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