-
Notifications
You must be signed in to change notification settings - Fork 1
/
phaserprocessor.cpp
282 lines (253 loc) · 7.35 KB
/
phaserprocessor.cpp
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/***************************************************************************
phaserprocessor.cpp - description
-------------------
begin : Tue Aug 22 2000
copyright : (C) 2000 by Jozef Kosoru
: (C) 2011 by Kasper Laudrup
email : jozef.kosoru@pobox.sk
: laudrup@stacktrace.dk
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License version 2 *
* as published by the Free Software Foundation. *
* *
***************************************************************************/
/*
* to do: linear sweep
* notch filter
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <cstring>
#include <cmath>
#include <iostream>
#include <cerrno>
#include "crdatastream.h"
#include "phaserprocessor.h"
PhaserProcessor::PhaserProcessor(PhaserParameters* parameters)
:SoundProcessor(parameters)
{
registerProcessor("phaser", 1.0f);
mo_parameters = parameters;
(void)pthread_mutex_init(&m_mutex, NULL);
m_coefBuffer = 0;
mr_coefBuffer = 0;
}
PhaserProcessor::~PhaserProcessor()
{
cleanup();
pthread_mutex_destroy(&m_mutex);
#ifdef _DEBUG
std::cerr << "PhaserProcessor deleted...\n";
#endif
}
void PhaserProcessor::initialize()
{
mp_samplesPerHalfCycle = mp_bottomFrequency = mp_topFrequency = mp_resonance = -1.0f;
m_halfSamplerate = (m_samplerate_f / 2.0f) * 0.85f;
}
void PhaserProcessor::computeParameters()
{
mr_inputGain = exp10f(mo_parameters->inputGain / 20.0f);
mr_sweepGain = exp10f(mo_parameters->sweepGain / 20.0f);
mr_dryMix = mo_parameters->dryMix / 100.0f;
float bottomFrequency = mo_parameters->centerFrequency / mo_parameters->depth;
if (bottomFrequency < 16.0f)
{
bottomFrequency = 16.0f;
}
float topFrequency = mo_parameters->centerFrequency * mo_parameters->depth;
if (topFrequency > m_halfSamplerate)
{
topFrequency = m_halfSamplerate;
}
const float resonance = mo_parameters->resonance * 2.0f;
const int samplesPerHalfCycle = (roundToInt(m_samplerate_d / mo_parameters->sweepFrequency) >> 1);
mr_recalculate = false;
if (samplesPerHalfCycle != mp_samplesPerHalfCycle ||
bottomFrequency != mp_bottomFrequency ||
topFrequency != mp_topFrequency ||
resonance != mp_resonance)
{
const float expStep = powf(topFrequency / bottomFrequency,
1.0f / static_cast<float>(samplesPerHalfCycle - 1));
// make lookup table for short periods only (2 x 44100(halfPeriod)
// samples = 0.5Hz = 334.5Kb in 44100bit/sec)
float* const coefBuffer = ((samplesPerHalfCycle << 1) < 88201)
? (new float[samplesPerHalfCycle << 1]) : 0;
//we need two lookupTables (alpha & cs)
pthread_mutex_lock(&m_mutex);
mr_expStep = expStep;
mr_stepFrequency = mp_bottomFrequency = bottomFrequency;
mr_resonance = mp_resonance = resonance;
delete[] mr_coefBuffer;
mr_coefBuffer = coefBuffer;
mr_coefBufferSize = samplesPerHalfCycle << 1;
pthread_mutex_unlock(&m_mutex);
mr_recalculate = true;
mp_samplesPerHalfCycle = samplesPerHalfCycle;
mp_topFrequency = topFrequency;
}
}
void PhaserProcessor::setParameters_run()
{
m_inputGain = mr_inputGain;
m_sweepGain = mr_sweepGain;
m_dryMix = mr_dryMix;
if (mr_recalculate)
{
if (pthread_mutex_trylock(&m_mutex) != -EBUSY)
{
m_recalculate = true;
m_expStep = mr_expStep;
