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BALibrary/src/LibBasicFunctions.h

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/**************************************************************************//**
* @file
* @author Steve Lascos
* @company Blackaddr Audio
*
* LibBasicFunctions is a collection of helpful functions and classes that make
* it easier to perform common tasks in Audio applications.
*
* @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 <cstddef>
#include <new>
#include <arm_math.h>
#include "Arduino.h"
#include "Audio.h"
#include "BATypes.h"
#include "LibMemoryManagement.h"
#ifndef __LIBBASICFUNCTIONS_H
#define __LIBBASICFUNCTIONS_H
namespace BAGuitar {
/**************************************************************************//**
* QueuePosition is used for storing the index (in an array of queues) and the
* offset within an audio_block_t data buffer. Useful for dealing with large
* windows of audio spread across multiple audio data blocks.
*****************************************************************************/
struct QueuePosition {
int offset; ///< offset in samples within an audio_block_t data buffer
int index; ///< index in an array of audio data blocks
};
/// Calculate the exact sample position in an array of audio blocks that corresponds
/// to a particular offset given as time.
/// @param milliseconds length of the interval in milliseconds
/// @returns a struct containing the index and offset
QueuePosition calcQueuePosition(float milliseconds);
/// Calculate the exact sample position in an array of audio blocks that corresponds
/// to a particular offset given as a number of samples
/// @param milliseconds length of the interval in milliseconds
/// @returns a struct containing the index and offset
QueuePosition calcQueuePosition(size_t numSamples);
/// Calculate the number of audio samples (rounded up) that correspond to a
/// given length of time.
/// @param milliseconds length of the interval in milliseconds
/// @returns the number of corresonding audio samples.
size_t calcAudioSamples(float milliseconds);
/// Calculate the number of audio samples (usually an offset) from
/// a queue position.
/// @param position specifies the index and offset within a queue
/// @returns the number of samples from the start of the queue array to the
/// specified position.
size_t calcOffset(QueuePosition position);
void clearAudioBlock(audio_block_t *block);
void alphaBlend(audio_block_t *out, audio_block_t *dry, audio_block_t* wet, float mix);
template <class T>
class RingBuffer; // forward declare so AudioDelay can use it.
/**************************************************************************//**
* Audio delays are a very common function in audio processing. In addition to
* being used for simply create a delay effect, it can also be used for buffering
* a sliding window in time of audio samples. This is useful when combining
* several audio_block_t data buffers together to form one large buffer for
* FFTs, etc.
* @details The buffer works like a queue. You add new audio_block_t when available,
* and the class will return an old buffer when it is to be discarded from the queue.<br>
* Note that using INTERNAL memory means the class will only store a queue
* of pointers to audio_block_t buffers, since the Teensy Audio uses a shared memory
* approach. When using EXTERNAL memory, data is actually copyied to/from an external
* SRAM device.
*****************************************************************************/
class AudioDelay {
public:
AudioDelay() = delete;
/// Construct an audio buffer using INTERNAL memory by specifying the max number
/// of audio samples you will want.
/// @param maxSamples equal or greater than your longest delay requirement
AudioDelay(size_t maxSamples);
/// Construct an audio buffer using INTERNAL memory by specifying the max amount of
/// time you will want available in the buffer.
/// @param maxDelayTimeMs max length of time you want in the buffer specified in milliseconds
AudioDelay(float maxDelayTimeMs);
/// Construct an audio buffer using a slot configured with the BAGuitar::ExternalSramManager
/// @param slot a pointer to the slot representing the memory you wish to use for the buffer.
AudioDelay(ExtMemSlot *slot, bool useDma=true);
~AudioDelay();
/// Add a new audio block into the buffer. When the buffer is filled,
/// adding a new block will push out the oldest once which is returned.
/// @param blockIn pointer to the most recent block of audio
/// @returns the buffer to be discarded, or nullptr if not filled (INTERNAL), or
/// not applicable (EXTERNAL).
audio_block_t *addBlock(audio_block_t *blockIn);
/// When using INTERNAL memory, returns the pointer for the specified index into buffer.
