0,0 → 1,563 |
/* |
* 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 / MPEG4 part10 parser. |
* @author Michael Niedermayer <michaelni@gmx.at> |
*/ |
|
#define UNCHECKED_BITSTREAM_READER 1 |
|
#include "libavutil/attributes.h" |
#include "parser.h" |
#include "h264data.h" |
#include "golomb.h" |
#include "internal.h" |
|
|
static int h264_find_frame_end(H264Context *h, const uint8_t *buf, |
int buf_size) |
{ |
int i, j; |
uint32_t state; |
ParseContext *pc = &h->parse_context; |
int next_avc= h->is_avc ? 0 : buf_size; |
|
// mb_addr= pc->mb_addr - 1; |
state = pc->state; |
if (state > 13) |
state = 7; |
|
if (h->is_avc && !h->nal_length_size) |
av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n"); |
|
for (i = 0; i < buf_size; i++) { |
if (i >= next_avc) { |
int nalsize = 0; |
i = next_avc; |
for (j = 0; j < h->nal_length_size; j++) |
nalsize = (nalsize << 8) | buf[i++]; |
if (nalsize <= 0 || nalsize > buf_size - i) { |
av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i); |
return buf_size; |
} |
next_avc = i + nalsize; |
state = 5; |
} |
|
if (state == 7) { |
i += h->h264dsp.h264_find_start_code_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 v = buf[i] & 0x1F; |
if (v == 6 || v == 7 || v == 8 || v == 9) { |
if (pc->frame_start_found) { |
i++; |
goto found; |
} |
} else if (v == 1 || v == 2 || v == 5) { |
state += 8; |
continue; |
} |
state = 7; |
} else { |
h->parse_history[h->parse_history_count++]= buf[i]; |
if (h->parse_history_count>3) { |
unsigned int mb, last_mb= h->parse_last_mb; |
GetBitContext gb; |
|
init_get_bits(&gb, h->parse_history, 8*h->parse_history_count); |
h->parse_history_count=0; |
mb= get_ue_golomb_long(&gb); |
last_mb= h->parse_last_mb; |
h->parse_last_mb= mb; |
if (pc->frame_start_found) { |
if (mb <= last_mb) |
goto found; |
} else |
pc->frame_start_found = 1; |
state = 7; |
} |
} |
} |
pc->state = state; |
if (h->is_avc) |
return next_avc; |
return END_NOT_FOUND; |
|
found: |
pc->state = 7; |
pc->frame_start_found = 0; |
if (h->is_avc) |
return next_avc; |
return i - (state & 5) - 3 * (state > 7); |
} |
|
static int scan_mmco_reset(AVCodecParserContext *s) |
{ |
H264Context *h = s->priv_data; |
|
h->slice_type_nos = s->pict_type & 3; |
|
if (h->pps.redundant_pic_cnt_present) |
get_ue_golomb(&h->gb); // redundant_pic_count |
|
if (ff_set_ref_count(h) < 0) |
return AVERROR_INVALIDDATA; |
|
if (h->slice_type_nos != AV_PICTURE_TYPE_I) { |
int list; |
for (list = 0; list < h->list_count; list++) { |
if (get_bits1(&h->gb)) { |
int index; |
for (index = 0; ; index++) { |
unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(&h->gb); |
|
if (reordering_of_pic_nums_idc < 3) |
get_ue_golomb(&h->gb); |
else if (reordering_of_pic_nums_idc > 3) { |
av_log(h->avctx, AV_LOG_ERROR, |
"illegal reordering_of_pic_nums_idc %d\n", |
reordering_of_pic_nums_idc); |
return AVERROR_INVALIDDATA; |
} else |
break; |
|
if (index >= h->ref_count[list]) { |
av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n"); |
return AVERROR_INVALIDDATA; |
} |
} |
} |
} |
} |
|
if ((h->pps.weighted_pred && h->slice_type_nos == AV_PICTURE_TYPE_P) || |
(h->pps.weighted_bipred_idc == 1 && h->slice_type_nos == AV_PICTURE_TYPE_B)) |
ff_pred_weight_table(h); |
|
if (get_bits1(&h->gb)) { // adaptive_ref_pic_marking_mode_flag |
int i; |
for (i = 0; i < MAX_MMCO_COUNT; i++) { |
MMCOOpcode opcode = get_ue_golomb_31(&h->gb); |
if (opcode > (unsigned) MMCO_LONG) { |
av_log(h->avctx, 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(&h->gb); |
if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED || |
opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) |
get_ue_golomb_31(&h->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 *buf, int buf_size) |
{ |
H264Context *h = s->priv_data; |
const uint8_t *buf_end = buf + buf_size; |
unsigned int pps_id; |
unsigned int slice_type; |
int state = -1, got_reset = 0; |
const uint8_t *ptr; |
int q264 = buf_size >=4 && !memcmp("Q264", buf, 4); |
int field_poc[2]; |
|
/* set some sane default values */ |
s->pict_type = AV_PICTURE_TYPE_I; |
s->key_frame = 0; |
