64 lines
2 KiB
C
64 lines
2 KiB
C
|
/*
|
||
|
|
* Canopus common routines
|
||
|
|
* Copyright (c) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
|
||
|
|
*
|
||
|
|
* 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 <stdint.h>
|
||
|
|
|
||
|
|
#include "libavutil/rational.h"
|
||
|
|
|
||
|
|
#include "avcodec.h"
|
||
|
|
#include "bytestream.h"
|
||
|
|
#include "canopus.h"
|
||
|
|
|
||
|
|
int ff_canopus_parse_info_tag(AVCodecContext *avctx,
|
||
|
|
const uint8_t *src, size_t size)
|
||
|
|
{
|
||
|
|
GetByteContext gbc;
|
||
|
|
int par_x, par_y, field_order;
|
||
|
|
|
||
|
|
bytestream2_init(&gbc, src, size);
|
||
|
|
|
||
|
|
/* Parse aspect ratio. */
|
||
|
|
bytestream2_skip(&gbc, 8); // unknown, 16 bits 1
|
||
|
|
par_x = bytestream2_get_le32(&gbc);
|
||
|
|
par_y = bytestream2_get_le32(&gbc);
|
||
|
|
if (par_x && par_y)
|
||
|
|
av_reduce(&avctx->sample_aspect_ratio.num,
|
||
|
|
&avctx->sample_aspect_ratio.den,
|
||
|
|
par_x, par_y, 255);
|
||
|
|
|
||
|
|
/* Short INFO tag (used in CLLC) has only AR data. */
|
||
|
|
if (size == 0x18)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
bytestream2_skip(&gbc, 16); // unknown RDRT tag
|
||
|
|
|
||
|
|
/* Parse FIEL tag. */
|
||
|
|
bytestream2_skip(&gbc, 8); // 'FIEL' and 4 bytes 0
|
||
|
|
field_order = bytestream2_get_le32(&gbc);
|
||
|
|
switch (field_order) {
|
||
|
|
case 0: avctx->field_order = AV_FIELD_TT; break;
|
||
|
|
case 1: avctx->field_order = AV_FIELD_BB; break;
|
||
|
|
case 2: avctx->field_order = AV_FIELD_PROGRESSIVE; break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|