/// @details, the most recent block is 0, 2nd most recent is 1, ..., etc.
/// @param index the specifies how many buffers older than the current to retrieve
/// @returns a pointer to the requested audio_block_t
audio_block_t *getBlock(size_t index);
/// Retrieve an audio block (or samples) from the buffer.
/// @details when using INTERNAL memory, only supported size is AUDIO_BLOCK_SAMPLES. When using
/// EXTERNAL, a size smaller than AUDIO_BLOCK_SAMPLES can be requested.
/// @param dest pointer to the target audio block to write the samples to.
/// @param offset data will start being transferred offset samples from the start of the audio buffer
/// @param numSamples default value is AUDIO_BLOCK_SAMPLES, so typically you don't have to specify this parameter.
/// @returns true on success, false on error.
bool getSamples(audio_block_t *dest, size_t offset, size_t numSamples = AUDIO_BLOCK_SAMPLES);
/// When using EXTERNAL memory, this function can return a pointer to the underlying ExtMemSlot object associated
/// with the buffer.
/// @returns pointer to the underlying ExtMemSlot.
ExtMemSlot *getSlot() const { return m_slot; }
void readDmaBufferContents(audio_block_t *dest, size_t numSamples = AUDIO_BLOCK_SAMPLES, size_t bufferOffset = 0);
RingBuffer<audio_block_t*> *getRingBuffer() const { return m_ringBuffer; }
private:
/// enumerates whether the underlying memory buffer uses INTERNAL or EXTERNAL memory
enum class MemType : unsigned {
MEM_INTERNAL = 0, ///< internal audio_block_t from the Teensy Audio Library is used
MEM_EXTERNAL ///< external SPI based ram is used
};
MemType m_type; ///< when 0, INTERNAL memory, when 1, external MEMORY.
RingBuffer<audio_block_t *> *m_ringBuffer = nullptr; ///< When using INTERNAL memory, a RingBuffer will be created.
ExtMemSlot *m_slot = nullptr; ///< When using EXTERNAL memory, an ExtMemSlot must be provided.
};
/**************************************************************************//**
* IIR BiQuad Filter - Direct Form I <br>
* y[n] = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2]<br>
* Some design tools (like Matlab assume the feedback coefficients 'a' are negated. You
* may have to negate your 'a' coefficients.
* @details Note that the ARM CMSIS-DSP library requires an extra zero between first
* and second 'b' coefficients. E.g. <br>
* {b10, 0, b11, b12, a11, a12, b20, 0, b21, b22, a21, a22, ...}
*****************************************************************************/
class IirBiQuadFilter {
public:
IirBiQuadFilter() = delete;
IirBiQuadFilter(unsigned numStages, const int32_t *coeffs, int coeffShift = 0);
virtual ~IirBiQuadFilter();
bool process(int16_t *output, int16_t *input, size_t numSamples);
private:
const unsigned NUM_STAGES;
int32_t *m_coeffs = nullptr;
// ARM DSP Math library filter instance
arm_biquad_casd_df1_inst_q31 m_iirCfg;
int32_t *m_state = nullptr;
};
class IirBiQuadFilterHQ {
public:
IirBiQuadFilterHQ() = delete;
IirBiQuadFilterHQ(unsigned numStages, const int32_t *coeffs, int coeffShift = 0);
virtual ~IirBiQuadFilterHQ();
bool process(int16_t *output, int16_t *input, size_t numSamples);
private:
const unsigned NUM_STAGES;
int32_t *m_coeffs = nullptr;
// ARM DSP Math library filter instance
arm_biquad_cas_df1_32x64_ins_q31 m_iirCfg;
int64_t *m_state = nullptr;
};
class IirBiQuadFilterFloat {
public:
IirBiQuadFilterFloat() = delete;
IirBiQuadFilterFloat(unsigned numStages, const float *coeffs);
virtual ~IirBiQuadFilterFloat();
bool process(float *output, float *input, size_t numSamples);
private:
const unsigned NUM_STAGES;
float *m_coeffs = nullptr;
// ARM DSP Math library filter instance
arm_biquad_cascade_df2T_instance_f32 m_iirCfg;
float *m_state = nullptr;
};
