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/*
* CRI parser
* Copyright (c) 2021 Paul B Mahol
*
* 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
*/
/**
* @file
* CRI parser
*/
#include "libavutil/bswap.h"
#include "libavutil/common.h"
#include "parser.h"
typedef struct CRIParser {
ParseContext pc;
int count;
int chunk;
int read_bytes;
int skip_bytes;
} CRIParser;
#define KEY (((uint64_t)'\1' << 56) | ((uint64_t)'\0' << 48) | \
((uint64_t)'\0' << 40) | ((uint64_t)'\0' << 32) | \
((uint64_t)'\4' << 24) | ((uint64_t)'\0' << 16) | \
((uint64_t)'\0' << 8) | ((uint64_t)'\0' << 0))
static int cri_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
CRIParser *bpc = s->priv_data;
uint64_t state = bpc->pc.state64;
int next = END_NOT_FOUND, i = 0;
s->pict_type = AV_PICTURE_TYPE_I;
s->key_frame = 1;
s->duration = 1;
*poutbuf_size = 0;
*poutbuf = NULL;
for (; i < buf_size; i++) {
state = (state << 8) | buf[i];
bpc->read_bytes++;
if (bpc->skip_bytes > 0) {
bpc->skip_bytes--;
if (bpc->skip_bytes == 0)
bpc->read_bytes = 0;
} else {
if (state != KEY)
continue;
}
if (bpc->skip_bytes == 0 && bpc->read_bytes >= 8) {
bpc->skip_bytes = av_bswap32(state & 0xFFFFFFFF);
bpc->chunk = state >> 32;
bpc->read_bytes = 0;
bpc->count++;
}
if (bpc->chunk == 0x01000000 && bpc->skip_bytes == 4 &&
bpc->read_bytes == 0 && bpc->count > 1) {
next = i - 7;
break;
}
}
bpc->pc.state64 = state;
if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
AVCodecParser ff_cri_parser = {
.codec_ids = { AV_CODEC_ID_CRI },
.priv_data_size = sizeof(CRIParser),
.parser_parse = cri_parse,
.parser_close = ff_parse_close,
};
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