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Feature/add lfo (#1)

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* Basic working tremolo

* LFO now works as a vector

* Added standard tremolo demo
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Blackaddr Audio 6 years ago committed by GitHub
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  1. 131
      examples/Modulation/TemoloDemo/TemoloDemo.ino
  2. 19
      examples/Modulation/TemoloDemo/name.c
  3. 192
      examples/Modulation/TremoloDemoExpansion/TremoloDemoExpansion.ino
  4. 126
      src/AudioEffectTremolo.h
  5. 1
      src/BAEffects.h
  6. 59
      src/LibBasicFunctions.h
  7. 145
      src/common/LowFrequencyOscillator.cpp
  8. 0
      src/effects/AudioEffectDelayExternal.cpp
  9. 163
      src/effects/AudioEffectTremolo.cpp

131
examples/Modulation/TemoloDemo/TemoloDemo.ino
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/*************************************************************************
* This demo uses the BALibrary library to provide enhanced control of
* the TGA Pro board.
*
* The latest copy of the BA Guitar library can be obtained from
* https://github.com/Blackaddr/BALibrary
*
* This example demonstrates teh AudioEffectsTremolo effect. It can
* be controlled using USB MIDI. You can get a free USB MIDI Controller
* appliation at
* http://www.blackaddr.com/downloads/BAMidiTester/
* or the source code at
* https://github.com/Blackaddr/BAMidiTester
*
* Even if you don't control the guitar effect with USB MIDI, you must set
* the Arduino IDE USB-Type under Tools to "Serial + MIDI"
*/
#include <MIDI.h>
#include "BALibrary.h"
#include "BAEffects.h"
using namespace midi;
using namespace BAEffects;
using namespace BALibrary;
AudioInputI2S i2sIn;
AudioOutputI2S i2sOut;
BAAudioControlWM8731 codec;
/// IMPORTANT /////
// YOU MUST USE TEENSYDUINO 1.41 or greater
// YOU MUST COMPILE THIS DEMO USING Serial + Midi
//#define USE_EXT // uncomment this line to use External MEM0
#define MIDI_DEBUG // uncomment to see raw MIDI info in terminal
AudioEffectTremolo tremolo;
AudioFilterBiquad cabFilter; // We'll want something to cut out the highs and smooth the tone, just like a guitar cab.
// Simply connect the input to the tremolo, and the output
// to both i2s channels
AudioConnection input(i2sIn,0, tremolo,0);
AudioConnection tremoloOut(tremolo, 0, cabFilter, 0);
AudioConnection leftOut(cabFilter,0, i2sOut, 0);
AudioConnection rightOut(cabFilter,0, i2sOut, 1);
int loopCount = 0;
void setup() {
delay(100);
Serial.begin(57600); // Start the serial port
// Disable the codec first
codec.disable();
delay(100);
AudioMemory(128);
delay(5);
// Enable the codec
Serial.println("Enabling codec...\n");
codec.enable();
delay(100);
// Configure which MIDI CC's will control the effect parameters
tremolo.mapMidiControl(AudioEffectTremolo::BYPASS,16);
tremolo.mapMidiControl(AudioEffectTremolo::RATE,20);
tremolo.mapMidiControl(AudioEffectTremolo::DEPTH,21);
tremolo.mapMidiControl(AudioEffectTremolo::VOLUME,22);
// Besure to enable the tremolo. When disabled, audio is is completely blocked
// to minimize resources to nearly zero.
tremolo.enable();
// Set some default values.
