CallbackStream Class Reference

CallbackStream: A Stream that allows to register callback methods for accessing and providing and updating data. The callbacks can be lambda expressions. The update callback can also be used just to read the data without changing it. Warning: this class does not propagate audio info changes to the target stream. You need to do this manually. More...

#include <AudioStreams.h>

Inheritance diagram for CallbackStream:

Public Member Functions
	CallbackStream ()=default
	CallbackStream (Print &out, size_t(*cb_update)(uint8_t *data, size_t len))
	Allows to change the audio before sending it to the output.
	CallbackStream (size_t(*cb_read)(uint8_t *data, size_t len), size_t(*cb_write)(const uint8_t *data, size_t len))
	CallbackStream (Stream &io, size_t(*cb_update)(uint8_t *data, size_t len))
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
int	available () override
virtual int	availableForWrite () override
virtual bool	begin () override
virtual bool	begin (AudioInfo info)
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
void	end () override
virtual void	flush () override
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
virtual	operator bool ()
size_t	readBytes (uint8_t *data, size_t len) override
virtual size_t	readSilence (uint8_t *buffer, size_t length)
	Source to generate silence: just sets the buffer to 0.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
void	setAudioInfo (AudioInfo info) override
	Updates the audio info and calls the callback.
void	setAudioInfoCallback (void(*cb)(AudioInfo info))
	defines the callback to receive the actual audio info
void	setAvailable (int val)
	optioinally define available bytes for next read
void	setAvailableCallback (int(*cb)())
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)
virtual void	setOutput (AudioOutput &out)
	Defines/Changes the output target and registers for audio change notifications.
void	setOutput (Print &out) override
	Defines/Changes the output target.
void	setOutput (Stream &in)
	same as setStream
void	setReadCallback (size_t(*cb_read)(uint8_t *data, size_t len))
	Instead of reading from the input stream we call this method.
virtual void	setStream (AudioStream &io)
	Defines/Changes the input & output and registers for audio change notifications.
void	setStream (Print &out)
	same as set Output
void	setStream (Stream &in) override
	Defines/Changes the input & output.
void	setUpdateCallback (size_t(*cb_update)(uint8_t *data, size_t len))
	After Reading or before writing we call this method to allow to modify the data.
void	setWriteBufferSize (int size)
void	setWriteCallback (size_t(*cb_write)(const uint8_t *data, size_t len))
	Instead of writing to the output stream we call this method.
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)
	Writes len bytes of silence (=0).

Protected Member Functions
virtual int	not_supported (int out, const char *msg="")
void	notifyAudioChange (AudioInfo info)
void	refillReadBuffer ()
	Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read()

Protected Attributes
int	_timeout = 10
bool	active = true
int	available_bytes = -1
void(*	cb_audio_info )(AudioInfo info) = nullptr
int(*	cb_available )() = nullptr
size_t(*	cb_read )(uint8_t *data, size_t len) = nullptr
size_t(*	cb_update )(uint8_t *data, size_t len) = nullptr
size_t(*	cb_write )(const uint8_t *data, size_t len) = nullptr
AudioInfo	info
bool	is_notify_active = true
Vector< AudioInfoSupport * >	notify_vector
Print *	p_out = nullptr
Stream *	p_stream = nullptr
RingBuffer< uint8_t >	tmp_in {0}
RingBuffer< uint8_t >	tmp_out {0}
int	write_buffer_size = MAX_SINGLE_CHARS

Detailed Description

CallbackStream: A Stream that allows to register callback methods for accessing and providing and updating data. The callbacks can be lambda expressions. The update callback can also be used just to read the data without changing it. Warning: this class does not propagate audio info changes to the target stream. You need to do this manually.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

CallbackStream() [1/4]

CallbackStream ( )

default

CallbackStream() [2/4]

CallbackStream ( Stream &  io, size_t(*)(uint8_t *data, size_t len)  cb_update  )

inline

Allows to change the audio before sending it to the output or before getting it from the original input

CallbackStream() [3/4]

CallbackStream ( Print &  out, size_t(*)(uint8_t *data, size_t len)  cb_update  )

inline

Allows to change the audio before sending it to the output.

