FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
iss.c
Go to the documentation of this file.
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 {
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  sscanf(token, "%d", &iss->packet_size);
80  get_token(pb, token, sizeof(token)); //File ID
81  get_token(pb, token, sizeof(token)); //out size
82  get_token(pb, token, sizeof(token)); //stereo
83  sscanf(token, "%d", &stereo);
84  get_token(pb, token, sizeof(token)); //Unknown1
85  get_token(pb, token, sizeof(token)); //RateDivisor
86  sscanf(token, "%d", &rate_divisor);
87  get_token(pb, token, sizeof(token)); //Unknown2
88  get_token(pb, token, sizeof(token)); //Version ID
89  get_token(pb, token, sizeof(token)); //Size
90 
91  if (iss->packet_size <= 0) {
92  av_log(s, AV_LOG_ERROR, "packet_size %d is invalid\n", iss->packet_size);
93  return AVERROR_INVALIDDATA;
94  }
95 
96  iss->sample_start_pos = avio_tell(pb);
97 
98  st = avformat_new_stream(s, NULL);
99  if (!st)
100  return AVERROR(ENOMEM);
103  if (stereo) {
104  st->codec->channels = 2;
106  } else {
107  st->codec->channels = 1;
109  }
110  st->codec->sample_rate = 44100;
111  if(rate_divisor > 0)
112  st->codec->sample_rate /= rate_divisor;
113  st->codec->bits_per_coded_sample = 4;
114  st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
116  st->codec->block_align = iss->packet_size;
117  avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate);
118 
119  return 0;
120 }
121 
123 {
124  IssDemuxContext *iss = s->priv_data;
125  int ret = av_get_packet(s->pb, pkt, iss->packet_size);
126 
127  if(ret != iss->packet_size)
128  return AVERROR(EIO);
129 
130  pkt->stream_index = 0;
131  pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
132  if(s->streams[0]->codec->channels > 0)
133  pkt->pts /= s->streams[0]->codec->channels*2;
134  return 0;
135 }
136 
138  .name = "iss",
139  .long_name = NULL_IF_CONFIG_SMALL("Funcom ISS"),
140  .priv_data_size = sizeof(IssDemuxContext),
144 };