QMediaRecorder Class

recorder = new QMediaRecorder(camera);

QAudioEncoderSettings audioSettings;
audioSettings.setCodec("audio/amr");
audioSettings.setQuality(QMultimedia::HighQuality);

recorder->setAudioSettings(audioSettings);

recorder->setOutputLocation(QUrl::fromLocalFile(fileName));
recorder->record();

Member Function Documentation

QMediaRecorder::QMediaRecorder(QMediaObject *mediaObject, QObject *parent = nullptr)

Constructs a media recorder which records the media produced by mediaObject.

The parent is passed to QMediaObject.

[virtual] QMediaRecorder::~QMediaRecorder()

Destroys a media recorder object.

[signal] void QMediaRecorder::actualLocationChanged(const QUrl &location)

Signals that the actual location of the recorded media has changed. This signal is usually emitted when recording starts.

Note: Notifier signal for property actualLocation.

QString QMediaRecorder::audioCodecDescription(const QString &codec) const

Returns a description of an audio codec.

QAudioEncoderSettings QMediaRecorder::audioSettings() const

Returns the audio encoder settings being used.

See also setAudioSettings() and setEncodingSettings().

QMultimedia::AvailabilityStatus QMediaRecorder::availability() const

Returns the availability of this functionality.

See also availabilityChanged().

[signal] void QMediaRecorder::availabilityChanged(bool available)

Signals that the media recorder is now available (if available is true), or not.

Note: Signal availabilityChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(mediaRecorder, QOverload<bool>::of(&QMediaRecorder::availabilityChanged),
    [=](bool available){ /* ... */ });

[signal] void QMediaRecorder::availabilityChanged(QMultimedia::AvailabilityStatus availability)

Signals that the service availability has changed to availability.

Note: Signal availabilityChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(mediaRecorder, QOverload<QMultimedia::AvailabilityStatus>::of(&QMediaRecorder::availabilityChanged),
    [=](QMultimedia::AvailabilityStatus availability){ /* ... */ });

QStringList QMediaRecorder::availableMetaData() const

Returns a list of keys there is meta-data available for.

QString QMediaRecorder::containerDescription(const QString &format) const

Returns a description of a container format.

QString QMediaRecorder::containerFormat() const

Returns the selected container format.

See also setContainerFormat().

[signal] void QMediaRecorder::durationChanged(qint64 duration)

Signals that the duration of the recorded media has changed.

Note: Notifier signal for property duration.

QMediaRecorder::Error QMediaRecorder::error() const

Returns the current error state.

See also errorString().

[signal] void QMediaRecorder::error(QMediaRecorder::Error error)

Signals that an error has occurred.

Note: Signal error is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(mediaRecorder, QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
    [=](QMediaRecorder::Error error){ /* ... */ });

QString QMediaRecorder::errorString() const

Returns a string describing the current error state.

See also error().

bool QMediaRecorder::isAvailable() const

Returns true if media recorder service ready to use.

See also availabilityChanged().

[override virtual] QMediaObject *QMediaRecorder::mediaObject() const

Reimplemented from QMediaBindableInterface::mediaObject().

Returns the QMediaObject instance that this QMediaRecorder is bound too, or 0 otherwise.

QVariant QMediaRecorder::metaData(const QString &key) const

Returns the value associated with a meta-data key.

See also setMetaData().

[signal] void QMediaRecorder::metaDataAvailableChanged(bool available)

Signals that the available state of a media object's meta-data has changed.

Note: Notifier signal for property metaDataAvailable.

[signal] void QMediaRecorder::metaDataChanged()

Signals that a media object's meta-data has changed.

If multiple meta-data elements are changed, metaDataChanged(const QString &key, const QVariant &value) signal is emitted for each of them with metaDataChanged() changed emitted once.

Note: Signal metaDataChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(mediaRecorder, QOverload<>::of(&QMediaRecorder::metaDataChanged),
    [=](){ /* ... */ });

[signal] void QMediaRecorder::metaDataChanged(const QString &key, const QVariant &value)

Signal the changes of one meta-data element value with the given key.

Note: Signal metaDataChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(mediaRecorder, QOverload<const QString &, const QVariant &>::of(&QMediaRecorder::metaDataChanged),
    [=](const QString &key, const QVariant &value){ /* ... */ });

[signal] void QMediaRecorder::metaDataWritableChanged(bool writable)

Signals that the writable state of a media object's meta-data has changed.

Note: Notifier signal for property metaDataWritable.

[signal] void QMediaRecorder::mutedChanged(bool muted)

Signals that the muted state has changed. If true the recording is being muted.

Note: Notifier signal for property muted.

[slot] void QMediaRecorder::pause()

Pause recording.

The recorder state is changed to QMediaRecorder::PausedState.

Depending on platform recording pause may be not supported, in this case the recorder state stays unchanged.

