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Initial chorus development check in

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feature/AudioEffectAnalogChorus
Steve Lascos 6 years ago
parent 362d0928d2
commit 9b09021ef0
6 changed files with 617 additions and 129 deletions
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  1. 217
      examples/Modulation/AnalogChorusDemoExpansion/AnalogChorusDemoExpansion.ino
  2. 19
      examples/Modulation/AnalogChorusDemoExpansion/name.c
  3. 196
      src/AudioEffectAnalogChorus.h
  4. 1
      src/BAEffects.h
  5. 172
      src/effects/AudioEffectAnalogChorus.cpp
  6. 83
      src/effects/AudioEffectAnalogChorusFilters.h

217
examples/Modulation/AnalogChorusDemoExpansion/AnalogChorusDemoExpansion.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 BAAudioEffectsAnalogChorus effect. It can
* be controlled using the Blackaddr Audio "Expansion Control Board".
*
* POT1 (left) controls the modulation rate
* POT2 (right) controls the modulation depth
* 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;
//#define USE_EXT // uncomment this line to use External MEM0
#ifdef USE_EXT
// If using external SPI memory, we will instantiate a SRAM
// manager and create an external memory slot to use as the memory
// for our audio delay
ExternalSramManager externalSram;
ExtMemSlot delaySlot; // Declare an external memory slot.
// Instantiate the AudioEffectAnalogChorus to use external memory by
/// passing it the delay slot.
AudioEffectAnalogChorus analogChorus(&delaySlot);
#else
AudioEffectAnalogChorus analogChorus; // default chorus delays
#endif
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, analogChorus,0);
AudioConnection chorusOut(analogChorus, 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 wet/dry mix.
// - 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 three built in analog filter styles available.
// - 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 filterIndex = 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, filterHandle, rateHandle, depthHandle, mixHandle, 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
filterHandle = 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);
mixHandle = 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
// If using external memory request request memory from the manager
// for the slot
#ifdef USE_EXT
Serial.println("Using EXTERNAL memory");
// We have to request memory be allocated to our slot.
externalSram.requestMemory(&delaySlot, 40.0f, MemSelect::MEM0, true); // 40 ms is enough to handle the full range of the chorus delay
#else
Serial.println("Using INTERNAL memory");
#endif
// Besure to enable the delay. When disabled, audio is is completely blocked by the effect
// to minimize resource usage to nearly to nearly zero.
analogChorus.enable();
// Set some default values.
// These can be changed using the controls on the Blackaddr Audio Expansion Board
analogChorus.bypass(false);
analogChorus.rate(0.5f);
analogChorus.mix(0.5f);
analogChorus.depth(1.0f);
//////////////////////////////////
// AnalogChorus filter selection //
// These are commented out, in this example we'll use SW2 to cycle through the different filters
//analogChorus.setFilter(AudioEffectAnalogChorus::Filter::CE2); // The default filter. Naturally bright echo (highs stay, lows fade away)
//analogChorus.setFilter(AudioEffectAnalogChorus::Filter::WARM); // A warm filter with a smooth frequency rolloff above 2Khz
//analogChorus.setFilter(AudioEffectAnalogChorus::Filter::DARK); // A very dark filter, with a sharp rolloff above 1Khz
// 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 = analogChorus.isBypass(); // get the current state
bypass = !bypass; // change it
analogChorus.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 filters
controls.setOutput(led2Handle, controls.getSwitchValue(led2Handle));
if (controls.isSwitchToggled(filterHandle)) {
filterIndex = (filterIndex + 1) % 3; // update and potentionall roll the counter 0, 1, 2, 0, 1, 2, ...
