Role-independent front end shared by USB Audio devices (USBAudioDeviceBase, aliased as USBAudioStream) and USB Audio hosts (USBAudioHostBase, aliased as USBAudioHostStream). More...

#include <USBAudioStreamBase.h>

Inheritance diagram for USBAudioStreamBase:

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

virtual AudioInfo	audioInfoOut ()

int	available () override
	Bytes of received audio waiting in the RX buffer.

int	availableForWrite () override
	Bytes of free space in the TX buffer.

virtual bool	begin ()

virtual BaseBuffer< uint8_t > &	bufferRx ()=0
	Returns the RX audio buffer. Must be overridden by subclasses.

virtual BaseBuffer< uint8_t > &	bufferTx ()=0
	Returns the TX audio buffer. Must be overridden by subclasses.

virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.

const USBAudioConfig &	config () const
	Provides the active configuration.

virtual void	end ()

virtual void	flush () override

virtual int	getActualCore () const
	Returns the actual core on which the call is running (for RP2040)

bool	isEpInEnabled () const
	Returns true if the IN endpoint is enabled.

bool	isEpOutEnabled () const
	Returns true if the OUT endpoint is enabled.

bool	isMute (uint8_t channel=0) const
	Returns the current mute state for the given channel.

bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.

bool	isStreamingActive () const
	Returns true if either the TX or RX stream is open.

virtual bool	isStreamingActiveRx () const =0
	Returns true if the stream used by readBytes() is open.

virtual bool	isStreamingActiveTx () const =0
	Returns true if the stream used by write() is open.

virtual bool	mounted ()=0
	Returns true if the USB connection is established (device: enumerated by the host; host: an audio device is attached).

	operator bool () override

size_t	readBytes (uint8_t *buffer, size_t bufsize)
	Receive audio data from the USB peer. Until bufferRx() has filled past config.rx_start_fill_percent at least once after begin(), no data is returned. This is a one-shot startup prime only – once reached, readBytes() keeps draining normally for the rest of the session and is not gated again by later underruns.

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.

virtual void	serviceUSB ()=0
	Process pending USB events on platforms where the application drives the stack. No-op where a dedicated task runs the stack.

virtual void	setAudioInfo (AudioInfo newInfo) override
	Defines the input AudioInfo.

bool	setMute (bool m, uint8_t channel=0)
	Set the mute state for a channel and notify the USB peer.

void	setMuteCallback (std::function< void(bool, uint8_t)> cb)
	Register a callback invoked when the mute state changes.

void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)

void	setSampleRateCallback (std::function< void(uint32_t)> cb)
	Register a callback invoked when the sample rate changes.

void	setStreamingStateCallback (std::function< void(bool, bool)> cb)
	Register a callback invoked when the streaming state changes (a streaming interface was opened or closed).

bool	setVolume (float vol, uint8_t channel)
	Set the volume for a channel and notify the USB peer.

bool	setVolume (float volume) override
	sets the volume for the master channel (channel 0)

void	setVolumeCallback (std::function< void(float, uint8_t)> cb)
	Register a callback invoked when the volume changes.

void	setWriteBufferSize (int size)

float	volume () override
	gets the volume for the master channel (channel 0)

float	volume (uint8_t channel)
	Returns the current volume for the given channel.

size_t	write (const uint8_t *data, size_t len)
	Send audio data to the USB peer. Silently discards data while the TX stream is not open so StreamCopy doesn't report write errors before streaming starts.

virtual size_t	write (uint8_t ch) override

virtual void	writeSilence (size_t len)
	Writes len bytes of silence (=0).

Protected Member Functions
virtual bool	beginUSB ()=0
	Override in platform subclasses to start the USB stack.

bool	configChanged (const USBAudioConfig &n)

float	getVolumeExt (uint8_t channel) const
	Returns the effective volume for a per-channel index (1-based). Combines master volume (index 0) with per-channel volume and mute.

