libavformat/iss.c

   1 /*
   2  * ISS (.iss) file demuxer
   3  * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
   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  * @file
  24  * Funcom ISS file demuxer
  25  * @author Jaikrishnan Menon
  26  * @see http://wiki.multimedia.cx/index.php?title=FunCom_ISS
  27  */
  28
  29 #include "libavutil/channel_layout.h"
  30 #include "avformat.h"
  31 #include "demux.h"
  32 #include "internal.h"
  33 #include "libavutil/avstring.h"
  34
  35 #define ISS_SIG "IMA_ADPCM_Sound"
  36 #define ISS_SIG_LEN 15
  37 #define MAX_TOKEN_SIZE 20
  38
  39 typedef struct IssDemuxContext {
  40     int packet_size;
  41     int sample_start_pos;
  42 } IssDemuxContext;
  43
  44 static void get_token(AVIOContext *s, char *buf, int maxlen)
  45 {
  46     int i = 0;
  47     char c;
  48
  49     while ((c = avio_r8(s))) {
  50         if(c == ' ')
  51             break;
  52         if (i < maxlen-1)
  53             buf[i++] = c;
  54     }
  55
  56     if(!c)
  57         avio_r8(s);
  58
  59     buf[i] = 0; /* Ensure null terminated, but may be truncated */
  60 }
  61
  62 static int iss_probe(const AVProbeData *p)
  63 {
  64     if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
  65         return 0;
  66
  67     return AVPROBE_SCORE_MAX;
  68 }
  69
  70 static av_cold int iss_read_header(AVFormatContext *s)
  71 {
  72     IssDemuxContext *iss = s->priv_data;
  73     AVIOContext *pb = s->pb;
  74     AVStream *st;
  75     char token[MAX_TOKEN_SIZE];
  76     int stereo, rate_divisor;
  77
  78     get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound"
  79     get_token(pb, token, sizeof(token)); //packet size
  80     if (sscanf(token, "%d", &iss->packet_size) != 1) {
  81         av_log(s, AV_LOG_ERROR, "Failed parsing packet size\n");
  82         return AVERROR_INVALIDDATA;
  83     }
  84     get_token(pb, token, sizeof(token)); //File ID
  85     get_token(pb, token, sizeof(token)); //out size
  86     get_token(pb, token, sizeof(token)); //stereo
  87     if (sscanf(token, "%d", &stereo) != 1) {
  88         av_log(s, AV_LOG_ERROR, "Failed parsing stereo flag\n");
  89         return AVERROR_INVALIDDATA;
  90     }
  91     get_token(pb, token, sizeof(token)); //Unknown1
  92     get_token(pb, token, sizeof(token)); //RateDivisor
  93     if (sscanf(token, "%d", &rate_divisor) != 1) {
  94         av_log(s, AV_LOG_ERROR, "Failed parsing rate_divisor\n");
  95         return AVERROR_INVALIDDATA;
  96     }
  97     get_token(pb, token, sizeof(token)); //Unknown2
  98     get_token(pb, token, sizeof(token)); //Version ID
  99     get_token(pb, token, sizeof(token)); //Size
 100
 101     if (iss->packet_size <= 0) {
 102         av_log(s, AV_LOG_ERROR, "packet_size %d is invalid\n", iss->packet_size);
 103         return AVERROR_INVALIDDATA;
 104     }
 105
 106     iss->sample_start_pos = avio_tell(pb);
 107
 108     st = avformat_new_stream(s, NULL);
 109     if (!st)
 110         return AVERROR(ENOMEM);
 111     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 112     st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_ISS;
 113
 114     if (stereo) {
 115         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
 116     } else {
 117         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
 118     }
 119
 120     st->codecpar->sample_rate = 44100;
 121     if(rate_divisor > 0)
 122          st->codecpar->sample_rate /= rate_divisor;
 123     st->codecpar->bits_per_coded_sample = 4;
 124     st->codecpar->bit_rate = st->codecpar->ch_layout.nb_channels *
 125                              st->codecpar->sample_rate *
 126                              st->codecpar->bits_per_coded_sample;
 127     st->codecpar->block_align = iss->packet_size;
 128     avpriv_set_pts_info(st, 32, 1, st->codecpar->sample_rate);
 129
 130     return 0;
 131 }
 132
 133 static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
 134 {
 135     IssDemuxContext *iss = s->priv_data;
 136     int ret = av_get_packet(s->pb, pkt, iss->packet_size);
 137
 138     if(ret != iss->packet_size)
 139         return AVERROR_INVALIDDATA;
 140
 141     pkt->stream_index = 0;
 142     pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
 143     if (s->streams[0]->codecpar->ch_layout.nb_channels > 0)
 144         pkt->pts /= s->streams[0]->codecpar->ch_layout.nb_channels * 2;
 145     return 0;
 146 }
 147
 148 const FFInputFormat ff_iss_demuxer = {
 149     .p.name         = "iss",
 150     .p.long_name    = NULL_IF_CONFIG_SMALL("Funcom ISS"),
 151     .priv_data_size = sizeof(IssDemuxContext),
 152     .read_probe     = iss_probe,
 153     .read_header    = iss_read_header,
 154     .read_packet    = iss_read_packet,
 155 };