juce::BufferingAudioSource Class Reference

An AudioSource which takes another source as input, and buffers it using a thread. More...

#include <juce_BufferingAudioSource.h>

Inheritance diagram for juce::BufferingAudioSource:

Collaboration diagram for juce::BufferingAudioSource:

Public Member Functions
	BufferingAudioSource (PositionableAudioSource *source, TimeSliceThread &backgroundThread, bool deleteSourceWhenDeleted, int numberOfSamplesToBuffer, int numberOfChannels=2, bool prefillBufferOnPrepareToPlay=true)
	Creates a BufferingAudioSource. More...
	~BufferingAudioSource () override
	Destructor. More...
void	getNextAudioBlock (const AudioSourceChannelInfo &) override
	Implementation of the AudioSource method. More...
int64	getNextReadPosition () const override
	Implements the PositionableAudioSource method. More...
int64	getTotalLength () const override
	Implements the PositionableAudioSource method. More...
bool	isLooping () const override
	Implements the PositionableAudioSource method. More...
void	prepareToPlay (int samplesPerBlockExpected, double sampleRate) override
	Implementation of the AudioSource method. More...
void	releaseResources () override
	Implementation of the AudioSource method. More...
virtual void	setLooping (bool shouldLoop)
	Tells the source whether you'd like it to play in a loop. More...
void	setNextReadPosition (int64 newPosition) override
	Implements the PositionableAudioSource method. More...
bool	waitForNextAudioBlockReady (const AudioSourceChannelInfo &info, const uint32 timeout)
	A useful function to block until the next the buffer info can be filled. More...

Private Member Functions
void	readBufferSection (int64 start, int length, int bufferOffset)
bool	readNextBufferChunk ()
int	useTimeSlice () override
	Called back by a TimeSliceThread. More...

Private Attributes
TimeSliceThread &	backgroundThread
AudioBuffer< float >	buffer
WaitableEvent	bufferReadyEvent
CriticalSection	bufferStartPosLock
std::atomic< int64 >	bufferValidEnd { 0 }
std::atomic< int64 >	bufferValidStart { 0 }
bool	isPrepared = false
std::atomic< int64 >	nextPlayPos { 0 }
int	numberOfChannels
int	numberOfSamplesToBuffer
bool	prefillBuffer
double	sampleRate = 0
OptionalScopedPointer< PositionableAudioSource >	source
bool	wasSourceLooping = false

Detailed Description

An AudioSource which takes another source as input, and buffers it using a thread.

Create this as a wrapper around another thread, and it will read-ahead with a background thread to smooth out playback. You can either create one of these directly, or use it indirectly using an AudioTransportSource.

See also

PositionableAudioSource, AudioTransportSource

{Audio}

Constructor & Destructor Documentation

BufferingAudioSource()

juce::BufferingAudioSource::BufferingAudioSource	(	PositionableAudioSource *	source,
		TimeSliceThread &	backgroundThread,
		bool	deleteSourceWhenDeleted,
		int	numberOfSamplesToBuffer,
		int	numberOfChannels = 2,
		bool	prefillBufferOnPrepareToPlay = true
	)

Creates a BufferingAudioSource.

Parameters

source	the input source to read from
backgroundThread	a background thread that will be used for the background read-ahead. This object must not be deleted until after any BufferingAudioSources that are using it have been deleted!
deleteSourceWhenDeleted	if true, then the input source object will be deleted when this object is deleted
numberOfSamplesToBuffer	the size of buffer to use for reading ahead
numberOfChannels	the number of channels that will be played
prefillBufferOnPrepareToPlay	if true, then calling prepareToPlay on this object will block until the buffer has been filled

~BufferingAudioSource()

juce::BufferingAudioSource::~BufferingAudioSource ( )

override

Destructor.

The input source may be deleted depending on whether the deleteSourceWhenDeleted flag was set in the constructor.

Member Function Documentation

getNextAudioBlock()

void juce::BufferingAudioSource::getNextAudioBlock ( const AudioSourceChannelInfo &  )

overridevirtual

Implementation of the AudioSource method.

Implements juce::AudioSource.

getNextReadPosition()

int64 juce::BufferingAudioSource::getNextReadPosition ( ) const

overridevirtual

Implements the PositionableAudioSource method.

