PWMAudioOutput Class Reference

Common functionality for PWM output. We generate audio using PWM with a frequency that is above the hearing range. The sample rate is usually quite restricted, so we also automatically decimate the data. Further info see PWMConfig. More...

#include <AudioPWM.h>

Inheritance diagram for PWMAudioOutput:

Public Member Functions
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
AudioInfo	audioInfoOut () override
int	availableForWrite () override
bool	begin ()
virtual bool	begin (AudioInfo info)
bool	begin (PWMConfig config)
	starts the processing using Streams
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
PWMConfig	config ()
virtual PWMConfig	defaultConfig (RxTxMode mode=TX_MODE)
PWMDriver *	driver ()
	Provides access to the driver.
virtual void	end () override
virtual void	flush ()
uint32_t	framesPerSecond ()
virtual bool	isDeletable ()
	If true we need to release the related memory in the destructor.
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
virtual	operator bool ()
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
void	setAudioInfo (AudioInfo info) override
	updates the sample rate dynamically
void	setBuffer (BaseBuffer< uint8_t > *buffer)
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)
uint32_t	underflowsPerSecond ()
size_t	write (const uint8_t *data, size_t len) override
virtual size_t	write (uint8_t ch) override
virtual void	writeSilence (size_t len)

Protected Member Functions
void	notifyAudioChange (AudioInfo info)

Protected Attributes
int	_timeout = 10
PWMConfig	audio_config
AudioInfo	cfg
bool	is_active = false
bool	is_notify_active = true
Vector< AudioInfoSupport * >	notify_vector
PWMDriver	pwm
SingleBuffer< uint8_t >	tmp {MAX_SINGLE_CHARS}
int	tmpPos = 0

Detailed Description

Common functionality for PWM output. We generate audio using PWM with a frequency that is above the hearing range. The sample rate is usually quite restricted, so we also automatically decimate the data. Further info see PWMConfig.

Member Function Documentation

addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, MP3DecoderMAD, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, MP3DecoderHelix, OggContainerDecoder, Pipeline, and Pipeline::ModifyingStreamAdapter.

audioInfo()

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in AdapterPrintToAudioOutput, and AdapterAudioStreamToAudioOutput.

audioInfoOut()

AudioInfo audioInfoOut ( )

inlineoverridevirtual

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented from AudioInfoSupport.

availableForWrite()

int availableForWrite ( )

inlineoverridevirtual

Reimplemented from AudioOutput.

begin() [1/2]

bool begin ( )

inlinevirtual

Reimplemented from AudioOutput.

begin() [2/2]

virtual bool begin ( AudioInfo  info )

inlinevirtualinherited

Reimplemented in AudioESP32ULP, CsvOutput< T >, and EncodedAudioOutput.

end()

virtual void end ( )

inlineoverridevirtual

Reimplemented from AudioOutput.

flush()

virtual void flush ( )

inlinevirtualinherited

Reimplemented from Print.

isDeletable()

virtual bool isDeletable ( )

inlinevirtualinherited

If true we need to release the related memory in the destructor.

Reimplemented in AdapterPrintToAudioOutput, and AdapterAudioStreamToAudioOutput.

operator bool()

virtual operator bool ( )

inlinevirtualinherited

Reimplemented in EncodedAudioOutput, and RTSPOutput.

setAudioInfo()

void setAudioInfo ( AudioInfo  info )

inlineoverridevirtual

updates the sample rate dynamically

Reimplemented from AudioOutput.

setBuffer()

void setBuffer ( BaseBuffer< uint8_t > *  buffer )

inline

You can assign your own custom buffer impelementation: must be allocated on the heap and will be cleaned up by this class

write()

size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

Implements AudioOutput.

writeSilence()

virtual void writeSilence ( size_t  len )

inlinevirtualinherited

Writes n 0 values (= silence)

Parameters

len

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

• src/AudioTools/CoreAudio/AudioPWM/AudioPWM.h