// These can be changed by sending MIDI CC messages over the USB using
// the BAMidiTester application.
tremolo.rate(0.5f); // initial LFO rate of 1/2 max which is about 10 Hz
tremolo.bypass(false);
tremolo.depth(0.5f); // 50% depth modulation
// Setup 2-stages of LPF, cutoff 4500 Hz, Q-factor 0.7071 (a 'normal' Q-factor)
cabFilter.setLowpass(0, 4500, .7071);
cabFilter.setLowpass(1, 4500, .7071);
}
void OnControlChange(byte channel, byte control, byte value) {
tremolo.processMidi(channel, control, value);
#ifdef MIDI_DEBUG
Serial.print("Control Change, ch=");
Serial.print(channel, DEC);
Serial.print(", control=");
Serial.print(control, DEC);
Serial.print(", value=");
Serial.print(value, DEC);
Serial.println();
#endif
}
void loop() {
// usbMIDI.read() needs to be called rapidly from loop(). When
// each MIDI messages arrives, it return true. The message must
// be fully processed before usbMIDI.read() is called again.
if (loopCount % 524288 == 0) {
Serial.print("Processor Usage, Total: "); Serial.print(AudioProcessorUsage());
Serial.print("% ");
Serial.print(" tremolo: "); Serial.print(tremolo.processorUsage());
Serial.println("%");
}
loopCount++;
// check for new MIDI from USB
if (usbMIDI.read()) {
// this code entered only if new MIDI received
byte type, channel, data1, data2, cable;
type = usbMIDI.getType(); // which MIDI message, 128-255
channel = usbMIDI.getChannel(); // which MIDI channel, 1-16
data1 = usbMIDI.getData1(); // first data byte of message, 0-127
data2 = usbMIDI.getData2(); // second data byte of message, 0-127
Serial.println(String("Received a MIDI message on channel ") + channel);
if (type == MidiType::ControlChange) {
// if type is 3, it's a CC MIDI Message
// Note: the Arduino MIDI library encodes channels as 1-16 instead
// of 0 to 15 as it should, so we must subtract one.
OnControlChange(channel-1, data1, data2);
}
}
}

19
examples/Modulation/TemoloDemo/name.c
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// To give your project a unique name, this code must be
// placed into a .c file (its own tab). It can not be in
// a .cpp file or your main sketch (the .ino file).
#include "usb_names.h"
// Edit these lines to create your own name. The length must
// match the number of characters in your custom name.
#define MIDI_NAME {'B','l','a','c','k','a','d','d','r',' ','A','u','d','i','o',' ','T','G','A',' ','P','r','o'}
#define MIDI_NAME_LEN 23
// Do not change this part. This exact format is required by USB.
struct usb_string_descriptor_struct usb_string_product_name = {
2 + MIDI_NAME_LEN * 2,
3,
MIDI_NAME
};

192
examples/Modulation/TremoloDemoExpansion/TremoloDemoExpansion.ino
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/*************************************************************************
* This demo uses the BALibrary library to provide enhanced control of
* the TGA Pro board.
*
* The latest copy of the BA Guitar library can be obtained from
* https://github.com/Blackaddr/BALibrary
*
* This example demonstrates teh BAAudioEffectsTremolo effect. It can
* be controlled using the Blackaddr Audio "Expansion Control Board".
*
* POT1 (left) controls amount of delay
* POT2 (right) controls amount of feedback
* POT3 (center) controls the wet/dry mix
* SW1 will enable/bypass the audio effect. LED1 will be on when effect is enabled.
* SW2 will cycle through the 3 pre-programmed analog filters. LED2 will be on when SW2 is pressed.
*
*
* Using the Serial Montitor, send 'u' and 'd' characters to increase or decrease
* the headphone volume between values of 0 and 9.
*/
#define TGA_PRO_REVB // Set which hardware revision of the TGA Pro we're using
#define TGA_PRO_EXPAND_REV2 // pull in the pin definitions for the Blackaddr Audio Expansion Board.
#include "BALibrary.h"
#include "BAEffects.h"
using namespace BAEffects;
using namespace BALibrary;
AudioInputI2S i2sIn;
AudioOutputI2S i2sOut;
BAAudioControlWM8731 codec;
AudioEffectTremolo tremolo;
AudioFilterBiquad cabFilter; // We'll want something to cut out the highs and smooth the tone, just like a guitar cab.