Implements juce::PositionableAudioSource.

getTotalLength()

int64 juce::BufferingAudioSource::getTotalLength ( ) const

inlineoverridevirtual

Implements the PositionableAudioSource method.

Implements juce::PositionableAudioSource.

References juce::PositionableAudioSource::getTotalLength().

isLooping()

bool juce::BufferingAudioSource::isLooping ( ) const

inlineoverridevirtual

Implements the PositionableAudioSource method.

Implements juce::PositionableAudioSource.

References juce::PositionableAudioSource::isLooping().

prepareToPlay()

void juce::BufferingAudioSource::prepareToPlay ( int  samplesPerBlockExpected, double  sampleRate  )

overridevirtual

Implementation of the AudioSource method.

Implements juce::AudioSource.

readBufferSection()

void juce::BufferingAudioSource::readBufferSection ( int64  start, int  length, int  bufferOffset  )

private

readNextBufferChunk()

bool juce::BufferingAudioSource::readNextBufferChunk ( )

private

releaseResources()

void juce::BufferingAudioSource::releaseResources ( )

overridevirtual

Implementation of the AudioSource method.

Implements juce::AudioSource.

setLooping()

virtual void juce::PositionableAudioSource::setLooping ( bool  shouldLoop )

inlinevirtualinherited

Tells the source whether you'd like it to play in a loop.

Reimplemented in juce::AudioFormatReaderSource.

References juce::ignoreUnused().

setNextReadPosition()

void juce::BufferingAudioSource::setNextReadPosition ( int64  newPosition )

overridevirtual

Implements the PositionableAudioSource method.

Implements juce::PositionableAudioSource.

useTimeSlice()

int juce::BufferingAudioSource::useTimeSlice ( )

overrideprivatevirtual

Called back by a TimeSliceThread.

When you register this class with it, a TimeSliceThread will repeatedly call this method.

The implementation of this method should use its time-slice to do something that's quick - never block for longer than absolutely necessary.

Returns

Your method should return the number of milliseconds which it would like to wait before being called again. Returning 0 will make the thread call again as soon as possible (after possibly servicing other busy clients). If you return a value below zero, your client will be removed from the list of clients, and won't be called again. The value you specify isn't a guaranteee, and is only used as a hint by the thread - the actual time before the next callback may be more or less than specified. You can force the TimeSliceThread to wake up and poll again immediately by calling its notify() method.

Implements juce::TimeSliceClient.

waitForNextAudioBlockReady()

bool juce::BufferingAudioSource::waitForNextAudioBlockReady	(	const AudioSourceChannelInfo &	info,
		const uint32	timeout
	)

A useful function to block until the next the buffer info can be filled.

This is useful for offline rendering.

Member Data Documentation

backgroundThread

TimeSliceThread& juce::BufferingAudioSource::backgroundThread

private

buffer

AudioBuffer<float> juce::BufferingAudioSource::buffer

private

bufferReadyEvent

WaitableEvent juce::BufferingAudioSource::bufferReadyEvent

private

bufferStartPosLock

CriticalSection juce::BufferingAudioSource::bufferStartPosLock

private

bufferValidEnd

std::atomic<int64> juce::BufferingAudioSource::bufferValidEnd { 0 }

private

bufferValidStart

std::atomic<int64> juce::BufferingAudioSource::bufferValidStart { 0 }

private

isPrepared

bool juce::BufferingAudioSource::isPrepared = false

private

nextPlayPos

std::atomic<int64> juce::BufferingAudioSource::nextPlayPos { 0 }

private

numberOfChannels

int juce::BufferingAudioSource::numberOfChannels

private

numberOfSamplesToBuffer

int juce::BufferingAudioSource::numberOfSamplesToBuffer

private

prefillBuffer

bool juce::BufferingAudioSource::prefillBuffer

private

sampleRate

double juce::BufferingAudioSource::sampleRate = 0

private

source

OptionalScopedPointer<PositionableAudioSource> juce::BufferingAudioSource::source

private

wasSourceLooping

bool juce::BufferingAudioSource::wasSourceLooping = false

private

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

• juce_BufferingAudioSource.h