libavformat/sol.c

   1 /*
   2  * Sierra SOL demuxer
   3  * Copyright Konstantin Shishkov
   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 /*
  23  * Based on documents from Game Audio Player and own research
  24  */
  25
  26 #include "libavutil/bswap.h"
  27 #include "avformat.h"
  28 #include "raw.h"
  29
  30 /* if we don't know the size in advance */
  31 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
  32
  33 static int sol_probe(AVProbeData *p)
  34 {
  35     /* check file header */
  36     uint16_t magic;
  37     magic=le2me_16(*((uint16_t*)p->buf));
  38     if ((magic == 0x0B8D || magic == 0x0C0D || magic == 0x0C8D) &&
  39         p->buf[2] == 'S' && p->buf[3] == 'O' &&
  40         p->buf[4] == 'L' && p->buf[5] == 0)
  41         return AVPROBE_SCORE_MAX;
  42     else
  43         return 0;
  44 }
  45
  46 #define SOL_DPCM    1
  47 #define SOL_16BIT   4
  48 #define SOL_STEREO 16
  49
  50 static enum CodecID sol_codec_id(int magic, int type)
  51 {
  52     if (magic == 0x0B8D)
  53     {
  54         if (type & SOL_DPCM) return CODEC_ID_SOL_DPCM;
  55         else return CODEC_ID_PCM_U8;
  56     }
  57     if (type & SOL_DPCM)
  58     {
  59         if (type & SOL_16BIT) return CODEC_ID_SOL_DPCM;
  60         else if (magic == 0x0C8D) return CODEC_ID_SOL_DPCM;
  61         else return CODEC_ID_SOL_DPCM;
  62     }
  63     if (type & SOL_16BIT) return CODEC_ID_PCM_S16LE;
  64     return CODEC_ID_PCM_U8;
  65 }
  66
  67 static int sol_codec_type(int magic, int type)
  68 {
  69     if (magic == 0x0B8D) return 1;//SOL_DPCM_OLD;
  70     if (type & SOL_DPCM)
  71     {
  72         if (type & SOL_16BIT) return 3;//SOL_DPCM_NEW16;
  73         else if (magic == 0x0C8D) return 1;//SOL_DPCM_OLD;
  74         else return 2;//SOL_DPCM_NEW8;
  75     }
  76     return -1;
  77 }
  78
  79 static int sol_channels(int magic, int type)
  80 {
  81     if (magic == 0x0B8D || !(type & SOL_STEREO)) return 1;
  82     return 2;
  83 }
  84
  85 static int sol_read_header(AVFormatContext *s,
  86                           AVFormatParameters *ap)
  87 {
  88     int size;
  89     unsigned int magic,tag;
  90     ByteIOContext *pb = s->pb;
  91     unsigned int id, channels, rate, type;
  92     enum CodecID codec;
  93     AVStream *st;
  94
  95     /* check ".snd" header */
  96     magic = get_le16(pb);
  97     tag = get_le32(pb);
  98     if (tag != MKTAG('S', 'O', 'L', 0))
  99         return -1;
 100     rate = get_le16(pb);
 101     type = get_byte(pb);
 102     size = get_le32(pb);
 103     if (magic != 0x0B8D)
 104         get_byte(pb); /* newer SOLs contain padding byte */
 105
 106     codec = sol_codec_id(magic, type);
 107     channels = sol_channels(magic, type);
 108
 109     if (codec == CODEC_ID_SOL_DPCM)
 110         id = sol_codec_type(magic, type);
 111     else id = 0;
 112
 113     /* now we are ready: build format streams */
 114     st = av_new_stream(s, 0);
 115     if (!st)
 116         return -1;
 117     st->codec->codec_type = CODEC_TYPE_AUDIO;
 118     st->codec->codec_tag = id;
 119     st->codec->codec_id = codec;
 120     st->codec->channels = channels;
 121     st->codec->sample_rate = rate;
 122     av_set_pts_info(st, 64, 1, rate);
 123     return 0;
 124 }
 125
 126 #define MAX_SIZE 4096
 127
 128 static int sol_read_packet(AVFormatContext *s,
 129                           AVPacket *pkt)
 130 {
 131     int ret;
 132
 133     if (url_feof(s->pb))
 134         return AVERROR(EIO);
 135     ret= av_get_packet(s->pb, pkt, MAX_SIZE);
 136     pkt->stream_index = 0;
 137
 138     /* note: we need to modify the packet size here to handle the last
 139        packet */
 140     pkt->size = ret;
 141     return 0;
 142 }
 143
 144 AVInputFormat sol_demuxer = {
 145     "sol",
 146     NULL_IF_CONFIG_SMALL("Sierra SOL format"),
 147     0,
 148     sol_probe,
 149     sol_read_header,
 150     sol_read_packet,
 151     NULL,
 152     pcm_read_seek,
 153 };