/*
  * SUP muxer
  * Copyright (c) 2014 Petri Hintukainen <phintuka@users.sourceforge.net>
  *
  * 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 "libavutil/intreadwrite.h"
 
 #define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
 
 static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     uint8_t *data = pkt->data;
     size_t size = pkt->size;
     uint32_t pts = 0, dts = 0;
 
     if (pkt->pts != AV_NOPTS_VALUE) {

         pts = pkt->pts;

     }
     if (pkt->dts != AV_NOPTS_VALUE) {

         dts = pkt->dts;

     }
 
     /*
       Split frame to segments.
       mkvmerge stores multiple segments in one frame.
     */
     while (size > 2) {
         size_t len = AV_RB16(data + 1) + 3;
 
         if (len > size) {

             av_log(s, AV_LOG_ERROR, "Not enough data, skipping %"SIZE_SPECIFIER" bytes\n",
                    size);

             return AVERROR_INVALIDDATA;
         }
 
         /* header */
         avio_wb16(s->pb, SUP_PGS_MAGIC);
         avio_wb32(s->pb, pts);
         avio_wb32(s->pb, dts);
 
         avio_write(s->pb, data, len);
 
         data += len;
         size -= len;
     }
 
     if (size > 0) {

         av_log(s, AV_LOG_ERROR, "Skipping %"SIZE_SPECIFIER" bytes after last segment in frame\n",
                size);

         return AVERROR_INVALIDDATA;
     }
 
     return 0;
 }
 
 static int sup_write_header(AVFormatContext *s)
 {
     if (s->nb_streams != 1) {
         av_log(s, AV_LOG_ERROR, "%s files have exactly one stream\n",
                s->oformat->name);
         return AVERROR(EINVAL);
     }
 
     avpriv_set_pts_info(s->streams[0], 32, 1, 90000);
 
     return 0;
 }
 
 AVOutputFormat ff_sup_muxer = {
     .name           = "sup",
     .long_name      = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
     .extensions     = "sup",
     .mime_type      = "application/x-pgs",
     .subtitle_codec = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
     .write_header   = sup_write_header,
     .write_packet   = sup_write_packet,
     .flags          = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
 };