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BALibrary_parasitstudio/src/effects/AudioEffectAnalogChorus.cpp

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12 KiB

/*
* AudioEffectAnalogChorus.cpp
*
* Created on: Jan 7, 2018
* Author: slascos
*/
#include <new>
#include <cmath>
#include "AudioEffectAnalogChorusFilters.h"
#include "AudioEffectAnalogChorus.h"
using namespace BALibrary;
namespace BAEffects {
constexpr int MIDI_CHANNEL = 0;
constexpr int MIDI_CONTROL = 1;
constexpr float DELAY_REFERENCE_F = static_cast<float>(AUDIO_BLOCK_SAMPLES/2);
AudioEffectAnalogChorus::AudioEffectAnalogChorus()
: AudioStream(1, m_inputQueueArray)
{
m_memory = new AudioDelay(m_DEFAULT_AVERAGE_DELAY_MS + m_DELAY_RANGE);
m_maxDelaySamples = calcAudioSamples(m_DEFAULT_AVERAGE_DELAY_MS + m_DELAY_RANGE);
m_averageDelaySamples = static_cast<float>(calcAudioSamples(m_DEFAULT_AVERAGE_DELAY_MS));
m_delayRange = static_cast<float>(calcAudioSamples(m_DELAY_RANGE));
m_constructFilter();
m_lfo.setWaveform(Waveform::TRIANGLE);
m_lfo.setRateAudio(4.0f); // Default to 4 Hz
}
AudioEffectAnalogChorus::~AudioEffectAnalogChorus()
{
if (m_memory) delete m_memory;
if (m_iir) delete m_iir;
}
// This function just sets up the default filter and coefficients
void AudioEffectAnalogChorus::m_constructFilter(void)
{
// Use CE2 coefficients by default
m_iir = new IirBiQuadFilterHQ(CE2_NUM_STAGES, reinterpret_cast<const int32_t *>(&CE2), CE2_COEFF_SHIFT);
}
void AudioEffectAnalogChorus::setWaveform(BALibrary::Waveform waveform)
{
switch(waveform) {
case Waveform::SINE :
case Waveform::TRIANGLE :
case Waveform::SAWTOOTH :
m_lfo.setWaveform(waveform);
break;
default :
Serial.println("AudioEffectAnalogChorus::setWaveform: Unsupported Waveform");
}
}
void AudioEffectAnalogChorus::setFilterCoeffs(int numStages, const int32_t *coeffs, int coeffShift)
{
m_iir->changeFilterCoeffs(numStages, coeffs, coeffShift);
}
void AudioEffectAnalogChorus::setFilter(Filter filter)
{
switch(filter) {
case Filter::WARM :
m_iir->changeFilterCoeffs(WARM_NUM_STAGES, reinterpret_cast<const int32_t *>(&WARM), WARM_COEFF_SHIFT);
break;
case Filter::DARK :
m_iir->changeFilterCoeffs(DARK_NUM_STAGES, reinterpret_cast<const int32_t *>(&DARK), DARK_COEFF_SHIFT);
break;
case Filter::CE2 :
default:
m_iir->changeFilterCoeffs(CE2_NUM_STAGES, reinterpret_cast<const int32_t *>(&CE2), CE2_COEFF_SHIFT);
break;
}
}
void AudioEffectAnalogChorus::update(void)
{
audio_block_t *inputAudioBlock = receiveReadOnly(); // get the next block of input samples
// Check is block is disabled
if (m_enable == false) {
// do not transmit or proess any audio, return as quickly as possible.
if (inputAudioBlock) release(inputAudioBlock);
// release all held memory resources
if (m_previousBlock) {
release(m_previousBlock); m_previousBlock = nullptr;
}
if (!m_externalMemory) {
// when using internal memory we have to release all references in the ring buffer
while (m_memory->getRingBuffer()->size() > 0) {
audio_block_t *releaseBlock = m_memory->getRingBuffer()->front();
m_memory->getRingBuffer()->pop_front();
if (releaseBlock) release(releaseBlock);
}
}
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;
}
// Otherwise perform normal processing
// In order to make use of the SPI DMA, we need to request the read from memory first,
// then do other processing while it fills in the back.
audio_block_t *blockToOutput = nullptr; // this will hold the output audio
blockToOutput = allocate();
if (!blockToOutput) return; // skip this update cycle due to failure
// get the data. If using external memory with DMA, this won't be filled until
// later.
