SynthLab::AudioBuffer Class Reference

Encapsulates the audio buffering requirements of any module that uses audio samples for input and/or output. More...

#include <synthbase.h>

Inheritance diagram for SynthLab::AudioBuffer:

Public Member Functions
	AudioBuffer (uint32_t _numInputChannels, uint32_t _numOutputChannels, uint32_t _blockSize)
	Specialized constructor that initializes the buffers during construction. More...
	~AudioBuffer ()
	As one of the few objects that uses naked pointers (for maximum compatibility between plugin frameworks and/or plugin APIs and the easiest of use) this deletes the audio buffer arrays.
void	init (uint32_t _numInputChannels, uint32_t _numOutputChannels, uint32_t _blockSize)
	Main initializer that creates the new arrays and sets up the object. More...
void	flushBuffers ()
	clear out the audio; used often More...
float *	getInputBuffer (uint32_t channel)
	Get a naked pointer to an audio INPUT buffer by channel. More...
float *	getOutputBuffer (uint32_t channel)
	Get a naked pointer to an audio OUTPUT buffer by channel. More...
float **	getInputBuffers ()
float **	getOutputBuffers ()
uint32_t	getInputChannelCount ()
uint32_t	getOutputChannelCount ()
uint32_t	getBlockSize ()
uint32_t	getSamplesInBlock ()
void	setSamplesInBlock (uint32_t _samplesInBlock)
	Set the number of samples in a block for processing. More...

Protected Member Functions
void	destroyInputBuffers ()
	Destroy dynamically allocated input buffer; done at destruct time, or if client want to re-size buffers.
void	destroyOutputBuffers ()
	Destroy dynamically allocated output buffer; done at destruct time, or if client want to re-size buffers.

Protected Attributes
float **	inputBuffer = nullptr
	array of input buffer pointers
float **	outputBuffer = nullptr
	array of output buffer pointers
uint32_t	numInputChannels = 1
uint32_t	numOutputChannels = 1
uint32_t	blockSize = 64
	the maximum block size
uint32_t	samplesInBlock = 64
	the number of samples to process in the block (in case of partial blocks)

Detailed Description

Encapsulates the audio buffering requirements of any module that uses audio samples for input and/or output.

• includes sepearate audio input and output buffers (arrays)
• audio buffers are channel-independent so there are separate Left and Right channel buffers for each direction
• automatically supports multi-channel operation beyond stereo
• follows identical design pattern as that used in all plugin APIs and DAWs
• uses float buffers for maximum compatibility across target APIs and DAWs
• audio buffers are used to move frequency modulation values (FM) or phase modualtion values (PM) in addition to the normal input/output
• FM and PM buffers are also categorized as INPUT or OUTPU depending on origin and destination

Author

Will Pirkle http://www.willpirkle.com

Remarks

This object is included and described in further detail in Designing Software Synthesizer Plugins in C++ 2nd Ed. by Will Pirkle

Version

Revision : 1.0

Date

Date : 2021 / 04 / 26

Constructor & Destructor Documentation

AudioBuffer()

SynthLab::AudioBuffer::AudioBuffer	(	uint32_t	_numInputChannels,
		uint32_t	_numOutputChannels,
		uint32_t	_blockSize
	)

Specialized constructor that initializes the buffers during construction.

Parameters

_numInputChannels	input channel count (1 = mono, 2 = stereo, may be greater than 2 if needed)
_numOutputChannels	input channel count (1 = mono, 2 = stereo, may be greater than 2 if needed)
_blockSize	the MAXIMUM block size that sets the buffer sizes; this can never be exceeded

Member Function Documentation

flushBuffers()

void SynthLab::AudioBuffer::flushBuffers

(

)

clear out the audio; used often

Fast clearing of audio buffer data; this is important because buffers are re-used all the time.

getBlockSize()

uint32_t SynthLab::AudioBuffer::getBlockSize ( )

inline

current block size in frames - one sample per channel

getInputBuffer()

float * SynthLab::AudioBuffer::getInputBuffer

(

uint32_t

channel

)

Get a naked pointer to an audio INPUT buffer by channel.

get a pointer to an input or output buffer for a certain channel

• for mono/stereo operation: channel 0 = mono or left, channel 1 = right
• may also be used with > 2 channel operation

Parameters

channel

index of channel to get input buffer

getInputBuffers()

float** SynthLab::AudioBuffer::getInputBuffers ( )

inline

arrays of pointers to ALL input and output buffers

getInputChannelCount()

uint32_t SynthLab::AudioBuffer::getInputChannelCount ( )

inline

get number of input or output channels; these valued do not change once initialized

getOutputBuffer()

float * SynthLab::AudioBuffer::getOutputBuffer

(

uint32_t

channel

)

Get a naked pointer to an audio OUTPUT buffer by channel.

• for mono/stereo operation: channel 0 = mono or left, channel 1 = right
• may also be used with > 2 channel operation

Parameters

channel

index of channel to get input buffer

init()

void SynthLab::AudioBuffer::init	(	uint32_t	_numInputChannels,
		uint32_t	_numOutputChannels,
		uint32_t	_blockSize
	)

Main initializer that creates the new arrays and sets up the object.

setup the buffers for a set number of channels - this cannot change after init

Parameters

_numInputChannels	input channel count (1 = mono, 2 = stereo, may be greater than 2 if needed)
_numOutputChannels	input channel count (1 = mono, 2 = stereo, may be greater than 2 if needed)
_blockSize	the MAXIMUM block size that sets the buffer sizes; this can never be exceeded

setSamplesInBlock()

void SynthLab::AudioBuffer::setSamplesInBlock

(

uint32_t

_samplesInBlock

)

Set the number of samples in a block for processing.

• only used because the block size COULD be variable if the host DAW or plugin framework supplies an input or output buffer that is a partial block size; very rare, but still possible

Parameters

_samplesInBlock

numner of samples in block

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The documentation for this class was generated from the following files:

• C:/RackAFX Projects/SynthLab_SDK/source/synthbase.h
• C:/RackAFX Projects/SynthLab_SDK/source/synthbase.cpp