m_stepFrequency = mr_stepFrequency;
m_resonance = mr_resonance;
delete[] m_coefBuffer;
if (mr_coefBuffer)
{ //use lookupTable
m_coefBuffer = m_coefBuffPrelim = m_coefBuffSweep = const_cast<float*>(mr_coefBuffer);
mr_coefBuffer = 0;
m_coefBuffEnd = m_coefBuffer + mr_coefBufferSize;
m_useLookupTable = true;
}
else
{
m_coefBuffer = 0;
m_phaseCounter = 0;
m_halfPhaseSize = mr_coefBufferSize >> 1;
m_stepFrequency_first = m_stepFrequency;
m_useLookupTable = false;
}
pthread_mutex_unlock(&m_mutex);
}
m_x1 = m_x2 = m_y1 = m_y2 = 0.0f;
m_sweepDirection = true;
}
}
void PhaserProcessor::signalFlow_run(const int length)
{
const float* inputBuffer = m_inputBuffer;
float* outputBuffer = m_outputBuffer;
if (m_useLookupTable)
{
for (int count = 0; count < length; count++)
{
// precalculate cs & alpha
if (m_recalculate)
{
const float omega = 2.0f * float(M_PI) * m_stepFrequency / m_samplerate_d;
float sn, cs;
sincosf(omega, &sn, &cs);
*(m_coefBuffPrelim++) = cs; // cs
*(m_coefBuffPrelim++) = sn / m_resonance; // alpha (m_resonance = 2.0*resonance)
m_stepFrequency *= m_expStep;
if (m_coefBuffPrelim == m_coefBuffEnd)
{
m_recalculate=false;
}
}
// coefficients
register float cs, alpha;
if (m_sweepDirection)
{
cs = *(m_coefBuffSweep++);
alpha = *(m_coefBuffSweep++);
if (m_coefBuffSweep == m_coefBuffEnd)
{
m_sweepDirection = !m_sweepDirection;
}
}
else
{
alpha = *(--m_coefBuffSweep);
cs = *(--m_coefBuffSweep);
if (m_coefBuffSweep == m_coefBuffer)
{
m_sweepDirection = !m_sweepDirection;
}
}
//b0 = alpha;
//b1 = 0.0f;
//b2 = -b0;
//a0 = 1.0f + alpha;
//a1 = (-2.0f*cs);
//a2 = (1.0f-alpha);
// perform filter
const float input = *(inputBuffer++) * m_inputGain;
const float output = ((alpha * input) + ((-alpha) * m_x2)
- (((-2.0f) * cs) * m_y1) - ((1.0f - alpha) * m_y2))
/ (1.0f + alpha);
m_x2 = m_x1;
m_x1 = input;
m_y2 = m_y1;
m_y1 = output;
*(outputBuffer++) = (output * m_sweepGain) + (input * m_dryMix);
}
}
else
{ //don't use lookupTable
for (int count=0; count<length; count++)
{
const float omega = 2.0f * float(M_PI) * m_stepFrequency / m_samplerate_d;
if(m_sweepDirection)
{
m_stepFrequency *= m_expStep;
}
else
{
m_stepFrequency /= m_expStep;
}
if ((++m_phaseCounter) == m_halfPhaseSize)
{
m_phaseCounter = 0;
if (!m_sweepDirection)
{
m_stepFrequency = m_stepFrequency_first;
//this protects against cumulating of a floating point error
}
m_sweepDirection = !m_sweepDirection;
}
float sn, cs;
sincosf(omega, &sn, &cs);
register const float alpha = sn / m_resonance; // alpha (m_resonance = 2.0 * resonance)
// perform filter
const float input = *(inputBuffer++) * m_inputGain;
const float output = ((alpha * input) + ((-alpha) * m_x2)
- (((-2.0f) * cs) * m_y1) - ((1.0f - alpha) * m_y2))
/ (1.0f + alpha);
m_x2 = m_x1;
m_x1 = input;
m_y2 = m_y1;
m_y1 = output;
*(outputBuffer++) = (output*m_sweepGain) + (input * m_dryMix);
}
}
}
void PhaserProcessor::cleanup()
{
if (mr_coefBuffer == m_coefBuffer)
{
delete[] mr_coefBuffer;
}
else
{
delete[] m_coefBuffer;
delete[] mr_coefBuffer;
}
mr_coefBuffer = m_coefBuffer = 0;
}
void PhaserProcessor::prepareEnabled()
{
m_x1 = m_x2 = m_y1 = m_y2 = 0.0f;
}
void PhaserProcessor::operator>>(CrInputDataStream& inputStream) const
{
inputStream << *mo_parameters;
}
void PhaserProcessor::operator<<(CrOutputDataStream& outputStream)
{
outputStream >> *mo_parameters;
}