Generates a square wave sound. Uses the same 32 bit phase accumulator as SawToothGenerator/FastIntSineGenerator: no floating point operations or sin() calls in the readSample() hot path. A square wave needs neither a sine approximation nor a lookup table - just the sign bit of the ramp - so readSample() is a single comparison, making this a good fit for MCUs without a hardware FPU (e.g. RP2040), where the previous FastSineGenerator based implementation still did a float polynomial evaluation per sample just to keep its sign. More...

#include <CodecOpusOgg.h>

Inheritance diagram for SquareWaveGenerator< T >:

Public Member Functions
	SquareWaveGenerator (float amplitude=NumberConverter::maxValueT< T >(), float phase=0.0f)
	SquareWaveGenerator (float amplitude=NumberConverter::maxValueT< T >(), float phase=0.0f)
virtual AudioInfo	audioInfo ()
	Provides the AudioInfo.
bool	begin () override
bool	begin () override
bool	begin (AudioInfo info) override
	Starts the processing with the provided AudioInfo.
bool	begin (AudioInfo info) override
	Starts the processing with the provided AudioInfo.
bool	begin (AudioInfo info, float frequency)
bool	begin (AudioInfo info, float frequency)
bool	begin (int channels, int sample_rate, float frequency)
bool	begin (int channels, int sample_rate, float frequency)
virtual AudioInfo	defaultConfig ()
	Provides the default configuration.
virtual void	end ()
virtual bool	isActive ()
	Checks if the begin method has been called - after end() isActive is false.
virtual size_t	readBytes (uint8_t *data, size_t len)
	Provides the data as byte array with the requested number of channels.
virtual T	readSample () override
	Provides a single sample - integer only, no float ops!
virtual T	readSample () override
	Provides a single sample - integer only, no float ops!
virtual size_t	readSamples (int16_t *data, size_t len)
virtual void	restart ()
	Restarts the generator, e.g. after a play time has been defined and reached.
void	setAmplitude (float amp)
void	setAmplitude (float amp)
virtual void	setAudioInfo (AudioInfo info) override
	Defines/updates the AudioInfo.
virtual void	setAudioInfo (AudioInfo info) override
	Defines/updates the AudioInfo.
void	setFrequency (float frequency) override
	Defines the frequency - the only place where float math is used.
void	setFrequency (float frequency) override
	Defines the frequency - the only place where float math is used.
void	setPhase (float phase)
	Defines the starting phase in radians.
void	setPhase (float phase)
	Defines the starting phase in radians.
virtual void	setPlayTime (uint32_t playMs, uint8_t upPercent=20, uint8_t downPercent=30)
	Defines the play time in ms and the ramp up and ramp down time in percent.
virtual void	setRampTimes (uint32_t playMs, uint32_t upMs=5, uint32_t downMs=5)

Protected Member Functions
int16_t	applyRamp (int16_t sample)
size_t	readBytesFrames (uint8_t *buffer, size_t lengthBytes, int frames, int channels)
size_t	readBytesFromBuffer (uint8_t *buffer, size_t lengthBytes, int frame_size, int channels)
void	recalculatePlayTime ()
void	updatePhaseIncrement ()
void	updatePhaseIncrement ()

Protected Attributes
bool	active
bool	activeWarningIssued
uint32_t	currentSample
uint32_t	downMs
uint8_t	downPercent
uint32_t	downSamples
float	factor
AudioInfo	info
float	m_amplitude = 1.0f
int32_t	m_amplitude_i = 32767
volatile float	m_frequency = 0.0f
uint32_t	m_phase_acc = 0
uint32_t	m_phase_increment = 0
uint32_t	m_phase_offset = 0
uint32_t	playMs
uint32_t	playSamples
float	rampDownDec
float	rampUpInc
RingBuffer< uint8_t >	ring_buffer
uint32_t	upMs
uint8_t	upPercent
uint32_t	upSamples

Detailed Description

template<class T = int16_t>
class audio_tools::audio_tools::SquareWaveGenerator< T >

Generates a square wave sound. Uses the same 32 bit phase accumulator as SawToothGenerator/FastIntSineGenerator: no floating point operations or sin() calls in the readSample() hot path. A square wave needs neither a sine approximation nor a lookup table - just the sign bit of the ramp - so readSample() is a single comparison, making this a good fit for MCUs without a hardware FPU (e.g. RP2040), where the previous FastSineGenerator based implementation still did a float polynomial evaluation per sample just to keep its sign.

Author: Phil Schatzmann

Copyright: GPLv3

Constructor & Destructor Documentation

◆ SquareWaveGenerator() [1/2]

template<class T = int16_t>

SquareWaveGenerator	(	float	amplitude = NumberConverter::maxValueT<T>(),
		float	phase = 0.0f )

inline

◆ SquareWaveGenerator() [2/2]

template<class T = int16_t>

SquareWaveGenerator	(	float	amplitude = NumberConverter::maxValueT<T>(),
		float	phase = 0.0f )

inline

Member Function Documentation

◆ applyRamp()

int16_t applyRamp ( int16_t sample )

inlineprotectedinherited

◆ audioInfo()

virtual AudioInfo audioInfo ( )

inlinevirtualinherited

Provides the AudioInfo.