s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN; |
|
h->avctx = avctx; |
ff_h264_reset_sei(h); |
h->sei_fpa.frame_packing_arrangement_cancel_flag = -1; |
|
if (!buf_size) |
return 0; |
|
for (;;) { |
int src_length, dst_length, consumed, nalsize = 0; |
if (h->is_avc) { |
int i; |
if (h->nal_length_size >= buf_end - buf) break; |
nalsize = 0; |
for (i = 0; i < h->nal_length_size; i++) |
nalsize = (nalsize << 8) | *buf++; |
if (nalsize <= 0 || nalsize > buf_end - buf) { |
av_log(h->avctx, AV_LOG_ERROR, "AVC: nal size %d\n", nalsize); |
break; |
} |
src_length = nalsize; |
} else { |
buf = avpriv_find_start_code(buf, buf_end, &state); |
if (buf >= buf_end) |
break; |
--buf; |
src_length = buf_end - buf; |
} |
switch (state & 0x1f) { |
case NAL_SLICE: |
case NAL_IDR_SLICE: |
// Do not walk the whole buffer just to decode slice header |
if ((state & 0x1f) == 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; |
} |
ptr = ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length); |
if (ptr == NULL || dst_length < 0) |
break; |
|
init_get_bits(&h->gb, ptr, 8 * dst_length); |
switch (h->nal_unit_type) { |
case NAL_SPS: |
ff_h264_decode_seq_parameter_set(h); |
break; |
case NAL_PPS: |
ff_h264_decode_picture_parameter_set(h, h->gb.size_in_bits); |
break; |
case NAL_SEI: |
ff_h264_decode_sei(h); |
break; |
case NAL_IDR_SLICE: |
s->key_frame = 1; |
|
h->prev_frame_num = 0; |
h->prev_frame_num_offset = 0; |
h->prev_poc_msb = |
h->prev_poc_lsb = 0; |
/* fall through */ |
case NAL_SLICE: |
get_ue_golomb_long(&h->gb); // skip first_mb_in_slice |
slice_type = get_ue_golomb_31(&h->gb); |
s->pict_type = golomb_to_pict_type[slice_type % 5]; |
if (h->sei_recovery_frame_cnt >= 0) { |
/* key frame, since recovery_frame_cnt is set */ |
s->key_frame = 1; |
} |
pps_id = get_ue_golomb(&h->gb); |
if (pps_id >= MAX_PPS_COUNT) { |
av_log(h->avctx, AV_LOG_ERROR, |
"pps_id out of range\n"); |
return -1; |
} |
if (!h->pps_buffers[pps_id]) { |
av_log(h->avctx, AV_LOG_ERROR, |
"non-existing PPS referenced\n"); |
return -1; |
} |
h->pps = *h->pps_buffers[pps_id]; |
if (!h->sps_buffers[h->pps.sps_id]) { |
av_log(h->avctx, AV_LOG_ERROR, |
"non-existing SPS referenced\n"); |
return -1; |
} |
h->sps = *h->sps_buffers[h->pps.sps_id]; |
h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num); |
|
if(h->sps.ref_frame_count <= 1 && h->pps.ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I) |
s->key_frame = 1; |
|
avctx->profile = ff_h264_get_profile(&h->sps); |
avctx->level = h->sps.level_idc; |
|
if (h->sps.frame_mbs_only_flag) { |
h->picture_structure = PICT_FRAME; |
} else { |
if (get_bits1(&h->gb)) { // field_pic_flag |
h->picture_structure = PICT_TOP_FIELD + get_bits1(&h->gb); // bottom_field_flag |
} else { |
h->picture_structure = PICT_FRAME; |
} |
} |
|
if (h->nal_unit_type == NAL_IDR_SLICE) |
get_ue_golomb(&h->gb); /* idr_pic_id */ |
if (h->sps.poc_type == 0) { |
h->poc_lsb = get_bits(&h->gb, h->sps.log2_max_poc_lsb); |
|
if (h->pps.pic_order_present == 1 && |
h->picture_structure == PICT_FRAME) |
h->delta_poc_bottom = get_se_golomb(&h->gb); |
} |
|
if (h->sps.poc_type == 1 && |
!h->sps.delta_pic_order_always_zero_flag) { |
h->delta_poc[0] = get_se_golomb(&h->gb); |
|
if (h->pps.pic_order_present == 1 && |
h->picture_structure == PICT_FRAME) |
h->delta_poc[1] = get_se_golomb(&h->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; |
ff_init_poc(h, field_poc, &s->output_picture_number); |
|
/* 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 (h->nal_ref_idc && h->nal_unit_type != NAL_IDR_SLICE) { |
got_reset = scan_mmco_reset(s); |
if (got_reset < 0) |
return got_reset; |
} |
|
/* Set up the prev_ values for decoding POC of the next picture. */ |
h->prev_frame_num = got_reset ? 0 : h->frame_num; |
h->prev_frame_num_offset = got_reset ? 0 : h->frame_num_offset; |
if (h->nal_ref_idc != 0) { |
if (!got_reset) { |
h->prev_poc_msb = h->poc_msb; |
h->prev_poc_lsb = h->poc_lsb; |
} else { |
h->prev_poc_msb = 0; |
h->prev_poc_lsb = |
h->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0]; |
} |
} |
|
