/*
  * AIX demuxer
  * Copyright (c) 2016 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 "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "internal.h"
 
 static int aix_probe(AVProbeData *p)
 {
     if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||
         AV_RB32(p->buf +  8) != 0x01000014 ||
         AV_RB32(p->buf + 12) != 0x00000800)
         return 0;
 
     return AVPROBE_SCORE_MAX;
 }
 
 static int aix_read_header(AVFormatContext *s)
 {
     unsigned nb_streams, first_offset, nb_segments;
     unsigned stream_list_offset;
     unsigned segment_list_offset = 0x20;
     unsigned segment_list_entry_size = 0x10;
     unsigned size;
     int i;
 
     avio_skip(s->pb, 4);
     first_offset = avio_rb32(s->pb) + 8;
     avio_skip(s->pb, 16);
     nb_segments = avio_rb16(s->pb);
     if (nb_segments == 0)
         return AVERROR_INVALIDDATA;
     stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;
     if (stream_list_offset >= first_offset)
         return AVERROR_INVALIDDATA;
     avio_seek(s->pb, stream_list_offset, SEEK_SET);
     nb_streams = avio_r8(s->pb);
     if (nb_streams == 0)
         return AVERROR_INVALIDDATA;
     avio_skip(s->pb, 7);
     for (i = 0; i < nb_streams; i++) {
         AVStream *st = avformat_new_stream(s, NULL);
 
         if (!st)
             return AVERROR(ENOMEM);

         st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
         st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_ADX;
         st->codecpar->sample_rate = avio_rb32(s->pb);
         st->codecpar->channels    = avio_r8(s->pb);
         avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);

         avio_skip(s->pb, 3);
     }
 
     avio_seek(s->pb, first_offset, SEEK_SET);
     for (i = 0; i < nb_streams; i++) {
         if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))
             return AVERROR_INVALIDDATA;
         size = avio_rb32(s->pb);
         if (size <= 8)
             return AVERROR_INVALIDDATA;
         avio_skip(s->pb, 8);

         ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);

     }
 
     return 0;
 }
 
 static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     unsigned size, index, duration, chunk;
     int64_t pos;
     int sequence, ret, i;
 
     pos = avio_tell(s->pb);
     if (avio_feof(s->pb))
         return AVERROR_EOF;
     chunk = avio_rl32(s->pb);
     size = avio_rb32(s->pb);
     if (chunk == MKTAG('A','I','X','E')) {
         avio_skip(s->pb, size);
         for (i = 0; i < s->nb_streams; i++) {
             if (avio_feof(s->pb))
                 return AVERROR_EOF;
             chunk = avio_rl32(s->pb);
             size = avio_rb32(s->pb);
             avio_skip(s->pb, size);
         }
         pos = avio_tell(s->pb);
         chunk = avio_rl32(s->pb);
         size = avio_rb32(s->pb);
     }
 
     if (chunk != MKTAG('A','I','X','P'))
         return AVERROR_INVALIDDATA;
     if (size <= 8)
         return AVERROR_INVALIDDATA;
     index = avio_r8(s->pb);
     if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)
         return AVERROR_INVALIDDATA;
     duration = avio_rb16(s->pb);
     sequence = avio_rb32(s->pb);
     if (sequence < 0) {
         avio_skip(s->pb, size - 8);
         return 0;
     }
 
     ret = av_get_packet(s->pb, pkt, size - 8);
     pkt->stream_index = index;
     pkt->duration = duration;
     pkt->pos = pos;
     return ret;
 }
 
 AVInputFormat ff_aix_demuxer = {
     .name        = "aix",
     .long_name   = NULL_IF_CONFIG_SMALL("CRI AIX"),
     .read_probe  = aix_probe,
     .read_header = aix_read_header,
     .read_packet = aix_read_packet,
     .extensions  = "aix",
     .flags       = AVFMT_GENERIC_INDEX,
 };