///**************************************************************************//**
// * Customer RingBuffer with random access
// *****************************************************************************/
//template <class T>
//class RingBuffer {
//public:
// RingBuffer() = delete;
//
// /// Construct a RingBuffer of specified max size
// /// @param maxSize number of entries in ring buffer
// RingBuffer(const size_t maxSize) : m_maxSize(maxSize) {
// m_buffer = new T[maxSize]();
// }
// virtual ~RingBuffer(){
// if (m_buffer) delete [] m_buffer;
// }
//
// /// Add an element to the back of the queue
// /// @param element element to add to queue
// /// returns 0 if success, otherwise error
// int push_back(T element) {
//
// //Serial.println(String("RingBuffer::push_back...") + m_head + String(":") + m_tail + String(":") + m_size);
// if ( (m_head == m_tail) && (m_size > 0) ) {
// // overflow
// Serial.println("RingBuffer::push_back: overflow");
// return -1;
// }
//
// m_buffer[m_head] = element;
// if (m_head < (m_maxSize-1) ) {
// m_head++;
// } else {
// m_head = 0;
// }
// m_size++;
//
// return 0;
// }
//
// /// Remove the element at teh front of the queue
// /// @returns 0 if success, otherwise error
// int pop_front() {
//
// if (m_size == 0) {
// // buffer is empty
// //Serial.println("RingBuffer::pop_front: buffer is empty\n");
// return -1;
// }
// if (m_tail < m_maxSize-1) {
// m_tail++;
// } else {
// m_tail = 0;
// }
// m_size--;
// //Serial.println(String("RingBuffer::pop_front: ") + m_head + String(":") + m_tail + String(":") + m_size);
// return 0;
// }
//
// /// Get the element at the front of the queue
// /// @returns element at front of queue
// T front() const {
// return m_buffer[m_tail];
// }
//
// /// get the element at the back of the queue
// /// @returns element at the back of the queue
// T back() const {
// return m_buffer[m_head-1];
// }
//
// /// Get a previously pushed elememt
// /// @param offset zero is last pushed, 1 is second last, etc.
// /// @returns the absolute index corresponding to the requested offset.
// size_t get_index_from_back(size_t offset = 0) const {
// // the target at m_head - 1 - offset or m_maxSize + m_head -1 - offset;
// size_t idx = (m_maxSize + m_head -1 - offset);
//
// if ( idx >= m_maxSize) {
// idx -= m_maxSize;
// }
//
// return idx;
// }
//
// /// get the current size of the queue
// /// @returns size of the queue
// size_t size() const {
// return m_size;
// }
//
// /// get the maximum size the queue can hold
// /// @returns maximum size of the queue
// size_t max_size() const {
// return m_maxSize;
// }
//
// /// get the element at the specified absolute index
// /// @param index element to retrieve from absolute queue position
// /// @returns the request element
// T& operator[] (size_t index) {
// return m_buffer[index];
// }
//
// /// get the element at the specified absolute index
// /// @param index element to retrieve from absolute queue position
// /// @returns the request element
// T at(size_t index) const {
// return m_buffer[index];
// }
//
// /// DEBUG: Prints the status of the Ringbuffer. NOte using this much printing will usually cause audio glitches
// void print() const {
// for (int idx=0; idx<m_maxSize; idx++) {
// Serial.print(idx + String(" address: ")); Serial.print((uint32_t)m_buffer[idx], HEX);
// Serial.print(" data: "); Serial.println((uint32_t)m_buffer[idx]->data, HEX);
// }
// }
//private:
// size_t m_head=0; ///< back of the queue
// size_t m_tail=0; ///< front of the queue
// size_t m_size=0; ///< current size of the qeueu
// T *m_buffer = nullptr; ///< pointer to the allocated buffer array
// const size_t m_maxSize; ///< maximum size of the queue
//};
}
#endif /* __LIBBASICFUNCTIONS_H */