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/*

 * SubRip subtitle demuxer

 * Copyright (c) 2010  Aurelien Jacobs 

 *

 * 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/bprint.h"

#include "libavutil/intreadwrite.h"

typedef struct {

    FFDemuxSubtitlesQueue q;

} SRTContext;

static int srt_probe(AVProbeData *p)

{

    const unsigned char *ptr = p->buf;

    int i, v, num = 0;

    if (AV_RB24(ptr) == 0xEFBBBF)

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

    while (*ptr == '\r' || *ptr == '\n')

        ptr++;

    for (i=0; i<2; i++) {

        if ((num == i || num + 1 == i)

            && sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)

            return AVPROBE_SCORE_MAX;

        num = atoi(ptr);

        ptr += ff_subtitles_next_line(ptr);

    }

    return 0;

}

static int64_t get_pts(const char **buf, int *duration,

                       int32_t *x1, int32_t *y1, int32_t *x2, int32_t *y2)

{

    int i;

    for (i=0; i<2; i++) {

        int hh1, mm1, ss1, ms1;

        int hh2, mm2, ss2, ms2;

        if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"

                   "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",

                   &hh1, &mm1, &ss1, &ms1,

                   &hh2, &mm2, &ss2, &ms2,

                   x1, x2, y1, y2) >= 8) {

            int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;

            int64_t end   = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;

            *duration = end - start;

            *buf += ff_subtitles_next_line(*buf);

            return start;

        }

        *buf += ff_subtitles_next_line(*buf);

    }

    return AV_NOPTS_VALUE;

}

static int srt_read_header(AVFormatContext *s)

{

    SRTContext *srt = s->priv_data;

    AVBPrint buf;

    AVStream *st = avformat_new_stream(s, NULL);

    int res = 0;

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 64, 1, 1000);

    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

    st->codec->codec_id   = AV_CODEC_ID_SUBRIP;

    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);

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

        ff_subtitles_read_chunk(s->pb, &buf);

        if (buf.len) {

            int64_t pos = avio_tell(s->pb);

            int64_t pts;

            int duration;

            const char *ptr = buf.str;

            int32_t x1 = -1, y1 = -1, x2 = -1, y2 = -1;

            AVPacket *sub;

            pts = get_pts(&ptr, &duration, &x1, &y1, &x2, &y2);

            if (pts != AV_NOPTS_VALUE) {

                int len = buf.len - (ptr - buf.str);

                if (len <= 0)

                    continue;

                sub = ff_subtitles_queue_insert(&srt->q, ptr, len, 0);

                if (!sub) {

                    res = AVERROR(ENOMEM);

                    goto end;

                }

                sub->pos = pos;

                sub->pts = pts;

                sub->duration = duration;

                if (x1 != -1) {

                    uint8_t *p = av_packet_new_side_data(sub, AV_PKT_DATA_SUBTITLE_POSITION, 16);

                    if (p) {

                        AV_WL32(p,      x1);

                        AV_WL32(p +  4, y1);

                        AV_WL32(p +  8, x2);

                        AV_WL32(p + 12, y2);

                    }

                }

            }

        }

    }

    ff_subtitles_queue_finalize(&srt->q);

end:

    av_bprint_finalize(&buf, NULL);

    return res;

}

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

{

    SRTContext *srt = s->priv_data;

    return ff_subtitles_queue_read_packet(&srt->q, pkt);

}

static int srt_read_seek(AVFormatContext *s, int stream_index,

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

{

    SRTContext *srt = s->priv_data;

    return ff_subtitles_queue_seek(&srt->q, s, stream_index,

                                   min_ts, ts, max_ts, flags);

}

static int srt_read_close(AVFormatContext *s)

{

    SRTContext *srt = s->priv_data;

    ff_subtitles_queue_clean(&srt->q);

    return 0;

}

AVInputFormat ff_srt_demuxer = {

    .name        = "srt",

    .long_name   = NULL_IF_CONFIG_SMALL("SubRip subtitle"),

    .priv_data_size = sizeof(SRTContext),

    .read_probe  = srt_probe,

    .read_header = srt_read_header,

    .read_packet = srt_read_packet,

    .read_seek2  = srt_read_seek,

    .read_close  = srt_read_close,

};