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

void	notifyAudioChange (AudioInfo info)

void	notifyStreamingState ()

virtual void	onMuteChanged (uint8_t)

virtual void	onVolumeChanged (uint8_t)

template<typename T >
void	processVolume (T *data, size_t sample_count)

void	processVolume (uint8_t *data, size_t len)
	Process audio data for volume control.

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

virtual void	resizeBuffers ()=0
	Resize the platform audio buffers.

void	setConfig (const USBAudioConfig &cfg)
	Set the USB audio configuration (use begin(cfg) instead).

void	setupVolumeState ()
	(Re)sizes the volume and mute state: master (index 0) + one per channel

Static Protected Member Functions
static int16_t	floatToUac2 (float vol)
	Convert linear volume (0.0–1.0) to UAC2 int16 (1/256 dB). Linear mapping: 0.0 → -100 dB (min), 1.0 → 0 dB (max).

static bool	isValidBitsPerSample (uint8_t bps)

static float	uac2ToFloat (int16_t v)
	Convert UAC2 int16 (1/256 dB) to linear volume (0.0–1.0). Linear mapping within the -100..0 dB range reported by GET_RANGE.

Protected Attributes
int	_timeout = 10

USBAudioConfig	config_

int	core = -1

AudioInfo	info

bool	is_active_ = false

bool	is_notify_active = true

bool	is_started_ = false

std::vector< bool >	mute_

std::function< void(bool, uint8_t)>	mute_cb_

Vector< AudioInfoSupport * >	notify_vector

bool	rx_primed_ = false

std::function< void(uint32_t)>	sample_rate_cb_

std::function< void(bool, bool)>	streaming_state_cb_

RingBuffer< uint8_t >	tmp_in {0}

RingBuffer< uint8_t >	tmp_out {0}

bool	usb_task_active_ = false

std::vector< float >	volume_

std::function< void(float, uint8_t)>	volume_cb_

float	volume_value = 1.0f

int	write_buffer_size = MAX_SINGLE_CHARS

Static Protected Attributes
static constexpr int16_t	kVolumeMinDb256 = -25600
	Convert AudioTools volume (0.0–1.0) to UAC2 int16 (1/256 dB). 0.0 maps to 0x8000 (silence), 1.0 maps to 0 (0 dB).

Detailed Description

Role-independent front end shared by USB Audio devices (USBAudioDeviceBase, aliased as USBAudioStream) and USB Audio hosts (USBAudioHostBase, aliased as USBAudioHostStream).

It provides the identical public Arduino stream API for both roles: write() sends audio to the USB peer, readBytes() receives audio from it, plus volume/mute state, callbacks and the one-shot RX startup prime. The USB stack specific parts are provided by the subclasses via the pure virtual methods.

Author: Phil Schatzmann

Copyright: GPLv3

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, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

◆ available()

int available ( )

inlineoverridevirtual

Bytes of received audio waiting in the RX buffer.

Reimplemented from BaseStream.

◆ availableForWrite()

int availableForWrite ( )

inlineoverridevirtual

Bytes of free space in the TX buffer.

Reimplemented from BaseStream.

◆ begin()

virtual bool begin ( )

inlinevirtualinherited

Reimplemented in AudioOutputWithCallback, AudioMP34DT05, I2SCodecStream, MozziStream, PureDataStream, SPDIFOutput, VS1053Stream, WM8960Stream, AdaptiveResamplingStream, AudioLoRa, ESPNowStream, USBAudioDeviceBase, USBAudioHostBase, VBANStream, FrequencyDetectorAutoCorrelation, GoertzelStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, I2SStream, AudioTimeSourceStream, AudioStreamWrapper, TimerCallbackAudioStream, ResampleStreamT< TInterpolator >, FileLoopT< FileType >, FileLoopT< File >, EncodedAudioStream, AudioBoardStream, AudioKitStream, MiniAudioStream, PortAudioStream, StdioStream, HLSStreamT< URLStream >, NRF24Stream, AutomaticGainControlStream, MeasuringStream, QualityAnalysisStream, VolumeStream, AnalogAudioStream, AdapterAudioOutputToAudioStream, TimedStream, MemoryStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, ProgressStream, Throttle, InputMerge< T >, CallbackStream, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, VolumeMeter, AudioInputMonitor, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, CatStream, QueueStream< T >, QueueStream< uint8_t >, DynamicMemoryStream, Pipeline, Pipeline::ModifyingStreamAdapter, ResampleStream, SupportedRatesStream, AudioFFTBase, and EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >.

