blob: bc7d030c652d4c86115c72a21e1f7e7970830596 (
plain)
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
|
#pragma once
#include "util/types.h"
class EngineSideChainCompressor {
public:
EngineSideChainCompressor(const QString& group);
virtual ~EngineSideChainCompressor() { };
void setParameters(CSAMPLE threshold, CSAMPLE strength,
unsigned int attack_time, unsigned int decay_time) {
// TODO(owilliams): There is a race condition here because the parameters
// are not updated atomically. This function should instead take a
// struct.
m_threshold = threshold;
m_strength = strength;
m_attackTime = attack_time;
m_decayTime = decay_time;
calculateRates();
}
void setThreshold(CSAMPLE threshold) {
m_threshold = threshold;
calculateRates();
}
void setStrength(CSAMPLE strength) {
m_strength = strength;
calculateRates();
}
void setAttackTime(unsigned int attack_time) {
m_attackTime = attack_time;
calculateRates();
}
void setDecayTime(unsigned int decay_time) {
m_decayTime = decay_time;
calculateRates();
}
/// Forces the above threshold flag to the given value without calculations
void setAboveThreshold(bool value);
// Every loop, before calling process, first call processKey to feed
// the compressor the input key signal. It is safe to call this function
// multiple times for multiple keys, however they will not be summed together
// so compression will not be triggered unless at least one buffer would
// have triggered alone.
void processKey(const CSAMPLE* pIn, const int iBufferSize);
// Calculates a new gain value based on the current compression ratio
// over the given number of frames and whether the current input is above threshold.
double calculateCompressedGain(int frames);
private:
// Update the attack and decay rates.
void calculateRates();
// The current ratio the signal is being compressed. This is the same as m_strength
// when the compressor is at maximum engagement (not attacking or decaying).
CSAMPLE m_compressRatio;
// True if the input signal is above the threshold.
bool m_bAboveThreshold;
// The sample value above which the compressor is triggered.
CSAMPLE m_threshold;
// The largest ratio the signal can be compressed.
CSAMPLE m_strength;
// The length of time, in frames (samples/2), until maximum compression is reached.
unsigned int m_attackTime;
// The length of time, in frames, until compression is completely off.
unsigned int m_decayTime;
// These are the delta compression values per sample based on the strengths and timings.
CSAMPLE m_attackPerFrame;
CSAMPLE m_decayPerFrame;
};
|