// We need to grab two blocks of audio since the modulating delay value from the LFO
// can exceed the length of one audio block during the time frame of one audio block.
int16_t extendedBuffer[(2*AUDIO_BLOCK_SAMPLES)]; // need one more sample for interpolating between 128th and 129th (last sample)
// Get next vector of lfo values, they will range range from -1.0 to +1.0f.
float *lfoValues = m_lfo.getNextVector();
//float lfoValues[128];
for (int i=0; i<128; i++) { lfoValues[i] = lfoValues[i] * m_lfoDepth; }
// Calculate the starting delay from the first lfo sample. This will represent the 'reference' delay
// for this output block
float referenceDelay = m_averageDelaySamples + (lfoValues[0] * m_delayRange);
unsigned delaySamples = static_cast<unsigned>(referenceDelay); // round down to the nearest audio sample for indexing into AudioDelay class
// From a given current delay value, while reading out the next 128, the delay could slew up or down
// AUDIO_BLOCK_SAMPLES/2 cycles of delay. For example...
// Pitching up : current + 128 + 64
// Pitching down: current - 64 + 128
// We need to grab 2*AUDIO_BLOCK_SAMPLES. Be aware that audio samples are stored BACKWARDS in the buffers.
// m_memory->getSamples(extendedBuffer , delaySamples - (AUDIO_BLOCK_SAMPLES/2), AUDIO_BLOCK_SAMPLES);
// m_memory->getSamples(extendedBuffer + AUDIO_BLOCK_SAMPLES, delaySamples +( AUDIO_BLOCK_SAMPLES/2), AUDIO_BLOCK_SAMPLES);
m_memory->getSamples(extendedBuffer + AUDIO_BLOCK_SAMPLES, delaySamples - (AUDIO_BLOCK_SAMPLES/2), AUDIO_BLOCK_SAMPLES);
m_memory->getSamples(extendedBuffer , delaySamples +( AUDIO_BLOCK_SAMPLES/2), AUDIO_BLOCK_SAMPLES);
// If using DMA, we need something else to do while that read executes, so
// move on to input preprocessing
// Preprocessing
audio_block_t *preProcessed = allocate();
// mix the input with the feedback path in the pre-processing stage
m_preProcessing(preProcessed, inputAudioBlock, m_previousBlock);
// consider doing the BBD post processing here to use up more time while waiting
// for the read data to come back
audio_block_t *blockToRelease = m_memory->addBlock(preProcessed);
// BACK TO OUTPUT PROCESSING
double bufferIndexFloat;
int delayIndex;
for (int i=0, j=AUDIO_BLOCK_SAMPLES-1; i<AUDIO_BLOCK_SAMPLES; i++,j--) {
// each output sample will be an interpolated value between two samples
// the precise delay value will be based on the LFO vector values.
// For each output sample, calculate the floating point delay offset from the reference delay.
// This will be an offset from location AUDIO_BLOCK_SAMPLES/2 (e.g. 64) in the buffer.
