The QAudioSource class provides an interface for receiving audio data from an audio input device. More...

#include <qaudiosource.h>

Inheritance diagram for QAudioSource:

Collaboration diagram for QAudioSource:

Signals
void	stateChanged (QAudio::State state)
	This signal is emitted when the device state has changed.

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QAudioSource (const QAudioFormat &format=QAudioFormat(), QObject *parent=nullptr)
	Construct a new audio input and attach it to parent.

	QAudioSource (const QAudioDevice &audioDeviceInfo, const QAudioFormat &format=QAudioFormat(), QObject *parent=nullptr)
	Construct a new audio input and attach it to parent.

	~QAudioSource ()
	Destroy this audio input.

bool	isNull () const
	Returns `true` if the audio source is `null`, otherwise returns `false`.

QAudioFormat	format () const
	Returns the QAudioFormat being used.

void	start (QIODevice *device)
	Starts transferring audio data from the system's audio input to the device.

QIODevice *	start ()
	Returns a pointer to the internal QIODevice being used to transfer data from the system's audio input.

void	stop ()
	Stops the audio input, detaching from the system resource.

void	reset ()
	Drops all audio data in the buffers, resets buffers to zero.

void	suspend ()
	Stops processing audio data, preserving buffered audio data.

void	resume ()
	Resumes processing audio data after a suspend().

void	setBufferSize (qsizetype bytes)
	Sets the audio buffer size to value bytes.

qsizetype	bufferSize () const
	Returns the audio buffer size in bytes.

qsizetype	bytesAvailable () const
	Returns the amount of audio data available to read in bytes.

void	setVolume (qreal volume)
	Sets the input volume to volume.

qreal	volume () const
	Returns the input volume.

qint64	processedUSecs () const
	Returns the amount of audio data processed since start() was called in microseconds.

qint64	elapsedUSecs () const
	Returns the microseconds since start() was called, including time in Idle and Suspend states.

QtAudio::Error	error () const
	Returns the error state.

QtAudio::State	state () const
	Returns the state of audio processing.

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

virtual bool	eventFilter (QObject watched, QEvent event)
	Filters events if this object has been installed as an event filter for the watched object.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

The QAudioSource class provides an interface for receiving audio data from an audio input device.

\inmodule QtMultimedia

You can construct an audio input with the system's default audio input device. It is also possible to create QAudioSource with a specific QAudioDevice. When you create the audio input, you should also send in the QAudioFormat to be used for the recording (see the QAudioFormat class description for details).

To record to a file:

QAudioSource lets you record audio with an audio input device. The default constructor of this class will use the systems default audio device, but you can also specify a QAudioDevice for a specific device. You also need to pass in the QAudioFormat in which you wish to record.

Starting up the QAudioSource is simply a matter of calling start() with a QIODevice opened for writing. For instance, to record to a file, you can:

This will start recording if the format specified is supported by the input device (you can check this with QAudioDevice::isFormatSupported(). In case there are any snags, use the error() function to check what went wrong. We stop recording in the stopRecording() slot.

At any point in time, QAudioSource will be in one of four states: active, suspended, stopped, or idle. These states are specified by the QtAudio::State enum. You can request a state change directly through suspend(), resume(), stop(), reset(), and start(). The current state is reported by state(). QAudioSink will also signal you when the state changes (stateChanged()).

QAudioSource provides several ways of measuring the time that has passed since the start() of the recording. The processedUSecs() function returns the length of the stream in microseconds written, i.e., it leaves out the times the audio input was suspended or idle. The elapsedUSecs() function returns the time elapsed since start() was called regardless of which states the QAudioSource has been in.

If an error should occur, you can fetch its reason with error(). The possible error reasons are described by the QtAudio::Error enum. The QAudioSource will enter the \l{QtAudio::}{StoppedState} when an error is encountered. Connect to the stateChanged() signal to handle the error:

See also: QAudioSink, QAudioDevice

Definition at line 21 of file qaudiosource.h.

Constructor & Destructor Documentation

◆ QAudioSource() [1/2]

QAudioSource::QAudioSource	(	const QAudioFormat &	format = QAudioFormat(),
		QObject *	parent = nullptr )

explicit

Construct a new audio input and attach it to parent.

The default audio input device is used with the output format parameters.

Definition at line 85 of file qaudiosource.cpp.

◆ QAudioSource() [2/2]

QAudioSource::QAudioSource	(	const QAudioDevice &	audioDevice,
		const QAudioFormat &	format = QAudioFormat(),
		QObject *	parent = nullptr )

explicit

Construct a new audio input and attach it to parent.

The device referenced by audioDevice is used with the input format parameters.

Definition at line 96 of file qaudiosource.cpp.

◆ ~QAudioSource()

QAudioSource::~QAudioSource ( )

Destroy this audio input.

Definition at line 123 of file qaudiosource.cpp.

Member Function Documentation

◆ bufferSize()

qsizetype QAudioSource::bufferSize ( ) const

Returns the audio buffer size in bytes.

If called before start(), returns platform default value. If called before start() but setBufferSize() was called prior, returns value set by setBufferSize(). If called after start(), returns the actual buffer size being used. This may not be what was set previously by setBufferSize().

Definition at line 263 of file qaudiosource.cpp.

◆ bytesAvailable()

qsizetype QAudioSource::bytesAvailable ( ) const

Returns the amount of audio data available to read in bytes.