◆ beginUSB()

virtual bool beginUSB ( )

protectedpure virtual

Override in platform subclasses to start the USB stack.

Implemented in USBAudioDeviceESP32, USBAudioDeviceRenesas, USBAudioDeviceTinyUSB, USBAudioDeviceTinyUSBFreeRTOS, USBAudioHostBase, USBAudioHostESP32, and USBAudioHostTinyUSBFreeRTOS.

◆ bufferRx()

virtual BaseBuffer< uint8_t > & bufferRx ( )

pure virtual

Returns the RX audio buffer. Must be overridden by subclasses.

Implemented in USBAudioDeviceESP32, USBAudioDeviceRenesas, USBAudioDeviceTinyUSB, USBAudioDeviceTinyUSBFreeRTOS, USBAudioHostESP32, USBAudioHostTinyUSB, and USBAudioHostTinyUSBFreeRTOS.

◆ bufferTx()

virtual BaseBuffer< uint8_t > & bufferTx ( )

pure virtual

Returns the TX audio buffer. Must be overridden by subclasses.

Implemented in USBAudioDeviceESP32, USBAudioDeviceRenesas, USBAudioDeviceTinyUSB, USBAudioDeviceTinyUSBFreeRTOS, USBAudioHostESP32, USBAudioHostTinyUSB, and USBAudioHostTinyUSBFreeRTOS.

◆ clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

◆ config()

const USBAudioConfig & config ( ) const

inline

Provides the active configuration.

◆ configChanged()

bool configChanged ( const USBAudioConfig & n )

inlineprotected

◆ end()

virtual void end ( )

inlinevirtualinherited

Reimplemented in FaustStream< DSP >, AudioMP34DT05, I2SCodecStream, MozziStream, PureDataStream, SPDIFOutput, VS1053Stream, WM8960Stream, AdaptiveResamplingStream, AudioLoRa, ESPNowStream, BufferedTaskStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, USBAudioDeviceBase, USBAudioHostBase, GoertzelStream, Equalizer3BandsT< T >, I2SStream, AudioStreamWrapper, TimerCallbackAudioStream, FormatConverterStream, FileLoopT< FileType >, FileLoopT< File >, EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >, EncodedAudioStream, AudioKitStream, MiniAudioStream, PortAudioStream, StdioStream, A2DPStream, HLSStreamT< URLStream >, HttpRequest, ICYStreamT< T >, URLStream, URLStreamESP32, NRF24Stream, SPIAudioSlave, AutomaticGainControlStream, VolumeStream, AnalogAudioStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3BandsPerChannelT< T >, ReformatBaseStream, AdapterAudioOutputToAudioStream, MemoryStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, InputMixer< T, SumT >, InputMerge< T >, CallbackStream, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, ChannelFormatConverterStream, NumberFormatConverterStream, CatStream, QueueStream< T >, QueueStream< uint8_t >, DynamicMemoryStream, Pipeline, Pipeline::ModifyingStreamAdapter, SupportedRatesStream, AudioFFTBase, AudioBLEClient, AudioBLEClient, AudioBLEServer, AudioBLEServer, AbstractURLStream, and AudioBLEStream.

◆ floatToUac2()

static int16_t floatToUac2 ( float vol )

inlinestaticprotected

Convert linear volume (0.0–1.0) to UAC2 int16 (1/256 dB). Linear mapping: 0.0 → -100 dB (min), 1.0 → 0 dB (max).

◆ flush()

virtual void flush ( )

inlineoverridevirtualinherited

◆ getActualCore()

virtual int getActualCore ( ) const

inlinevirtual

Returns the actual core on which the call is running (for RP2040)

Reimplemented in USBAudioDeviceBase, USBAudioDeviceESP32, USBAudioDeviceTinyUSB, and USBAudioHostESP32.

