/*
  * 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"
 
 typedef struct ASSContext{
     unsigned int extra_index;
 }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 != CODEC_ID_SSA){
         av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
         return -1;
     }
 
     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)
 {

     avio_write(s->pb, pkt->data, pkt->size);

     avio_flush(s->pb);

 
     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);
 

     avio_flush(s->pb);

 
     return 0;
 }
 

 AVOutputFormat ff_ass_muxer = {

     .name           = "ass",
     .long_name      = NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle format"),
     .mime_type      = "text/x-ssa",
     .extensions     = "ass,ssa",
     .priv_data_size = sizeof(ASSContext),

     .subtitle_codec = CODEC_ID_SSA,

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

     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS,

 };