CallbackStream() [4/4]

CallbackStream ( size_t(*)(uint8_t *data, size_t len)  cb_read, size_t(*)(const uint8_t *data, size_t len)  cb_write  )

inline

Member Function Documentation

addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, CodecChain, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, RTSPClient< TcpClient, UdpSocket >, Pipeline, and Pipeline::ModifyingStreamAdapter.

audioInfo()

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in JupyterAudioT< T >, MozziStream, TimerCallbackAudioStream, EncodedAudioStream, PureDataStream, AdapterAudioOutputToAudioStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, and InputMerge< T >.

audioInfoOut()

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

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

Reimplemented in MP3EncoderShine, PureDataStream, PWMAudioOutput< PWMDriverT >, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, Pipeline, ResampleStream, and ResampleStreamT< TInterpolator >.

available()

int available ( )

inlineoverridevirtual

Reimplemented from BaseStream.

availableForWrite()

virtual int availableForWrite ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in AudioLoRa, UDPStream, VBANStream, AudioStreamWrapper, ConverterStream< T >, EncodedAudioStream, FaustStream< DSP >, I2SCodecStream, MiniAudioStream, StdioStream, A2DPStream, ESPNowStream, HammingFEC< bytecount, block_t >, AbstractURLStream, URLStreamESP32, NRF24Stream, ReedSolomonFEC< bytecount, additional_bytes >, SPIAudioSlave, USBAudioDeviceBase, AnalogAudioStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3Bands, Equalizer3BandsPerChannel, I2SStream, ReformatBaseStream, TimedStream, MemoryStream, RingBufferStream, MeasuringStream, ProgressStream, Throttle, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, QueueStream< T >, QueueStream< uint8_t >, DynamicMemoryStream, FadeStream, FrequencyDetectorAutoCorrelation, FrequencyDetectorZeroCrossing, Pipeline, QualityAnalysisStream, VolumeStream, AudioFFTBase, AudioBLEClient, AudioBLEClient, AudioBLEServer, and AudioBLEServer.

begin() [1/2]

virtual bool begin ( )

inlineoverridevirtual

Reimplemented from BaseStream.

begin() [2/2]

virtual bool begin ( AudioInfo  info )

inlinevirtual

clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

end()

void end ( )

inlineoverridevirtual

Reimplemented from BaseStream.

flush()

virtual void flush ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in PureDataStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, ReformatBaseStream, AudioStreamWrapper, ResampleStream, EncodedAudioStream, URLStream, BufferedTaskStream, I2SStream, MemoryStream, RingBufferStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, and BufferedStream.

isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

not_supported()

virtual int not_supported ( int  out, const char *  msg = ""  )

inlineprotectedvirtualinherited

notifyAudioChange()

void notifyAudioChange ( AudioInfo  info )

inlineprotectedinherited

operator bool()

virtual operator bool ( )

inlinevirtualinherited

Reimplemented in A2DPStream, ICYStreamT< T >, AudioBLEStream, PortAudioStream, URLStream, USBAudioDeviceBase, I2SStream, AdapterAudioOutputToAudioStream, TimedStream, MemoryStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, Pipeline, and AudioFFTBase.

readBytes()

size_t readBytes ( uint8_t *  data, size_t  len  )

inlineoverridevirtual

Reimplemented from AudioStream.

readSilence()

virtual size_t readSilence ( uint8_t *  buffer, size_t  length  )

inlinevirtualinherited

Source to generate silence: just sets the buffer to 0.

refillReadBuffer()

void refillReadBuffer ( )

inlineprotectedinherited

Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read()

removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Removes a target in order not to be notified about audio changes.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

setAudioInfo()

void setAudioInfo ( AudioInfo  info )

inlineoverridevirtual

Updates the audio info and calls the callback.