// Simply connect the input to the delay, and the output
// to both i2s channels
AudioConnection input(i2sIn,0, tremolo,0);
AudioConnection delayOut(tremolo, 0, cabFilter, 0);
AudioConnection leftOut(cabFilter,0, i2sOut, 0);
AudioConnection rightOut(cabFilter,0, i2sOut, 1);
//////////////////////////////////////////
// SETUP PHYSICAL CONTROLS
// - POT1 (left) will control the rate
// - POT2 (right) will control the depth
// - POT3 (centre) will control the volume
// - SW1 (left) will be used as a bypass control
// - LED1 (left) will be illuminated when the effect is ON (not bypass)
// - SW2 (right) will be used to cycle through the the waveforms
// - LED2 (right) will illuminate when pressing SW2.
//////////////////////////////////////////
// To get the calibration values for your particular board, first run the
// BAExpansionCalibrate.ino example and
constexpr int potCalibMin = 1;
constexpr int potCalibMax = 1018;
constexpr bool potSwapDirection = true;
// Create a control object using the number of switches, pots, encoders and outputs on the
// Blackaddr Audio Expansion Board.
BAPhysicalControls controls(BA_EXPAND_NUM_SW, BA_EXPAND_NUM_POT, BA_EXPAND_NUM_ENC, BA_EXPAND_NUM_LED);
int loopCount = 0;
unsigned waveformIndex = 0; // variable for storing which analog filter we're currently using.
constexpr unsigned MAX_HEADPHONE_VOL = 10;
unsigned headphoneVolume = 8; // control headphone volume from 0 to 10.
// BAPhysicalControls returns a handle when you register a new control. We'll uses these handles when working with the controls.
int bypassHandle, waveformHandle, rateHandle, depthHandle, volumeHandle, led1Handle, led2Handle; // Handles for the various controls
void setup() {
delay(100); // wait a bit for serial to be available
Serial.begin(57600); // Start the serial port
delay(100);
// Setup the controls. The return value is the handle to use when checking for control changes, etc.
// pushbuttons
bypassHandle = controls.addSwitch(BA_EXPAND_SW1_PIN); // will be used for bypass control
waveformHandle = controls.addSwitch(BA_EXPAND_SW2_PIN); // will be used for stepping through filters
// pots
rateHandle = controls.addPot(BA_EXPAND_POT1_PIN, potCalibMin, potCalibMax, potSwapDirection); // control the amount of delay
depthHandle = controls.addPot(BA_EXPAND_POT2_PIN, potCalibMin, potCalibMax, potSwapDirection);
volumeHandle = controls.addPot(BA_EXPAND_POT3_PIN, potCalibMin, potCalibMax, potSwapDirection);
// leds
led1Handle = controls.addOutput(BA_EXPAND_LED1_PIN);
led2Handle = controls.addOutput(BA_EXPAND_LED2_PIN); // will illuminate when pressing SW2
// Disable the audio codec first
codec.disable();
AudioMemory(128);
// Enable and configure the codec
Serial.println("Enabling codec...\n");
codec.enable();
codec.setHeadphoneVolume(1.0f); // Max headphone volume
// Besure to enable the tremolo. When disabled, audio is is completely blocked by the effect
// to minimize resource usage to nearly to nearly zero.
tremolo.enable();
// Set some default values.
