/*

 * 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

 */

/**

 * @file

 * AQTitle subtitles format demuxer

 *

 * @see http://web.archive.org/web/20070210095721/http://www.volny.cz/aberka/czech/aqt.html

 * @see https://trac.annodex.net/wiki/AQTitle

 */

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#include "subtitles.h"

#include "libavutil/opt.h"

typedef struct {

    const AVClass *class;

    FFDemuxSubtitlesQueue q;

    AVRational frame_rate;

} AQTitleContext;

static int aqt_probe(const AVProbeData *p)

{

    int frame;

    const char *ptr = p->buf;

    if (sscanf(ptr, "-->> %d", &frame) == 1)

        return AVPROBE_SCORE_EXTENSION;

    return 0;

}

static int aqt_read_header(AVFormatContext *s)

{

    AQTitleContext *aqt = s->priv_data;

    AVStream *st = avformat_new_stream(s, NULL);

    int new_event = 1;

    int64_t pos = 0, frame = AV_NOPTS_VALUE;

    AVPacket *sub = NULL;

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 64, aqt->frame_rate.den, aqt->frame_rate.num);

    st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;

    st->codecpar->codec_id   = AV_CODEC_ID_TEXT;

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

        char line[4096];

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

        if (!len)

            break;

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

        if (sscanf(line, "-->> %"SCNd64, &frame) == 1) {

            new_event = 1;

            pos = avio_tell(s->pb);

            if (sub) {

                if (frame >= sub->pts && (uint64_t)frame - sub->pts < INT64_MAX)

                    sub->duration = frame - sub->pts;

                sub = NULL;

            }

        } else if (*line) {

            if (!new_event) {

                sub = ff_subtitles_queue_insert(&aqt->q, "\n", 1, 1);

                if (!sub)

                    return AVERROR(ENOMEM);

            }

            sub = ff_subtitles_queue_insert(&aqt->q, line, strlen(line), !new_event);

            if (!sub)

                return AVERROR(ENOMEM);

            if (new_event) {

                sub->pts = frame;

                sub->duration = -1;

                sub->pos = pos;

            }

            new_event = 0;

        }

    }

    ff_subtitles_queue_finalize(s, &aqt->q);

    return 0;

}

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

{

    AQTitleContext *aqt = s->priv_data;

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

}

static int aqt_read_seek(AVFormatContext *s, int stream_index,

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

{

    AQTitleContext *aqt = s->priv_data;

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

                                   min_ts, ts, max_ts, flags);

}

static int aqt_read_close(AVFormatContext *s)

{

    AQTitleContext *aqt = s->priv_data;

    ff_subtitles_queue_clean(&aqt->q);

    return 0;

}

#define OFFSET(x) offsetof(AQTitleContext, x)

#define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM

static const AVOption aqt_options[] = {

    { "subfps", "set the movie frame rate", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=25}, 0, INT_MAX, SD },

    { NULL }

};

static const AVClass aqt_class = {

    .class_name = "aqtdec",

    .item_name  = av_default_item_name,

    .option     = aqt_options,

    .version    = LIBAVUTIL_VERSION_INT,

};

const FFInputFormat ff_aqtitle_demuxer = {

    .p.name         = "aqtitle",

    .p.long_name    = NULL_IF_CONFIG_SMALL("AQTitle subtitles"),

    .p.extensions   = "aqt",

    .p.priv_class   = &aqt_class,

    .priv_data_size = sizeof(AQTitleContext),

    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,

    .read_probe     = aqt_probe,

    .read_header    = aqt_read_header,

    .read_packet    = aqt_read_packet,

    .read_seek2     = aqt_read_seek,

    .read_close     = aqt_read_close,

};