libavformat/3dostr.c

   1 /*
   2  * 3DO STR demuxer
   3  * Copyright (c) 2015 Paul B Mahol
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avformat.h"
  23 #include "internal.h"
  24
  25 static int threedostr_probe(const AVProbeData *p)
  26 {
  27     if (memcmp(p->buf, "CTRL", 4) &&
  28         memcmp(p->buf, "SHDR", 4) &&
  29         memcmp(p->buf, "SNDS", 4))
  30         return 0;
  31
  32     return AVPROBE_SCORE_MAX / 3 * 2;
  33 }
  34
  35 static int threedostr_read_header(AVFormatContext *s)
  36 {
  37     unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;
  38     AVStream *st;
  39
  40     while (!avio_feof(s->pb) && !found_shdr) {
  41         chunk = avio_rl32(s->pb);
  42         size  = avio_rb32(s->pb);
  43
  44         if (size < 8)
  45             return AVERROR_INVALIDDATA;
  46         size -= 8;
  47
  48         switch (chunk) {
  49         case MKTAG('C','T','R','L'):
  50             ctrl_size = size;
  51             break;
  52         case MKTAG('S','N','D','S'):
  53             if (size < 56)
  54                 return AVERROR_INVALIDDATA;
  55             avio_skip(s->pb, 8);
  56             if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))
  57                 return AVERROR_INVALIDDATA;
  58             avio_skip(s->pb, 24);
  59
  60             st = avformat_new_stream(s, NULL);
  61             if (!st)
  62                 return AVERROR(ENOMEM);
  63
  64             st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
  65             st->codecpar->sample_rate = avio_rb32(s->pb);
  66             st->codecpar->channels    = avio_rb32(s->pb);
  67             if (st->codecpar->channels <= 0 || st->codecpar->sample_rate <= 0)
  68                 return AVERROR_INVALIDDATA;
  69             codec                  = avio_rl32(s->pb);
  70             avio_skip(s->pb, 4);
  71             if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)
  72                 st->duration       = (avio_rb32(s->pb) - 1) / st->codecpar->channels;
  73             else
  74                 st->duration       = avio_rb32(s->pb) * 16 / st->codecpar->channels;
  75             size -= 56;
  76             found_shdr = 1;
  77             break;
  78         case MKTAG('S','H','D','R'):
  79             if (size >  0x78) {
  80                 avio_skip(s->pb, 0x74);
  81                 size -= 0x78;
  82                 if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {
  83                     ctrl_size = avio_rb32(s->pb);
  84                     size -= 4;
  85                 }
  86             }
  87             break;
  88         default:
  89             av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
  90             break;
  91         }
  92
  93         avio_skip(s->pb, size);
  94     }
  95
  96     switch (codec) {
  97     case MKTAG('S','D','X','2'):
  98         st->codecpar->codec_id    = AV_CODEC_ID_SDX2_DPCM;
  99         st->codecpar->block_align = 1 * st->codecpar->channels;
 100         break;
 101     default:
 102         avpriv_request_sample(s, "codec %X", codec);
 103         return AVERROR_PATCHWELCOME;
 104     }
 105
 106     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
 107
 108     return 0;
 109 }
 110
 111 static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
 112 {
 113     unsigned chunk, size, found_ssmp = 0;
 114     AVStream *st = s->streams[0];
 115     int64_t pos;
 116     int ret = 0;
 117
 118     while (!found_ssmp) {
 119         if (avio_feof(s->pb))
 120             return AVERROR_EOF;
 121
 122         pos   = avio_tell(s->pb);
 123         chunk = avio_rl32(s->pb);
 124         size  = avio_rb32(s->pb);
 125
 126         if (!size)
 127             continue;
 128
 129         if (size < 8)
 130             return AVERROR_INVALIDDATA;
 131         size -= 8;
 132
 133         switch (chunk) {
 134         case MKTAG('S','N','D','S'):
 135             if (size <= 16)
 136                 return AVERROR_INVALIDDATA;
 137             avio_skip(s->pb, 8);
 138             if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))
 139                 return AVERROR_INVALIDDATA;
 140             avio_skip(s->pb, 4);
 141             size -= 16;
 142             ret = av_get_packet(s->pb, pkt, size);
 143             pkt->pos = pos;
 144             pkt->stream_index = 0;
 145             pkt->duration = size / st->codecpar->channels;
 146             size = 0;
 147             found_ssmp = 1;
 148             break;
 149         default:
 150             av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
 151             break;
 152         }
 153
 154         avio_skip(s->pb, size);
 155     }
 156
 157     return ret;
 158 }
 159
 160 AVInputFormat ff_threedostr_demuxer = {
 161     .name           = "3dostr",
 162     .long_name      = NULL_IF_CONFIG_SMALL("3DO STR"),
 163     .read_probe     = threedostr_probe,
 164     .read_header    = threedostr_read_header,
 165     .read_packet    = threedostr_read_packet,
 166     .extensions     = "str",
 167     .flags          = AVFMT_GENERIC_INDEX,
 168 };