// These can be changed using the controls on the Blackaddr Audio Expansion Board
tremolo.bypass(false);
tremolo.rate(0.0f);
tremolo.depth(1.0f);
//////////////////////////////////
// Waveform selection //
// These are commented out, in this example we'll use SW2 to cycle through the different filters
//tremolo.setWaveform(Waveform::SINE); // The default waveform
// Guitar cabinet: Setup 2-stages of LPF, cutoff 4500 Hz, Q-factor 0.7071 (a 'normal' Q-factor)
cabFilter.setLowpass(0, 4500, .7071);
cabFilter.setLowpass(1, 4500, .7071);
}
void loop() {
float potValue;
// Check if SW1 has been toggled (pushed)
if (controls.isSwitchToggled(bypassHandle)) {
bool bypass = tremolo.isBypass(); // get the current state
bypass = !bypass; // change it
tremolo.bypass(bypass); // set the new state
controls.setOutput(led1Handle, !bypass); // Set the LED when NOT bypassed
Serial.println(String("BYPASS is ") + bypass);
}
// Use SW2 to cycle through the waveforms
controls.setOutput(led2Handle, controls.getSwitchValue(led2Handle));
if (controls.isSwitchToggled(waveformHandle)) {
waveformIndex = (waveformIndex + 1) % static_cast<unsigned>(Waveform::NUM_WAVEFORMS);
// cast the index
tremolo.setWaveform(static_cast<Waveform>(waveformIndex));
Serial.println(String("Waveform set to ") + waveformIndex);
}
// Use POT1 (left) to control the rate setting
if (controls.checkPotValue(rateHandle, potValue)) {
// Pot has changed
Serial.println(String("New RATE setting: ") + potValue);
tremolo.rate(potValue);
}
// Use POT2 (right) to control the depth setting
if (controls.checkPotValue(depthHandle, potValue)) {
// Pot has changed
Serial.println(String("New DEPTH setting: ") + potValue);
tremolo.depth(potValue);
}
// Use POT3 (centre) to control the volume setting
if (controls.checkPotValue(volumeHandle, potValue)) {
// Pot has changed
Serial.println(String("New VOLUME setting: ") + potValue);
tremolo.volume(potValue);
}
// Use the 'u' and 'd' keys to adjust volume across ten levels.
if (Serial) {
if (Serial.available() > 0) {
while (Serial.available()) {
char key = Serial.read();
if (key == 'u') {
headphoneVolume = (headphoneVolume + 1) % MAX_HEADPHONE_VOL;
Serial.println(String("Increasing HEADPHONE volume to ") + headphoneVolume);
}
else if (key == 'd') {
headphoneVolume = (headphoneVolume - 1) % MAX_HEADPHONE_VOL;
Serial.println(String("Decreasing HEADPHONE volume to ") + headphoneVolume);
}
codec.setHeadphoneVolume(static_cast<float>(headphoneVolume) / static_cast<float>(MAX_HEADPHONE_VOL));
}
}
}
// Use the loopCounter to roughly measure human timescales. Every few seconds, print the CPU usage
// to the serial port. About 500,000 loops!
//if (loopCount % 524288 == 0) {
if (loopCount % 25000 == 0) {
Serial.print("Processor Usage, Total: "); Serial.print(AudioProcessorUsage());
Serial.print("% ");
Serial.print(" tremolo: "); Serial.print(tremolo.processorUsage());
Serial.println("%");
}
loopCount++;
}

126
src/AudioEffectTremolo.h
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/**************************************************************************//**
* @file
* @author Steve Lascos
* @company Blackaddr Audio
*
* Tremolo is a classic volume modulate effect.
*
* @copyright This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.*
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY__BAEFFECTS_AUDIOEFFECTDELAYEXTERNAL_H; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************/
#ifndef __BAEFFECTS_AUDIOEFFECTTREMOLO_H
#define __BAEFFECTS_AUDIOEFFECTTREMOLO_H
#include <Audio.h>
#include "LibBasicFunctions.h"
namespace BAEffects {
/**************************************************************************//**
* AudioEffectTremolo
*****************************************************************************/
class AudioEffectTremolo : public AudioStream {
public:
///< List of AudioEffectTremolo MIDI controllable parameters
enum {
BYPASS = 0, ///< controls effect bypass
RATE, ///< controls the rate of the modulation
DEPTH, ///< controls the depth of the modulation
WAVEFORM, ///< select the modulation waveform
VOLUME, ///< controls the output volume level
NUM_CONTROLS ///< this can be used as an alias for the number of MIDI controls
};
// *** CONSTRUCTORS ***
AudioEffectTremolo();
virtual ~AudioEffectTremolo(); ///< Destructor
// *** PARAMETERS ***
void rate(float rateValue);
void depth(float depthValue) { m_depth = depthValue; }
void setWaveform(BALibrary::Waveform waveform);
/// Bypass the effect.
