ffmpeg/libavcodec/mpegutils.c

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/*
* Mpeg video formats-related defines and utility functions
*
* 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 <stdint.h>
#include "libavutil/common.h"
#include "libavutil/frame.h"
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "mpegutils.h"
void ff_draw_horiz_band(AVCodecContext *avctx,
AVFrame *cur, AVFrame *last,
int y, int h, int picture_structure,
int first_field, int low_delay)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
int vshift = desc->log2_chroma_h;
const int field_pic = picture_structure != PICT_FRAME;
if (field_pic) {
h <<= 1;
y <<= 1;
}
h = FFMIN(h, avctx->height - y);
if (field_pic && first_field &&
!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD))
return;
if (avctx->draw_horiz_band) {
AVFrame *src;
int offset[AV_NUM_DATA_POINTERS];
int i;
if (cur->pict_type == AV_PICTURE_TYPE_B || low_delay ||
(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
src = cur;
else if (last)
src = last;
else
return;
if (cur->pict_type == AV_PICTURE_TYPE_B &&
picture_structure == PICT_FRAME &&
avctx->codec_id != AV_CODEC_ID_SVQ3) {
for (i = 0; i < AV_NUM_DATA_POINTERS; i++)
offset[i] = 0;
} else {
offset[0]= y * src->linesize[0];
offset[1]=
offset[2]= (y >> vshift) * src->linesize[1];
for (i = 3; i < AV_NUM_DATA_POINTERS; i++)
offset[i] = 0;
}
emms_c();
avctx->draw_horiz_band(avctx, src, offset,
y, picture_structure, h);
}
}