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
|
/*
* Copyright 2013 Phil Burk, Mobileer Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jsyn.unitgen;
import java.util.Arrays;
import com.jsyn.data.SpectralWindow;
import com.jsyn.data.Spectrum;
import com.jsyn.ports.UnitInputPort;
import com.jsyn.ports.UnitSpectralOutputPort;
import com.softsynth.math.FourierMath;
/**
* Periodically transform the input signal using an FFT. Output complete spectra.
*
* @author Phil Burk (C) 2013 Mobileer Inc
* @version 016
* @see SpectralIFFT
* @see Spectrum
* @see SpectralFilter
*/
public class SpectralFFT extends UnitGenerator {
public UnitInputPort input;
/**
* Provides complete complex spectra when the FFT completes.
*/
public UnitSpectralOutputPort output;
private double[] buffer;
private int cursor;
private SpectralWindow window = RectangularWindow.getInstance();
private int sizeLog2;
private int offset;
private boolean running;
/* Define Unit Ports used by connect() and set(). */
public SpectralFFT() {
this(Spectrum.DEFAULT_SIZE_LOG_2);
}
/**
* @param sizeLog2 for example, pass 10 to get a 1024 bin FFT
*/
public SpectralFFT(int sizeLog2) {
addPort(input = new UnitInputPort("Input"));
addPort(output = new UnitSpectralOutputPort("Output", 1 << sizeLog2));
setSizeLog2(sizeLog2);
}
/**
* Please do not change the size of the FFT while JSyn is running.
*
* @param sizeLog2 for example, pass 9 to get a 512 bin FFT
*/
public void setSizeLog2(int sizeLog2) {
this.sizeLog2 = sizeLog2;
output.setSize(1 << sizeLog2);
buffer = output.getSpectrum().getReal();
cursor = 0;
}
public int getSizeLog2() {
return sizeLog2;
}
@Override
public void generate(int start, int limit) {
if (!running) {
int mask = (1 << sizeLog2) - 1;
if (((getSynthesisEngine().getFrameCount() - offset) & mask) == 0) {
running = true;
cursor = 0;
}
}
// Don't use "else" because "running" may have changed in above block.
if (running) {
double[] inputs = input.getValues();
for (int i = start; i < limit; i++) {
buffer[cursor] = inputs[i] * window.get(cursor);
++cursor;
// When it is full, do the FFT.
if (cursor == buffer.length) {
Spectrum spectrum = output.getSpectrum();
Arrays.fill(spectrum.getImaginary(), 0.0);
FourierMath.fft(buffer.length, spectrum.getReal(), spectrum.getImaginary());
output.advance();
cursor = 0;
}
}
}
}
public SpectralWindow getWindow() {
return window;
}
/**
* Multiply input data by this window before doing the FFT. The default is a RectangularWindow.
*/
public void setWindow(SpectralWindow window) {
this.window = window;
}
/**
* The FFT will be performed on a frame that is a multiple of the size plus this offset.
*
* @param offset
*/
public void setOffset(int offset) {
this.offset = offset;
}
public int getOffset() {
return offset;
}
}
|
