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FFmpeg/libavformat/cavsvideodec.c

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/*
* RAW Chinese AVS video demuxer
* Copyright (c) 2009 Stefan Gehrer <stefan.gehrer@gmx.de>
*
* 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 "libavcodec/startcode.h"
#include "avformat.h"
#include "rawdec.h"
#define CAVS_SEQ_START_CODE 0x000001b0
#define CAVS_PIC_I_START_CODE 0x000001b3
#define CAVS_UNDEF_START_CODE 0x000001b4
#define CAVS_PIC_PB_START_CODE 0x000001b6
#define CAVS_VIDEO_EDIT_CODE 0x000001b7
#define CAVS_PROFILE_JIZHUN 0x20 // AVS1 P2
#define CAVS_PROFILE_GUANGDIAN 0x48 // AVS1 P16/AVS+
static int cavsvideo_probe(const AVProbeData *p)
{
uint32_t code= -1;
int pic=0, seq=0, slice_pos = 0;
const uint8_t *ptr = p->buf, *end = p->buf + p->buf_size;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &code);
if ((code & 0xffffff00) == 0x100) {
if(code < CAVS_SEQ_START_CODE) {
/* slices have to be consecutive */
if(code < slice_pos)
return 0;
slice_pos = code;
} else {
slice_pos = 0;
}
if (code == CAVS_SEQ_START_CODE) {
seq++;
/* check for the only currently supported profile */
if (*ptr != CAVS_PROFILE_JIZHUN && *ptr != CAVS_PROFILE_GUANGDIAN)
return 0;
} else if ((code == CAVS_PIC_I_START_CODE) ||
(code == CAVS_PIC_PB_START_CODE)) {
pic++;
} else if ((code == CAVS_UNDEF_START_CODE) ||
(code > CAVS_VIDEO_EDIT_CODE)) {
return 0;
}
}
}
if(seq && seq*9<=pic*10)
return AVPROBE_SCORE_EXTENSION+1;
return 0;
}
FF_DEF_RAWVIDEO_DEMUXER(cavsvideo, "raw Chinese AVS (Audio Video Standard)", cavsvideo_probe, "avs", AV_CODEC_ID_CAVS)