if (h->sps.pic_struct_present_flag) { |
switch (h->sei_pic_struct) { |
case SEI_PIC_STRUCT_TOP_FIELD: |
case SEI_PIC_STRUCT_BOTTOM_FIELD: |
s->repeat_pict = 0; |
break; |
case SEI_PIC_STRUCT_FRAME: |
case SEI_PIC_STRUCT_TOP_BOTTOM: |
case SEI_PIC_STRUCT_BOTTOM_TOP: |
s->repeat_pict = 1; |
break; |
case SEI_PIC_STRUCT_TOP_BOTTOM_TOP: |
case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM: |
s->repeat_pict = 2; |
break; |
case SEI_PIC_STRUCT_FRAME_DOUBLING: |
s->repeat_pict = 3; |
break; |
case SEI_PIC_STRUCT_FRAME_TRIPLING: |
s->repeat_pict = 5; |
break; |
default: |
s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0; |
break; |
} |
} else { |
s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0; |
} |
|
if (h->picture_structure == PICT_FRAME) { |
s->picture_structure = AV_PICTURE_STRUCTURE_FRAME; |
if (h->sps.pic_struct_present_flag) { |
switch (h->sei_pic_struct) { |
case SEI_PIC_STRUCT_TOP_BOTTOM: |
case SEI_PIC_STRUCT_TOP_BOTTOM_TOP: |
s->field_order = AV_FIELD_TT; |
break; |
case SEI_PIC_STRUCT_BOTTOM_TOP: |
case 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 (h->picture_structure == PICT_TOP_FIELD) |
s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD; |
else |
s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD; |
s->field_order = AV_FIELD_UNKNOWN; |
} |
|
return 0; /* no need to evaluate the rest */ |
} |
buf += h->is_avc ? nalsize : consumed; |
} |
if (q264) |
return 0; |
/* didn't find a picture! */ |
av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size); |
return -1; |
} |
|
static int h264_parse(AVCodecParserContext *s, |
AVCodecContext *avctx, |
const uint8_t **poutbuf, int *poutbuf_size, |
const uint8_t *buf, int buf_size) |
{ |
H264Context *h = s->priv_data; |
ParseContext *pc = &h->parse_context; |
int next; |
|
if (!h->got_first) { |
h->got_first = 1; |
if (avctx->extradata_size) { |
h->avctx = avctx; |
// must be done like in decoder, otherwise opening the parser, |
// letting it create extradata and then closing and opening again |
// will cause has_b_frames to be always set. |
// Note that estimate_timings_from_pts does exactly this. |
if (!avctx->has_b_frames) |
h->low_delay = 1; |
ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size); |
} |
} |
|
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
next = buf_size; |
} else { |
next = h264_find_frame_end(h, buf, buf_size); |
|
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(h, &pc->buffer[pc->last_index + next], -next); // update state |
} |
} |
|
parse_nal_units(s, avctx, buf, buf_size); |
|
if (h->sei_cpb_removal_delay >= 0) { |
s->dts_sync_point = h->sei_buffering_period_present; |
s->dts_ref_dts_delta = h->sei_cpb_removal_delay; |
s->pts_dts_delta = h->sei_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; |
} |
|
*poutbuf = buf; |
*poutbuf_size = buf_size; |
return next; |
} |
|
static int h264_split(AVCodecContext *avctx, |
const uint8_t *buf, int buf_size) |
{ |
int i; |
uint32_t state = -1; |
int has_sps = 0; |
|
for (i = 0; i <= buf_size; i++) { |
if ((state & 0xFFFFFF1F) == 0x107) |
has_sps = 1; |
/* if ((state&0xFFFFFF1F) == 0x101 || |
* (state&0xFFFFFF1F) == 0x102 || |
* (state&0xFFFFFF1F) == 0x105) { |
* } |
*/ |
if ((state & 0xFFFFFF00) == 0x100 && (state & 0xFFFFFF1F) != 0x107 && |
(state & 0xFFFFFF1F) != 0x108 && (state & 0xFFFFFF1F) != 0x109) { |
if (has_sps) { |
while (i > 4 && buf[i - 5] == 0) |
i--; |
return i - 4; |
} |
} |
if (i < buf_size) |
state = (state << 8) | buf[i]; |
} |
return 0; |
} |
|
static void close(AVCodecParserContext *s) |
{ |
H264Context *h = s->priv_data; |
ParseContext *pc = &h->parse_context; |
|
av_free(pc->buffer); |
ff_h264_free_context(h); |
} |
|
static av_cold int init(AVCodecParserContext *s) |
{ |
H264Context *h = s->priv_data; |
h->thread_context[0] = h; |
h->slice_context_count = 1; |
ff_h264dsp_init(&h->h264dsp, 8, 1); |
return 0; |
} |
|
AVCodecParser ff_h264_parser = { |
.codec_ids = { AV_CODEC_ID_H264 }, |
.priv_data_size = sizeof(H264Context), |
.parser_init = init, |
.parser_parse = h264_parse, |
.parser_close = close, |
.split = h264_split, |
}; |