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/*
* Avid DNxUncomressed / SMPTE RDD 50 parser
* Copyright (c) 2024 Martin Schitter
*
* 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
*/
/*
* This parser for DNxUncompressed video data is mostly based on the public
* SMPTE RDD 50:2019 specification.
*/
#include "parser.h"
#include "libavutil/bswap.h"
typedef struct DNxUcParseContext {
ParseContext pc;
uint32_t remaining;
} DNxUcParseContext;
static int dnxuc_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
DNxUcParseContext *ipc = s->priv_data;
int next = END_NOT_FOUND;
s->pict_type = AV_PICTURE_TYPE_NONE;
*poutbuf_size = 0;
*poutbuf = NULL;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
if (ipc->remaining == 0) {
uint64_t state = ipc->pc.state64;
for (int i = 0; i < buf_size; i++) {
state = (state << 8) | buf[i];
if (ipc->pc.index + i >= 7 && (uint32_t)state == MKBETAG('p','a','c','k')) {
uint32_t size = av_bswap32(state >> 32);
if (size >= 8) {
next = i - 7;
ipc->remaining = size + FFMIN(next, 0);
break;
}
}
}
ipc->pc.state64 = state;
} else if (ipc->remaining <= buf_size) {
next = ipc->remaining;
ipc->remaining = 0;
} else {
ipc->remaining -= buf_size;
}
if (ff_combine_frame(&ipc->pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_dnxuc_parser = {
.codec_ids = { AV_CODEC_ID_DNXUC },
.priv_data_size = sizeof(DNxUcParseContext),
.parser_parse = dnxuc_parse,
};
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