NAL_SLICE || nalu_type == H264_NAL_DPA ||
nalu_type == H264_NAL_IDR_SLICE) {
state += 8;
continue;
}
state = 7;
} else {
unsigned int mb, last_mb = p->parse_last_mb;
GetBitContext gb;
p->parse_history[p->parse_history_count++] = buf[i];
init_get_bits(&gb, p->parse_history, 8*p->parse_history_count);
mb= get_ue_golomb_long(&gb);
if (get_bits_left(&gb) > 0 || p->parse_history_count > 5) {
p->parse_last_mb = mb;
if (pc->frame_start_found) {
if (mb <= last_mb) {
i -= p->parse_history_count - 1;
p->parse_history_count = 0;
goto found;
}
} else
pc->frame_start_found = 1;
p->parse_history_count = 0;
state = 7;
}
}
}
pc->state = state;
if (p->is_avc)
return next_avc;
return END_NOT_FOUND;
found:
pc->state = 7;
pc->frame_start_found = 0;
if (p->is_avc)
return next_avc;
return i - (state & 5);
}
static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,
void *logctx)
{
H264PredWeightTable pwt;
int slice_type_nos = s->pict_type & 3;
H264ParseContext *p = s->priv_data;
int list_count, ref_count[2];
if (p->ps.pps->redundant_pic_cnt_present)
get_ue_golomb(gb); // redundant_pic_count
if (slice_type_nos == AV_PICTURE_TYPE_B)
get_bits1(gb); // direct_spatial_mv_pred
if (ff_h264_parse_ref_count(&list_count, ref_count, gb, p->ps.pps,
slice_type_nos, p->picture_structure, logctx) < 0)
return AVERROR_INVALIDDATA;
if (slice_type_nos != AV_PICTURE_TYPE_I) {
int list;
for (list = 0; list < list_count; list++) {
if (get_bits1(gb)) {
int index;
for (index = 0; ; index++) {
unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(gb);
if (reordering_of_pic_nums_idc < 3)
get_ue_golomb_long(gb);
else if (reordering_of_pic_nums_idc > 3) {
av_log(logctx, AV_LOG_ERROR,
"illegal reordering_of_pic_nums_idc %d\n",
reordering_of_pic_nums_idc);
return AVERROR_INVALIDDATA;
} else
break;
if (index >= ref_count[list]) {
av_log(logctx, AV_LOG_ERROR,
"reference count %d overflow\n", index);
return AVERROR_INVALIDDATA;
}
}
}
}
}
if ((p->ps.pps->weighted_pred && slice_type_nos == AV_PICTURE_TYPE_P) ||
(p->ps.pps->weighted_bipred_idc == 1 && slice_type_nos == AV_PICTURE_TYPE_B))
ff_h264_pred_weight_table(gb, p->ps.sps, ref_count, slice_type_nos,
&pwt, p->picture_structure, logctx);
if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
int i;
for (i = 0; i < H264_MAX_MMCO_COUNT; i++) {
MMCOOpcode opcode = get_ue_golomb_31(gb);
if (opcode > (unsigned) MMCO_LONG) {
av_log(logctx, AV_LOG_ERROR,
"illegal memory management control operation %d\n",
opcode);
return AVERROR_INVALIDDATA;
}
if (opcode == MMCO_END)
return 0;
else if (opcode == MMCO_RESET)
return 1;
if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG)
get_ue_golomb_long(gb); // difference_of_pic_nums_minus1
if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG)
get_ue_golomb_31(gb);
}
}
return 0;
}
/**
* 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.