// cast the index between 0 to 2 to the enum class AudioEffectAnalogChorus::Filter
analogChorus.setFilter(static_cast<AudioEffectAnalogChorus::Filter>(filterIndex)); // will cycle through 0 to 2
Serial.println(String("Filter set to ") + filterIndex);
}
// Use POT1 (left) to control the rate setting
if (controls.checkPotValue(rateHandle, potValue)) {
// Pot has changed
Serial.println(String("New RATE setting: ") + potValue);
analogChorus.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);
analogChorus.depth(potValue);
}
// Use POT3 (centre) to control the mix setting
if (controls.checkPotValue(mixHandle, potValue)) {
// Pot has changed
Serial.println(String("New MIX setting: ") + potValue);
analogChorus.mix(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) {
Serial.print("Processor Usage, Total: "); Serial.print(AudioProcessorUsage());
Serial.print("% ");
Serial.print(" AnalogChorus: "); Serial.print(analogChorus.processorUsage());
Serial.println("%");
}
loopCount++;
}

19
examples/Modulation/AnalogChorusDemoExpansion/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
};

196
src/AudioEffectAnalogChorus.h
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/**************************************************************************//**
* @file
* @author Steve Lascos
* @company Blackaddr Audio
*
* AudioEffectAnalogChorus is a class for simulating a classic BBD based chorus
* like the Boss CE-2. This class works with either internal RAM, or external
* SPI RAM. The external RAM uses DMA to minimize load on the
* CPU.
*
* @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; 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_BAAUDIOEFFECTANALOGCHORUS_H
#define __BAEFFECTS_BAAUDIOEFFECTANALOGCHORUS_H
#include <Audio.h>
#include "LibBasicFunctions.h"
namespace BAEffects {
/**************************************************************************//**
* AudioEffectAnalogChorus models BBD based analog chorus. It provides controls
* for rate, depth, mix and output level. All parameters can be
* controlled by MIDI. The class supports internal memory, or external SPI
* memory by providing an ExtMemSlot. External memory access uses DMA to reduce
* process load.
*****************************************************************************/
class AudioEffectAnalogChorus : public AudioStream {
public:
///< List of AudioEffectAnalogChorus MIDI controllable parameters
enum {
BYPASS = 0, ///< controls effect bypass
RATE, ///< controls the modulate rate of the LFO
DEPTH, ///< controls the depth of modulation of the LFO
MIX, ///< controls the the mix of input and chorus signals
VOLUME, ///< controls the output volume level
NUM_CONTROLS ///< this can be used as an alias for the number of MIDI controls
};
enum class Filter {
CE2 = 0,
WARM,
DARK
};
/// Construct an analog chorus using internal memory. The chorus will have the
/// default average delay.
AudioEffectAnalogChorus();
/// Construct an analog chorus using external SPI via an ExtMemSlot. The chorus will have
/// the default average delay.
/// @param slot A pointer to the ExtMemSlot to use for the delay.
AudioEffectAnalogChorus(BALibrary::ExtMemSlot *slot); // requires sufficiently sized pre-allocated memory
virtual ~AudioEffectAnalogChorus(); ///< Destructor
// *** PARAMETERS ***
/// Set the chorus average delay in milliseconds
/// The value should be between 0.0f and 1.0f
void setDelayConfig(float averageDelayMs, float delayRangeMs);
/// Set the chorus average delay in number of audio samples
/// The value should be between 0.0f and 1.0f
void setDelayConfig(size_t averageDelayNumSamples, size_t delayRangeNumSamples);
/// 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 LFO frequency where 0.0f is MIN and 1.0f is MAX
void rate(float rate);
/// Set the depth of LFO modulation.
/// @param lfoDepth must be a float between 0.0f and 1.0f
void depth(float lfoDepth) { m_lfoDepth = lfoDepth; }
/// Set the amount of blending between dry and wet (echo) at the output.
/// @param mix When 0.0, output is 100% dry, when 1.0, output is 100% wet. When
/// 0.5, output is 50% Dry, 50% Wet.
void mix(float mix) { m_mix = mix; }
/// 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);
// ** FILTER COEFFICIENTS **
/// Set the filter coefficients to one of the presets. See AudioEffectAnalogChorus::Filter
/// for options.
