/*
  * SubRip subtitle demuxer
  * 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 "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)
 {
     int i, v, num = 0;

     FFTextReader tr;

     ff_text_init_buf(&tr, p->buf, p->buf_size);

     while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
         ff_text_r8(&tr);

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

         char buf[128];
         if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
             break;

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

             && buf[0] >= '0' && buf[1] <= '9' && strstr(buf, " --> ")

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

             return AVPROBE_SCORE_MAX;

         num = atoi(buf);

     }
     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;

     FFTextReader tr;
     ff_text_init_avio(&tr, s->pb);

 
     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 (!ff_text_eof(&tr)) {
         ff_subtitles_read_text_chunk(&tr, &buf);

 
         if (buf.len) {

             int64_t pos = ff_text_pos(&tr);

             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,

 };