/*

 * SubRip subtitle decoder

 * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>

 *

 * 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 "config_components.h"

#include "libavutil/avstring.h"

#include "libavutil/common.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/parseutils.h"

#include "avcodec.h"

#include "ass.h"

#include "codec_internal.h"

#include "htmlsubtitles.h"

static int srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,

                       const char *in, int x1, int y1, int x2, int y2)

{

    if (x1 >= 0 && y1 >= 0) {

        /* XXX: here we rescale coordinate assuming they are in DVD resolution

         * (720x480) since we don't have anything better */

        if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1) && x2 >= x1 && y2 >= y1) {

            /* text rectangle defined, write the text at the center of the rectangle */

            const int cx = x1 + (x2 - x1)/2;

            const int cy = y1 + (y2 - y1)/2;

            const int scaled_x = cx * (int64_t)ASS_DEFAULT_PLAYRESX / 720;

            const int scaled_y = cy * (int64_t)ASS_DEFAULT_PLAYRESY / 480;

            av_bprintf(dst, "{\\an5}{\\pos(%d,%d)}", scaled_x, scaled_y);

        } else {

            /* only the top left corner, assume the text starts in that corner */

            const int scaled_x = x1 * (int64_t)ASS_DEFAULT_PLAYRESX / 720;

            const int scaled_y = y1 * (int64_t)ASS_DEFAULT_PLAYRESY / 480;

            av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", scaled_x, scaled_y);

        }

    }

    return ff_htmlmarkup_to_ass(avctx, dst, in);

}

static int srt_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,

                            int *got_sub_ptr, const AVPacket *avpkt)

{

    AVBPrint buffer;

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

    int ret;

    size_t size;

    const uint8_t *p = av_packet_get_side_data(avpkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);

    FFASSDecoderContext *s = avctx->priv_data;

    if (p && size == 16) {

        x1 = AV_RL32(p     );

        y1 = AV_RL32(p +  4);

        x2 = AV_RL32(p +  8);

        y2 = AV_RL32(p + 12);

    }

    if (avpkt->size <= 0)

        return avpkt->size;

    av_bprint_init(&buffer, 0, AV_BPRINT_SIZE_UNLIMITED);

    ret = srt_to_ass(avctx, &buffer, avpkt->data, x1, y1, x2, y2);

    if (ret >= 0)

        ret = ff_ass_add_rect(sub, buffer.str, s->readorder++, 0, NULL, NULL);

    av_bprint_finalize(&buffer, NULL);

    if (ret < 0)

        return ret;

    *got_sub_ptr = sub->num_rects > 0;

    return avpkt->size;

}

#if CONFIG_SRT_DECODER

/* deprecated decoder */

const FFCodec ff_srt_decoder = {

    .p.name       = "srt",

    CODEC_LONG_NAME("SubRip subtitle"),

    .p.type       = AVMEDIA_TYPE_SUBTITLE,

    .p.id         = AV_CODEC_ID_SUBRIP,

    .init         = ff_ass_subtitle_header_default,

    FF_CODEC_DECODE_SUB_CB(srt_decode_frame),

    .flush        = ff_ass_decoder_flush,

    .priv_data_size = sizeof(FFASSDecoderContext),

};

#endif

#if CONFIG_SUBRIP_DECODER

const FFCodec ff_subrip_decoder = {

    .p.name       = "subrip",

    CODEC_LONG_NAME("SubRip subtitle"),

    .p.type       = AVMEDIA_TYPE_SUBTITLE,

    .p.id         = AV_CODEC_ID_SUBRIP,

    .init         = ff_ass_subtitle_header_default,

    FF_CODEC_DECODE_SUB_CB(srt_decode_frame),

    .flush        = ff_ass_decoder_flush,

    .priv_data_size = sizeof(FFASSDecoderContext),

};

#endif