/// @param byp when true, bypass wil disable the effect, when false, effect is enabled.
/// Note that audio still passes through when bypass is enabled.
void bypass(bool byp) { m_bypass = byp; }
/// Get if the effect is bypassed
/// @returns true if bypassed, false if not bypassed
bool isBypass() { return m_bypass; }
/// Toggle the bypass effect
void toggleBypass() { m_bypass = !m_bypass; }
/// Set the output volume. This affect both the wet and dry signals.
/// @details The default is 1.0.
/// @param vol Sets the output volume between -1.0 and +1.0
void volume(float vol) {m_volume = vol; }
// ** ENABLE / DISABLE **
/// Enables audio processing. Note: when not enabled, CPU load is nearly zero.
void enable() { m_enable = true; }
/// Disables audio process. When disabled, CPU load is nearly zero.
void disable() { m_enable = false; }
// ** MIDI **
/// Sets whether MIDI OMNI channel is processig on or off. When on,
/// all midi channels are used for matching CCs.
/// @param isOmni when true, all channels are processed, when false, channel
/// must match configured value.
void setMidiOmni(bool isOmni) { m_isOmni = isOmni; }
/// Configure an effect parameter to be controlled by a MIDI CC
/// number on a particular channel.
/// @param parameter one of the parameter names in the class enum
/// @param midiCC the CC number from 0 to 127
/// @param midiChannel the effect will only response to the CC on this channel
/// when OMNI mode is off.
void mapMidiControl(int parameter, int midiCC, int midiChannel = 0);
/// process a MIDI Continous-Controller (CC) message
/// @param channel the MIDI channel from 0 to 15)
/// @param midiCC the CC number from 0 to 127
/// @param value the CC value from 0 to 127
void processMidi(int channel, int midiCC, int value);
virtual void update(void); ///< update automatically called by the Teesny Audio Library
private:
audio_block_t *m_inputQueueArray[1];
BALibrary::LowFrequencyOscillatorVector<float> m_osc;
int m_midiConfig[NUM_CONTROLS][2]; // stores the midi parameter mapping
bool m_isOmni = false;
bool m_bypass = true;
bool m_enable = false;
float m_rate = 0.0f;
float m_depth = 0.0f;
BALibrary::Waveform m_waveform = BALibrary::Waveform::SINE;
float m_volume = 1.0f;
};
}
#endif /* __BAEFFECTS_AUDIOEFFECTTREMOLO_H */

1
src/BAEffects.h
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#include "BAAudioEffectDelayExternal.h" #include "BAAudioEffectDelayExternal.h"
#include "AudioEffectAnalogDelay.h" #include "AudioEffectAnalogDelay.h"
#include "AudioEffectSOS.h" #include "AudioEffectSOS.h"
#include "AudioEffectTremolo.h"
#endif /* __BAEFFECTS_H */ #endif /* __BAEFFECTS_H */

59
src/LibBasicFunctions.h
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#include <cstddef> #include <cstddef>
#include <new> #include <new>
#include <atomic>
#include <arm_math.h> #include <arm_math.h>
#include "Arduino.h" #include "Arduino.h"
@ -396,6 +397,64 @@ private:
bool m_running = false; bool m_running = false;
}; };
/// Supported LFO waveforms
enum class Waveform : unsigned {
SINE, ///< sinewave
TRIANGLE, ///< triangle wave
SQUARE, ///< square wave
SAWTOOTH, ///< sawtooth wave
RANDOM, ///< a non-repeating random waveform
NUM_WAVEFORMS, ///< the number of defined waveforms
};
/**************************************************************************//**
* The LFO is commonly used on modulation effects where some parameter (delay,
* volume, etc.) is modulated via waveform at a frequency below 20 Hz. Waveforms
* vary between -1.0f and +1.0f.
