QAudioDevice Class Reference

The QAudioDevice class provides an information about audio devices and their functionality. More...

#include <qaudiodevice.h>

Collaboration diagram for QAudioDevice:

Public Types
enum	Mode { Null , Input , Output }
	Describes the mode of this device. More...

Public Member Functions
	QAudioDevice ()
	Describes an audio device.
	QAudioDevice (const QAudioDevice &other)
	Constructs a copy of other.
	~QAudioDevice ()
	Destroy this audio device info.
	QAudioDevice (QAudioDevice &&other) noexcept=default
	Move constructs from other.
void	swap (QAudioDevice &other) noexcept
	Swaps the audio device with the other.
QAudioDevice &	operator= (const QAudioDevice &other)
	Sets the QAudioDevice object to be equal to other.
bool	operator== (const QAudioDevice &other) const
	Returns true if this QAudioDevice class represents the same audio device as other.
bool	operator!= (const QAudioDevice &other) const
	Returns true if this QAudioDevice class represents a different audio device than other.
bool	isNull () const
	Returns whether this QAudioDevice object holds a valid device definition.
QByteArray	id () const
QString	description () const
bool	isDefault () const
QAudioDevice::Mode	mode () const
bool	isFormatSupported (const QAudioFormat &format) const
	Returns true if the supplied settings are supported by the audio device described by this QAudioDevice.
QAudioFormat	preferredFormat () const
	Returns the default audio format settings for this device.
int	minimumSampleRate () const
	Returns the minimum supported sample rate (in Hertz).
int	maximumSampleRate () const
	Returns the maximum supported sample rate (in Hertz).
int	minimumChannelCount () const
	Returns the minimum number of supported channel counts.
int	maximumChannelCount () const
	Returns the maximum number of supported channel counts.
QList< QAudioFormat::SampleFormat >	supportedSampleFormats () const
	Returns a list of supported sample types.
QAudioFormat::ChannelConfig	channelConfiguration () const
	Returns the channel configuration of the device.
const QAudioDevicePrivate *	handle () const

Properties
QByteArray	id
	\qmlproperty string QtMultimedia::audioDevice::id
QString	description
	\qmlproperty string QtMultimedia::audioDevice::description
bool	isDefault
	\qmlproperty bool QtMultimedia::audioDevice::isDefault
Mode	mode
	\qmlproperty enumeration QtMultimedia::audioDevice::mode

Friends
class	QAudioDevicePrivate

Detailed Description

The QAudioDevice class provides an information about audio devices and their functionality.

\inmodule QtMultimedia

QAudioDevice describes an audio device available in the system, either for input or for playback.

A QAudioDevice is used by Qt to construct classes that communicate with the device – such as QAudioSource, and QAudioSink. It is also used to determine the input or output device to use in a capture session or during media playback.

You can also query each device for the formats it supports. A format in this context is a set consisting of a channel count, sample rate, and sample type. A format is represented by the QAudioFormat class.

The values supported by the device for each of these parameters can be fetched with minimumChannelCount(), maximumChannelCount(), minimumSampleRate(), maximumSampleRate() and supportedSampleFormats(). The combinations supported are dependent on the audio device capabilities. If you need a specific format, you can check if the device supports it with isFormatSupported(). For instance:

The set of available devices can be retrieved from the QMediaDevices class.

For instance:

In this code sample, we loop through all devices that are able to output sound, i.e., play an audio stream in a supported format. For each device we find, we simply print the deviceName().

See also

QAudioSink, QAudioSource, QAudioFormat

Definition at line 24 of file qaudiodevice.h.

Member Enumeration Documentation

Mode

enum QAudioDevice::Mode

Describes the mode of this device.

\value Null A null device. \value Input An input device. \value Output An output device.

Enumerator
Null
Input
Output

Definition at line 32 of file qaudiodevice.h.

Constructor & Destructor Documentation

QAudioDevice() [1/3]

QAudioDevice::QAudioDevice ( )

default

Describes an audio device.

\qmlvaluetype audioDevice
\inqmlmodule QtMultimedia
\since 6.2

! \instantiates QAudioDevice

The audioDevice value type describes the properties of an audio device that is connected to the system.

The list of audio input or output devices can be queried from the \l{MediaDevices} type. To select a certain audio device for input or output set it as the device on \l{AudioInput} or \l{AudioOutput}.

\qml MediaPlayer { audioOutput: AudioOutput { device: mediaDevices.defaultAudioOutput } } MediaDevices { id: mediaDevices } \endqml

Constructs a null QAudioDevice object.

