/*
  * SSA/ASS muxer
  * 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 "avformat.h"

 #include "internal.h"

 
 typedef struct ASSContext{
     unsigned int extra_index;

     int write_ts; // 0: ssa (timing in payload), 1: ass (matroska like)

 }ASSContext;
 
 static int write_header(AVFormatContext *s)
 {
     ASSContext *ass = s->priv_data;
     AVCodecContext *avctx= s->streams[0]->codec;
     uint8_t *last= NULL;
 

     if (s->nb_streams != 1 || (avctx->codec_id != AV_CODEC_ID_SSA &&
                                avctx->codec_id != AV_CODEC_ID_ASS)) {

         av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
         return -1;
     }

     ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS;
     avpriv_set_pts_info(s->streams[0], 64, 1, 100);

 
     while(ass->extra_index < avctx->extradata_size){
         uint8_t *p  = avctx->extradata + ass->extra_index;
         uint8_t *end= strchr(p, '\n');
         if(!end) end= avctx->extradata + avctx->extradata_size;
         else     end++;
 

         avio_write(s->pb, p, end-p);

         ass->extra_index += end-p;
 
         if(last && !memcmp(last, "[Events]", 8))
             break;
         last=p;
     }
 

     avio_flush(s->pb);

 
     return 0;
 }
 
 static int write_packet(AVFormatContext *s, AVPacket *pkt)
 {

     ASSContext *ass = s->priv_data;
 
     if (ass->write_ts) {
         long int layer;
         char *p;
         int64_t start = pkt->pts;
         int64_t end   = start + pkt->duration;
         int hh1, mm1, ss1, ms1;
         int hh2, mm2, ss2, ms2;
 
         p = pkt->data + strcspn(pkt->data, ",") + 1; // skip ReadOrder
         layer = strtol(p, &p, 10);
         if (*p == ',')
             p++;
         hh1 = (int)(start / 360000);    mm1 = (int)(start / 6000) % 60;
         hh2 = (int)(end   / 360000);    mm2 = (int)(end   / 6000) % 60;
         ss1 = (int)(start / 100) % 60;  ms1 = (int)(start % 100);
         ss2 = (int)(end   / 100) % 60;  ms2 = (int)(end   % 100);
         if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
         if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
         avio_printf(s->pb, "Dialogue: %ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
                     layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p);
     } else {
         avio_write(s->pb, pkt->data, pkt->size);
     }

     return 0;
 }
 
 static int write_trailer(AVFormatContext *s)
 {
     ASSContext *ass = s->priv_data;
     AVCodecContext *avctx= s->streams[0]->codec;
 

     avio_write(s->pb, avctx->extradata      + ass->extra_index,

                       avctx->extradata_size - ass->extra_index);
 
     return 0;
 }
 

 AVOutputFormat ff_ass_muxer = {

     .name           = "ass",

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

     .mime_type      = "text/x-ssa",
     .extensions     = "ass,ssa",
     .priv_data_size = sizeof(ASSContext),

     .subtitle_codec = AV_CODEC_ID_SSA,

     .write_header   = write_header,
     .write_packet   = write_packet,
     .write_trailer  = write_trailer,

     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT,

 };