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FFmpeg/libavcodec/h264_parse.c

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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 "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;
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;
}
}
}
}
if (slice_type_nos != AV_PICTURE_TYPE_B)
break;
}
pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
return 0;
}