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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"
#include "dnxhddata.h"
typedef struct {
ParseContext pc;
int cur_byte;
int remaining;
int w, h;
} 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;
if (!pic_found) {
for (i = 0; i < buf_size; i++) {
state = (state << 8) | buf[i];
if (ff_dnxhd_check_header_prefix(state & 0xffffffffff00LL) != 0) {
i++;
pic_found = 1;
dctx->cur_byte = 0;
dctx->remaining = 0;
break;
}
}
}
if (pic_found && !dctx->remaining) {
if (!buf_size) /* EOF considered as end of frame */
return 0;
for (; i < buf_size; i++) {
dctx->cur_byte++;
state = (state << 8) | buf[i];
if (dctx->cur_byte == 24) {
dctx->h = (state >> 32) & 0xFFFF;
} else if (dctx->cur_byte == 26) {
dctx->w = (state >> 32) & 0xFFFF;
} else if (dctx->cur_byte == 42) {
int cid = (state >> 32) & 0xFFFFFFFF;
int remaining;
if (cid <= 0)
continue;
remaining = avpriv_dnxhd_get_frame_size(cid);
if (remaining <= 0) {
remaining = avpriv_dnxhd_get_hr_frame_size(cid, dctx->w, dctx->h);
if (remaining <= 0)
continue;
}
remaining += i - 47;
dctx->remaining = remaining;
if (buf_size >= dctx->remaining) {
pc->frame_start_found = 0;
pc->state64 = -1;
dctx->cur_byte = 0;
dctx->remaining = 0;
return remaining;
} else {
dctx->remaining -= buf_size;
// Update variables for correctness, they are currently not used beyond here
state = -1;
dctx->cur_byte += buf_size - i;
break;
}
}
}
} else if (pic_found) {
if (dctx->remaining > buf_size) {
dctx->remaining -= buf_size;
} else {
int remaining = dctx->remaining;
pc->frame_start_found = 0;
pc->state64 = -1;
dctx->cur_byte = 0;
dctx->remaining = 0;
return remaining;
}
}
pc->frame_start_found = pic_found;
pc->state64 = state;
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;
}
const 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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