The QAudioDecoder class implements decoding audio. More...

#include <qaudiodecoder.h>

Inheritance diagram for QAudioDecoder:

Collaboration diagram for QAudioDecoder:

Public Types
enum	Error { NoError , ResourceError , FormatError , AccessDeniedError , NotSupportedError }
	Defines a media player error condition. More...

Public Slots
void	start ()
	Starts decoding the audio resource.

void	stop ()
	Stop decoding audio.

Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals
void	bufferAvailableChanged (bool)
	Signals the availability (if available is true) of a new buffer.

void	bufferReady ()
	Signals that a new decoded audio buffer is available to be read.

void	finished ()
	Signals that the decoding has finished successfully.

void	isDecodingChanged (bool)

void	formatChanged (const QAudioFormat &format)
	Signals that the current audio format of the decoder has changed to format.

void	error (QAudioDecoder::Error error)
	Signals that an error condition has occurred.

void	sourceChanged ()
	Signals that the current source of the decoder has changed.

void	positionChanged (qint64 position)
	Signals that the current position of the decoder has changed.

void	durationChanged (qint64 duration)
	Signals that the estimated duration of the decoded data 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
	QAudioDecoder (QObject *parent=nullptr)
	Construct an QAudioDecoder instance with parent.

	~QAudioDecoder ()
	Destroys the audio decoder object.

bool	isSupported () const
	Returns true is audio decoding is supported on this platform.

bool	isDecoding () const

QUrl	source () const
	Returns the current file name to decode.

void	setSource (const QUrl &fileName)
	Sets the current audio file name to fileName.

QIODevice *	sourceDevice () const
	Returns the current source QIODevice, if one was set.

void	setSourceDevice (QIODevice *device)
	Sets the current audio QIODevice to device.

QAudioFormat	audioFormat () const
	Returns the audio format the decoder is set to.

void	setAudioFormat (const QAudioFormat &format)
	Set the desired audio format for decoded samples to format.

Error	error () const
	Returns the current error state of the QAudioDecoder.

QString	errorString () const

QAudioBuffer	read () const
	Read a buffer from the decoder, if one is available.

bool	bufferAvailable () const
	Returns true if a buffer is available to be read, and false otherwise.

qint64	position () const
	Returns position (in milliseconds) of the last buffer read from the decoder or -1 if no buffers have been read.

qint64	duration () const
	Returns total duration (in milliseconds) of the audio stream or -1 if not available.

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.

void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children.

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::milliseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

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

template<typename T >
T	findChild (const QString &aName=QString(), 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 (const QString &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 >
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`.

Properties
QUrl	source
	the active filename being decoded by the decoder object.

bool	isDecoding
	`true` if the decoder is currently running and decoding audio data.

QString	error
	Returns a human readable description of the current error, or an empty string is there is no error.

bool	bufferAvailable
	whether there is a decoded audio buffer available

Properties inherited from QObject
QString	objectName
	the name of this object

Additional Inherited Members
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

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 QAudioDecoder class implements decoding audio.

\inmodule QtMultimedia

\preliminary

The QAudioDecoder class is a high level class for decoding audio media files. It is similar to the QMediaPlayer class except that audio is provided back through this API rather than routed directly to audio hardware.

See also: QAudioBuffer

Definition at line 15 of file qaudiodecoder.h.

Member Enumeration Documentation

◆ Error

enum QAudioDecoder::Error

Defines a media player error condition.

\value NoError No error has occurred. \value ResourceError A media resource couldn't be resolved. \value FormatError The format of a media resource isn't supported. \value AccessDeniedError There are not the appropriate permissions to play a media resource. \value NotSupportedError QAudioDecoder is not supported on this platform

Enumerator
NoError
ResourceError
FormatError
AccessDeniedError
NotSupportedError

Definition at line 24 of file qaudiodecoder.h.

Constructor & Destructor Documentation

◆ QAudioDecoder()

QAudioDecoder::QAudioDecoder ( QObject * parent = nullptr )

explicit

Construct an QAudioDecoder instance with parent.

Definition at line 41 of file qaudiodecoder.cpp.

References QPlatformMediaIntegration::createAudioDecoder(), QPlatformMediaIntegration::instance(), and qWarning.