QAudioDevice() [2/3]

QAudioDevice::QAudioDevice ( const QAudioDevice &  other )

default

Constructs a copy of other.

~QAudioDevice()

QAudioDevice::~QAudioDevice ( )

default

Destroy this audio device info.

QAudioDevice() [3/3]

QAudioDevice::QAudioDevice ( QAudioDevice &&  other )

defaultnoexcept

Move constructs from other.

Member Function Documentation

channelConfiguration()

QAudioFormat::ChannelConfig QAudioDevice::channelConfiguration

(

)

const

Returns the channel configuration of the device.

Definition at line 300 of file qaudiodevice.cpp.

References QAudioFormat::ChannelConfigUnknown, QAudioDevicePrivate::channelConfiguration, and isNull().

Referenced by QAudioOutputStream::startOutput(), and QFFmpeg::AudioRenderer::updateOutput().

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description()

QString QAudioDevice::description

(

)

const

Definition at line 195 of file qaudiodevice.cpp.

References QAudioDevicePrivate::description, and isNull().

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handle()

QAudioDevicePrivate QAudioDevice::handle ( ) const

inline

Definition at line 71 of file qaudiodevice.h.

References d.

Referenced by QDarwinAudioSink::QDarwinAudioSink(), QDarwinAudioSource::QDarwinAudioSource(), QWindowsMediaDevices::createAudioSink(), QWindowsMediaDevices::createAudioSource(), QGstreamerAudioInput::setAudioDevice(), and QGstreamerAudioOutput::setAudioDevice().

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id()

QByteArray QAudioDevice::id

(

)

const

Definition at line 175 of file qaudiodevice.cpp.

References QAudioDevicePrivate::id, and isNull().

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isDefault()

bool QAudioDevice::isDefault

(

)

const

Definition at line 211 of file qaudiodevice.cpp.

References QAudioDevicePrivate::isDefault.

isFormatSupported()

bool QAudioDevice::isFormatSupported

(

const QAudioFormat &

format

)

const

Returns true if the supplied settings are supported by the audio device described by this QAudioDevice.

Definition at line 220 of file qaudiodevice.cpp.

References QListSpecialMethodsBase< T >::contains(), isNull(), QAudioDevicePrivate::maximumChannelCount, QAudioDevicePrivate::maximumSampleRate, QAudioDevicePrivate::minimumChannelCount, QAudioDevicePrivate::minimumSampleRate, settings, and QAudioDevicePrivate::supportedSampleFormats.

Referenced by QDarwinAudioSink::start(), QDarwinAudioSource::start(), QDarwinAudioSink::start(), and QDarwinAudioSource::start().

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isNull()

bool QAudioDevice::isNull

(

)

const

Returns whether this QAudioDevice object holds a valid device definition.

Definition at line 151 of file qaudiodevice.cpp.

Referenced by QDarwinAudioSink::QDarwinAudioSink(), QDarwinAudioSource::QDarwinAudioSource(), channelConfiguration(), description(), id(), isFormatSupported(), maximumChannelCount(), maximumSampleRate(), minimumChannelCount(), minimumSampleRate(), preferredFormat(), QGstreamerAudioInput::setAudioDevice(), and supportedSampleFormats().

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maximumChannelCount()

int QAudioDevice::maximumChannelCount

(

)

const

Returns the maximum number of supported channel counts.

This is typically 1 for mono sound, or 2 for stereo sound.

Definition at line 284 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::maximumChannelCount.

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maximumSampleRate()

int QAudioDevice::maximumSampleRate

(

)

const

Returns the maximum supported sample rate (in Hertz).

Definition at line 264 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::maximumSampleRate.

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minimumChannelCount()

int QAudioDevice::minimumChannelCount

(

)

const

Returns the minimum number of supported channel counts.

This is typically 1 for mono sound, or 2 for stereo sound.

Definition at line 274 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::minimumChannelCount.

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minimumSampleRate()

int QAudioDevice::minimumSampleRate

(

)

const

Returns the minimum supported sample rate (in Hertz).

Definition at line 256 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::minimumSampleRate.

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mode()

QAudioDevice::Mode QAudioDevice::mode

(

)

const

Definition at line 346 of file qaudiodevice.cpp.

References QAudioDevicePrivate::mode, and Null.

operator!=()

bool QAudioDevice::operator!=

(

const QAudioDevice &

other

)

const

Returns true if this QAudioDevice class represents a different audio device than other.

Definition at line 143 of file qaudiodevice.cpp.

References operator==(), and other().

