FFmpeg4/libavcodec/vp8_parser.c

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2023-07-02 12:20:28 +00:00
/*
* 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
static int parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
unsigned int frame_type;
unsigned int profile;
*poutbuf = buf;
*poutbuf_size = buf_size;
if (buf_size < 3)
return buf_size;
frame_type = buf[0] & 1;
profile = (buf[0] >> 1) & 7;
if (profile > 3) {
av_log(avctx, AV_LOG_ERROR, "Invalid profile %u.\n", profile);
return buf_size;
}
avctx->profile = profile;
s->key_frame = frame_type == 0;
s->pict_type = frame_type ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
s->format = AV_PIX_FMT_YUV420P;
s->field_order = AV_FIELD_PROGRESSIVE;
s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
if (frame_type == 0) {
unsigned int sync_code;
unsigned int width, height;
if (buf_size < 10)
return buf_size;
sync_code = AV_RL24(buf + 3);
if (sync_code != 0x2a019d) {
av_log(avctx, AV_LOG_ERROR, "Invalid sync code %06x.\n", sync_code);
return buf_size;
}
width = AV_RL16(buf + 6) & 0x3fff;
height = AV_RL16(buf + 8) & 0x3fff;
s->width = width;
s->height = height;
s->coded_width = FFALIGN(width, 16);
s->coded_height = FFALIGN(height, 16);
}
return buf_size;
}
AVCodecParser ff_vp8_parser = {
.codec_ids = { AV_CODEC_ID_VP8 },
.parser_parse = parse,
};