Here is the call graph for this function:

◆ ~QAudioDecoder()

QAudioDecoder::~QAudioDecoder ( )

default

Destroys the audio decoder object.

Member Function Documentation

◆ audioFormat()

QAudioFormat QAudioDecoder::audioFormat ( ) const

Returns the audio format the decoder is set to.

Note: This may be different than the format of the decoded samples, if the audio format was set to an invalid one.

See also: setAudioFormat(), formatChanged()

Definition at line 188 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::audioFormat().

Here is the call graph for this function:

◆ bufferAvailable()

bool QAudioDecoder::bufferAvailable ( ) const

Returns true if a buffer is available to be read, and false otherwise.

If there is no buffer available, calling the \l read() function will return an invalid buffer.

Definition at line 227 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::bufferAvailable().

Here is the call graph for this function:

◆ bufferAvailableChanged

void QAudioDecoder::bufferAvailableChanged ( bool available )

signal

Signals the availability (if available is true) of a new buffer.

If available is false, there are no buffers available.

See also: bufferAvailable(), bufferReady()

◆ bufferReady

void QAudioDecoder::bufferReady ( )

signal

Signals that a new decoded audio buffer is available to be read.

See also: read(), bufferAvailable()

Referenced by AudioDecodingExample::decode(), and QAmbientSoundPrivate::load().

Here is the caller graph for this function:

◆ duration()

qint64 QAudioDecoder::duration ( ) const

Returns total duration (in milliseconds) of the audio stream or -1 if not available.

Definition at line 247 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::duration().

Here is the call graph for this function:

◆ durationChanged

void QAudioDecoder::durationChanged ( qint64 duration )

signal

Signals that the estimated duration of the decoded data has changed.

See also: positionChanged()

◆ error() [1/2]

QAudioDecoder::Error QAudioDecoder::error ( ) const

Returns the current error state of the QAudioDecoder.

Definition at line 79 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::error(), and NotSupportedError.

Here is the call graph for this function:

◆ error [2/2]

void QAudioDecoder::error ( QAudioDecoder::Error error )

signal

Signals that an error condition has occurred.

See also: errorString()

◆ errorString()

QString QAudioDecoder::errorString ( ) const

Definition at line 90 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::errorString(), and tr.

Here is the call graph for this function:

◆ finished

void QAudioDecoder::finished ( )

signal

Signals that the decoding has finished successfully.

If decoding fails, error signal is emitted instead.

See also: start(), stop(), error()

Referenced by QAmbientSoundPrivate::load().

Here is the caller graph for this function:

◆ formatChanged

void QAudioDecoder::formatChanged ( const QAudioFormat & format )

signal

Signals that the current audio format of the decoder has changed to format.

See also: audioFormat(), setAudioFormat()

◆ isDecoding()

bool QAudioDecoder::isDecoding ( ) const

Definition at line 70 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::isDecoding().

Here is the call graph for this function:

◆ isDecodingChanged

void QAudioDecoder::isDecodingChanged ( bool )

signal

◆ isSupported()

bool QAudioDecoder::isSupported ( ) const

Returns true is audio decoding is supported on this platform.

Definition at line 61 of file qaudiodecoder.cpp.

◆ position()

qint64 QAudioDecoder::position ( ) const

Returns position (in milliseconds) of the last buffer read from the decoder or -1 if no buffers have been read.

Definition at line 237 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::position().

Here is the call graph for this function:

◆ positionChanged

void QAudioDecoder::positionChanged ( qint64 position )

signal

Signals that the current position of the decoder has changed.

See also: durationChanged()

◆ read()

QAudioBuffer QAudioDecoder::read ( ) const

Read a buffer from the decoder, if one is available.

Returns an invalid buffer if there are no decoded buffers currently available, or on failure. In both cases this function will not block.

You should either respond to the \l bufferReady() signal or check the \l bufferAvailable() function before calling read() to make sure you get useful data.

Definition at line 262 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::read().

Here is the call graph for this function:

◆ setAudioFormat()

void QAudioDecoder::setAudioFormat ( const QAudioFormat & format )

Set the desired audio format for decoded samples to format.

This property can only be set while the decoder is stopped. Setting this property at other times will be ignored.

If the decoder does not support this format, \l error() will be set to FormatError.

If you do not specify a format, the format of the decoded audio itself will be used. Otherwise, some format conversion will be applied.

