Qt 4.7: QAudioFormat Class Reference

Qt Reference Documentation

# QAudioFormat Class Reference

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

     #include <QAudioFormat>

This class was introduced in Qt 4.6.

- List of all members, including inherited members
- Obsolete 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 | channelCount () const
QString | codec () const
bool | isValid () const
int | sampleRate () const
int | sampleSize () const
QAudioFormat::SampleType | sampleType () const
void | setByteOrder ( QAudioFormat::Endian byteOrder )
void | setChannelCount ( int channels )
void | setCodec ( const QString & codec )
void | setSampleRate ( int samplerate )
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
--- | ---
Sample Rate | 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 bits)
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:

- sampleRate() = -1
- channelCount() = -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.

See also setByteOrder().

### int QAudioFormat::channelCount () const

Returns the current channel count value.

This function was introduced in Qt 4.7.

See also setChannelCount().

### QString QAudioFormat::codec () const

Returns the current codec value.

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

### bool QAudioFormat::isValid () const

Returns true if all of the parameters are valid.

### int QAudioFormat::sampleRate () const

Returns the current sample rate in Hertz.

This function was introduced in Qt 4.7.

See also setSampleRate().

### int QAudioFormat::sampleSize () const

Returns the current sample size value.

See also setSampleSize().

### QAudioFormat::SampleType QAudioFormat::sampleType () const

Returns the current SampleType value.

See also setSampleType().

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

Sets the byteOrder to byteOrder.

See also byteOrder().

### void QAudioFormat::setChannelCount ( int channels )

Sets the channel count to channels.

This function was introduced in Qt 4.7.

See also channelCount().

### void QAudioFormat::setCodec ( const QString & codec )

Sets the codec to codec.

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

### void QAudioFormat::setSampleRate ( int samplerate )

Sets the sample rate to samplerate Hertz.

This function was introduced in Qt 4.7.

See also sampleRate().

### void QAudioFormat::setSampleSize ( int sampleSize )

Sets the sample size to the sampleSize specified.

See also sampleSize().

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

Sets the sampleType to sampleType.

See also 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.

All elements of QAudioFormat are used for the comparison.