ffmpeg/libavformat/mj2kdec.c

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/*
* MJPEG 2000 Demuxer
* Copyright (c) 2016 Ståle Kristoffersen
*
* 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "rawdec.h"
static int mjpeg2000_probe(const AVProbeData *p)
{
const uint8_t *b = p->buf;
int i, marker, marker_size;
int frames = 0, invalid = 0;
for (i = 0; i < p->buf_size - 5; i++) {
if (AV_RB32(b) == 0xff4fff51){
marker_size = AV_RB16(b+4);
if (marker_size + i < p->buf_size - 4) {
marker = AV_RB8(b+4+marker_size);
if (marker == 0xff)
frames++;
else
invalid++;
}
}
b += 1;
}
if (invalid*4 + 1 < frames) {
if (invalid == 0 && frames > 2)
return AVPROBE_SCORE_EXTENSION / 2;
return AVPROBE_SCORE_EXTENSION / 4;
}
return 0;
}
FF_DEF_RAWVIDEO_DEMUXER2(mjpeg_2000, "raw MJPEG 2000 video", mjpeg2000_probe, "j2k", AV_CODEC_ID_JPEG2000, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)