/// @details See AudioEffectAnalogChorusFIlters.h for more details.
/// @param filter the preset filter. E.g. AudioEffectAnalogChorus::Filter::WARM
void setFilter(Filter filter);
/// Override the default coefficients with your own. The number of filters stages affects how
/// much CPU is consumed.
/// @details The effect uses the CMSIS-DSP library for biquads which requires coefficents.
/// be in q31 format, which means they are 32-bit signed integers representing -1.0 to slightly
/// less than +1.0. The coeffShift parameter effectively multiplies the coefficients by 2^shift. <br>
/// Example: If you really want +1.5, must instead use +0.75 * 2^1, thus 0.75 in q31 format is
/// (0.75 * 2^31) = 1610612736 and coeffShift = 1.
/// @param numStages the actual number of filter stages you want to use. Must be <= MAX_NUM_FILTER_STAGES.
/// @param coeffs pointer to an integer array of coefficients in q31 format.
/// @param coeffShift Coefficient scaling factor = 2^coeffShift.
void setFilterCoeffs(int numStages, const int32_t *coeffs, int coeffShift);
virtual void update(void); ///< update automatically called by the Teesny Audio Library
private:
static constexpr float m_DEFAULT_DELAY_MS = 20.0f; ///< default average delay of chorus in milliseconds
static constexpr float m_DELAY_RANGE = 15.0f; ///< default range of delay variation in milliseconds
static constexpr float m_LFO_MIN_RATE = 2.0f; ///< slowest possible LFO rate in milliseconds
static constexpr float m_LFO_RANGE = 8.0f; ///< fastest possible LFO rate in milliseconds
audio_block_t *m_inputQueueArray[1];
bool m_isOmni = false;
bool m_bypass = true;
bool m_enable = false;
bool m_externalMemory = false;
BALibrary::AudioDelay *m_memory = nullptr;
BALibrary::LowFrequencyOscillatorVector<float> m_lfo;
size_t m_maxDelaySamples = 0;
audio_block_t *m_previousBlock = nullptr;
audio_block_t *m_blockToRelease = nullptr;
BALibrary::IirBiQuadFilterHQ *m_iir = nullptr;
// Controls
int m_midiConfig[NUM_CONTROLS][2]; // stores the midi parameter mapping
size_t m_delaySamples = 0;
float m_lfoDepth = 0.0f;
float m_mix = 0.0f;
float m_volume = 1.0f;
void m_preProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet);
void m_postProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet);
// Coefficients
void m_constructFilter(void);
};
}
#endif /* __BAEFFECTS_BAAUDIOEFFECTAnalogChorus_H */

1
src/BAEffects.h
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@ -26,5 +26,6 @@
#include "AudioEffectAnalogDelay.h" #include "AudioEffectAnalogDelay.h"
#include "AudioEffectSOS.h" #include "AudioEffectSOS.h"
#include "AudioEffectTremolo.h" #include "AudioEffectTremolo.h"
#include "AudioEffectAnalogChorus.h"
#endif /* __BAEFFECTS_H */ #endif /* __BAEFFECTS_H */

172
src/effects/AudioEffectAnalogDelay.cpp.interpolated → src/effects/AudioEffectAnalogChorus.cpp
