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/*

 * MicroDVD subtitle demuxer

 * Copyright (c) 2010  Aurelien Jacobs 

 * Copyright (c) 2012  Clément Bœsch 

 *

 * 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"

#include "internal.h"

#include "subtitles.h"

#include "libavutil/intreadwrite.h"

#define MAX_LINESIZE 2048

typedef struct {

    FFDemuxSubtitlesQueue q;

} MicroDVDContext;

static int microdvd_probe(AVProbeData *p)

{

    unsigned char c;

    const uint8_t *ptr = p->buf;

    int i;

    if (AV_RB24(ptr) == 0xEFBBBF)

        ptr += 3;  /* skip UTF-8 BOM */

    for (i=0; i<3; i++) {

        if (sscanf(ptr, "{%*d}{}%c",     &c) != 1 &&

            sscanf(ptr, "{%*d}{%*d}%c",  &c) != 1 &&

            sscanf(ptr, "{DEFAULT}{}%c", &c) != 1)

            return 0;

        ptr += ff_subtitles_next_line(ptr);

    }

    return AVPROBE_SCORE_MAX;

}

static int64_t get_pts(const char *buf)

{

    int frame;

    char c;

    if (sscanf(buf, "{%d}{%c", &frame, &c) == 2)

        return frame;

    return AV_NOPTS_VALUE;

}

static int get_duration(const char *buf)

{

    int frame_start, frame_end;

    if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2)

        return frame_end - frame_start;

    return -1;

}

static int microdvd_read_header(AVFormatContext *s)

{

    AVRational pts_info = (AVRational){ 2997, 125 };  /* default: 23.976 fps */

    MicroDVDContext *microdvd = s->priv_data;

    AVStream *st = avformat_new_stream(s, NULL);

    int i = 0;

    char line[MAX_LINESIZE];

    if (!st)

        return AVERROR(ENOMEM);

    while (!url_feof(s->pb)) {

        char *p = line;

        AVPacket *sub;

        int64_t pos = avio_tell(s->pb);

        int len = ff_get_line(s->pb, line, sizeof(line));

        if (!len)

            break;

        line[strcspn(line, "\r\n")] = 0;

        if (i++ < 3) {

            int frame;

            double fps;

            char c;

            if ((sscanf(line, "{%d}{}%6lf",    &frame, &fps) == 2 ||

                 sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2)

                && frame <= 1 && fps > 3 && fps < 100)

                pts_info = av_d2q(fps, 100000);

            if (!st->codec->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {

                st->codec->extradata = av_strdup(line + 11);

                if (!st->codec->extradata)

                    return AVERROR(ENOMEM);

                st->codec->extradata_size = strlen(st->codec->extradata) + 1;

                continue;

            }

        }

#define SKIP_FRAME_ID                                       \

    p = strchr(p, '}');                                     \

    if (!p) {                                               \

        av_log(s, AV_LOG_WARNING, "Invalid event \"%s\""    \

               " at line %d\n", line, i);                   \

        continue;                                           \

    }                                                       \

    p++

        SKIP_FRAME_ID;

        SKIP_FRAME_ID;

        if (!*p)

            continue;

        sub = ff_subtitles_queue_insert(µdvd->q, p, strlen(p), 0);

        if (!sub)

            return AVERROR(ENOMEM);

        sub->pos = pos;

        sub->pts = get_pts(line);

        sub->duration = get_duration(line);

    }

    ff_subtitles_queue_finalize(µdvd->q);

    avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);

    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

    st->codec->codec_id   = AV_CODEC_ID_MICRODVD;

    return 0;

}

static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    MicroDVDContext *microdvd = s->priv_data;

    return ff_subtitles_queue_read_packet(µdvd->q, pkt);

}

static int microdvd_read_seek(AVFormatContext *s, int stream_index,

                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

{

    MicroDVDContext *microdvd = s->priv_data;

    return ff_subtitles_queue_seek(µdvd->q, s, stream_index,

                                   min_ts, ts, max_ts, flags);

}

static int microdvd_read_close(AVFormatContext *s)

{

    MicroDVDContext *microdvd = s->priv_data;

    ff_subtitles_queue_clean(µdvd->q);

    return 0;

}

AVInputFormat ff_microdvd_demuxer = {

    .name           = "microdvd",

    .long_name      = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"),

    .priv_data_size = sizeof(MicroDVDContext),

    .read_probe     = microdvd_probe,

    .read_header    = microdvd_read_header,

    .read_packet    = microdvd_read_packet,

    .read_seek2     = microdvd_read_seek,

    .read_close     = microdvd_read_close,

};