Async::AudioJitterFifo Class Reference

A FIFO class for handling audio samples. More...

#include <AsyncAudioJitterFifo.h>

Inheritance diagram for Async::AudioJitterFifo:

Public Member Functions
	AudioJitterFifo (unsigned fifo_size)
	Constuctor.
virtual	~AudioJitterFifo (void)
	Destructor.
void	setSize (unsigned new_size)
	Set the size of the FIFO.
bool	empty (void) const
	Check if the FIFO is empty.
unsigned	samplesInFifo (void) const
	Find out how many samples there are in the FIFO.
void	clear (void)
	Clear all samples from the FIFO.
virtual int	writeSamples (const float *samples, int count)
	Write samples into the FIFO.
virtual void	flushSamples (void)
	Tell the FIFO to flush the previously written samples.
virtual void	resumeOutput (void)
	Resume audio output to the connected sink.
Public Member Functions inherited from Async::AudioSink
	AudioSink (void)
	Default constuctor.
virtual	~AudioSink (void)
	Destructor.
bool	registerSource (AudioSource *source)
	Register an audio source to provide samples to this sink.
void	unregisterSource (void)
	Unregister the previously registered audio source.
bool	isRegistered (void) const
	Check if an audio source has been registered.
AudioSource *	source (void) const
	Get the registered audio source.
Public Member Functions inherited from Async::AudioSource
	AudioSource (void)
	Default constuctor.
virtual	~AudioSource (void)
	Destructor.
bool	registerSink (AudioSink *sink, bool managed=false)
	Register an audio sink to provide samples to.
void	unregisterSink (void)
	Unregister the previously registered audio sink.
bool	isRegistered (void) const
	Check if an audio sink has been registered.
AudioSink *	sink (void) const
	Get the registered audio sink.
bool	sinkManaged (void) const
	Check if the sink is managed or not.
void	handleAllSamplesFlushed (void)
	The registered sink has flushed all samples.

Protected Member Functions
virtual void	allSamplesFlushed (void)
	The registered sink has flushed all samples.
Protected Member Functions inherited from Async::AudioSink
void	sourceResumeOutput (void)
	Tell the source that we are ready to accept more samples.
void	sourceAllSamplesFlushed (void)
	Tell the source that all samples have been flushed.
bool	setHandler (AudioSink *handler)
	Setup another sink to handle the incoming audio.
void	clearHandler (void)
	Clear a handler that was previously setup with setHandler.
AudioSink *	handler (void) const
Protected Member Functions inherited from Async::AudioSource
int	sinkWriteSamples (const float *samples, int len)
void	sinkFlushSamples (void)
bool	setHandler (AudioSource *handler)
	Setup another source to handle the outgoing audio.
AudioSource *	handler (void) const
void	clearHandler (void)
	Clear a handler that was previously setup with setHandler.

Detailed Description

A FIFO class for handling audio samples.

Author

Tobias Blomberg / SM0SVX

Date

2007-10-06

This class implements a jitter-tolerant FIFO for handling audio samples. The FIFO is intended to buffer samples that arrive with a certain amount of sample rate or packet jitter. Under normal operation, the FIFO is kept half full. Varying sample rates or packet rates slowly move the amount of samples out of center. When the FIFO reaches a full or empty state, it is automatically reset to the half-full state.

Definition at line 120 of file AsyncAudioJitterFifo.h.

Constructor & Destructor Documentation

AudioJitterFifo()

Async::AudioJitterFifo::AudioJitterFifo ( unsigned fifo_size )

explicit

Constuctor.

Parameters

fifo_size

This is the size of the fifo expressed in number of samples.

~AudioJitterFifo()

virtual Async::AudioJitterFifo::~AudioJitterFifo ( void )

virtual

Destructor.

Member Function Documentation

allSamplesFlushed()

virtual void Async::AudioJitterFifo::allSamplesFlushed ( void )

protectedvirtual

The registered sink has flushed all samples.

This function will be called when all samples have been flushed in the registered sink. This function is normally only called from a connected sink object.

Reimplemented from Async::AudioSource.

clear()

void Async::AudioJitterFifo::clear

(

void

)

Clear all samples from the FIFO.

This will immediately reset the FIFO and discard all samples. The source will be told that all samples have been flushed.

empty()

bool Async::AudioJitterFifo::empty ( void ) const

inline

Check if the FIFO is empty.

Returns

Returns true if the FIFO is empty or else false

Definition at line 149 of file AsyncAudioJitterFifo.h.

flushSamples()

virtual void Async::AudioJitterFifo::flushSamples ( void )

virtual

Tell the FIFO to flush the previously written samples.

This function is used to tell the FIFO to flush previously written samples. This function is normally only called from a connected source object.

Reimplemented from Async::AudioSink.

resumeOutput()

virtual void Async::AudioJitterFifo::resumeOutput ( void )

virtual

Resume audio output to the connected sink.

This function will be called when the registered audio sink is ready to accept more samples. This function is normally only called from a connected sink object.

Reimplemented from Async::AudioSource.

samplesInFifo()

unsigned Async::AudioJitterFifo::samplesInFifo

(

void

)

const

Find out how many samples there are in the FIFO.

Returns

Returns the number of samples in the FIFO

setSize()

void Async::AudioJitterFifo::setSize

(

unsigned

new_size

)

Set the size of the FIFO.

Parameters

new_size

This is the size of the fifo expressed in number of samples.

Use this function to set the size of the FIFO. In doing this, the FIFO will also be cleared.

writeSamples()

virtual int Async::AudioJitterFifo::writeSamples ( const float * samples, int count )

virtual

Write samples into the FIFO.

Parameters

samples	The buffer containing the samples
count	The number of samples in the buffer

Returns

Returns the number of samples that has been taken care of

This function is used to write audio into the FIFO. If it returns 0, no more samples should be written until the resumeOutput function in the source have been called. This function is normally only called from a connected source object.

Reimplemented from Async::AudioSink.

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

• AsyncAudioJitterFifo.h