A type of AudioSource which can be repositioned. More...

#include <juce_PositionableAudioSource.h>

Inheritance diagram for juce::PositionableAudioSource:

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Collaboration diagram for juce::PositionableAudioSource:

Public Member Functions
	~PositionableAudioSource () override=default
	Destructor. More...

virtual void	getNextAudioBlock (const AudioSourceChannelInfo &bufferToFill)=0
	Called repeatedly to fetch subsequent blocks of audio data. More...

virtual int64	getNextReadPosition () const =0
	Returns the position from which the next block will be returned. More...

virtual int64	getTotalLength () const =0
	Returns the total length of the stream (in samples). More...

virtual bool	isLooping () const =0
	Returns true if this source is actually playing in a loop. More...

virtual void	prepareToPlay (int samplesPerBlockExpected, double sampleRate)=0
	Tells the source to prepare for playing. More...

virtual void	releaseResources ()=0
	Allows the source to release anything it no longer needs after playback has stopped. More...

virtual void	setLooping (bool shouldLoop)
	Tells the source whether you'd like it to play in a loop. More...

virtual void	setNextReadPosition (int64 newPosition)=0
	Tells the stream to move to a new position. More...

Protected Member Functions
	PositionableAudioSource ()=default
	Creates the PositionableAudioSource. More...

Detailed Description

A type of AudioSource which can be repositioned.

The basic AudioSource just streams continuously with no idea of a current time or length, so the PositionableAudioSource is used for a finite stream that has a current read position.

See also: AudioSource, AudioTransportSource

@tags{Audio}

Constructor & Destructor Documentation

◆ PositionableAudioSource()

juce::PositionableAudioSource::PositionableAudioSource ( )

protecteddefault

Creates the PositionableAudioSource.

◆ ~PositionableAudioSource()

juce::PositionableAudioSource::~PositionableAudioSource ( )

overridedefault

Destructor.

Member Function Documentation

◆ getNextAudioBlock()

virtual void juce::AudioSource::getNextAudioBlock ( const AudioSourceChannelInfo & bufferToFill )

pure virtualinherited

Called repeatedly to fetch subsequent blocks of audio data.

After calling the prepareToPlay() method, this callback will be made each time the audio playback hardware (or whatever other destination the audio data is going to) needs another block of data.

It will generally be called on a high-priority system thread, or possibly even an interrupt, so be careful not to do too much work here, as that will cause audio glitches!

See also: AudioSourceChannelInfo, prepareToPlay, releaseResources

Implemented in juce::AudioAppComponent, juce::MemoryAudioSource, juce::AudioTransportSource, juce::ChannelRemappingAudioSource, juce::MixerAudioSource, juce::BufferingAudioSource, juce::AudioFormatReaderSource, juce::ResamplingAudioSource, juce::ReverbAudioSource, juce::ToneGeneratorAudioSource, and juce::IIRFilterAudioSource.

◆ getNextReadPosition()

virtual int64 juce::PositionableAudioSource::getNextReadPosition ( ) const

pure virtual

Returns the position from which the next block will be returned.

See also: setNextReadPosition

Implemented in juce::AudioTransportSource, juce::BufferingAudioSource, juce::AudioFormatReaderSource, and juce::MemoryAudioSource.

◆ getTotalLength()

virtual int64 juce::PositionableAudioSource::getTotalLength ( ) const

pure virtual

Returns the total length of the stream (in samples).

Implemented in juce::AudioTransportSource, juce::BufferingAudioSource, juce::AudioFormatReaderSource, and juce::MemoryAudioSource.

◆ isLooping()

virtual bool juce::PositionableAudioSource::isLooping ( ) const

pure virtual

Returns true if this source is actually playing in a loop.

Implemented in juce::AudioTransportSource, juce::BufferingAudioSource, juce::MemoryAudioSource, and juce::AudioFormatReaderSource.

◆ prepareToPlay()

virtual void juce::AudioSource::prepareToPlay	(	int	samplesPerBlockExpected,
		double	sampleRate
	)

pure virtualinherited

Tells the source to prepare for playing.

An AudioSource has two states: prepared and unprepared.

The prepareToPlay() method is guaranteed to be called at least once on an 'unprepared' source to put it into a 'prepared' state before any calls will be made to getNextAudioBlock(). This callback allows the source to initialise any resources it might need when playing.

Once playback has finished, the releaseResources() method is called to put the stream back into an 'unprepared' state.

Note that this method could be called more than once in succession without a matching call to releaseResources(), so make sure your code is robust and can handle that kind of situation.

Parameters

samplesPerBlockExpected	the number of samples that the source will be expected to supply each time its getNextAudioBlock() method is called. This number may vary slightly, because it will be dependent on audio hardware callbacks, and these aren't guaranteed to always use a constant block size, so the source should be able to cope with small variations.
sampleRate	the sample rate that the output will be used at - this is needed by sources such as tone generators.

See also: releaseResources, getNextAudioBlock

Implemented in juce::AudioAppComponent, juce::AudioTransportSource, juce::ChannelRemappingAudioSource, juce::MixerAudioSource, juce::BufferingAudioSource, juce::AudioFormatReaderSource, juce::ResamplingAudioSource, juce::ReverbAudioSource, juce::IIRFilterAudioSource, juce::ToneGeneratorAudioSource, and juce::MemoryAudioSource.

◆ releaseResources()

virtual void juce::AudioSource::releaseResources ( )

pure virtualinherited

Allows the source to release anything it no longer needs after playback has stopped.

This will be called when the source is no longer going to have its getNextAudioBlock() method called, so it should release any spare memory, etc. that it might have allocated during the prepareToPlay() call.

Note that there's no guarantee that prepareToPlay() will actually have been called before releaseResources(), and it may be called more than once in succession, so make sure your code is robust and doesn't make any assumptions about when it will be called.