*/
static inline int parse_nal_units(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t * const buf, int buf_size)
{
H264ParseContext *p = s->priv_data;
H2645RBSP rbsp = { NULL };
H2645NAL nal = { NULL };
int buf_index, next_avc;
unsigned int pps_id;
unsigned int slice_type;
int state = -1, got_reset = 0;
int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
int field_poc[2];
int ret;
/* set some sane default values */
s->pict_type = AV_PICTURE_TYPE_I;
s->key_frame = 0;
s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
ff_h264_sei_uninit(&p->sei);
p->sei.common.frame_packing.arrangement_cancel_flag = -1;
p->sei.common.unregistered.x264_build = -1;
if (!buf_size)
return 0;
av_fast_padded_malloc(&rbsp.rbsp_buffer, &rbsp.rbsp_buffer_alloc_size, buf_size);
if (!rbsp.rbsp_buffer)
return AVERROR(ENOMEM);
buf_index = 0;
next_avc = p->is_avc ? 0 : buf_size;
for (;;) {
const SPS *sps;
int src_length, consumed, nalsize = 0;
if (buf_index >= next_avc) {
nalsize = get_nalsize(p->nal_length_size, buf, buf_size, &buf_index, avctx);
if (nalsize < 0)
break;
next_avc = buf_index + nalsize;
} else {
buf_index = find_start_code(buf, buf_size, buf_index, next_avc);
if (buf_index >= buf_size)
break;
if (buf_index >= next_avc)
continue;
}
src_length = next_avc - buf_index;
state = buf[buf_index];
switch (state & 0x1f) {
case H264_NAL_SLICE:
case H264_NAL_IDR_SLICE:
// Do not walk the whole buffer just to decode slice header
if ((state & 0x1f) == H264_NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) {
/* IDR or disposable slice
* No need to decode many bytes because MMCOs shall not be present. */
if (src_length > 60)
src_length = 60;
} else {
/* To decode up to MMCOs */
if (src_length > 1000)
src_length = 1000;
}
break;
}
consumed = ff_h2645_extract_rbsp(buf + buf_index, src_length, &rbsp, &nal, 1);
if (consumed < 0)
break;
buf_index += consumed;
ret = init_get_bits8(&nal.gb, nal.data, nal.size);
if (ret < 0)
goto fail;
get_bits1(&nal.gb);
nal.ref_idc = get_bits(&nal.gb, 2);
nal.type = get_bits(&nal.gb, 5);
switch (nal.type) {
case H264_NAL_SPS:
ff_h264_decode_seq_parameter_set(&nal.gb, avctx, &p->ps, 0);
break;
case H264_NAL_PPS:
ff_h264_decode_picture_parameter_set(&nal.gb, avctx, &p->ps,
nal.size_bits);
break;
case H264_NAL_SEI:
ff_h264_sei_decode(&p->sei, &nal.gb, &p->ps, avctx);
break;
case H264_NAL_IDR_SLICE:
s->key_frame = 1;
p->poc.prev_frame_num = 0;
p->poc.prev_frame_num_offset = 0;
p->poc.prev_poc_msb =
p->poc.prev_poc_lsb = 0;
/* fall through */
case H264_NAL_SLICE:
get_ue_golomb_long(&nal.gb); // skip first_mb_in_slice
slice_type = get_ue_golomb_31(&nal.gb);
s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
/* key frame, since recovery_frame_cnt is set */
s->key_frame = 1;
}
pps_id = get_ue_golomb(&nal.gb);
if (pps_id >= MAX_PPS_COUNT) {
av_log(avctx, AV_LOG_ERROR,
"pps_id %u out of range\n", pps_id);
goto fail;
}
if (!p->ps.pps_list[pps_id]) {
av_log(avctx, AV_LOG_ERROR,
"non-existing PPS %u referenced\n", pps_id);
goto fail;
}
av_buffer_unref(&p->ps.pps_ref);
p->ps.pps = NULL;
p->ps.sps = NULL;
p->ps.pps_ref = av_buffer_ref(p->ps.pps_list[pps_id]);
if (!p->ps.pps_ref)
goto fail;
p->ps.pps = (const PPS*)p->ps.pps_ref->data;
p->ps.sps = p->ps.pps->sps;
sps = p->ps.sps;
// heuristic to detect non marked keyframes
if (p->ps.sps->ref_frame_count <= 1 && p->ps.pps->ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I)
s->key_frame = 1;
p->poc.frame_num = get_bits(&nal.gb, sps->log2_max_frame_num);
s->coded_width = 16 * sps->mb_width;
s->coded_height = 16 * sps->mb_height;
s->width = s->coded_width - (sps->crop_right + sps->crop_left);
s->height = s->coded_height - (sps->crop_top + sps->crop_bottom);
if (s->width <= 0 || s->height <= 0) {
s->width = s->coded_width;
s->height = s->coded_height;
}
switch (sps->bit_depth_luma) {
case 9:
if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P9;
else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P9;
else s->format = AV_PIX_FMT_YUV420P9;
break;
case 10:
if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P10;
else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P10;
else s->format = AV_PIX_FMT_YUV420P10;
break;
case 8:
if (sps->chroma_format_idc == 3) s->format = AV_PIX_FMT_YUV444P;
else if (sps->chroma_format_idc == 2) s->format = AV_PIX_FMT_YUV422P;
else s->format = AV_PIX_FMT_YUV420P;
break;
default:
s->format = AV_PIX_FMT_NONE;
}
avctx->profile = ff_h264_get_profile(sps);
avctx->level = sps->level_idc;
if (sps->frame_mbs_only_flag) {
p->picture_structure = PICT_FRAME;
} else {
if (get_bits1(&nal.gb)) { // field_pic_flag
p->picture_structure = PICT_TOP_FIELD + get_bits1(&nal.gb); // bottom_field_flag
} else {
p->picture_structure = PICT_FRAME;
}
}
if (nal.type == H264_NAL_IDR_SLICE)
get_ue_golomb_long(&nal.gb); /* idr_pic_id */
if (sps->poc_type == 0) {
p->poc.poc_lsb = get_bits(&nal.gb, sps->log2_max_poc_lsb);
if (p->ps.pps->pic_order_present == 1 &&
p->picture_structure == PICT_FRAME)
p->poc.delta_poc_bottom = get_se_golomb(&nal.gb);
}
if (sps->poc_type == 1 &&
!sps->delta_pic_order_always_zero_flag) {
p->poc.delta_poc[0] = get_se_golomb(&nal.gb);
if (p->ps.pps->pic_order_present == 1 &&
p->picture_structure == PICT_FRAME)
p->poc.delta_poc[1] = get_se_golomb(&nal.gb);
}
/* Decode POC of this picture.