◆ getVolumeExt()

float getVolumeExt ( uint8_t channel ) const

inlineprotected

Returns the effective volume for a per-channel index (1-based). Combines master volume (index 0) with per-channel volume and mute.

◆ isEpInEnabled()

bool isEpInEnabled ( ) const

inline

Returns true if the IN endpoint is enabled.

◆ isEpOutEnabled()

bool isEpOutEnabled ( ) const

inline

Returns true if the OUT endpoint is enabled.

◆ isMute()

bool isMute ( uint8_t channel = 0 ) const

inline

Returns the current mute state for the given channel.

Parameters

channel 0 = master, 1..N = per-channel.

◆ isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isStreamingActive()

bool isStreamingActive ( ) const

inline

Returns true if either the TX or RX stream is open.

◆ isStreamingActiveRx()

virtual bool isStreamingActiveRx ( ) const

pure virtual

Returns true if the stream used by readBytes() is open.

Implemented in USBAudioDeviceBase, and USBAudioHostBase.

◆ isStreamingActiveTx()

virtual bool isStreamingActiveTx ( ) const

pure virtual

Returns true if the stream used by write() is open.

Implemented in USBAudioDeviceBase, and USBAudioHostBase.

◆ isValidBitsPerSample()

static bool isValidBitsPerSample ( uint8_t bps )

inlinestaticprotected

◆ mounted()

virtual bool mounted ( )

pure virtual

Returns true if the USB connection is established (device: enumerated by the host; host: an audio device is attached).

Implemented in USBAudioDeviceBase, and USBAudioHostBase.

◆ not_supported()

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

inlineprotectedvirtualinherited

◆ notifyAudioChange()

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ notifyStreamingState()

void notifyStreamingState ( )

inlineprotected

◆ onMuteChanged()

virtual void onMuteChanged ( uint8_t )

inlineprotectedvirtual

Called by setMute() after the state was updated: propagate the change to the USB peer.

Reimplemented in USBAudioDeviceBase, and USBAudioHostBase.

◆ onVolumeChanged()

virtual void onVolumeChanged ( uint8_t )

inlineprotectedvirtual

Called by setVolume() after the state was updated: propagate the change to the USB peer.

Reimplemented in USBAudioDeviceBase, and USBAudioHostBase.

◆ operator bool()

operator bool ( )

inlineoverridevirtual

Returns true when begin() has been called and the USB connection is established.

Reimplemented from AudioStream.

◆ processVolume() [1/2]

template<typename T >

void processVolume	(	T *	data,
		size_t	sample_count
	)

inlineprotected

◆ processVolume() [2/2]

void processVolume	(	uint8_t *	data,
		size_t	len
	)

inlineprotected

Process audio data for volume control.

◆ readBytes()

size_t readBytes	(	uint8_t *	buffer,
		size_t	bufsize
	)

inlinevirtual

Receive audio data from the USB peer. Until bufferRx() has filled past config.rx_start_fill_percent at least once after begin(), no data is returned. This is a one-shot startup prime only – once reached, readBytes() keeps draining normally for the rest of the session and is not gated again by later underruns.

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 >.

◆ resizeBuffers()

virtual void resizeBuffers ( )

protectedpure virtual

Resize the platform audio buffers.

Implemented in USBAudioDeviceESP32, USBAudioDeviceRenesas, USBAudioDeviceTinyUSB, USBAudioDeviceTinyUSBFreeRTOS, USBAudioHostESP32, USBAudioHostTinyUSB, and USBAudioHostTinyUSBFreeRTOS.

◆ serviceUSB()

virtual void serviceUSB ( )

pure virtual

Process pending USB events on platforms where the application drives the stack. No-op where a dedicated task runs the stack.

Implemented in USBAudioDeviceESP32, USBAudioDeviceRenesas, USBAudioDeviceTinyUSB, USBAudioHostESP32, USBAudioHostTinyUSB, and USBAudioDeviceBase.