◆ begin() [1/8]

template<class T = int16_t>

bool begin ( )

inlineoverride

◆ begin() [2/8]

template<class T = int16_t>

bool begin ( )

inlineoverride

◆ begin() [3/8]

template<class T = int16_t>

bool begin ( AudioInfo info )

inlineoverridevirtual

Starts the processing with the provided AudioInfo.

Reimplemented from SoundGenerator< int16_t >.

◆ begin() [4/8]

template<class T = int16_t>

bool begin ( AudioInfo info )

inlineoverridevirtual

Starts the processing with the provided AudioInfo.

Reimplemented from SoundGenerator< int16_t >.

◆ begin() [5/8]

template<class T = int16_t>

bool begin	(	AudioInfo	info,
		float	frequency )

inline

◆ begin() [6/8]

template<class T = int16_t>

bool begin	(	AudioInfo	info,
		float	frequency )

inline

◆ begin() [7/8]

template<class T = int16_t>

bool begin	(	int	channels,
		int	sample_rate,
		float	frequency )

inline

◆ begin() [8/8]

template<class T = int16_t>

bool begin	(	int	channels,
		int	sample_rate,
		float	frequency )

inline

◆ defaultConfig()

virtual AudioInfo defaultConfig ( )

inlinevirtualinherited

Provides the default configuration.

Reimplemented in FloatSineGenerator< T >, FloatSineGenerator< T >, FloatSineGenerator< int16_t >, FloatSineGenerator< T >, STKGenerator< StkCls, T >, STKGenerator< stk::Instrmnt, int16_t >, and STKGenerator< StkCls, int16_t >.

◆ end()

virtual void end ( )

inlinevirtualinherited

Reimplemented in GeneratorFromArray< T >, GeneratorFromArray< T >, GeneratorQueue< T >, GeneratorQueue< T >, GeneratorFromArray< T >, and GeneratorQueue< T >.

◆ isActive()

virtual bool isActive ( )

inlinevirtualinherited

Checks if the begin method has been called - after end() isActive is false.

◆ readBytes()

virtual size_t readBytes	(	uint8_t *	data,
		size_t	len )

inlinevirtualinherited

Provides the data as byte array with the requested number of channels.

Reimplemented in GeneratorQueue< T >, GeneratorQueue< T >, and GeneratorQueue< T >.

◆ readBytesFrames()

size_t readBytesFrames	(	uint8_t *	buffer,
		size_t	lengthBytes,
		int	frames,
		int	channels )

inlineprotectedinherited

◆ readBytesFromBuffer()

size_t readBytesFromBuffer	(	uint8_t *	buffer,
		size_t	lengthBytes,
		int	frame_size,
		int	channels )

inlineprotectedinherited

◆ readSample() [1/2]

template<class T = int16_t>

virtual T readSample ( )

inlineoverridevirtual

Provides a single sample - integer only, no float ops!

Implements SoundGenerator< int16_t >.

◆ readSample() [2/2]

template<class T = int16_t>

virtual T readSample ( )

inlineoverridevirtual

Provides a single sample - integer only, no float ops!

Implements SoundGenerator< int16_t >.

◆ readSamples()

virtual size_t readSamples	(	int16_t *	data,
		size_t	len )

inlinevirtualinherited

Provides the data as T array (interleaved by channel) with the requested number of samples (values, not frames)

◆ recalculatePlayTime()

void recalculatePlayTime ( )

inlineprotectedinherited

◆ restart()

virtual void restart ( )

inlinevirtualinherited

Restarts the generator, e.g. after a play time has been defined and reached.

◆ setAmplitude() [1/2]

template<class T = int16_t>

void setAmplitude ( float amp )

inline

◆ setAmplitude() [2/2]

template<class T = int16_t>

void setAmplitude ( float amp )

inline

◆ setAudioInfo() [1/2]

template<class T = int16_t>

virtual void setAudioInfo ( AudioInfo info )

inlineoverridevirtual

Defines/updates the AudioInfo.

Reimplemented from SoundGenerator< int16_t >.

◆ setAudioInfo() [2/2]

template<class T = int16_t>

virtual void setAudioInfo ( AudioInfo info )

inlineoverridevirtual

Defines/updates the AudioInfo.

Reimplemented from SoundGenerator< int16_t >.

◆ setFrequency() [1/2]

template<class T = int16_t>

void setFrequency ( float frequency )

inlineoverridevirtual

Defines the frequency - the only place where float math is used.

Reimplemented from SoundGenerator< int16_t >.

◆ setFrequency() [2/2]

template<class T = int16_t>

void setFrequency ( float frequency )

inlineoverridevirtual

Defines the frequency - the only place where float math is used.

