1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/* ScummVM - Scumm Interpreter
* Copyright (C) 2005 The ScummVM project
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*
*/
#include "stdafx.h"
#include "common/util.h"
#include "common/stream.h"
#include "sound/audiostream.h"
#include "sound/mixer.h"
#include "sound/wave.h"
#include "sound/adpcm.h"
bool loadWAVFromStream(Common::SeekableReadStream &stream, int &size, int &rate, byte &flags, uint16 *wavType) {
const uint32 initialPos = stream.pos();
byte buf[4+1];
buf[4] = 0;
stream.read(buf, 4);
if (memcmp(buf, "RIFF", 4) != 0) {
warning("getWavInfo: No 'RIFF' header");
return false;
}
uint32 wavLength = stream.readUint32LE();
stream.read(buf, 4);
if (memcmp(buf, "WAVE", 4) != 0) {
warning("getWavInfo: No 'WAVE' header");
return false;
}
stream.read(buf, 4);
if (memcmp(buf, "fmt ", 4) != 0) {
warning("getWavInfo: No 'fmt' header");
return false;
}
uint32 fmtLength = stream.readUint32LE();
if (fmtLength < 16) {
// A valid fmt chunk always contains at least 16 bytes
warning("getWavInfo: 'fmt' header is too short");
return false;
}
// Next comes the "type" field of the fmt header. Some typical
// values for it:
// 1 -> uncompressed PCM
// 17 -> IMA ADPCM compressed WAVE
// See <http://www.saettler.com/RIFFNEW/RIFFNEW.htm> for a more complete
// list of common WAVE compression formats...
uint16 type = stream.readUint16LE(); // == 1 for PCM data
uint16 numChannels = stream.readUint16LE(); // 1 for mono, 2 for stereo
uint32 samplesPerSec = stream.readUint32LE(); // in Hz
uint32 avgBytesPerSec = stream.readUint32LE(); // == SampleRate * NumChannels * BitsPerSample/8
uint16 blockAlign = stream.readUint16LE(); // == NumChannels * BitsPerSample/8
uint16 bitsPerSample = stream.readUint16LE(); // 8, 16 ...
// 8 bit data is unsigned, 16 bit data signed
if (wavType != 0)
*wavType = type;
#if 0
printf("WAVE information:\n");
printf(" total size: %d\n", wavLength);
printf(" fmt size: %d\n", fmtLength);
printf(" type: %d\n", type);
printf(" numChannels: %d\n", numChannels);
printf(" samplesPerSec: %d\n", samplesPerSec);
printf(" avgBytesPerSec: %d\n", avgBytesPerSec);
printf(" blockAlign: %d\n", blockAlign);
printf(" bitsPerSample: %d\n", bitsPerSample);
#endif
if (type != 1 && type != 17) {
warning("getWavInfo: only PCM or IMA ADPCM data is supported (type %d)", type);
return false;
}
if (blockAlign != numChannels * bitsPerSample / 8) {
debug(0, "getWavInfo: blockAlign is invalid");
}
if (avgBytesPerSec != samplesPerSec * blockAlign) {
debug(0, "getWavInfo: avgBytesPerSec is invalid");
}
// Prepare the return values.
rate = samplesPerSec;
flags = 0;
if (bitsPerSample == 8) // 8 bit data is unsigned
flags |= Audio::Mixer::FLAG_UNSIGNED;
else if (bitsPerSample == 16) // 16 bit data is signed little endian
flags |= (Audio::Mixer::FLAG_16BITS | Audio::Mixer::FLAG_LITTLE_ENDIAN);
else if (bitsPerSample == 4 && type == 17) // IMA ADPCM compressed. We decompress it
flags |= (Audio::Mixer::FLAG_16BITS | Audio::Mixer::FLAG_LITTLE_ENDIAN);
else {
warning("getWavInfo: unsupported bitsPerSample %d", bitsPerSample);
return false;
}
if (numChannels == 2)
flags |= Audio::Mixer::FLAG_STEREO;
else if (numChannels != 1) {
warning("getWavInfo: unsupported number of channels %d", numChannels);
return false;
}
// It's almost certainly a WAV file, but we still need to find its
// 'data' chunk.
// Skip over the rest of the fmt chunk.
int offset = fmtLength - 16;
do {
stream.seek(offset, SEEK_CUR);
if (stream.pos() >= initialPos + wavLength + 8) {
warning("getWavInfo: Can't find 'data' chunk");
return false;
}
stream.read(buf, 4);
offset = stream.readUint32LE();
#if 0
printf(" found a '%s' tag of size %d\n", buf, offset);
#endif
} while (memcmp(buf, "data", 4) != 0);
// Stream now points at 'offset' bytes of sample data...
size = offset;
return true;
}
AudioStream *makeWAVStream(Common::SeekableReadStream &stream) {
int size, rate;
byte flags;
uint16 type;
if (!loadWAVFromStream(stream, size, rate, flags, &type))
return 0;
if (type == 17) // IMA ADPCM
return makeADPCMStream(stream, size, kADPCMIma);
byte *data = (byte *)malloc(size);
assert(data);
stream.read(data, size);
flags |= Audio::Mixer::FLAG_AUTOFREE;
return makeLinearInputStream(rate, flags, data, size, 0, 0);
}
|
