/**************************************************************************//**
* @file
* @author Steve Lascos
* @company Blackaddr Audio
*
* AudioEffectAnalogDelay is a class for simulating a classic BBD based delay
* like the Boss DM-2. This class works with either internal RAM, or external
* SPI RAM for longer delays. The exteranl 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 .
*****************************************************************************/
#ifndef __BAEFFECTS_BAAUDIOEFFECTANALOGDELAY_H
#define __BAEFFECTS_BAAUDIOEFFECTANALOGDELAY_H
#include
#include "LibBasicFunctions.h"
namespace BAEffects {
/**************************************************************************//**
* AudioEffectAnalogDelay models BBD based analog delays. It provides controls
* for delay, feedback (or regen), 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 AudioEffectAnalogDelay : public AudioStream {
public:
///< List of AudioEffectAnalogDelay MIDI controllable parameters
enum {
BYPASS = 0, ///< controls effect bypass
DELAY, ///< controls the amount of delay
FEEDBACK, ///< controls the amount of echo feedback (regen)
MIX, ///< controls the the mix of input and echo 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 {
DM3 = 0,
WARM,
DARK
};
// *** CONSTRUCTORS ***
AudioEffectAnalogDelay() = delete;
/// Construct an analog delay using internal memory by specifying the maximum
/// delay in milliseconds.
/// @param maxDelayMs maximum delay in milliseconds. Larger delays use more memory.
AudioEffectAnalogDelay(float maxDelayMs);
/// Construct an analog delay using internal memory by specifying the maximum
/// delay in audio samples.
/// @param numSamples maximum delay in audio samples. Larger delays use more memory.
AudioEffectAnalogDelay(size_t numSamples);
/// Construct an analog delay using external SPI via an ExtMemSlot. The amount of
/// delay will be determined by the amount of memory in the slot.
/// @param slot A pointer to the ExtMemSlot to use for the delay.
AudioEffectAnalogDelay(BALibrary::ExtMemSlot *slot); // requires sufficiently sized pre-allocated memory
virtual ~AudioEffectAnalogDelay(); ///< Destructor
// *** PARAMETERS ***
/// Set the delay in milliseconds.
/// @param milliseconds the request delay in milliseconds. Must be less than max delay.
void delay(float milliseconds);
/// Set the delay in number of audio samples.
/// @param delaySamples the request delay in audio samples. Must be less than max delay.
void delay(size_t delaySamples);
/// Set the delay as a fraction of the maximum delay.
/// The value should be between 0.0f and 1.0f
void delayFractionMax(float delayFraction);
/// 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 amount of echo feedback (a.k.a regeneration).
/// @param feedback a floating point number between 0.0 and 1.0.
void feedback(float feedback) { m_feedback = feedback; }
/// 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 AudioEffectAnalogDelay::Filter
/// for options.
/// @details See AudioEffectAnalogDelayFIlters.h for more details.
/// @param filter the preset filter. E.g. AudioEffectAnalogDelay::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.
/// 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:
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;
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_feedback = 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_BAAUDIOEFFECTANALOGDELAY_H */