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@ -1,40 +1,32 @@
/* /*
* AudioEffectAnalogDelay.cpp * AudioEffectAnalogChorus.cpp
* *
* Created on: Jan 7, 2018 * Created on: Jan 7, 2018
* Author: slascos * Author: slascos
*/ */
#include <new> #include <new>
#include "AudioEffectAnalogDelayFilters.h" #include "AudioEffectAnalogChorusFilters.h"
#include "AudioEffectAnalogDelay.h" #include "AudioEffectAnalogChorus.h"
using namespace BALibrary; using namespace BALibrary;
#define INTERPOLATED_DELAY Uncomment this line to test the inteprolated delay which adds 1/10th of a sample //#define INTERPOLATED_DELAY Uncomment this line to test the inteprolated delay which adds 1/10th of a sample
namespace BAEffects { namespace BAEffects {
constexpr int MIDI_CHANNEL = 0; constexpr int MIDI_CHANNEL = 0;
constexpr int MIDI_CONTROL = 1; constexpr int MIDI_CONTROL = 1;
AudioEffectAnalogDelay::AudioEffectAnalogDelay(float maxDelayMs) AudioEffectAnalogChorus::AudioEffectAnalogChorus()
: AudioStream(1, m_inputQueueArray) : AudioStream(1, m_inputQueueArray)
{ {
m_memory = new AudioDelay(maxDelayMs); m_memory = new AudioDelay(m_DEFAULT_DELAY_MS + m_DELAY_RANGE);
m_maxDelaySamples = calcAudioSamples(maxDelayMs); m_maxDelaySamples = calcAudioSamples(m_DEFAULT_DELAY_MS + m_DELAY_RANGE);
m_constructFilter();
}
AudioEffectAnalogDelay::AudioEffectAnalogDelay(size_t numSamples)
: AudioStream(1, m_inputQueueArray)
{
m_memory = new AudioDelay(numSamples);
m_maxDelaySamples = numSamples;
m_constructFilter(); m_constructFilter();
} }
// requires preallocated memory large enough // requires preallocated memory large enough
AudioEffectAnalogDelay::AudioEffectAnalogDelay(ExtMemSlot *slot) AudioEffectAnalogChorus::AudioEffectAnalogChorus(ExtMemSlot *slot)
: AudioStream(1, m_inputQueueArray) : AudioStream(1, m_inputQueueArray)
{ {
m_memory = new AudioDelay(slot); m_memory = new AudioDelay(slot);
@ -43,25 +35,25 @@ AudioEffectAnalogDelay::AudioEffectAnalogDelay(ExtMemSlot *slot)
m_constructFilter(); m_constructFilter();
} }
AudioEffectAnalogDelay::~AudioEffectAnalogDelay() AudioEffectAnalogChorus::~AudioEffectAnalogChorus()
{ {
if (m_memory) delete m_memory; if (m_memory) delete m_memory;
if (m_iir) delete m_iir; if (m_iir) delete m_iir;
} }
// This function just sets up the default filter and coefficients // This function just sets up the default filter and coefficients
void AudioEffectAnalogDelay::m_constructFilter(void) void AudioEffectAnalogChorus::m_constructFilter(void)
{ {
// Use DM3 coefficients by default // Use CE2 coefficients by default
m_iir = new IirBiQuadFilterHQ(DM3_NUM_STAGES, reinterpret_cast<const int32_t *>(&DM3), DM3_COEFF_SHIFT); m_iir = new IirBiQuadFilterHQ(CE2_NUM_STAGES, reinterpret_cast<const int32_t *>(&CE2), CE2_COEFF_SHIFT);
} }
