/*

 * RAW dvbsub demuxer

 * Copyright (c) 2015 Michael Niedermayer <michaelni@gmx.at>

 *

 * 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 dvbsub_probe(const AVProbeData *p)

{

    int i, j, k;

    const uint8_t *end = p->buf + p->buf_size;

    int type, len;

    int max_score = 0;

    for(i=0; i<p->buf_size; i++){

        if (p->buf[i] == 0x0f) {

            const uint8_t *ptr = p->buf + i;

            uint8_t histogram[6] = {0};

            int min = 255;

            for(j=0; 6 < end - ptr; j++) {

                if (*ptr != 0x0f)

                    break;

                type    = ptr[1];

                //page_id = AV_RB16(ptr + 2);

                len     = AV_RB16(ptr + 4);

                if (type == 0x80) {

                    ;

                } else if (type >= 0x10 && type <= 0x14) {

                    histogram[type - 0x10] ++;

                } else

                    break;

                if (6 + len > end - ptr)

                    break;

                ptr += 6 + len;

            }

            for (k=0; k < 4; k++) {

                min = FFMIN(min, histogram[k]);

            }

            if (min && j > max_score)

                max_score = j;

        }

    }

    if (max_score > 5)

        return AVPROBE_SCORE_EXTENSION;

    return 0;

}

FF_DEF_RAWSUB_DEMUXER(dvbsub, "raw dvbsub", dvbsub_probe, NULL, AV_CODEC_ID_DVB_SUBTITLE, AVFMT_GENERIC_INDEX)