If you wish to reset the decoded format to that of the original audio file, you can specify an invalid format.

Warning: Setting a desired audio format is not yet supported on the Android backend. It does work with the default FFMPEG backend.

Definition at line 213 of file qaudiodecoder.cpp.

References isDecoding, and QPlatformAudioDecoder::setAudioFormat().

Referenced by AudioDecodingExample::decode().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ setSource()

void QAudioDecoder::setSource ( const QUrl & fileName )

Sets the current audio file name to fileName.

When this property is set any current decoding is stopped, and any audio buffers are discarded.

You can only specify either a source filename or a source QIODevice. Setting one will unset the other.

Definition at line 147 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::clearError(), fileName, and QPlatformAudioDecoder::setSource().

Referenced by AudioDecodingExample::decode().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ setSourceDevice()

void QAudioDecoder::setSourceDevice ( QIODevice * device )

Sets the current audio QIODevice to device.

When this property is set any current decoding is stopped, and any audio buffers are discarded.

You can only specify either a source filename or a source QIODevice. Setting one will unset the other.

Definition at line 174 of file qaudiodecoder.cpp.

References device, and QPlatformAudioDecoder::setSourceDevice().

Here is the call graph for this function:

◆ source()

QUrl QAudioDecoder::source ( ) const

Returns the current file name to decode.

If \l setSourceDevice was called, this will be empty.

Definition at line 133 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::source().

Here is the call graph for this function:

◆ sourceChanged

void QAudioDecoder::sourceChanged ( )

signal

Signals that the current source of the decoder has changed.

See also: source(), sourceDevice()

◆ sourceDevice()

QIODevice * QAudioDecoder::sourceDevice ( ) const

Returns the current source QIODevice, if one was set.

If \l setSource() was called, this will be a nullptr.

Definition at line 160 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::sourceDevice().

Here is the call graph for this function:

◆ start

void QAudioDecoder::start ( )

slot

Starts decoding the audio resource.

As data gets decoded, the \l bufferReady() signal will be emitted when enough data has been decoded. Calling \l read() will then return an audio buffer without blocking.

If you call read() before a buffer is ready, an invalid buffer will be returned, again without blocking.

See also: read()

Definition at line 109 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::clearError(), and QPlatformAudioDecoder::start().

Referenced by AudioDecodingExample::decode().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ stop

void QAudioDecoder::stop ( )

slot

Stop decoding audio.

Calling \l start() again will resume decoding from the beginning.

Definition at line 122 of file qaudiodecoder.cpp.

References QPlatformAudioDecoder::stop().

Here is the call graph for this function:

Property Documentation

◆ bufferAvailable

QAudioDecoder::bufferAvailable

read

whether there is a decoded audio buffer available

Definition at line 82 of file qaudiodecoder.h.

◆ error

QAudioDecoder::error

read

Returns a human readable description of the current error, or an empty string is there is no error.

Definition at line 82 of file qaudiodecoder.h.

◆ isDecoding

QAudioDecoder::isDecoding

read

true if the decoder is currently running and decoding audio data.

Definition at line 82 of file qaudiodecoder.h.

Referenced by setAudioFormat().

◆ source

QAudioDecoder::source

readwrite

the active filename being decoded by the decoder object.

Definition at line 82 of file qaudiodecoder.h.

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

qtmultimedia/src/multimedia/audio/qaudiodecoder.h
qtmultimedia/src/multimedia/audio/qaudiodecoder.cpp

Public Types

Public Slots

Signals

Public Member Functions

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Error

Constructor & Destructor Documentation

◆ QAudioDecoder()

◆ ~QAudioDecoder()

Member Function Documentation

◆ audioFormat()

◆ bufferAvailable()

◆ bufferAvailableChanged

◆ bufferReady

◆ duration()

◆ durationChanged

◆ error() [1/2]

◆ error [2/2]

◆ errorString()

◆ finished

◆ formatChanged

◆ isDecoding()

◆ isDecodingChanged

◆ isSupported()

◆ position()

◆ positionChanged

◆ read()

◆ setAudioFormat()

◆ setSource()

◆ setSourceDevice()

◆ source()

◆ sourceChanged

◆ sourceDevice()

◆ start

◆ stop

Property Documentation

◆ bufferAvailable

◆ error

◆ isDecoding

◆ source