* The prev_ values needed for decoding POC of the next picture are not set here. */
field_poc[0] = field_poc[1] = INT_MAX;
ret = ff_h264_init_poc(field_poc, &s->output_picture_number, sps,
&p->poc, p->picture_structure, nal.ref_idc);
if (ret < 0)
goto fail;
/* Continue parsing to check if MMCO_RESET is present.
* FIXME: MMCO_RESET could appear in non-first slice.
* Maybe, we should parse all undisposable non-IDR slice of this
* picture until encountering MMCO_RESET in a slice of it. */
if (nal.ref_idc && nal.type != H264_NAL_IDR_SLICE) {
got_reset = scan_mmco_reset(s, &nal.gb, avctx);
if (got_reset < 0)
goto fail;
}
/* Set up the prev_ values for decoding POC of the next picture. */
p->poc.prev_frame_num = got_reset ? 0 : p->poc.frame_num;
p->poc.prev_frame_num_offset = got_reset ? 0 : p->poc.frame_num_offset;
if (nal.ref_idc != 0) {
if (!got_reset) {
p->poc.prev_poc_msb = p->poc.poc_msb;
p->poc.prev_poc_lsb = p->poc.poc_lsb;
} else {
p->poc.prev_poc_msb = 0;
p->poc.prev_poc_lsb =
p->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0];
}
}
if (p->sei.picture_timing.present) {
ret = ff_h264_sei_process_picture_timing(&p->sei.picture_timing,
sps, avctx);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Error processing the picture timing SEI\n");
p->sei.picture_timing.present = 0;
}
}
if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
switch (p->sei.picture_timing.pic_struct) {
case H264_SEI_PIC_STRUCT_TOP_FIELD:
case H264_SEI_PIC_STRUCT_BOTTOM_FIELD:
s->repeat_pict = 0;
break;
case H264_SEI_PIC_STRUCT_FRAME:
case H264_SEI_PIC_STRUCT_TOP_BOTTOM:
case H264_SEI_PIC_STRUCT_BOTTOM_TOP:
s->repeat_pict = 1;
break;
case H264_SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
case H264_SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
s->repeat_pict = 2;
break;
case H264_SEI_PIC_STRUCT_FRAME_DOUBLING:
s->repeat_pict = 3;
break;
case H264_SEI_PIC_STRUCT_FRAME_TRIPLING:
s->repeat_pict = 5;
break;
default:
s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
break;
}
} else {
s->repeat_pict = p->picture_structure == PICT_FRAME ? 1 : 0;
}
if (p->picture_structure == PICT_FRAME) {
s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
switch (p->sei.picture_timing.pic_struct) {
case H264_SEI_PIC_STRUCT_TOP_BOTTOM:
case H264_SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
s->field_order = AV_FIELD_TT;
break;
case H264_SEI_PIC_STRUCT_BOTTOM_TOP:
case H264_SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
s->field_order = AV_FIELD_BB;
break;
default:
s->field_order = AV_FIELD_PROGRESSIVE;
break;
}
} else {
if (field_poc[0] < field_poc[1])
s->field_order = AV_FIELD_TT;
else if (field_poc[0] > field_poc[1])
s->field_order = AV_FIELD_BB;
else
s->field_order = AV_FIELD_PROGRESSIVE;
}
} else {
if (p->picture_structure == PICT_TOP_FIELD)
s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD;
else
s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD;
if (p->poc.frame_num == p->last_frame_num &&
p->last_picture_structure != AV_PICTURE_STRUCTURE_UNKNOWN &&
p->last_picture_structure != AV_PICTURE_STRUCTURE_FRAME &&
p->last_picture_structure != s->picture_structure) {
if (p->last_picture_structure == AV_PICTURE_STRUCTURE_TOP_FIELD)
s->field_order = AV_FIELD_TT;
else