Reimplemented from SoundGenerator< int16_t >.

◆ setPhase() [1/2]

template<class T = int16_t>

void setPhase ( float phase )

inline

Defines the starting phase in radians.

◆ setPhase() [2/2]

template<class T = int16_t>

void setPhase ( float phase )

inline

Defines the starting phase in radians.

◆ setPlayTime()

virtual void setPlayTime	(	uint32_t	playMs,
		uint8_t	upPercent = 20,
		uint8_t	downPercent = 30 )

inlinevirtualinherited

Defines the play time in ms and the ramp up and ramp down time in percent.

Reimplemented in GeneratorQueue< T >, GeneratorQueue< T >, and GeneratorQueue< T >.

◆ setRampTimes()

virtual void setRampTimes	(	uint32_t	playMs,
		uint32_t	upMs = 5,
		uint32_t	downMs = 5 )

inlinevirtualinherited

Alternative to setPlayTime. It sets ramp-up and ramp-down times in ms instead of percentages. If playMs == 0, it will play indefinitely. restart();begin(); starts the ramp-up and sustain as normal, but it will sustain forever. end(true) triggers a ramp-down then inactive.

◆ updatePhaseIncrement() [1/2]

template<class T = int16_t>

void updatePhaseIncrement ( )

inlineprotected

◆ updatePhaseIncrement() [2/2]

template<class T = int16_t>

void updatePhaseIncrement ( )

inlineprotected

Member Data Documentation

◆ active

bool active

protectedinherited

◆ activeWarningIssued

bool activeWarningIssued

protectedinherited

◆ currentSample

uint32_t currentSample

protectedinherited

◆ downMs

uint32_t downMs

protectedinherited

◆ downPercent

uint8_t downPercent

protectedinherited

◆ downSamples

uint32_t downSamples

protectedinherited

◆ factor

float factor

protectedinherited

◆ info

AudioInfo info

protectedinherited

◆ m_amplitude

template<class T = int16_t>

float m_amplitude = 1.0f

protected

◆ m_amplitude_i

template<class T = int16_t>

int32_t m_amplitude_i = 32767

protected

◆ m_frequency

template<class T = int16_t>

volatile float m_frequency = 0.0f

protected

◆ m_phase_acc

template<class T = int16_t>

uint32_t m_phase_acc = 0

protected

◆ m_phase_increment

template<class T = int16_t>

uint32_t m_phase_increment = 0

protected

◆ m_phase_offset

template<class T = int16_t>

uint32_t m_phase_offset = 0

protected

◆ playMs

uint32_t playMs

protectedinherited

◆ playSamples

uint32_t playSamples

protectedinherited

◆ rampDownDec

float rampDownDec

protectedinherited

◆ rampUpInc

float rampUpInc

protectedinherited

◆ ring_buffer

RingBuffer< uint8_t > ring_buffer

protectedinherited

◆ upMs

uint32_t upMs

protectedinherited

◆ upPercent

uint8_t upPercent

protectedinherited

◆ upSamples

uint32_t upSamples

protectedinherited

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

src/AudioTools/AudioCodecs/CodecOpusOgg.h
src/AudioTools/AudioCodecs/CodecTSDemux.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SquareWaveGenerator() [1/2]

◆ SquareWaveGenerator() [2/2]

Member Function Documentation

◆ applyRamp()

◆ audioInfo()

◆ begin() [1/8]

◆ begin() [2/8]

◆ begin() [3/8]

◆ begin() [4/8]

◆ begin() [5/8]

◆ begin() [6/8]

◆ begin() [7/8]

◆ begin() [8/8]

◆ defaultConfig()

◆ end()

◆ isActive()

◆ readBytes()

◆ readBytesFrames()

◆ readBytesFromBuffer()

◆ readSample() [1/2]

◆ readSample() [2/2]

◆ readSamples()

◆ recalculatePlayTime()

◆ restart()

◆ setAmplitude() [1/2]

◆ setAmplitude() [2/2]

◆ setAudioInfo() [1/2]

◆ setAudioInfo() [2/2]

◆ setFrequency() [1/2]

◆ setFrequency() [2/2]

◆ setPhase() [1/2]

◆ setPhase() [2/2]

◆ setPlayTime()

◆ setRampTimes()

◆ updatePhaseIncrement() [1/2]

◆ updatePhaseIncrement() [2/2]

Member Data Documentation

◆ active

◆ activeWarningIssued

◆ currentSample

◆ downMs

◆ downPercent

◆ downSamples

◆ factor

◆ info

◆ m_amplitude

◆ m_amplitude_i

◆ m_frequency

◆ m_phase_acc

◆ m_phase_increment

◆ m_phase_offset

◆ playMs

◆ playSamples

◆ rampDownDec

◆ rampUpInc

◆ ring_buffer

◆ upMs

◆ upPercent

◆ upSamples