Reimplemented from AudioStream.

setAudioInfoCallback()

void setAudioInfoCallback ( void(*)(AudioInfo info)  cb )

inline

defines the callback to receive the actual audio info

setAvailable()

void setAvailable ( int  val )

inline

optioinally define available bytes for next read

setAvailableCallback()

void setAvailableCallback ( int(*)()  cb )

inline

setNotifyActive()

void setNotifyActive ( bool  flag )

inlineinherited

Deactivate/Reactivate automatic AudioInfo updates: (default is active)

setOutput() [1/3]

virtual void setOutput ( AudioOutput &  out )

inlinevirtualinherited

Defines/Changes the output target and registers for audio change notifications.

Reimplemented in TimedStream, VolumeMeter, AudioInputMonitor, QualityAnalysisStream, ReformatBaseStream, FormatConverterStream, and EncodedAudioStream.

setOutput() [2/3]

void setOutput ( Print &  out )

inlineoverridevirtual

Defines/Changes the output target.

Implements ModifyingStream.

setOutput() [3/3]

void setOutput ( Stream &  in )

inline

same as setStream

setReadCallback()

void setReadCallback ( size_t(*)(uint8_t *data, size_t len)  cb_read )

inline

Instead of reading from the input stream we call this method.

setStream() [1/3]

virtual void setStream ( AudioStream &  io )

inlinevirtualinherited

Defines/Changes the input & output and registers for audio change notifications.

Reimplemented in VolumeMeter, AudioInputMonitor, QualityAnalysisStream, FormatConverterStream, ReformatBaseStream, TimedStream, and EncodedAudioStream.

setStream() [2/3]

void setStream ( Print &  out )

inline

same as set Output

setStream() [3/3]

void setStream ( Stream &  in )

inlineoverridevirtual

Defines/Changes the input & output.

Implements ModifyingStream.

setUpdateCallback()

void setUpdateCallback ( size_t(*)(uint8_t *data, size_t len)  cb_update )

inline

After Reading or before writing we call this method to allow to modify the data.

setWriteBufferSize()

void setWriteBufferSize ( int  size )

inlineinherited

setWriteCallback()

void setWriteCallback ( size_t(*)(const uint8_t *data, size_t len)  cb_write )

inline

Instead of writing to the output stream we call this method.

write() [1/2]

size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

Reimplemented from AudioStream.

write() [2/2]

virtual size_t write ( uint8_t  ch )

inlineoverridevirtualinherited

Reimplemented in MemoryStream, AudioStreamWrapper, BufferedTaskStream, RingBufferStream, BufferedStream, and URLStream.

writeSilence()

virtual void writeSilence ( size_t  len )

inlinevirtualinherited

Writes len bytes of silence (=0).

Member Data Documentation

_timeout

int _timeout = 10

protectedinherited

active

bool active = true

protected

available_bytes

int available_bytes = -1

protected

cb_audio_info

void(* cb_audio_info) (AudioInfo info) = nullptr

protected

cb_available

int(* cb_available) () = nullptr

protected

cb_read

size_t(* cb_read) (uint8_t *data, size_t len) = nullptr

protected

cb_update

size_t(* cb_update) (uint8_t *data, size_t len) = nullptr

protected

cb_write

size_t(* cb_write) (const uint8_t *data, size_t len) = nullptr

protected

info

AudioInfo info

protectedinherited

is_notify_active

bool is_notify_active = true

protectedinherited

notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

p_out

Print* p_out = nullptr

protected

p_stream

Stream* p_stream = nullptr

protected

tmp_in

RingBuffer<uint8_t> tmp_in {0}

protectedinherited

tmp_out

RingBuffer<uint8_t> tmp_out {0}

protectedinherited

write_buffer_size

int write_buffer_size = MAX_SINGLE_CHARS

protectedinherited

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

• src/AudioTools/CoreAudio/AudioStreams.h