* @details this LFO is for operating on vectors of audio block samples.
*****************************************************************************/
template <class T>
class LowFrequencyOscillatorVector {
public:
/// Default constructor, uses SINE as default waveform
LowFrequencyOscillatorVector() {}
/// Specifies the desired waveform at construction time.
/// @param waveform specifies desired waveform
LowFrequencyOscillatorVector(Waveform waveform) : m_waveform(waveform) {};
/// Default destructor
~LowFrequencyOscillatorVector() {}
/// Change the waveform
/// @param waveform specifies desired waveform
void setWaveform(Waveform waveform) { m_waveform = waveform; }
/// Set the LFO rate in Hertz
/// @param frequencyHz the LFO frequency in Hertz
void setRateAudio(float frequencyHz);
/// Set the LFO rate as a fraction
/// @param ratio the radians/sample will be 2*pi*ratio
void setRateRatio(float ratio);
/// Get the next waveform value
/// @returns the next vector of phase values
T *getNextVector();
private:
void m_updatePhase(); ///< called internally when updating the phase vector
void m_initPhase(T radiansPerSample); ///< called internally to reset phase upon rate change
Waveform m_waveform = Waveform::SINE; ///< LFO waveform
T m_phaseVec[AUDIO_BLOCK_SAMPLES]; ///< the vector of next phase values
T m_radiansPerBlock = 0.0f; ///< stores the change in radians over one block of data
T m_outputVec[AUDIO_BLOCK_SAMPLES]; ///< stores the output LFO values
std::atomic_flag m_phaseLock = ATOMIC_FLAG_INIT; ///< used for thread-safety on m_phaseVec
const T PI_F = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899; ///< 2*PI
const T TWO_PI_F = 2.0 * 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899; ///< 2*PI
const T PI_DIV2_F = 0.5 * 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899; ///< PI/2
};
} // BALibrary } // BALibrary

145
src/common/LowFrequencyOscillator.cpp
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/*
* LowFrequencyOscillator.cpp
*
* Created on: October 12, 2018
* Author: Steve Lascos
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.*
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include "Audio.h"
#include "LibBasicFunctions.h"
namespace BALibrary {
template <class T>
void LowFrequencyOscillatorVector<T>::m_initPhase(T radiansPerSample)
{
// Initialize the phase vector starting at 0 radians, and incrementing
// by radiansPerSample for each element in the vector.
T initialPhase[AUDIO_BLOCK_SAMPLES];
for (auto i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
initialPhase[i] = (T)i * radiansPerSample;
}
m_radiansPerBlock = radiansPerSample * (T)AUDIO_BLOCK_SAMPLES;
// there could be different threads controlling the LFO rate and consuming
// the LFO output, so we need to protected the m_phaseVec for thread-safety.
while (m_phaseLock.test_and_set()) {}
memcpy(m_phaseVec, initialPhase, sizeof(T)*AUDIO_BLOCK_SAMPLES);
m_phaseLock.clear();
}
// This function takes in the frequency of the LFO in hertz and uses knowledge
// about the the audio sample rate to calcuate the correct radians per sample.
template <class T>
void LowFrequencyOscillatorVector<T>::setRateAudio(float frequencyHz)
{
T radiansPerSample;
if (frequencyHz == 0) {
radiansPerSample = 0;
} else {
T periodSamples = AUDIO_SAMPLE_RATE_EXACT / frequencyHz;
radiansPerSample = (T)TWO_PI_F / periodSamples;
}
m_initPhase(radiansPerSample);
}
// This function is used when the LFO is being called at some rate other than
// the audio rate. Here you can manually set the radians per sample as a fraction
// of 2*PI
template <class T>
void LowFrequencyOscillatorVector<T>::setRateRatio(float ratio)
{
T radiansPerSample;
if (ratio == 0) {
radiansPerSample = 0;
} else {
radiansPerSample = (T)TWO_PI_F * ratio;
}
m_initPhase(radiansPerSample);
}
// When this function is called, it will update the phase vector by incrementing by
// radians per block which is radians per sample * block size.
