/*
  * 3DO STR demuxer
  * Copyright (c) 2015 Paul B Mahol
  *
  * 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"
 
 static int threedostr_probe(AVProbeData *p)
 {
     if (memcmp(p->buf, "CTRL", 4) &&
         memcmp(p->buf, "SHDR", 4) &&
         memcmp(p->buf, "SNDS", 4))
         return 0;
 
     return AVPROBE_SCORE_MAX / 3 * 2;
 }
 
 static int threedostr_read_header(AVFormatContext *s)
 {
     unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;
     AVStream *st;
 
     while (!avio_feof(s->pb) && !found_shdr) {
         chunk = avio_rl32(s->pb);
         size  = avio_rb32(s->pb);
 
         if (size < 8)
             return AVERROR_INVALIDDATA;
         size -= 8;
 
         switch (chunk) {
         case MKTAG('C','T','R','L'):
             ctrl_size = size;
             break;
         case MKTAG('S','N','D','S'):
             if (size < 56)
                 return AVERROR_INVALIDDATA;
             avio_skip(s->pb, 8);
             if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))
                 return AVERROR_INVALIDDATA;
             avio_skip(s->pb, 24);
 
             st = avformat_new_stream(s, NULL);
             if (!st)
                 return AVERROR(ENOMEM);
 
             st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
             st->codec->sample_rate = avio_rb32(s->pb);
             st->codec->channels    = avio_rb32(s->pb);
             if (st->codec->channels <= 0)
                 return AVERROR_INVALIDDATA;
             codec                  = avio_rl32(s->pb);
             avio_skip(s->pb, 4);
             if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)
                 st->duration       = (avio_rb32(s->pb) - 1) / st->codec->channels;
             else
                 st->duration       = avio_rb32(s->pb) * 16 / st->codec->channels;
             size -= 56;
             found_shdr = 1;
             break;
         case MKTAG('S','H','D','R'):
             if (size >  0x78) {
                 avio_skip(s->pb, 0x74);
                 size -= 0x78;
                 if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {
                     ctrl_size = avio_rb32(s->pb);

                     size -= 4;

                 }
             }
             break;
         default:
             av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
             break;
         }
 
         avio_skip(s->pb, size);
     }
 
     switch (codec) {
     case MKTAG('S','D','X','2'):
         st->codec->codec_id    = AV_CODEC_ID_SDX2_DPCM;
         st->codec->block_align = 1 * st->codec->channels;
         break;
     default:
         avpriv_request_sample(s, "codec %X", codec);
         return AVERROR_PATCHWELCOME;
     }
 
     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 
     return 0;
 }
 
 static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     unsigned chunk, size, found_ssmp = 0;
     AVStream *st = s->streams[0];
     int64_t pos;
     int ret = 0;
 
     while (!found_ssmp) {
         if (avio_feof(s->pb))
             return AVERROR_EOF;
 
         pos   = avio_tell(s->pb);
         chunk = avio_rl32(s->pb);
         size  = avio_rb32(s->pb);
 
         if (!size)
             continue;
 
         if (size < 8)
             return AVERROR_INVALIDDATA;
         size -= 8;
 
         switch (chunk) {
         case MKTAG('S','N','D','S'):
             if (size <= 16)
                 return AVERROR_INVALIDDATA;
             avio_skip(s->pb, 8);
             if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))
                 return AVERROR_INVALIDDATA;
             avio_skip(s->pb, 4);
             size -= 16;
             ret = av_get_packet(s->pb, pkt, size);
             pkt->pos = pos;
             pkt->stream_index = 0;
             pkt->duration = size / st->codec->channels;
             size = 0;
             found_ssmp = 1;
             break;
         default:
             av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
             break;
         }
 
         avio_skip(s->pb, size);
     }
 
     return ret;
 }
 
 AVInputFormat ff_threedostr_demuxer = {
     .name           = "3dostr",
     .long_name      = NULL_IF_CONFIG_SMALL("3DO STR"),
     .read_probe     = threedostr_probe,
     .read_header    = threedostr_read_header,
     .read_packet    = threedostr_read_packet,
     .extensions     = "str",
     .flags          = AVFMT_GENERIC_INDEX,
 };