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iss.c
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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 
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 {
42 
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 
61 static int iss_probe(AVProbeData *p)
62 {
63  if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
64  return 0;
65 
66  return AVPROBE_SCORE_MAX;
67 }
68 
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);
112  if (stereo) {
113  st->codec->channels = 2;
115  } else {
116  st->codec->channels = 1;
118  }
119  st->codec->sample_rate = 44100;
120  if(rate_divisor > 0)
121  st->codec->sample_rate /= rate_divisor;
122  st->codec->bits_per_coded_sample = 4;
123  st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
125  st->codec->block_align = iss->packet_size;
126  avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate);
127 
128  return 0;
129 }
130 
132 {
133  IssDemuxContext *iss = s->priv_data;
134  int ret = av_get_packet(s->pb, pkt, iss->packet_size);
135 
136  if(ret != iss->packet_size)
137  return AVERROR(EIO);
138 
139  pkt->stream_index = 0;
140  pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
141  if(s->streams[0]->codec->channels > 0)
142  pkt->pts /= s->streams[0]->codec->channels*2;
143  return 0;
144 }
145 
147  .name = "iss",
148  .long_name = NULL_IF_CONFIG_SMALL("Funcom ISS"),
149  .priv_data_size = sizeof(IssDemuxContext),
153 };