cavsvideodec.c 2.35 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 * 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 "avformat.h"
23
#include "rawdec.h"
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

#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

static int cavsvideo_probe(AVProbeData *p)
{
    uint32_t code= -1;
    int pic=0, seq=0, slice_pos = 0;
    int i;

    for(i=0; i<p->buf_size; i++){
        code = (code<<8) + p->buf[i];
        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(p->buf[i+1] != CAVS_PROFILE_JIZHUN)
                    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)
64
        return AVPROBE_SCORE_EXTENSION;
65 66 67
    return 0;
}

68
FF_DEF_RAWVIDEO_DEMUXER(cavsvideo, "raw Chinese AVS (Audio Video Standard)", cavsvideo_probe, NULL, AV_CODEC_ID_CAVS)