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FFmpeg/libavcodec/h264_parse.c

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/*
* 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 "bytestream.h"
#include "get_bits.h"
#include "golomb.h"
#include "h264.h"
#include "h264dec.h"
#include "h264_parse.h"
#include "h264_ps.h"
int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
const int *ref_count, int slice_type_nos,
H264PredWeightTable *pwt,
int picture_structure, void *logctx)
{
int list, i, j;
int luma_def, chroma_def;
pwt->use_weight = 0;
pwt->use_weight_chroma = 0;
pwt->luma_log2_weight_denom = get_ue_golomb(gb);
if (pwt->luma_log2_weight_denom > 7U) {
av_log(logctx, AV_LOG_ERROR, "luma_log2_weight_denom %d is out of range\n", pwt->luma_log2_weight_denom);
pwt->luma_log2_weight_denom = 0;
}
luma_def = 1 << pwt->luma_log2_weight_denom;
if (sps->chroma_format_idc) {
pwt->chroma_log2_weight_denom = get_ue_golomb(gb);
if (pwt->chroma_log2_weight_denom > 7U) {
av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom);
pwt->chroma_log2_weight_denom = 0;
}
chroma_def = 1 << pwt->chroma_log2_weight_denom;
}
for (list = 0; list < 2; list++) {
pwt->luma_weight_flag[list] = 0;
pwt->chroma_weight_flag[list] = 0;
for (i = 0; i < ref_count[list]; i++) {
int luma_weight_flag, chroma_weight_flag;
luma_weight_flag = get_bits1(gb);
if (luma_weight_flag) {
pwt->luma_weight[i][list][0] = get_se_golomb(gb);
pwt->luma_weight[i][list][1] = get_se_golomb(gb);
if ((int8_t)pwt->luma_weight[i][list][0] != pwt->luma_weight[i][list][0] ||
(int8_t)pwt->luma_weight[i][list][1] != pwt->luma_weight[i][list][1])
goto out_range_weight;
if (pwt->luma_weight[i][list][0] != luma_def ||
pwt->luma_weight[i][list][1] != 0) {
pwt->use_weight = 1;
pwt->luma_weight_flag[list] = 1;
}
} else {
pwt->luma_weight[i][list][0] = luma_def;
pwt->luma_weight[i][list][1] = 0;
}
if (sps->chroma_format_idc) {
chroma_weight_flag = get_bits1(gb);
if (chroma_weight_flag) {
int j;
for (j = 0; j < 2; j++) {
pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);
if ((int8_t)pwt->chroma_weight[i][list][j][0] != pwt->chroma_weight[i][list][j][0] ||
(int8_t)pwt->chroma_weight[i][list][j][1] != pwt->chroma_weight[i][list][j][1]) {
pwt->chroma_weight[i][list][j][0] = chroma_def;
pwt->chroma_weight[i][list][j][1] = 0;
goto out_range_weight;
}
if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
pwt->chroma_weight[i][list][j][1] != 0) {
pwt->use_weight_chroma = 1;
pwt->chroma_weight_flag[list] = 1;
}
}
} else {
int j;
for (j = 0; j < 2; j++) {
pwt->chroma_weight[i][list][j][0] = chroma_def;
pwt->chroma_weight[i][list][j][1] = 0;
}
}
}
// for MBAFF
if (picture_structure == PICT_FRAME) {
pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
if (sps->chroma_format_idc) {
for (j = 0; j < 2; j++) {
pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
}
}
}
}
if (slice_type_nos != AV_PICTURE_TYPE_B)
break;
}
pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
return 0;
out_range_weight:
avpriv_request_sample(logctx, "Out of range weight");
return AVERROR_INVALIDDATA;
}
/**
* Check if the top & left blocks are available if needed and
* change the dc mode so it only uses the available blocks.
*/
int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
int top_samples_available, int left_samples_available)
{
static const int8_t top[12] = {
-1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
};
static const int8_t left[12] = {
0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
};
int i;
if (!(top_samples_available & 0x8000)) {
for (i = 0; i < 4; i++) {
int status = top[pred_mode_cache[scan8[0] + i]];
if (status < 0) {
av_log(logctx, AV_LOG_ERROR,
"top block unavailable for requested intra mode %d\n",
status);
return AVERROR_INVALIDDATA;
} else if (status) {
pred_mode_cache[scan8[0] + i] = status;
}
}
}
if ((left_samples_available & 0x8888) != 0x8888) {
static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
for (i = 0; i < 4; i++)
if (!(left_samples_available & mask[i])) {
int status = left[pred_mode_cache[scan8[0] + 8 * i]];
if (status < 0) {
av_log(logctx, AV_LOG_ERROR,
"left block unavailable for requested intra4x4 mode %d\n",
status);
return AVERROR_INVALIDDATA;
} else if (status) {
pred_mode_cache[scan8[0] + 8 * i] = status;
}
}
}
return 0;
}
/**
* Check if the top & left blocks are available if needed and
* change the dc mode so it only uses the available blocks.
