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/*
* DNxHD/VC-3 parser
* Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
*
* 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
* DNxHD/VC-3 parser
*/
#include "parser.h"
#define DNXHD_HEADER_PREFIX 0x000002800100
typedef struct {
ParseContext pc;
int interlaced;
int cur_field; /* first field is 0, second is 1 */
} DNXHDParserContext;
static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
const uint8_t *buf, int buf_size)
{
ParseContext *pc = &dctx->pc;
uint64_t state = pc->state64;
int pic_found = pc->frame_start_found;
int i = 0;
int interlaced = dctx->interlaced;
int cur_field = dctx->cur_field;
if (!pic_found) {
for (i = 0; i < buf_size; i++) {
state = (state<<8) | buf[i];
if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
i++;
pic_found = 1;
interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */
cur_field = state&1;
break;
}
}
}
if (pic_found) {
if (!buf_size) /* EOF considered as end of frame */
return 0;
for (; i < buf_size; i++) {
state = (state<<8) | buf[i];
if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
if (!interlaced || dctx->cur_field) {
pc->frame_start_found = 0;
pc->state64 = -1;
dctx->interlaced = interlaced;
dctx->cur_field = 0;
return i-5;
} else {
/* continue, to get the second field */
dctx->interlaced = interlaced = (state&2)>>1;
dctx->cur_field = cur_field = state&1;
}
}
}
}
pc->frame_start_found = pic_found;
pc->state64 = state;
dctx->interlaced = interlaced;
dctx->cur_field = cur_field;
return END_NOT_FOUND;
}
static int dnxhd_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
DNXHDParserContext *dctx = s->priv_data;
ParseContext *pc = &dctx->pc;
int next;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = dnxhd_find_frame_end(dctx, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
AVCodecParser ff_dnxhd_parser = {
.codec_ids = { AV_CODEC_ID_DNXHD },
.priv_data_size = sizeof(DNXHDParserContext),
.parser_parse = dnxhd_parse,
.parser_close = ff_parse_close,
};
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