template <class T>
inline void LowFrequencyOscillatorVector<T>::m_updatePhase()
{
if (m_phaseLock.test_and_set()) { return; }
if (m_phaseVec[0] > TWO_PI_F) {
arm_offset_f32(m_phaseVec, -TWO_PI_F + m_radiansPerBlock, m_phaseVec, AUDIO_BLOCK_SAMPLES);
} else {
arm_offset_f32(m_phaseVec, m_radiansPerBlock, m_phaseVec, AUDIO_BLOCK_SAMPLES);
}
m_phaseLock.clear();
}
// This function will compute the vector of samples for the output waveform using
// the current phase vector.
template <class T>
T *LowFrequencyOscillatorVector<T>::getNextVector()
{
switch(m_waveform) {
case Waveform::SINE :
for (auto i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
m_outputVec[i] = arm_sin_f32(m_phaseVec[i]);
}
break;
case Waveform::SQUARE :
for (auto i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
if (m_phaseVec[i] > 3*PI_F) {
m_outputVec[i] = 0.0f;
}
else if (m_phaseVec[i] > 2*PI_F) {
m_outputVec[i] = 1.0f;
}
else if (m_phaseVec[i] > PI_F) {
m_outputVec[i] = 0.0f;
} else {
m_outputVec[i] = 1.0f;
}
}
break;
case Waveform::TRIANGLE :
// for (auto i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
// if (m_phaseVec[i] > 3*PI_F) {
// m_outputVec[i] = ;
// }
// else if (m_phaseVec[i] > 2*PI_F) {
// m_outputVec[i] = 1.0f;
// }
// else if (m_phaseVec[i] > PI_F) {
// m_outputVec[i] = 0.0f;
// } else {
// m_outputVec[i] = 1.0f;
// }
// }
break;
case Waveform::RANDOM :
break;
default :
assert(0); // This occurs if a Waveform type is missing from the switch statement
}
m_updatePhase();
return m_outputVec;
}
template class LowFrequencyOscillatorVector<float>;
} // namespace BALibrary

0
src/effects/BAAudioEffectDelayExternal.cpp → src/effects/AudioEffectDelayExternal.cpp
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163
src/effects/AudioEffectTremolo.cpp
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@ -0,0 +1,163 @@
/*
* AudioEffectTremolo.cpp
*
* Created on: Jan 7, 2018
* Author: slascos
*/
#include <cmath> // std::roundf
#include "AudioEffectTremolo.h"
using namespace BALibrary;
namespace BAEffects {
constexpr int MIDI_CHANNEL = 0;
constexpr int MIDI_CONTROL = 1;
constexpr float MAX_RATE_HZ = 20.0f;
AudioEffectTremolo::AudioEffectTremolo()
: AudioStream(1, m_inputQueueArray)
{
m_osc.setWaveform(m_waveform);
}
AudioEffectTremolo::~AudioEffectTremolo()
{
}
void AudioEffectTremolo::update(void)
{
audio_block_t *inputAudioBlock = receiveWritable(); // get the next block of input samples
// Check is block is disabled
if (m_enable == false) {
// do not transmit or process any audio, return as quickly as possible.
