AudioPlayer Class Reference

Class for playback of audio stream, via speaker or other audio dev. More...

#include <audioplayer.h>

Inheritance diagram for AudioPlayer:

Collaboration diagram for AudioPlayer:

Public Slots
void	insertAudioFrame (const QByteArray &aFrame)
void	finishedPlaying (QAudio::State aState)
void	notify ()

Signals
void	error (int aError, const QString &aExplanation)
void	audioMaxLevel (float aMaxVolume)

Public Member Functions
	AudioPlayer (Model &aModel, int aFrequency=8000, int aNumChannels=1, int aSampleSize=16)
	~AudioPlayer ()
void	stop ()
virtual qint64	bytesAvailable () const

Protected Member Functions
virtual qint64	writeData (const char *data, qint64 maxSize)
virtual qint64	readData (char *data, qint64 maxSize)
virtual bool	open (OpenMode mode)
virtual bool	isSequential () const

Private Attributes
QAudioFormat	iFormat
QAudioOutput *	iAudioOutput
QByteArray	iAudioBuffer
bool	iNeedsToRun
Model &	iModel
const int	iFrequency
const int	iNumChannels
const int	iSampleSize

Detailed Description

Class for playback of audio stream, via speaker or other audio dev.

This class encapsulates audio output device and expects input as array of floats.

Constructor & Destructor Documentation

AudioPlayer()

AudioPlayer::AudioPlayer	(	Model &	aModel,
		int	aFrequency = 8000,
		int	aNumChannels = 1,
		int	aSampleSize = 16
	)

Constructor. Currently only samplesize 16 is supported, all other sizes will output only noise. Also see input data format at insertAudioFrame method.

Parameters

aFrequency	is number of samples per second
aNumChannels	is number of channels in stream
aSampleSize	is number of bits in each sample. As currently the audio format is in array of floats that are anyway in native format and in [-1,1] range this parameter is a little bit meaningless.

~AudioPlayer()

AudioPlayer::~AudioPlayer

(

)

Member Function Documentation

audioMaxLevel

void AudioPlayer::audioMaxLevel ( float  aMaxVolume )

signal

signals that communicates max value of a outputted frame

bytesAvailable()

virtual qint64 AudioPlayer::bytesAvailable ( ) const

inlinevirtual

error

void AudioPlayer::error ( int  aError, const QString &  aExplanation  )

signal

this is not method but signal ; if in error, get emit()ted

finishedPlaying

void AudioPlayer::finishedPlaying ( QAudio::State  aState )

slot

Notify slot from actual player device

insertAudioFrame

void AudioPlayer::insertAudioFrame ( const QByteArray &  aFrame )

slot

Method/slot for playing back snippet of audio.

Parameters

aFrame

32-bit, native-encoding, floating point format audio/pcm data in 8kHz. Floating point range in [-1,1].

isSequential()

virtual bool AudioPlayer::isSequential ( ) const

inlineprotectedvirtual

notify

void AudioPlayer::notify ( )

slot

notify from audio output device

open()

virtual bool AudioPlayer::open ( OpenMode  mode )

protectedvirtual

method for opening QIODevice: sets the open mode that's about it.

readData()

virtual qint64 AudioPlayer::readData ( char *  data, qint64  maxSize  )

protectedvirtual

From QIODevice: method that QAudioOutput class instance will use to read the actual audio data. Data comes from internal buffer and is inserted into buffer using insertAudioFrame.

Parameters

data	pointer to buffer where data will be written
maxSize	max data size available in buffer

Returns

number of bytes actually written into buffer

stop()

void AudioPlayer::stop

(

)

method for stopping playback

writeData()

virtual qint64 AudioPlayer::writeData ( const char *  data, qint64  maxSize  )

protectedvirtual

Write-method of QIODevice - QIODevice here is used for feeding the player and data is actually written using insertAudioFrame method so implementation of this method is actually empty.

Parameters

data	that will not be written anywhere.
maxSize	max data size to be not written

Returns

always 0

Member Data Documentation

iAudioBuffer

QByteArray AudioPlayer::iAudioBuffer

private

first buffered here, then written in chunks

iAudioOutput

QAudioOutput* AudioPlayer::iAudioOutput

private

iFormat

QAudioFormat AudioPlayer::iFormat

private

iFrequency

const int AudioPlayer::iFrequency

private

datamodel

iModel

Model& AudioPlayer::iModel

private

iNeedsToRun

bool AudioPlayer::iNeedsToRun

private

iNumChannels

const int AudioPlayer::iNumChannels

private

iSampleSize

const int AudioPlayer::iSampleSize

private

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

• audioplayer.h