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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef WebAudioUtils_h_
#define WebAudioUtils_h_
#include <cmath>
#include <limits>
#include <type_traits>
#include "mozilla/FloatingPoint.h"
#include "mozilla/Logging.h"
#include "MediaSegment.h"
// Forward declaration
typedef struct SpeexResamplerState_ SpeexResamplerState;
namespace mozilla {
class AudioNodeTrack;
extern LazyLogModule gWebAudioAPILog;
#define WEB_AUDIO_API_LOG(...) \
MOZ_LOG(gWebAudioAPILog, LogLevel::Debug, (__VA_ARGS__))
namespace dom {
struct AudioTimelineEvent;
namespace WebAudioUtils {
// 32 is the minimum required by the spec for createBuffer() and
// createScriptProcessor() and matches what is used by Blink. The limit
// protects against large memory allocations.
const size_t MaxChannelCount = 32;
// AudioContext::CreateBuffer() "must support sample-rates in at least the
// range 22050 to 96000."
const uint32_t MinSampleRate = 8000;
const uint32_t MaxSampleRate = 192000;
inline bool FuzzyEqual(float v1, float v2) { return fabsf(v1 - v2) < 1e-7f; }
inline bool FuzzyEqual(double v1, double v2) { return fabs(v1 - v2) < 1e-7; }
/**
* Converts an AudioTimelineEvent's floating point time values to tick values
* with respect to a destination AudioNodeTrack.
*
* This needs to be called for each AudioTimelineEvent that gets sent to an
* AudioNodeEngine, on the engine side where the AudioTimlineEvent is
* received. This means that such engines need to be aware of their
* destination tracks as well.
*/
void ConvertAudioTimelineEventToTicks(AudioTimelineEvent& aEvent,
AudioNodeTrack* aDest);
/**
* Converts a linear value to decibels. Returns aMinDecibels if the linear
* value is 0.
*/
inline float ConvertLinearToDecibels(float aLinearValue, float aMinDecibels) {
return aLinearValue ? 20.0f * std::log10(aLinearValue) : aMinDecibels;
}
/**
* Converts a decibel value to a linear value.
*/
inline float ConvertDecibelsToLinear(float aDecibels) {
return std::pow(10.0f, 0.05f * aDecibels);
}
/**
* Converts a decibel to a linear value.
*/
inline float ConvertDecibelToLinear(float aDecibel) {
return std::pow(10.0f, 0.05f * aDecibel);
}
inline void FixNaN(double& aDouble) {
if (IsNaN(aDouble) || IsInfinite(aDouble)) {
aDouble = 0.0;
}
}
inline double DiscreteTimeConstantForSampleRate(double timeConstant,
double sampleRate) {
return 1.0 - std::exp(-1.0 / (sampleRate * timeConstant));
}
inline bool IsTimeValid(double aTime) {
return aTime >= 0 && aTime <= (MEDIA_TIME_MAX >> TRACK_RATE_MAX_BITS);
}
/**
* Converts a floating point value to an integral type in a safe and
* platform agnostic way. The following program demonstrates the kinds
* of ways things can go wrong depending on the CPU architecture you're
* compiling for:
*
* #include <stdio.h>
* volatile float r;
* int main()
* {
* unsigned int q;
* r = 1e100;
* q = r;
* printf("%f %d\n", r, q);
* r = -1e100;
* q = r;
* printf("%f %d\n", r, q);
* r = 1e15;
* q = r;
* printf("%f %x\n", r, q);
* r = 0/0.;
* q = r;
* printf("%f %d\n", r, q);
* }
*
* This program, when compiled for unsigned int, generates the following
* results depending on the architecture:
*
* x86 and x86-64
* ---
* inf 0
* -inf 0
* 999999995904.000000 -727384064 d4a50000
* nan 0
*
* ARM
* ---
* inf -1
* -inf 0
* 999999995904.000000 -1
* nan 0
*
* When compiled for int, this program generates the following results:
*
* x86 and x86-64
* ---
* inf -2147483648
* -inf -2147483648
* 999999995904.000000 -2147483648
* nan -2147483648
*
* ARM
* ---
* inf 2147483647
* -inf -2147483648
* 999999995904.000000 2147483647
* nan 0
*
* Note that the caller is responsible to make sure that the value
* passed to this function is not a NaN. This function will abort if
* it sees a NaN.
*/
template <typename IntType, typename FloatType>
IntType TruncateFloatToInt(FloatType f) {
using std::numeric_limits;
static_assert(std::is_integral_v<IntType> == true,
"IntType must be an integral type");
static_assert(std::is_floating_point_v<FloatType> == true,
"FloatType must be a floating point type");
if (mozilla::IsNaN(f)) {
// It is the responsibility of the caller to deal with NaN values.
// If we ever get to this point, we have a serious bug to fix.
MOZ_CRASH("We should never see a NaN here");
}
// If the floating point value is outside of the range of maximum
// integral value for this type, just clamp to the maximum value.
// The equality case must also return max() due to loss of precision when
// converting max() to float.
if (f >= FloatType(numeric_limits<IntType>::max())) {
return numeric_limits<IntType>::max();
}
if (f <= FloatType(numeric_limits<IntType>::min())) {
// If the floating point value is outside of the range of minimum
// integral value for this type, just clamp to the minimum value.
return numeric_limits<IntType>::min();
}
// Otherwise, this conversion must be well defined.
return IntType(f);
}
void Shutdown();
int SpeexResamplerProcess(SpeexResamplerState* aResampler, uint32_t aChannel,
const float* aIn, uint32_t* aInLen, float* aOut,
uint32_t* aOutLen);
int SpeexResamplerProcess(SpeexResamplerState* aResampler, uint32_t aChannel,
const int16_t* aIn, uint32_t* aInLen, float* aOut,
uint32_t* aOutLen);
int SpeexResamplerProcess(SpeexResamplerState* aResampler, uint32_t aChannel,
const int16_t* aIn, uint32_t* aInLen, int16_t* aOut,
uint32_t* aOutLen);
void LogToDeveloperConsole(uint64_t aWindowID, const char* aKey);
} // namespace WebAudioUtils
} // namespace dom
} // namespace mozilla
#endif
|