*/
int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
int left_samples_available,
int mode, int is_chroma)
{
static const int8_t top[4] = { LEFT_DC_PRED8x8, 1, -1, -1 };
static const int8_t left[5] = { TOP_DC_PRED8x8, -1, 2, -1, DC_128_PRED8x8 };
if (mode > 3U) {
av_log(logctx, AV_LOG_ERROR,
"out of range intra chroma pred mode\n");
return AVERROR_INVALIDDATA;
}
if (!(top_samples_available & 0x8000)) {
mode = top[mode];
if (mode < 0) {
av_log(logctx, AV_LOG_ERROR,
"top block unavailable for requested intra mode\n");
return AVERROR_INVALIDDATA;
}
}
if ((left_samples_available & 0x8080) != 0x8080) {
mode = left[mode];
if (mode < 0) {
av_log(logctx, AV_LOG_ERROR,
"left block unavailable for requested intra mode\n");
return AVERROR_INVALIDDATA;
}
if (is_chroma && (left_samples_available & 0x8080)) {
// mad cow disease mode, aka MBAFF + constrained_intra_pred
mode = ALZHEIMER_DC_L0T_PRED8x8 +
(!(left_samples_available & 0x8000)) +
2 * (mode == DC_128_PRED8x8);
}
}
return mode;
}
int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
GetBitContext *gb, const PPS *pps,
int slice_type_nos, int picture_structure, void *logctx)
{
int list_count;
int num_ref_idx_active_override_flag;
// set defaults, might be overridden a few lines later
ref_count[0] = pps->ref_count[0];
ref_count[1] = pps->ref_count[1];
if (slice_type_nos != AV_PICTURE_TYPE_I) {
unsigned max[2];
max[0] = max[1] = picture_structure == PICT_FRAME ? 15 : 31;
num_ref_idx_active_override_flag = get_bits1(gb);
if (num_ref_idx_active_override_flag) {
ref_count[0] = get_ue_golomb(gb) + 1;
if (slice_type_nos == AV_PICTURE_TYPE_B) {
ref_count[1] = get_ue_golomb(gb) + 1;
} else
// full range is spec-ok in this case, even for frames
ref_count[1] = 1;
}
if (ref_count[0] - 1 > max[0] || ref_count[1] - 1 > max[1]) {
av_log(logctx, AV_LOG_ERROR, "reference overflow %u > %u or %u > %u\n",
ref_count[0] - 1, max[0], ref_count[1] - 1, max[1]);
ref_count[0] = ref_count[1] = 0;
*plist_count = 0;
goto fail;
}
if (slice_type_nos == AV_PICTURE_TYPE_B)
list_count = 2;
else
list_count = 1;
} else {
list_count = 0;
ref_count[0] = ref_count[1] = 0;
}
*plist_count = list_count;
return 0;
fail:
*plist_count = 0;
ref_count[0] = 0;
ref_count[1] = 0;
return AVERROR_INVALIDDATA;
}
int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
const SPS *sps, H264POCContext *pc,
int picture_structure, int nal_ref_idc)
{
const int max_frame_num = 1 << sps->log2_max_frame_num;
int64_t field_poc[2];
pc->frame_num_offset = pc->prev_frame_num_offset;
if (pc->frame_num < pc->prev_frame_num)
pc->frame_num_offset += max_frame_num;
if (sps->poc_type == 0) {
const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
if (pc->poc_lsb < pc->prev_poc_lsb &&
pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
else if (pc->poc_lsb > pc->prev_poc_lsb &&
pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
else
pc->poc_msb = pc->prev_poc_msb;
field_poc[0] =
field_poc[1] = pc->poc_msb + pc->poc_lsb;
if (picture_structure == PICT_FRAME)
field_poc[1] += pc->delta_poc_bottom;
} else if (sps->poc_type == 1) {
int abs_frame_num, expected_delta_per_poc_cycle, expectedpoc;
int i;
if (sps->poc_cycle_length != 0)
abs_frame_num = pc->frame_num_offset + pc->frame_num;
else
abs_frame_num = 0;
if (nal_ref_idc == 0 && abs_frame_num > 0)
abs_frame_num--;
expected_delta_per_poc_cycle = 0;
for (i = 0; i < sps->poc_cycle_length; i++)
// FIXME integrate during sps parse
expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
if (abs_frame_num > 0) {
int poc_cycle_cnt = (abs_frame_num - 1) / sps->poc_cycle_length;
int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
for (i = 0; i <= frame_num_in_poc_cycle; i++)
expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
} else
expectedpoc = 0;
if (nal_ref_idc == 0)
expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
field_poc[0] = expectedpoc + pc->delta_poc[0];
field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
if (picture_structure == PICT_FRAME)
field_poc[1] += pc->delta_poc[1];
} else {
int poc = 2 * (pc->frame_num_offset + pc->frame_num);
if (!nal_ref_idc)
poc--;
field_poc[0] = poc;
field_poc[1] = poc;
}
if ( field_poc[0] != (int)field_poc[0]
|| field_poc[1] != (int)field_poc[1])
return AVERROR_INVALIDDATA;
if (picture_structure != PICT_BOTTOM_FIELD)
pic_field_poc[0] = field_poc[0];
if (picture_structure != PICT_TOP_FIELD)
pic_field_poc[1] = field_poc[1];
*pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
return 0;
}
static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
int is_avc, void *logctx)
{
H2645Packet pkt = { 0 };
int i, ret = 0;
ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1, 0);
if (ret < 0) {
ret = 0;
goto fail;
}
for (i = 0; i < pkt.nb_nals; i++) {
H2645NAL *nal = &pkt.nals[i];
switch (nal->type) {
case H264_NAL_SPS:
ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps, 0);
if (ret < 0)
goto fail;
break;
case H264_NAL_PPS:
ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
nal->size_bits);
if (ret < 0)
goto fail;
break;
default:
av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
nal->type);
break;
}
}
fail:
ff_h2645_packet_uninit(&pkt);
return ret;
}
/* There are (invalid) samples in the wild with mp4-style extradata, where the
* parameter sets are stored unescaped (i.e. as RBSP).
