/*
  * SSA/ASS demuxer
  * Copyright (c) 2008 Michael Niedermayer
  *
  * 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 <stdint.h>
 

 #include "avformat.h"

 #include "internal.h"

 #include "subtitles.h"

 #include "libavcodec/internal.h"

 #include "libavutil/bprint.h"

 typedef struct ASSContext {

     FFDemuxSubtitlesQueue q;

 } ASSContext;

 static int ass_probe(AVProbeData *p)

 {

     char buf[13];
     FFTextReader tr;
     ff_text_init_buf(&tr, p->buf, p->buf_size);

     ff_text_read(&tr, buf, sizeof(buf));
 
     if (!memcmp(buf, "[Script Info]", 13))

         return AVPROBE_SCORE_MAX;
 
     return 0;
 }
 

 static int ass_read_close(AVFormatContext *s)

 {
     ASSContext *ass = s->priv_data;

     ff_subtitles_queue_clean(&ass->q);

     return 0;
 }
 

 static int read_ts(const uint8_t *p, int64_t *start, int *duration)

 {

     int64_t end;
     int hh1, mm1, ss1, ms1;
     int hh2, mm2, ss2, ms2;
 
     if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
                &hh1, &mm1, &ss1, &ms1,
                &hh2, &mm2, &ss2, &ms2) == 8) {
         end    = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
         *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
         *duration = end - *start;
         return 0;
     }
     return -1;

 }
 

 static int64_t get_line(AVBPrint *buf, FFTextReader *tr)

 {

     int64_t pos = ff_text_pos(tr);

 
     av_bprint_clear(buf);
     for (;;) {

         char c = ff_text_r8(tr);

         if (!c)
             break;
         av_bprint_chars(buf, c, 1);
         if (c == '\n')
             break;
     }
     return pos;

 }
 

 static int ass_read_header(AVFormatContext *s)

 {
     ASSContext *ass = s->priv_data;

     AVBPrint header, line;
     int header_remaining, res = 0;

     AVStream *st;

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

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     avpriv_set_pts_info(st, 64, 1, 100);

     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

     st->codec->codec_id   = AV_CODEC_ID_SSA;

     header_remaining = INT_MAX;

     av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
     av_bprint_init(&line,   0, AV_BPRINT_SIZE_UNLIMITED);

     for (;;) {

         int64_t pos = get_line(&line, &tr);

         if (!line.str[0]) // EOF
             break;

         if (!memcmp(line.str, "[Events]", 8))

             header_remaining = 2;
         else if (line.str[0] == '[')
             header_remaining = INT_MAX;

         if (header_remaining) {
             av_bprintf(&header, "%s", line.str);
             header_remaining--;
         } else {
             int64_t ts_start = AV_NOPTS_VALUE;
             int duration = -1;
             AVPacket *sub;
 
             if (read_ts(line.str, &ts_start, &duration) < 0)
                 continue;
             sub = ff_subtitles_queue_insert(&ass->q, line.str, line.len, 0);
             if (!sub) {
                 res = AVERROR(ENOMEM);
                 goto end;
             }
             sub->pos = pos;
             sub->pts = ts_start;
             sub->duration = duration;
         }

     }
 

     av_bprint_finalize(&line, NULL);

     res = avpriv_bprint_to_extradata(st->codec, &header);

     if (res < 0)

         goto end;

     ff_subtitles_queue_finalize(&ass->q);

 end:
     return res;

 }
 

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

 {
     ASSContext *ass = s->priv_data;

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

 }
 

 static int ass_read_seek(AVFormatContext *s, int stream_index,
                          int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

 {
     ASSContext *ass = s->priv_data;

     return ff_subtitles_queue_seek(&ass->q, s, stream_index,
                                    min_ts, ts, max_ts, flags);

 }
 

 AVInputFormat ff_ass_demuxer = {

     .name           = "ass",

     .long_name      = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),

     .priv_data_size = sizeof(ASSContext),

     .read_probe     = ass_probe,
     .read_header    = ass_read_header,
     .read_packet    = ass_read_packet,
     .read_close     = ass_read_close,
     .read_seek2     = ass_read_seek,

 };