◆ setAudioInfo()

virtual void setAudioInfo ( AudioInfo info )

inlineoverridevirtualinherited

Defines the input AudioInfo.

Implements AudioInfoSupport.

Reimplemented in VS1053Stream, WM8960Stream, AutomaticGainControlStream, VolumeStream, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, MiniAudioStream, PortAudioStream, I2SCodecStream, MozziStream, SPDIFOutput, AudioLoRa, AnalogAudioStream, I2SStream, TimerCallbackAudioStream, AudioBLEStream, MDFEchoCancellationStream< T, SampleType >, AudioKitStream, NRF24Stream, SPIAudioSlave, USBAudioDeviceBase, USBAudioHostBase, VBANStream, GoertzelStream, MeasuringStream, QualityAnalysisStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, AdapterAudioOutputToAudioStream, TimedStream, ProgressStream, CallbackStream, VolumeMeter, AudioInputMonitor, FormatConverterStream, FadeStream, Pipeline::ModifyingStreamAdapter, AudioFFTBase, EncodedAudioStream, PureDataStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, Pipeline, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

◆ setConfig()

void setConfig ( const USBAudioConfig & cfg )

inlineprotected

Set the USB audio configuration (use begin(cfg) instead).

◆ setMute()

bool setMute	(	bool	m,
		uint8_t	channel = `0`
	)

inline

Set the mute state for a channel and notify the USB peer.

Parameters

m	true = muted, false = unmuted.
channel	0 = master, 1..N = per-channel.

Returns: true if the channel index was valid.

◆ setMuteCallback()

void setMuteCallback ( std::function< void(bool, uint8_t)> cb )

inline

Register a callback invoked when the mute state changes.

Parameters

cb	Callback receiving (bool muted, uint8_t channel).

◆ setNotifyActive()

void setNotifyActive ( bool flag )

inlineinherited

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

◆ setSampleRateCallback()

void setSampleRateCallback ( std::function< void(uint32_t)> cb )

inline

Register a callback invoked when the sample rate changes.

Parameters

cb	Callback receiving the new rate in Hz.

◆ setStreamingStateCallback()

void setStreamingStateCallback ( std::function< void(bool, bool)> cb )

inline

Register a callback invoked when the streaming state changes (a streaming interface was opened or closed).

Parameters

cb	Callback receiving (bool active_tx, bool active_rx).

◆ setupVolumeState()

void setupVolumeState ( )

inlineprotected

(Re)sizes the volume and mute state: master (index 0) + one per channel

◆ setVolume() [1/2]

bool setVolume	(	float	vol,
		uint8_t	channel
	)

inline

Set the volume for a channel and notify the USB peer.

Parameters

vol	Volume as a float 0.0 (silence) to 1.0 (0 dB).
channel	0 = master, 1..N = per-channel.

Returns: true if the channel index was valid.

◆ setVolume() [2/2]

bool setVolume ( float volume )

inlineoverridevirtual

sets the volume for the master channel (channel 0)

Reimplemented from VolumeSupport.

◆ setVolumeCallback()

void setVolumeCallback ( std::function< void(float, uint8_t)> cb )

inline

Register a callback invoked when the volume changes.

Parameters

cb	Callback receiving (float volume, uint8_t channel).

◆ setWriteBufferSize()

void setWriteBufferSize ( int size )

inlineinherited

◆ uac2ToFloat()

static float uac2ToFloat ( int16_t v )

inlinestaticprotected

Convert UAC2 int16 (1/256 dB) to linear volume (0.0–1.0). Linear mapping within the -100..0 dB range reported by GET_RANGE.

◆ volume() [1/2]

float volume ( )

inlineoverridevirtual

gets the volume for the master channel (channel 0)

Reimplemented from VolumeSupport.

◆ volume() [2/2]

float volume ( uint8_t channel )

inline

Returns the current volume for the given channel.

Parameters

channel 0 = master, 1..N = per-channel.