[slot] void QMediaRecorder::record()

Start recording.

While the recorder state is changed immediately to QMediaRecorder::RecordingState, recording may start asynchronously, with statusChanged(QMediaRecorder::RecordingStatus) signal emitted when recording starts.

If recording fails error() signal is emitted with recorder state being reset back to QMediaRecorder::StoppedState.

void QMediaRecorder::setAudioSettings(const QAudioEncoderSettings &settings)

Sets the audio encoder settings.

If some parameters are not specified, or null settings are passed, the encoder will choose default encoding parameters, depending on media source properties.

It's only possible to change settings when the encoder is in the QMediaEncoder::StoppedState state.

See also audioSettings(), videoSettings(), and containerFormat().

void QMediaRecorder::setContainerFormat(const QString &container)

Sets the media container format.

If the container format is not specified, the encoder will choose format, depending on media source properties and encoding settings selected.

It's only possible to change settings when the encoder is in the QMediaEncoder::StoppedState state.

See also audioSettings(), videoSettings(), and containerFormat().

void QMediaRecorder::setEncodingSettings(const QAudioEncoderSettings &audio, const QVideoEncoderSettings &video = QVideoEncoderSettings(), const QString &container = QString())

Sets the audio and video encoder settings and container format.

If some parameters are not specified, or null settings are passed, the encoder will choose default encoding parameters, depending on media source properties.

It's only possible to change settings when the encoder is in the QMediaEncoder::StoppedState state.

See also audioSettings(), videoSettings(), and containerFormat().

void QMediaRecorder::setMetaData(const QString &key, const QVariant &value)

Sets a value for a meta-data key.

Note: To ensure that meta data is set corretly, it should be set before starting the recording. Once the recording is stopped, any meta data set will be attached to the next recording.

See also metaData().

void QMediaRecorder::setVideoSettings(const QVideoEncoderSettings &settings)

Sets the video encoder settings.

If some parameters are not specified, or null settings are passed, the encoder will choose default encoding parameters, depending on media source properties.

It's only possible to change settings when the encoder is in the QMediaEncoder::StoppedState state.

See also audioSettings(), videoSettings(), and containerFormat().

QMediaRecorder::State QMediaRecorder::state() const

Returns the current media recorder state.

Note: Getter function for property state.

See also QMediaRecorder::State.

[signal] void QMediaRecorder::stateChanged(QMediaRecorder::State state)

Signals that a media recorder's state has changed.

Note: Notifier signal for property state.

QMediaRecorder::Status QMediaRecorder::status() const

Returns the current media recorder status.

Note: Getter function for property status.

See also QMediaRecorder::Status.

[slot] void QMediaRecorder::stop()

Stop recording.

The recorder state is changed to QMediaRecorder::StoppedState.

QStringList QMediaRecorder::supportedAudioCodecs() const

Returns a list of supported audio codecs.

QList<int> QMediaRecorder::supportedAudioSampleRates(const QAudioEncoderSettings &settings = QAudioEncoderSettings(), bool *continuous = nullptr) const

Returns a list of supported audio sample rates.

If non null audio settings parameter is passed, the returned list is reduced to sample rates supported with partial settings applied.

This can be used to query the list of sample rates, supported by specific audio codec.

If the encoder supports arbitrary sample rates within the supported rates range, *continuous is set to true, otherwise *continuous is set to false.

QStringList QMediaRecorder::supportedContainers() const

Returns a list of supported container formats.

QList<qreal> QMediaRecorder::supportedFrameRates(const QVideoEncoderSettings &settings = QVideoEncoderSettings(), bool *continuous = nullptr) const

Returns a list of frame rates video can be encoded at.

If non null video settings parameter is passed, the returned list is reduced to frame rates supported with partial settings like video codec or resolution applied.

If the encoder supports arbitrary frame rates within the supported range, *continuous is set to true, otherwise *continuous is set to false.

See also QVideoEncoderSettings::frameRate().

QList<QSize> QMediaRecorder::supportedResolutions(const QVideoEncoderSettings &settings = QVideoEncoderSettings(), bool *continuous = nullptr) const

Returns a list of resolutions video can be encoded at.

If non null video settings parameter is passed, the returned list is reduced to resolution supported with partial settings like video codec or framerate applied.

If the encoder supports arbitrary resolutions within the supported range, *continuous is set to true, otherwise *continuous is set to false.

See also QVideoEncoderSettings::resolution().

QStringList QMediaRecorder::supportedVideoCodecs() const

Returns a list of supported video codecs.

QString QMediaRecorder::videoCodecDescription(const QString &codec) const

Returns a description of a video codec.

See also setEncodingSettings().

QVideoEncoderSettings QMediaRecorder::videoSettings() const

Returns the video encoder settings being used.

See also setVideoSettings() and setEncodingSettings().