* This function catches the parameter set decoding failure and tries again
* after escaping it */
static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
int err_recognition, void *logctx)
{
int ret;
ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
GetByteContext gbc;
PutByteContext pbc;
uint8_t *escaped_buf;
int escaped_buf_size;
av_log(logctx, AV_LOG_WARNING,
"SPS decoding failure, trying again after escaping the NAL\n");
if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
return AVERROR(ERANGE);
escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
escaped_buf = av_mallocz(escaped_buf_size);
if (!escaped_buf)
return AVERROR(ENOMEM);
bytestream2_init(&gbc, buf, buf_size);
bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
while (bytestream2_get_bytes_left(&gbc)) {
if (bytestream2_get_bytes_left(&gbc) >= 3 &&
bytestream2_peek_be24(&gbc) <= 3) {
bytestream2_put_be24(&pbc, 3);
bytestream2_skip(&gbc, 2);
} else
bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
}
escaped_buf_size = bytestream2_tell_p(&pbc);
AV_WB16(escaped_buf, escaped_buf_size - 2);
(void)decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
// lorex.mp4 decodes ok even with extradata decoding failing
av_freep(&escaped_buf);
}
return 0;
}
int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
int *is_avc, int *nal_length_size,
int err_recognition, void *logctx)
{
int ret;
if (!data || size <= 0)
return -1;
if (data[0] == 1) {
int i, cnt, nalsize;
const uint8_t *p = data;
*is_avc = 1;
if (size < 7) {
av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
return AVERROR_INVALIDDATA;
}
// Decode sps from avcC
cnt = *(p + 5) & 0x1f; // Number of sps
p += 6;
for (i = 0; i < cnt; i++) {
nalsize = AV_RB16(p) + 2;
if (nalsize > size - (p - data))
return AVERROR_INVALIDDATA;
ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
if (ret < 0) {
av_log(logctx, AV_LOG_ERROR,
"Decoding sps %d from avcC failed\n", i);
return ret;
}
p += nalsize;
}
// Decode pps from avcC
cnt = *(p++); // Number of pps
for (i = 0; i < cnt; i++) {
nalsize = AV_RB16(p) + 2;
if (nalsize > size - (p - data))
return AVERROR_INVALIDDATA;
ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
if (ret < 0) {
av_log(logctx, AV_LOG_ERROR,
"Decoding pps %d from avcC failed\n", i);
return ret;
}
p += nalsize;
}
// Store right nal length size that will be used to parse all other nals
*nal_length_size = (data[4] & 0x03) + 1;
} else {
*is_avc = 0;
ret = decode_extradata_ps(data, size, ps, 0, logctx);
if (ret < 0)
return ret;
}
return size;
}
/**
* Compute profile from profile_idc and constraint_set?_flags.
*
* @param sps SPS
*
* @return profile as defined by FF_PROFILE_H264_*
*/
int ff_h264_get_profile(const SPS *sps)
{
int profile = sps->profile_idc;
switch (sps->profile_idc) {
case FF_PROFILE_H264_BASELINE:
// constraint_set1_flag set to 1
profile |= (sps->constraint_set_flags & 1 << 1) ? FF_PROFILE_H264_CONSTRAINED : 0;
break;
case FF_PROFILE_H264_HIGH_10:
case FF_PROFILE_H264_HIGH_422:
case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
// constraint_set3_flag set to 1
profile |= (sps->constraint_set_flags & 1 << 3) ? FF_PROFILE_H264_INTRA : 0;
break;
}
return profile;
}