float offsetDelayFromRef = m_averageDelaySamples + (lfoValues[i] * m_delayRange) - referenceDelay;
float bufferPosition = DELAY_REFERENCE_F + offsetDelayFromRef;
// Get the interpolation coefficients from the fractional part of the buffer position
float fraction1 = modf(bufferPosition, &bufferIndexFloat);
float fraction2 = 1.0f - fraction1;
//fraction1 = 0.5f;
//fraction2 = 0.5f;
delayIndex = static_cast<unsigned>(bufferIndexFloat);
if ( (delayIndex < 0) || (delayIndex > 256) ) {
Serial.println(String("lfoValues[") + i + String("]:") + lfoValues[i] +
String(" referenceDelay:") + referenceDelay +
String(" bufferPosition:") + bufferPosition +
String(" delayIndex:") + delayIndex) ;
}
//delayIndex = 64+i;
blockToOutput->data[j] = static_cast<int16_t>(
(static_cast<float>(extendedBuffer[j+delayIndex]) * fraction1) +
(static_cast<float>(extendedBuffer[j+delayIndex+1]) * fraction2) );
//blockToOutput->data[i] = extendedBuffer[64+i];
}
// perform the wet/dry mix mix
m_postProcessing(blockToOutput, inputAudioBlock, blockToOutput);
transmit(blockToOutput);
release(inputAudioBlock);
release(m_previousBlock);
m_previousBlock = blockToOutput;
// if (m_externalMemory && m_memory->getSlot()->isUseDma()) {
// // Using DMA
// if (m_blockToRelease) release(m_blockToRelease);
// m_blockToRelease = blockToRelease;
// }
if (m_blockToRelease) release(m_blockToRelease);
m_blockToRelease = blockToRelease;
}
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);
// TODO: Clean this up with proper preprocessing
// 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)
{
setDelayConfig(calcAudioSamples(averageDelayMs), calcAudioSamples(delayRangeMs));
}
void AudioEffectAnalogChorus::setDelayConfig(size_t averageDelayNumSamples, size_t delayRangeNumSamples)
{
size_t delaySamples = averageDelayNumSamples + delayRangeNumSamples;
m_averageDelaySamples = averageDelayNumSamples;
m_delayRange = delayRangeNumSamples;
if (delaySamples > m_memory->getMaxDelaySamples()) {
// this exceeds max delay value, limit it.
delaySamples = m_memory->getMaxDelaySamples();
m_averageDelaySamples = delaySamples/2;
m_delayRange = delaySamples/2;
}
if (!m_memory) { Serial.println("delay(): m_memory is not valid"); }
}
void AudioEffectAnalogChorus::rate(float rate)
{
// update the LFO by mapping the rate into the MIN/MAX range, pass to LFO in milliseconds
m_lfo.setRateAudio(m_LFO_MIN_RATE + (rate * m_LFO_RANGE));
}
void AudioEffectAnalogChorus::processMidi(int channel, int control, int value)
{
float val = (float)value / 127.0f;
if ((m_midiConfig[RATE][MIDI_CHANNEL] == channel) &&
(m_midiConfig[RATE][MIDI_CONTROL] == control)) {
// Rate
Serial.println(String("AudioEffectAnalogChorus::rate: ") + 100*val + String("%"));
rate(val);
return;
}
if ((m_midiConfig[BYPASS][MIDI_CHANNEL] == channel) &&
(m_midiConfig[BYPASS][MIDI_CONTROL] == control)) {
// Bypass
if (value >= 65) { bypass(false); Serial.println(String("AudioEffectAnalogChorus::not bypassed -> ON") + value); }
else { bypass(true); Serial.println(String("AudioEffectAnalogChorus::bypassed -> OFF") + value); }
return;
}
if ((m_midiConfig[DEPTH][MIDI_CHANNEL] == channel) &&
(m_midiConfig[DEPTH][MIDI_CONTROL] == control)) {
// depth
Serial.println(String("AudioEffectAnalogChorus::depth: ") + 100*val + String("%"));
depth(val);
return;
}
if ((m_midiConfig[MIX][MIDI_CHANNEL] == channel) &&
(m_midiConfig[MIX][MIDI_CONTROL] == control)) {
// Mix
Serial.println(String("AudioEffectAnalogChorus::mix: Dry: ") + 100*(1-val) + String("% Wet: ") + 100*val );
mix(val);
return;
}
if ((m_midiConfig[VOLUME][MIDI_CHANNEL] == channel) &&
(m_midiConfig[VOLUME][MIDI_CONTROL] == control)) {
// Volume
Serial.println(String("AudioEffectAnalogChorus::volume: ") + 100*val + String("%"));
volume(val);
return;
}
}
void AudioEffectAnalogChorus::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;
}
}