s->field_order = AV_FIELD_BB;
} else {
s->field_order = AV_FIELD_UNKNOWN;
}
p->last_picture_structure = s->picture_structure;
p->last_frame_num = p->poc.frame_num;
}
if (sps->timing_info_present_flag) {
int64_t den = sps->time_scale;
if (p->sei.common.unregistered.x264_build < 44U)
den *= 2;
av_reduce(&avctx->framerate.den, &avctx->framerate.num,
sps->num_units_in_tick * 2, den, 1 << 30);
}
av_freep(&rbsp.rbsp_buffer);
return 0; /* no need to evaluate the rest */
}
}
if (q264) {
av_freep(&rbsp.rbsp_buffer);
return 0;
}
/* didn't find a picture! */
av_log(avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
fail:
av_freep(&rbsp.rbsp_buffer);
return -1;
}
static int h264_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
H264ParseContext *p = s->priv_data;
ParseContext *pc = &p->pc;
AVRational time_base = { 0, 1 };
int next;
if (!p->got_first) {
p->got_first = 1;
if (avctx->extradata_size) {
ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
&p->ps, &p->is_avc, &p->nal_length_size,
avctx->err_recognition, avctx);
}
}
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = h264_find_frame_end(p, buf, buf_size, avctx);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
if (next < 0 && next != END_NOT_FOUND) {
av_assert1(pc->last_index + next >= 0);
h264_find_frame_end(p, &pc->buffer[pc->last_index + next], -next, avctx); // update state
}
}
parse_nal_units(s, avctx, buf, buf_size);
if (avctx->framerate.num)
time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){2, 1}));
if (p->sei.picture_timing.cpb_removal_delay >= 0) {
s->dts_sync_point = p->sei.buffering_period.present;
s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
s->pts_dts_delta = p->sei.picture_timing.dpb_output_delay;
} else {
s->dts_sync_point = INT_MIN;
s->dts_ref_dts_delta = INT_MIN;
s->pts_dts_delta = INT_MIN;
}
if (s->flags & PARSER_FLAG_ONCE) {
s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
}
if (s->dts_sync_point >= 0) {
int64_t den = time_base.den * (int64_t)avctx->pkt_timebase.num;
if (den > 0) {
int64_t num = time_base.num * (int64_t)avctx->pkt_timebase.den;
if (s->dts != AV_NOPTS_VALUE) {
// got DTS from the stream, update reference timestamp
p->reference_dts = s->dts - av_rescale(s->dts_ref_dts_delta, num, den);
} else if (p->reference_dts != AV_NOPTS_VALUE) {
// compute DTS based on reference timestamp
s->dts = p->reference_dts + av_rescale(s->dts_ref_dts_delta, num, den);
}
if (p->reference_dts != AV_NOPTS_VALUE && s->pts == AV_NOPTS_VALUE)
s->pts = s->dts + av_rescale(s->pts_dts_delta, num, den);
if (s->dts_sync_point > 0)
p->reference_dts = s->dts; // new reference
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
static void h264_close(AVCodecParserContext *s)
{
H264ParseContext *p = s->priv_data;
ParseContext *pc = &p->pc;
av_freep(&pc->buffer);
ff_h264_sei_uninit(&p->sei);
ff_h264_ps_uninit(&p->ps);
}
static av_cold int init(AVCodecParserContext *s)
{
H264ParseContext *p = s->priv_data;
p->reference_dts = AV_NOPTS_VALUE;
p->last_frame_num = INT_MAX;
ff_h264dsp_init(&p->h264dsp, 8, 1);
return 0;
}
const AVCodecParser ff_h264_parser = {
.codec_ids = { AV_CODEC_ID_H264 },
.priv_data_size = sizeof(H264ParseContext),
.parser_init = init,
.parser_parse = h264_parse,
.parser_close = h264_close,
};