libavformat/sol.c
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00001 /*
00002  * Sierra SOL demuxer
00003  * Copyright Konstantin Shishkov
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 /*
00023  * Based on documents from Game Audio Player and own research
00024  */
00025 
00026 #include "libavutil/intreadwrite.h"
00027 #include "avformat.h"
00028 #include "internal.h"
00029 #include "pcm.h"
00030 
00031 /* if we don't know the size in advance */
00032 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
00033 
00034 static int sol_probe(AVProbeData *p)
00035 {
00036     /* check file header */
00037     uint16_t magic = AV_RL32(p->buf);
00038     if ((magic == 0x0B8D || magic == 0x0C0D || magic == 0x0C8D) &&
00039         p->buf[2] == 'S' && p->buf[3] == 'O' &&
00040         p->buf[4] == 'L' && p->buf[5] == 0)
00041         return AVPROBE_SCORE_MAX;
00042     else
00043         return 0;
00044 }
00045 
00046 #define SOL_DPCM    1
00047 #define SOL_16BIT   4
00048 #define SOL_STEREO 16
00049 
00050 static enum CodecID sol_codec_id(int magic, int type)
00051 {
00052     if (magic == 0x0B8D)
00053     {
00054         if (type & SOL_DPCM) return CODEC_ID_SOL_DPCM;
00055         else return CODEC_ID_PCM_U8;
00056     }
00057     if (type & SOL_DPCM)
00058     {
00059         if (type & SOL_16BIT) return CODEC_ID_SOL_DPCM;
00060         else if (magic == 0x0C8D) return CODEC_ID_SOL_DPCM;
00061         else return CODEC_ID_SOL_DPCM;
00062     }
00063     if (type & SOL_16BIT) return CODEC_ID_PCM_S16LE;
00064     return CODEC_ID_PCM_U8;
00065 }
00066 
00067 static int sol_codec_type(int magic, int type)
00068 {
00069     if (magic == 0x0B8D) return 1;//SOL_DPCM_OLD;
00070     if (type & SOL_DPCM)
00071     {
00072         if (type & SOL_16BIT) return 3;//SOL_DPCM_NEW16;
00073         else if (magic == 0x0C8D) return 1;//SOL_DPCM_OLD;
00074         else return 2;//SOL_DPCM_NEW8;
00075     }
00076     return -1;
00077 }
00078 
00079 static int sol_channels(int magic, int type)
00080 {
00081     if (magic == 0x0B8D || !(type & SOL_STEREO)) return 1;
00082     return 2;
00083 }
00084 
00085 static int sol_read_header(AVFormatContext *s,
00086                           AVFormatParameters *ap)
00087 {
00088     unsigned int magic,tag;
00089     AVIOContext *pb = s->pb;
00090     unsigned int id, channels, rate, type;
00091     enum CodecID codec;
00092     AVStream *st;
00093 
00094     /* check ".snd" header */
00095     magic = avio_rl16(pb);
00096     tag = avio_rl32(pb);
00097     if (tag != MKTAG('S', 'O', 'L', 0))
00098         return -1;
00099     rate = avio_rl16(pb);
00100     type = avio_r8(pb);
00101     avio_skip(pb, 4); /* size */
00102     if (magic != 0x0B8D)
00103         avio_r8(pb); /* newer SOLs contain padding byte */
00104 
00105     codec = sol_codec_id(magic, type);
00106     channels = sol_channels(magic, type);
00107 
00108     if (codec == CODEC_ID_SOL_DPCM)
00109         id = sol_codec_type(magic, type);
00110     else id = 0;
00111 
00112     /* now we are ready: build format streams */
00113     st = avformat_new_stream(s, NULL);
00114     if (!st)
00115         return -1;
00116     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00117     st->codec->codec_tag = id;
00118     st->codec->codec_id = codec;
00119     st->codec->channels = channels;
00120     st->codec->sample_rate = rate;
00121     avpriv_set_pts_info(st, 64, 1, rate);
00122     return 0;
00123 }
00124 
00125 #define MAX_SIZE 4096
00126 
00127 static int sol_read_packet(AVFormatContext *s,
00128                           AVPacket *pkt)
00129 {
00130     int ret;
00131 
00132     if (s->pb->eof_reached)
00133         return AVERROR(EIO);
00134     ret= av_get_packet(s->pb, pkt, MAX_SIZE);
00135     if (ret < 0)
00136         return ret;
00137     pkt->stream_index = 0;
00138 
00139     /* note: we need to modify the packet size here to handle the last
00140        packet */
00141     pkt->size = ret;
00142     return 0;
00143 }
00144 
00145 AVInputFormat ff_sol_demuxer = {
00146     .name           = "sol",
00147     .long_name      = NULL_IF_CONFIG_SMALL("Sierra SOL format"),
00148     .read_probe     = sol_probe,
00149     .read_header    = sol_read_header,
00150     .read_packet    = sol_read_packet,
00151     .read_seek      = pcm_read_seek,
00152 };