Note: returned value is only valid while in QtAudio::ActiveState or QtAudio::IdleState state, otherwise returns zero.

Definition at line 275 of file qaudiosource.cpp.

◆ elapsedUSecs()

qint64 QAudioSource::elapsedUSecs ( ) const

Returns the microseconds since start() was called, including time in Idle and Suspend states.

Definition at line 334 of file qaudiosource.cpp.

◆ error()

QtAudio::Error QAudioSource::error ( ) const

Returns the error state.

Definition at line 343 of file qaudiosource.cpp.

◆ format()

QAudioFormat QAudioSource::format ( ) const

Returns the QAudioFormat being used.

Definition at line 181 of file qaudiosource.cpp.

◆ isNull()

bool QAudioSource::isNull ( ) const

inline

Returns true if the audio source is null, otherwise returns false.

Definition at line 30 of file qaudiosource.h.

◆ processedUSecs()

qint64 QAudioSource::processedUSecs ( ) const

Returns the amount of audio data processed since start() was called in microseconds.

Definition at line 322 of file qaudiosource.cpp.

◆ reset()

void QAudioSource::reset ( )

Drops all audio data in the buffers, resets buffers to zero.

Definition at line 203 of file qaudiosource.cpp.

◆ resume()

void QAudioSource::resume ( )

Resumes processing audio data after a suspend().

Sets error() to QtAudio::NoError. Sets state() to QtAudio::ActiveState if you previously called start(QIODevice*). Sets state() to QtAudio::IdleState if you previously called start(). emits stateChanged() signal.

Definition at line 231 of file qaudiosource.cpp.

◆ setBufferSize()

void QAudioSource::setBufferSize ( qsizetype value )

Sets the audio buffer size to value bytes.

Note: This function can be called anytime before start(), calls to this are ignored after start(). It should not be assumed that the buffer size set is the actual buffer size used, calling bufferSize() anytime after start() will return the actual buffer size being used.

Definition at line 247 of file qaudiosource.cpp.

◆ setVolume()

void QAudioSource::setVolume ( qreal volume )

Sets the input volume to volume.

The volume is scaled linearly from 0.0 (silence) to 1.0 (full volume). Values outside this range will be clamped.

If the device does not support adjusting the input volume then volume will be ignored and the input volume will remain at 1.0.

The default volume is 1.0.

Note: Adjustments to the volume will change the volume of this audio stream, not the global volume.

Definition at line 298 of file qaudiosource.cpp.

◆ start() [1/2]

QIODevice * QAudioSource::start ( )

Returns a pointer to the internal QIODevice being used to transfer data from the system's audio input.

The device will already be open and \l{QIODevice::read()}{read()} can read data directly from it.

Note: The pointer will become invalid after the stream is stopped or if you start another stream.

If the QAudioSource is able to access the system's audio device, state() returns QtAudio::IdleState, error() returns QtAudio::NoError and the stateChanged() signal is emitted.

If a problem occurs during this process, error() returns QtAudio::OpenError, state() returns QtAudio::StoppedState and the stateChanged() signal is emitted.

See also: QIODevice

Definition at line 169 of file qaudiosource.cpp.

◆ start() [2/2]

void QAudioSource::start ( QIODevice * device )

Starts transferring audio data from the system's audio input to the device.

The device must have been opened in the \l{QIODevice::WriteOnly}{WriteOnly}, \l{QIODevice::Append}{Append} or \l{QIODevice::ReadWrite}{ReadWrite} modes.

If the QAudioSource is able to successfully get audio data, state() returns either QtAudio::ActiveState or QtAudio::IdleState, error() returns QtAudio::NoError and the stateChanged() signal is emitted.

If a problem occurs during this process, error() returns QtAudio::OpenError, state() returns QtAudio::StoppedState and the stateChanged() signal is emitted.

See also: QIODevice

Definition at line 143 of file qaudiosource.cpp.

◆ state()

QtAudio::State QAudioSource::state ( ) const

Returns the state of audio processing.

Definition at line 352 of file qaudiosource.cpp.

◆ stateChanged

void QAudioSource::stateChanged ( QAudio::State state )

signal

This signal is emitted when the device state has changed.

Note: The QtAudio namespace was named QAudio up to and including Qt 6.6. String-based connections to this signal have to use {QAudio::State} as the parameter type: {connect(source, SIGNAL(stateChanged(QAudio::State)), ...);}

◆ stop()

void QAudioSource::stop ( )

Stops the audio input, detaching from the system resource.

Sets error() to QtAudio::NoError, state() to QtAudio::StoppedState and emit stateChanged() signal.

Definition at line 193 of file qaudiosource.cpp.

◆ suspend()

void QAudioSource::suspend ( )

Stops processing audio data, preserving buffered audio data.

Sets error() to QtAudio::NoError, state() to QtAudio::SuspendedState and emit stateChanged() signal.

Definition at line 216 of file qaudiosource.cpp.

◆ volume()

qreal QAudioSource::volume ( ) const

Returns the input volume.

If the device does not support adjusting the input volume the returned value will be 1.0.

Definition at line 312 of file qaudiosource.cpp.

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

qtmultimedia/src/multimedia/audio/qaudiosource.h (6f590d44bb186178902a5fc3dc4a12cee8e88eaa)
qtmultimedia/src/multimedia/audio/qaudiosource.cpp (6f590d44bb186178902a5fc3dc4a12cee8e88eaa)

Signals

Public Member Functions

Additional Inherited Members