Returns: Volume as a float in the range 0.0 (silence) to 1.0 (0 dB).

◆ write() [1/2]

size_t write	(	const uint8_t *	data,
		size_t	len
	)

inlinevirtual

Send audio data to the USB peer. Silently discards data while the TX stream is not open so StreamCopy doesn't report write errors before streaming starts.

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

◆ config_

USBAudioConfig config_

protected

◆ core

int core = -1

protected

◆ info

AudioInfo info

protectedinherited

◆ is_active_

bool is_active_ = false

protected

◆ is_notify_active

bool is_notify_active = true

protectedinherited

◆ is_started_

bool is_started_ = false

protected

◆ kVolumeMinDb256

constexpr int16_t kVolumeMinDb256 = -25600

staticconstexprprotected

Convert AudioTools volume (0.0–1.0) to UAC2 int16 (1/256 dB). 0.0 maps to 0x8000 (silence), 1.0 maps to 0 (0 dB).

◆ mute_

std::vector<bool> mute_

protected

◆ mute_cb_

std::function<void(bool, uint8_t)> mute_cb_

protected

◆ notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

◆ rx_primed_

bool rx_primed_ = false

protected

◆ sample_rate_cb_

std::function<void(uint32_t)> sample_rate_cb_

protected

◆ streaming_state_cb_

std::function<void(bool, bool)> streaming_state_cb_

protected

◆ tmp_in

RingBuffer<uint8_t> tmp_in {0}

protectedinherited

◆ tmp_out

RingBuffer<uint8_t> tmp_out {0}

protectedinherited

◆ usb_task_active_

bool usb_task_active_ = false

protected

◆ volume_

std::vector<float> volume_

protected

◆ volume_cb_

std::function<void(float, uint8_t)> volume_cb_

protected

◆ volume_value

float volume_value = 1.0f

protectedinherited

◆ write_buffer_size

int write_buffer_size = MAX_SINGLE_CHARS

protectedinherited

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

src/AudioTools/Communication/USB/USBAudioStreamBase.h

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Function Documentation

◆ addNotifyAudioChange()

◆ audioInfo()

◆ audioInfoOut()

◆ available()

◆ availableForWrite()

◆ begin()

◆ beginUSB()

◆ bufferRx()

◆ bufferTx()

◆ clearNotifyAudioChange()

◆ config()

◆ configChanged()

◆ end()

◆ floatToUac2()

◆ flush()

◆ getActualCore()

◆ getVolumeExt()

◆ isEpInEnabled()

◆ isEpOutEnabled()

◆ isMute()

◆ isNotifyActive()

◆ isStreamingActive()

◆ isStreamingActiveRx()

◆ isStreamingActiveTx()

◆ isValidBitsPerSample()

◆ mounted()

◆ not_supported()

◆ notifyAudioChange()

◆ notifyStreamingState()

◆ onMuteChanged()

◆ onVolumeChanged()

◆ operator bool()

◆ processVolume() [1/2]

◆ processVolume() [2/2]

◆ readBytes()

◆ readSilence()

◆ refillReadBuffer()

◆ removeNotifyAudioChange()

◆ resizeBuffers()

◆ serviceUSB()

◆ setAudioInfo()

◆ setConfig()

◆ setMute()

◆ setMuteCallback()

◆ setNotifyActive()

◆ setSampleRateCallback()

◆ setStreamingStateCallback()

◆ setupVolumeState()

◆ setVolume() [1/2]

◆ setVolume() [2/2]

◆ setVolumeCallback()

◆ setWriteBufferSize()

◆ uac2ToFloat()

◆ volume() [1/2]

◆ volume() [2/2]

◆ write() [1/2]

◆ write() [2/2]

◆ writeSilence()

Member Data Documentation

◆ _timeout

◆ config_

◆ core

◆ info

◆ is_active_

◆ is_notify_active

◆ is_started_

◆ kVolumeMinDb256

◆ mute_

◆ mute_cb_

◆ notify_vector

◆ rx_primed_

◆ sample_rate_cb_

◆ streaming_state_cb_