1 /* ScummVM - Graphic Adventure Engine
2 *
3 * ScummVM is the legal property of its developers, whose names
4 * are too numerous to list here. Please refer to the COPYRIGHT
5 * file distributed with this source distribution.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program 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
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 */
22
23 #include "bladerunner/aud_stream.h"
24
25 #include "bladerunner/audio_cache.h"
26
27 #include "common/util.h"
28
29 namespace BladeRunner {
30
AudStream(byte * data,int overrideFrequency)31 AudStream::AudStream(byte *data, int overrideFrequency) {
32 _hash = 0;
33 _cache = nullptr;
34 _overrideFrequency = overrideFrequency;
35
36 init(data);
37 }
38
AudStream(AudioCache * cache,int32 hash,int overrideFrequency)39 AudStream::AudStream(AudioCache *cache, int32 hash, int overrideFrequency) {
40 assert(cache != nullptr);
41
42 _cache = cache;
43 _hash = hash;
44 _overrideFrequency = overrideFrequency;
45
46 _cache->incRef(_hash);
47
48 init(_cache->findByHash(_hash));
49 }
50
init(byte * data)51 void AudStream::init(byte *data) {
52 _data = data;
53 _frequency = READ_LE_UINT16(_data);
54 _size = READ_LE_UINT32(_data + 2);
55 _sizeDecompressed = READ_LE_UINT32(_data + 6);
56 _flags = *(_data + 10);
57 _compressionType = *(_data + 11);
58
59 _end = _data + _size + 12;
60 assert(_end - _data >= 12);
61
62 _deafBlockRemain = 0;
63 _p = _data + 12;
64 }
65
~AudStream()66 AudStream::~AudStream() {
67 if (_cache) {
68 _cache->decRef(_hash);
69 }
70 }
71
readBuffer(int16 * buffer,const int numSamples)72 int AudStream::readBuffer(int16 *buffer, const int numSamples) {
73 int samplesRead = 0;
74
75 if (_compressionType == 99) {
76 assert(numSamples % 2 == 0);
77
78 while (samplesRead < numSamples) {
79 if (_deafBlockRemain == 0) {
80 if (_end - _p == 0)
81 break;
82
83 assert(_end - _p >= 6);
84
85 uint16 blockSize = READ_LE_UINT16(_p);
86 uint16 blockOutSize = READ_LE_UINT16(_p + 2);
87 uint32 sig = READ_LE_UINT32(_p + 4);
88 _p += 8;
89
90 assert(sig == 0xdeaf);
91 assert(_end - _p >= blockSize);
92
93 // TODO: Previously we asserted that
94 // blockOutSize == 4 * blockSize, but
95 // occasionally, at the end of an AUD,
96 // we see blockOutSize == 4 * blockSize + 2
97 // Investigate how BLADE.EXE handles this.
98
99 assert(blockOutSize / 4 == blockSize);
100
101 _deafBlockRemain = blockSize;
102 }
103
104 assert(_end - _p >= _deafBlockRemain);
105
106 int bytesConsumed = MIN<int>(_deafBlockRemain, (numSamples - samplesRead) / 2);
107 if (buffer) {
108 _decoder.decode(_p, bytesConsumed, buffer + samplesRead, false);
109 } else {
110 _decoder.decode(_p, bytesConsumed, nullptr, false);
111 }
112 _p += bytesConsumed;
113 _deafBlockRemain -= bytesConsumed;
114
115 samplesRead += 2 * bytesConsumed;
116 }
117 } else {
118 samplesRead = MIN(numSamples, (int)(_end - _p) / 2);
119 if (buffer) {
120 for (int i = 0; i < samplesRead; ++i, _p += 2) {
121 buffer[i] = READ_LE_UINT16(_p);
122 }
123 }
124 }
125
126 return samplesRead;
127 }
128
getBytesPerSecond() const129 int AudStream::getBytesPerSecond() const {
130 int bytesPerSecond = _overrideFrequency > 0 ? _overrideFrequency : _frequency;
131 if (_flags & 1) { // 16 bit
132 bytesPerSecond *= 2;
133 }
134 if (_flags & 2) { // stereo
135 bytesPerSecond *= 2;
136 }
137 return bytesPerSecond;
138 }
139
startAtSecond(uint32 startSecond)140 bool AudStream::startAtSecond(uint32 startSecond) {
141 uint32 audStreamLengthMillis = getLength();
142 if (startSecond == 0 || startSecond * 1000 > audStreamLengthMillis || audStreamLengthMillis == 0) {
143 return false;
144 }
145 if (rewind()) {
146 int samplesPerSecond = _overrideFrequency > 0 ? _overrideFrequency : _frequency;
147 readBuffer(nullptr, startSecond * samplesPerSecond);
148 return true;
149 }
150 return false;
151 }
152
rewind()153 bool AudStream::rewind() {
154 _p = _data + 12;
155 _decoder.setParameters(0, 0);
156 return true;
157 }
158
159 /**
160 * Returns audio length in milliseconds
161 */
getLength() const162 uint32 AudStream::getLength() const {
163 // since everything is 44100, we easily get overflows with ints
164 // thus we must use doubles
165 int bytesPerSecond = getBytesPerSecond();
166 if (bytesPerSecond <= 0) {
167 return 0u;
168 }
169 double res = (double)_sizeDecompressed * 1000.0 / (double)bytesPerSecond;
170 return (uint32)res;
171 }
172
173 } // End of namespace BladeRunner
174