void AudioEffectAnalogDelay::setFilterCoeffs(int numStages, const int32_t *coeffs, int coeffShift) void AudioEffectAnalogChorus::setFilterCoeffs(int numStages, const int32_t *coeffs, int coeffShift)
{ {
m_iir->changeFilterCoeffs(numStages, coeffs, coeffShift); m_iir->changeFilterCoeffs(numStages, coeffs, coeffShift);
} }
void AudioEffectAnalogDelay::setFilter(Filter filter) void AudioEffectAnalogChorus::setFilter(Filter filter)
{ {
switch(filter) { switch(filter) {
case Filter::WARM : case Filter::WARM :
@ -70,14 +62,14 @@ void AudioEffectAnalogDelay::setFilter(Filter filter)
case Filter::DARK : case Filter::DARK :
m_iir->changeFilterCoeffs(DARK_NUM_STAGES, reinterpret_cast<const int32_t *>(&DARK), DARK_COEFF_SHIFT); m_iir->changeFilterCoeffs(DARK_NUM_STAGES, reinterpret_cast<const int32_t *>(&DARK), DARK_COEFF_SHIFT);
break; break;
case Filter::DM3 : case Filter::CE2 :
default: default:
m_iir->changeFilterCoeffs(DM3_NUM_STAGES, reinterpret_cast<const int32_t *>(&DM3), DM3_COEFF_SHIFT); m_iir->changeFilterCoeffs(CE2_NUM_STAGES, reinterpret_cast<const int32_t *>(&CE2), CE2_COEFF_SHIFT);
break; break;
} }
} }
void AudioEffectAnalogDelay::update(void) void AudioEffectAnalogChorus::update(void)
{ {
audio_block_t *inputAudioBlock = receiveReadOnly(); // get the next block of input samples audio_block_t *inputAudioBlock = receiveReadOnly(); // get the next block of input samples
@ -179,9 +171,36 @@ void AudioEffectAnalogDelay::update(void)
m_blockToRelease = blockToRelease; m_blockToRelease = blockToRelease;
} }
void AudioEffectAnalogDelay::delay(float milliseconds) void AudioEffectAnalogChorus::m_preProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet)
{
memcpy(out->data, dry->data, sizeof(int16_t) * AUDIO_BLOCK_SAMPLES);
// if ( out && dry && wet) {
// alphaBlend(out, dry, wet, m_feedback);
// m_iir->process(out->data, out->data, AUDIO_BLOCK_SAMPLES);
// } else if (dry) {
// memcpy(out->data, dry->data, sizeof(int16_t) * AUDIO_BLOCK_SAMPLES);
// }
}
void AudioEffectAnalogChorus::m_postProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet)
{
if (!out) return; // no valid output buffer
if ( out && dry && wet) {
// Simulate the LPF IIR nature of the analog systems
//m_iir->process(wet->data, wet->data, AUDIO_BLOCK_SAMPLES);
alphaBlend(out, dry, wet, m_mix);
} else if (dry) {
memcpy(out->data, dry->data, sizeof(int16_t) * AUDIO_BLOCK_SAMPLES);
}
// Set the output volume
gainAdjust(out, out, m_volume, 1);
}
void AudioEffectAnalogChorus::setDelayConfig(float averageDelayMs, float delayRangeMs)
{ {
size_t delaySamples = calcAudioSamples(milliseconds); size_t delaySamples = calcAudioSamples(averageDelayMs + delayRangeMs);
if (delaySamples > m_memory->getMaxDelaySamples()) { if (delaySamples > m_memory->getMaxDelaySamples()) {
// this exceeds max delay value, limit it. // this exceeds max delay value, limit it.
