1/*
2 * RAW Chinese AVS video demuxer
3 * Copyright (c) 2009  Stefan Gehrer <stefan.gehrer@gmx.de>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avformat.h"
23#include "rawdec.h"
24
25#define CAVS_SEQ_START_CODE       0x000001b0
26#define CAVS_PIC_I_START_CODE     0x000001b3
27#define CAVS_UNDEF_START_CODE     0x000001b4
28#define CAVS_PIC_PB_START_CODE    0x000001b6
29#define CAVS_VIDEO_EDIT_CODE      0x000001b7
30#define CAVS_PROFILE_JIZHUN       0x20
31
32static int cavsvideo_probe(AVProbeData *p)
33{
34    uint32_t code= -1;
35    int pic=0, seq=0, slice_pos = 0;
36    int i;
37
38    for(i=0; i<p->buf_size; i++){
39        code = (code<<8) + p->buf[i];
40        if ((code & 0xffffff00) == 0x100) {
41            if(code < CAVS_SEQ_START_CODE) {
42                /* slices have to be consecutive */
43                if(code < slice_pos)
44                    return 0;
45                slice_pos = code;
46            } else {
47                slice_pos = 0;
48            }
49            if (code == CAVS_SEQ_START_CODE) {
50                seq++;
51                /* check for the only currently supported profile */
52                if(p->buf[i+1] != CAVS_PROFILE_JIZHUN)
53                    return 0;
54            } else if ((code == CAVS_PIC_I_START_CODE) ||
55                       (code == CAVS_PIC_PB_START_CODE)) {
56                pic++;
57            } else if ((code == CAVS_UNDEF_START_CODE) ||
58                       (code >  CAVS_VIDEO_EDIT_CODE)) {
59                return 0;
60            }
61        }
62    }
63    if(seq && seq*9<=pic*10)
64        return AVPROBE_SCORE_EXTENSION+1;
65    return 0;
66}
67
68FF_DEF_RAWVIDEO_DEMUXER(cavsvideo, "raw Chinese AVS (Audio Video Standard)", cavsvideo_probe, NULL, AV_CODEC_ID_CAVS)
69