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operator=()

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

default

Sets the QAudioDevice object to be equal to other.

Moves other into this QAudioDevice object.

operator==()

bool QAudioDevice::operator==

(

const QAudioDevice &

other

)

const

Returns true if this QAudioDevice class represents the same audio device as other.

Definition at line 128 of file qaudiodevice.cpp.

References QAudioDevicePrivate::id, QAudioDevicePrivate::isDefault, QAudioDevicePrivate::mode, and other().

Referenced by operator!=().

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preferredFormat()

QAudioFormat QAudioDevice::preferredFormat

(

)

const

Returns the default audio format settings for this device.

These settings are provided by the platform/audio plugin being used.

They are also dependent on the \l {QAudio}Mode being used.

A typical audio system would provide something like: \list

• Input settings: 48000Hz mono 16 bit.
• Output settings: 48000Hz stereo 16 bit. \endlist

Definition at line 248 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::preferredFormat.

Referenced by openSlDebugInfo().

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supportedSampleFormats()

QList< QAudioFormat::SampleFormat > QAudioDevice::supportedSampleFormats

(

)

const

Returns a list of supported sample types.

Definition at line 292 of file qaudiodevice.cpp.

References isNull(), and QAudioDevicePrivate::supportedSampleFormats.

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swap()

void QAudioDevice::swap ( QAudioDevice &  other )

inlinenoexcept

Swaps the audio device with the other.

Definition at line 45 of file qaudiodevice.h.

References d, and other().

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Friends And Related Symbol Documentation

QAudioDevicePrivate

friend class QAudioDevicePrivate

friend

Definition at line 73 of file qaudiodevice.h.

Property Documentation

description

QAudioDevice::description

read

\qmlproperty string QtMultimedia::audioDevice::description

Holds a human readable name of the audio device.

Use this string to present the device to the user.

Returns a human readable name of the audio device.

Use this string to present the device to the user.

Definition at line 82 of file qaudiodevice.h.

Referenced by QGstreamerAudioInput::setAudioDevice().

id

QAudioDevice::id

read

\qmlproperty string QtMultimedia::audioDevice::id

Holds an identifier for the audio device.

Device names vary depending on the platform/audio plugin being used.

They are a unique identifier for the audio device.

Returns an identifier for the audio device.

Device names vary depending on the platform/audio plugin being used.

They are a unique identifier for the audio device.

Definition at line 82 of file qaudiodevice.h.

Referenced by QDarwinAudioSink::QDarwinAudioSink(), QDarwinAudioSource::QDarwinAudioSource(), QQnxAudioSink::QQnxAudioSink(), AVFMediaPlayer::audioOutputChanged(), QWindowsMediaDeviceSession::audioOutputDeviceChanged(), QAlsaMediaDevices::createAudioSink(), QAndroidMediaDevices::createAudioSink(), QPulseAudioMediaDevices::createAudioSink(), QWasmMediaDevices::createAudioSink(), QAlsaMediaDevices::createAudioSource(), QAndroidMediaDevices::createAudioSource(), QPulseAudioMediaDevices::createAudioSource(), QWasmMediaDevices::createAudioSource(), QWindowsMediaDeviceSession::setActive(), QGstreamerAudioInput::setAudioDevice(), QGstreamerAudioOutput::setAudioDevice(), QWasmAudioInput::setAudioDevice(), QWasmAudioOutput::setAudioDevice(), QWindowsMediaDeviceSession::setAudioOutput(), QAndroidCaptureSession::setAudioOutput(), QWasmAudioOutput::setSource(), QAndroidCaptureSession::start(), QAndroidMediaPlayer::updateAudioDevice(), and AVFCameraSession::updateAudioOutput().

isDefault

QAudioDevice::isDefault

read

\qmlproperty bool QtMultimedia::audioDevice::isDefault

Is true if this is the default audio device.

Returns true if this is the default audio device.

Definition at line 82 of file qaudiodevice.h.

mode

QAudioDevice::mode

read

\qmlproperty enumeration QtMultimedia::audioDevice::mode

Holds whether this device is an input or output device.

The returned value can be one of the following:

\value audioDevice.Null A null device. \value audioDevice.Input input device. \value audioDevice.Output An output device.

Returns whether this device is an input or output device.

Definition at line 82 of file qaudiodevice.h.

Referenced by QAudioInput::QAudioInput(), and QAudioOutput::QAudioOutput().

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

• qtmultimedia/src/multimedia/audio/qaudiodevice.h
• qtmultimedia/src/multimedia/audio/qaudiodevice.cpp