@ -192,11 +211,9 @@ void AudioEffectAnalogDelay::delay(float milliseconds)
if (!m_externalMemory) { if (!m_externalMemory) {
// internal memory // internal memory
//QueuePosition queuePosition = calcQueuePosition(milliseconds); // Do nothing
//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
} else { } else {
// external memory // external memory
//Serial.println(String("CONFIG: delay:") + delaySamples);
ExtMemSlot *slot = m_memory->getSlot(); ExtMemSlot *slot = m_memory->getSlot();
if (!slot) { Serial.println("ERROR: slot ptr is not valid"); } if (!slot) { Serial.println("ERROR: slot ptr is not valid"); }
@ -205,32 +222,11 @@ void AudioEffectAnalogDelay::delay(float milliseconds)
Serial.println("WEIRD: slot was not enabled"); Serial.println("WEIRD: slot was not enabled");
} }
} }
m_delaySamples = delaySamples;
} }
void AudioEffectAnalogDelay::delay(size_t delaySamples) void AudioEffectAnalogChorus::setDelayConfig(size_t averageDelayNumSamples, size_t delayRangeNumSamples)
{ {
if (!m_memory) { Serial.println("delay(): m_memory is not valid"); } size_t delaySamples = averageDelayNumSamples + delayRangeNumSamples;
if (!m_externalMemory) {
// internal memory
//QueuePosition queuePosition = calcQueuePosition(delaySamples);
//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
} else {
// external memory
//Serial.println(String("CONFIG: delay:") + delaySamples);
ExtMemSlot *slot = m_memory->getSlot();
if (!slot->isEnabled()) {
slot->enable();
}
}
m_delaySamples = delaySamples;
}
void AudioEffectAnalogDelay::delayFractionMax(float delayFraction)
{
size_t delaySamples = static_cast<size_t>(static_cast<float>(m_memory->getMaxDelaySamples()) * delayFraction);
if (delaySamples > m_memory->getMaxDelaySamples()) { if (delaySamples > m_memory->getMaxDelaySamples()) {
// this exceeds max delay value, limit it. // this exceeds max delay value, limit it.
@ -241,82 +237,58 @@ void AudioEffectAnalogDelay::delayFractionMax(float delayFraction)
if (!m_externalMemory) { if (!m_externalMemory) {
// internal memory // internal memory
//QueuePosition queuePosition = calcQueuePosition(delaySamples); // Do nothing
//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
} else { } else {
// external memory // external memory
//Serial.println(String("CONFIG: delay:") + delaySamples);
ExtMemSlot *slot = m_memory->getSlot(); ExtMemSlot *slot = m_memory->getSlot();
if (!slot) { Serial.println("ERROR: slot ptr is not valid"); }
if (!slot->isEnabled()) { if (!slot->isEnabled()) {
slot->enable(); slot->enable();
Serial.println("WEIRD: slot was not enabled");
} }
} }
m_delaySamples = delaySamples;
} }
void AudioEffectAnalogDelay::m_preProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet) void AudioEffectAnalogChorus::rate(float rate)
{ {
if ( out && dry && wet) { // update the LFO by mapping the rate into the MIN/MAX range, pass to LFO in milliseconds
alphaBlend(out, dry, wet, m_feedback); m_lfo.setRateAudio(m_LFO_MIN_RATE + (rate * m_LFO_RANGE));
m_iir->process(out->data, out->data, AUDIO_BLOCK_SAMPLES);
} else if (dry) {
memcpy(out->data, dry->data, sizeof(int16_t) * AUDIO_BLOCK_SAMPLES);
} }
}
void AudioEffectAnalogDelay::m_postProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet)
{
if (!out) return; // no valid output buffer
if ( out && dry && wet) {
// Simulate the LPF IIR nature of the analog systems
//m_iir->process(wet->data, wet->data, AUDIO_BLOCK_SAMPLES);
alphaBlend(out, dry, wet, m_mix);
} else if (dry) {
memcpy(out->data, dry->data, sizeof(int16_t) * AUDIO_BLOCK_SAMPLES);
}
// Set the output volume
gainAdjust(out, out, m_volume, 1);
}
