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FFmpeg/libavcodec/h264_parse.c
Anton Khirnov b16e9b9ac9 h264: move initialising the explicit pred weight table for MBAFF 
Currently it's done in the code that initialises the ref list for
MBAFF, which is not a logical place for it. Move it to the function that
parses the pred table from the bitstream, which is analogous to what is
done for the implicit weight table as well.
2016-06-12 20:27:52 +02:00

487 lines
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/*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "h264_parse.h"
int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
const int *ref_count, int slice_type_nos,
H264PredWeightTable *pwt)
{
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 (sps->chroma_format_idc)
pwt->chroma_log2_weight_denom = get_ue_golomb(gb);
luma_def = 1 << pwt->luma_log2_weight_denom;
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 (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 (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
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];
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;
}
/**
* 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 intra4x4 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 (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);
}
if (mode < 0) {
av_log(logctx, AV_LOG_ERROR,
"left block unavailable for requested intra mode\n");
return AVERROR_INVALIDDATA;
}
}
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)
{
int list_count;
int num_ref_idx_active_override_flag, max_refs;
// 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) {
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 (ref_count[0] < 1)
goto fail;
if (slice_type_nos == AV_PICTURE_TYPE_B) {
ref_count[1] = get_ue_golomb(gb) + 1;
if (ref_count[1] < 1)
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;
}
max_refs = picture_structure == PICT_FRAME ? 16 : 32;
if (ref_count[0] > max_refs || ref_count[1] > max_refs)
goto fail;
*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;
int 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 (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);
if (ret < 0)
goto fail;
for (i = 0; i < pkt.nb_nals; i++) {
H2645NAL *nal = &pkt.nals[i];
switch (nal->type) {
case NAL_SPS:
ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps);
if (ret < 0)
goto fail;
break;
case 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);
ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
av_freep(&escaped_buf);
if (ret < 0)
return ret;
}
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[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 (p - data + nalsize > size)
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 (p - data + nalsize > size)
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 0;
}
/**
* 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;
}
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