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QAudioFormat Class Reference
[QtMultimedia module]

The QAudioFormat class stores audio parameter information. More...

 #include <QAudioFormat>

This class is not part of the Qt GUI Framework Edition.

This class was introduced in Qt 4.6.

List of all members, including inherited members

Public Types

enum	Endian { BigEndian, LittleEndian }
enum	SampleType { Unknown, SignedInt, UnSignedInt, Float }

Public Functions

	QAudioFormat ()
	QAudioFormat ( const QAudioFormat & other )
	~QAudioFormat ()
QAudioFormat::Endian	byteOrder () const
int	channels () const
QString	codec () const
int	frequency () const
bool	isValid () const
int	sampleSize () const
QAudioFormat::SampleType	sampleType () const
void	setByteOrder ( QAudioFormat::Endian byteOrder )
void	setChannels ( int channels )
void	setCodec ( const QString & codec )
void	setFrequency ( int frequency )
void	setSampleSize ( int sampleSize )
void	setSampleType ( QAudioFormat::SampleType sampleType )
bool	operator!= ( const QAudioFormat & other ) const
QAudioFormat &	operator= ( const QAudioFormat & other )
bool	operator== ( const QAudioFormat & other ) const

Detailed Description

The QAudioFormat class stores audio parameter information.

An audio format specifies how data in an audio stream is arranged, i.e, how the stream is to be interpreted. The encoding itself is specified by the codec() used for the stream.

In addition to the encoding, QAudioFormat contains other parameters that further specify how the audio data is arranged. These are the frequency, the number of channels, the sample size, the sample type, and the byte order. The following table describes these in more detail.

Parameter	Description
Frequency	Samples per second of audio data in Hertz.
Number of channels	The number of audio channels (typically one for mono or two for stereo)
Sample size	How much data is stored in each sample (typically 8 or 16)
Sample type	Numerical representation of sample (typically signed integer, unsigned integer or float)
Byte order	Byte ordering of sample (typically little endian, big endian)

You can obtain audio formats compatible with the audio device used through functions in QAudioDeviceInfo. This class also lets you query available parameter values for a device, so that you can set the parameters yourself. See the QAudioDeviceInfo class description for details. You need to know the format of the audio streams you wish to play. Qt does not set up formats for you.

Member Type Documentation

enum QAudioFormat::Endian

Constant	Value	Description
`QAudioFormat::BigEndian`	`QSysInfo::BigEndian`	samples are big endian byte order
`QAudioFormat::LittleEndian`	`QSysInfo::LittleEndian`	samples are little endian byte order

enum QAudioFormat::SampleType

Constant	Value	Description
`QAudioFormat::Unknown`	`0`	Not Set
`QAudioFormat::SignedInt`	`1`	samples are signed integers
`QAudioFormat::UnSignedInt`	`2`	samples are unsigned intergers
`QAudioFormat::Float`	`3`	samples are floats

Member Function Documentation

QAudioFormat::QAudioFormat ()

Construct a new audio format.

Values are initialized as follows:

frequency() = -1
channels() = -1
sampleSize() = -1
byteOrder() = QAudioFormat::Endian(QSysInfo::ByteOrder)
sampleType() = QAudioFormat::Unknown codec() = ""

QAudioFormat::QAudioFormat ( const QAudioFormat & other )

Construct a new audio format using other.

QAudioFormat::~QAudioFormat ()

Destroy this audio format.

QAudioFormat::Endian QAudioFormat::byteOrder () const

Returns the current byteOrder value.

int QAudioFormat::channels () const

Returns the current channel value.

QString QAudioFormat::codec () const

Returns the current codec value.

See also setCodec() and QAudioDeviceInfo::supportedCodecs().

int QAudioFormat::frequency () const

Returns the current frequency value.

bool QAudioFormat::isValid () const

Returns true if all of the parameters are valid.

int QAudioFormat::sampleSize () const

Returns the current sampleSize value.

QAudioFormat::SampleType QAudioFormat::sampleType () const

Returns the current SampleType value.

void QAudioFormat::setByteOrder ( QAudioFormat::Endian byteOrder )

Sets the byteOrder to byteOrder.

void QAudioFormat::setChannels ( int channels )

Sets the channels to channels.

void QAudioFormat::setCodec ( const QString & codec )

Sets the codec to codec.

See also codec() and QAudioDeviceInfo::supportedCodecs().

void QAudioFormat::setFrequency ( int frequency )

Sets the frequency to frequency.

void QAudioFormat::setSampleSize ( int sampleSize )

Sets the sampleSize to sampleSize.

void QAudioFormat::setSampleType ( QAudioFormat::SampleType sampleType )

Sets the sampleType to sampleType.

bool QAudioFormat::operator!= ( const QAudioFormat & other ) const

Returns true if this QAudioFormat is not equal to the other QAudioFormat; otherwise returns false.

All elements of QAudioFormat are used for the comparison.

QAudioFormat & QAudioFormat::operator= ( const QAudioFormat & other )

Assigns other to this QAudioFormat implementation.

bool QAudioFormat::operator== ( const QAudioFormat & other ) const

Returns true if this QAudioFormat is equal to the other QAudioFormat; otherwise returns false.