void AudioEffectAnalogDelay::processMidi(int channel, int control, int value) void AudioEffectAnalogChorus::processMidi(int channel, int control, int value)
{ {
float val = (float)value / 127.0f; float val = (float)value / 127.0f;
if ((m_midiConfig[DELAY][MIDI_CHANNEL] == channel) && if ((m_midiConfig[RATE][MIDI_CHANNEL] == channel) &&
(m_midiConfig[DELAY][MIDI_CONTROL] == control)) { (m_midiConfig[RATE][MIDI_CONTROL] == control)) {
// Delay // Rate
if (m_externalMemory) { m_maxDelaySamples = m_memory->getSlot()->size() / sizeof(int16_t); } Serial.println(String("AudioEffectAnalogChorus::rate: ") + 100*val + String("%"));
size_t delayVal = (size_t)(val * (float)m_maxDelaySamples); rate(val);
delay(delayVal);
Serial.println(String("AudioEffectAnalogDelay::delay (ms): ") + calcAudioTimeMs(delayVal)
+ String(" (samples): ") + delayVal + String(" out of ") + m_maxDelaySamples);
return; return;
} }
if ((m_midiConfig[BYPASS][MIDI_CHANNEL] == channel) && if ((m_midiConfig[BYPASS][MIDI_CHANNEL] == channel) &&
(m_midiConfig[BYPASS][MIDI_CONTROL] == control)) { (m_midiConfig[BYPASS][MIDI_CONTROL] == control)) {
// Bypass // Bypass
if (value >= 65) { bypass(false); Serial.println(String("AudioEffectAnalogDelay::not bypassed -> ON") + value); } if (value >= 65) { bypass(false); Serial.println(String("AudioEffectAnalogChorus::not bypassed -> ON") + value); }
else { bypass(true); Serial.println(String("AudioEffectAnalogDelay::bypassed -> OFF") + value); } else { bypass(true); Serial.println(String("AudioEffectAnalogChorus::bypassed -> OFF") + value); }
return; return;
} }
if ((m_midiConfig[FEEDBACK][MIDI_CHANNEL] == channel) && if ((m_midiConfig[DEPTH][MIDI_CHANNEL] == channel) &&
(m_midiConfig[FEEDBACK][MIDI_CONTROL] == control)) { (m_midiConfig[DEPTH][MIDI_CONTROL] == control)) {
// Feedback // depth
Serial.println(String("AudioEffectAnalogDelay::feedback: ") + 100*val + String("%")); Serial.println(String("AudioEffectAnalogChorus::depth: ") + 100*val + String("%"));
feedback(val); depth(val);
return; return;
} }
if ((m_midiConfig[MIX][MIDI_CHANNEL] == channel) && if ((m_midiConfig[MIX][MIDI_CHANNEL] == channel) &&
(m_midiConfig[MIX][MIDI_CONTROL] == control)) { (m_midiConfig[MIX][MIDI_CONTROL] == control)) {
// Mix // Mix
Serial.println(String("AudioEffectAnalogDelay::mix: Dry: ") + 100*(1-val) + String("% Wet: ") + 100*val ); Serial.println(String("AudioEffectAnalogChorus::mix: Dry: ") + 100*(1-val) + String("% Wet: ") + 100*val );
mix(val); mix(val);
return; return;
} }
@ -324,14 +296,14 @@ void AudioEffectAnalogDelay::processMidi(int channel, int control, int value)
if ((m_midiConfig[VOLUME][MIDI_CHANNEL] == channel) && if ((m_midiConfig[VOLUME][MIDI_CHANNEL] == channel) &&
(m_midiConfig[VOLUME][MIDI_CONTROL] == control)) { (m_midiConfig[VOLUME][MIDI_CONTROL] == control)) {
// Volume // Volume
Serial.println(String("AudioEffectAnalogDelay::volume: ") + 100*val + String("%")); Serial.println(String("AudioEffectAnalogChorus::volume: ") + 100*val + String("%"));
volume(val); volume(val);
return; return;
} }
} }
void AudioEffectAnalogDelay::mapMidiControl(int parameter, int midiCC, int midiChannel) void AudioEffectAnalogChorus::mapMidiControl(int parameter, int midiCC, int midiChannel)
{ {
if (parameter >= NUM_CONTROLS) { if (parameter >= NUM_CONTROLS) {
return ; // Invalid midi parameter return ; // Invalid midi parameter

83
src/effects/AudioEffectAnalogChorusFilters.h
Unescape View File

@ -0,0 +1,83 @@
/**************************************************************************//**
* @file
* @author Steve Lascos
* @company Blackaddr Audio
*
* This file constains precomputed co-efficients for the AudioEffectAnalogChorus
* class.