if (inputAudioBlock) release(inputAudioBlock);
return;
}
// Check is block is bypassed, if so either transmit input directly or create silence
if (m_bypass == true) {
// transmit the input directly
if (!inputAudioBlock) {
// create silence
inputAudioBlock = allocate();
if (!inputAudioBlock) { return; } // failed to allocate
else {
clearAudioBlock(inputAudioBlock);
}
}
transmit(inputAudioBlock, 0);
release(inputAudioBlock);
return;
}
// DO PROCESSING
// apply modulation wave
float *mod = m_osc.getNextVector();
for (auto i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
mod[i] = (mod[i] + 1.0f) / 2.0f;
mod[i] = (1.0f - m_depth) + mod[i]*m_depth;
mod[i] = m_volume * mod[i];
float sample = std::roundf(mod[i] * (float)inputAudioBlock->data[i]);
inputAudioBlock->data[i] = (int16_t)sample;
}
//Serial.println(String("mod: ") + mod[0]);
//float mod = (m_osc.getNext()+1.0f)/2.0f; // value between -1.0 and +1.0f
//float modVolume = (1.0f - m_depth) + mod*m_depth; // value between 0 to depth
//float finalVolume = m_volume * modVolume;
// Set the output volume
//gainAdjust(inputAudioBlock, inputAudioBlock, finalVolume, 1);
transmit(inputAudioBlock);
release(inputAudioBlock);
}
void AudioEffectTremolo::rate(float rateValue)
{
float rateAudioBlock = rateValue * MAX_RATE_HZ;
m_osc.setRateAudio(rateAudioBlock);
}
void AudioEffectTremolo::setWaveform(Waveform waveform)
{
m_waveform = waveform;
m_osc.setWaveform(waveform);
}
void AudioEffectTremolo::processMidi(int channel, int control, int value)
{
float val = (float)value / 127.0f;
if ((m_midiConfig[BYPASS][MIDI_CHANNEL] == channel) &&
(m_midiConfig[BYPASS][MIDI_CONTROL] == control)) {
// Bypass
if (value >= 65) { bypass(false); Serial.println(String("AudioEffectTremolo::not bypassed -> ON") + value); }
else { bypass(true); Serial.println(String("AudioEffectTremolo::bypassed -> OFF") + value); }
return;
}
if ((m_midiConfig[RATE][MIDI_CHANNEL] == channel) &&
(m_midiConfig[RATE][MIDI_CONTROL] == control)) {
// Rate
rate(val);
Serial.println(String("AudioEffectTremolo::rate: ") + m_rate);
return;
}
if ((m_midiConfig[DEPTH][MIDI_CHANNEL] == channel) &&
(m_midiConfig[DEPTH][MIDI_CONTROL] == control)) {
// Depth
depth(val);
Serial.println(String("AudioEffectTremolo::depth: ") + m_depth);
return;
}
if ((m_midiConfig[WAVEFORM][MIDI_CHANNEL] == channel) &&
(m_midiConfig[WAVEFORM][MIDI_CONTROL] == control)) {
// Waveform
if (value < 16) {
m_waveform = Waveform::SINE;
} else if (value < 32) {
m_waveform = Waveform::TRIANGLE;
} else if (value < 48) {
m_waveform = Waveform::SQUARE;
} else if (value < 64) {
m_waveform = Waveform::SAWTOOTH;
} else if (value < 80) {
m_waveform = Waveform::RANDOM;
}
Serial.println(String("AudioEffectTremolo::waveform: ") + static_cast<unsigned>(m_waveform));
return;
}
if ((m_midiConfig[VOLUME][MIDI_CHANNEL] == channel) &&
(m_midiConfig[VOLUME][MIDI_CONTROL] == control)) {
// Volume
Serial.println(String("AudioEffectTremolo::volume: ") + 100*val + String("%"));
volume(val);
return;
}
}
void AudioEffectTremolo::mapMidiControl(int parameter, int midiCC, int midiChannel)
{
if (parameter >= NUM_CONTROLS) {
return ; // Invalid midi parameter
}
m_midiConfig[parameter][MIDI_CHANNEL] = midiChannel;
m_midiConfig[parameter][MIDI_CONTROL] = midiCC;
}
}
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