*
* @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; 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 <cstdint>
namespace BAEffects {
// The number of stages in the analog-response Biquad filter
constexpr unsigned MAX_NUM_FILTER_STAGES = 4;
constexpr unsigned NUM_COEFFS_PER_STAGE = 5;
// Matlab/Octave can be helpful to design a filter. Once you have the IIR filter (bz,az) coefficients
// in the z-domain, they can be converted to second-order-sections. AudioEffectAnalogChorus is designed
// to accept up to a maximum of an 8th order filter, broken into four, 2nd order stages.
//
// Second order sections can be created with:
// [sos] = tf2sos(bz,az);
// The results coefficents must be converted the Q31 format required by the ARM CMSIS-DSP library. This means
// all coefficients must lie between -1.0 and +0.9999. If your (bz,az) coefficients exceed this, you must divide
// them down by a power of 2. For example, if your largest magnitude coefficient is -3.5, you must divide by
// 2^shift where 4=2^2 and thus shift = 2. You must then mutliply by 2^31 to get a 32-bit signed integer value
// that represents the required Q31 coefficient.
// BOSS DM-3 Filters
// b(z) = 1.0e-03 * (0.0032 0.0257 0.0900 0.1800 0.2250 0.1800 0.0900 0.0257 0.0032)
// a(z) = 1.0000 -5.7677 14.6935 -21.3811 19.1491 -10.5202 3.2584 -0.4244 -0.0067
constexpr unsigned CE2_NUM_STAGES = 4;
constexpr unsigned CE2_COEFF_SHIFT = 2;
constexpr int32_t CE2[5*MAX_NUM_FILTER_STAGES] = {
536870912, 988616936, 455608573, 834606945, -482959709,
536870912, 1031466345, 498793368, 965834205, -467402235,
536870912, 1105821939, 573646688, 928470657, -448083489,
2339, 5093, 2776, 302068995, 4412722
};
// Blackaddr WARM Filter
// Butterworth, 8th order, cutoff = 2000 Hz
// Matlab/Octave command: [bz, az] = butter(8, 2000/44100/2);
// b(z) = 1.0e-05 * (0.0086 0.0689 0.2411 0.4821 0.6027 0.4821 0.2411 0.0689 0.0086_
// a(z) = 1.0000 -6.5399 18.8246 -31.1340 32.3473 -21.6114 9.0643 -2.1815 0.2306
constexpr unsigned WARM_NUM_STAGES = 4;
constexpr unsigned WARM_COEFF_SHIFT = 2;
constexpr int32_t WARM[5*MAX_NUM_FILTER_STAGES] = {
536870912,1060309346,523602393,976869875,-481046241,
536870912,1073413910,536711084,891250612,-391829326,
536870912,1087173998,550475248,835222426,-333446881,
46,92,46,807741349,-304811072
};
// Blackaddr DARK Filter
// Chebychev Type II, 8th order, stopband = 60db, cutoff = 1000 Hz
// Matlab command: [bz, az] = cheby2(8, 60, 1000/44100/2);
// b(z) = 0.0009 -0.0066 0.0219 -0.0423 0.0522 -0.0423 0.0219 -0.0066 0.0009
// a(z) = 1.0000 -7.4618 24.3762 -45.5356 53.1991 -39.8032 18.6245 -4.9829 0.5836
constexpr unsigned DARK_NUM_STAGES = 4;
constexpr unsigned DARK_COEFF_SHIFT = 1;
constexpr int32_t DARK[5*MAX_NUM_FILTER_STAGES] = {
1073741824,-2124867808,1073741824,2107780229,-1043948409,
1073741824,-2116080466,1073741824,2042553796,-979786242,
1073741824,-2077777790,1073741824,1964779896,-904264933,
957356,-1462833,957356,1896884898,-838694612
};
};
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