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QMediaRecorder Class Reference

The QMediaRecorder class is used for the recording of media content. More...

 #include <QMediaRecorder>

Inherits: QObject and QMediaBindableInterface.

This class was introduced in Qt Mobility 1.0.

Public Types

enum Error { NoError, ResourceError, FormatError }
enum State { StoppedState, RecordingState, PausedState }

Properties

  • 1 property inherited from QObject

Public Functions

QMediaRecorder ( QMediaObject * mediaObject, QObject * parent = 0 )
~QMediaRecorder ()
QString audioCodecDescription ( const QString & codec ) const
QAudioEncoderSettings audioSettings () const
QtMultimediaKit::AvailabilityError availabilityError () const
QStringList availableExtendedMetaData () const
QList<QtMultimediaKit::MetaData> availableMetaData () const
QString containerDescription ( const QString & mimeType ) const
QString containerMimeType () const
qint64 duration () const
Error error () const
QString errorString () const
QVariant extendedMetaData ( const QString & key ) const
bool isAvailable () const
bool isMetaDataAvailable () const
bool isMetaDataWritable () const
bool isMuted () const
QVariant metaData ( QtMultimediaKit::MetaData key ) const
QUrl outputLocation () const
void setEncodingSettings ( const QAudioEncoderSettings & audio, const QVideoEncoderSettings & video = QVideoEncoderSettings(), const QString & container = QString() )
void setExtendedMetaData ( const QString & key, const QVariant & value )
void setMetaData ( QtMultimediaKit::MetaData key, const QVariant & value )
bool setOutputLocation ( const QUrl & location )
State state () const
QStringList supportedAudioCodecs () const
QList<int> supportedAudioSampleRates ( const QAudioEncoderSettings & settings = QAudioEncoderSettings(), bool * continuous = 0 ) const
QStringList supportedContainers () const
QList<qreal> supportedFrameRates ( const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = 0 ) const
QList<QSize> supportedResolutions ( const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = 0 ) const
QStringList supportedVideoCodecs () const
QString videoCodecDescription ( const QString & codec ) const
QVideoEncoderSettings videoSettings () const

Reimplemented Public Functions

virtual QMediaObject * mediaObject () const

Public Slots

void pause ()
void record ()
void setMuted ( bool muted )
void stop ()
  • 1 public slot inherited from QObject

Signals

void durationChanged ( qint64 duration )
void error ( QMediaRecorder::Error error )
void metaDataAvailableChanged ( bool available )
void metaDataChanged ()
void metaDataWritableChanged ( bool writable )
void mutedChanged ( bool muted )
void stateChanged ( QMediaRecorder::State state )

Additional Inherited Members

Detailed Description

The QMediaRecorder class is used for the recording of media content.

The QMediaRecorder class is a high level media recording class. It's not intended to be used alone but for accessing the media recording functions of other media objects, like QRadioTuner, or QAudioCaptureSource.

 // Audio only recording
 audioSource = new QAudioCaptureSource;
 recorder = new QMediaRecorder(audioSource);

 QAudioEncoderSettings audioSettings;
 audioSettings.setCodec("audio/vorbis");
 audioSettings.setQuality(QtMultimediaKit::HighQuality);

 recorder->setEncodingSettings(audioSettings);

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

See also QAudioCaptureSource.

Member Type Documentation

enum QMediaRecorder::Error

Constant Value Description
QMediaRecorder::NoError 0 No Errors.
QMediaRecorder::ResourceError 1 Device is not ready or not available.
QMediaRecorder::FormatError 2 Current format is not supported.

enum QMediaRecorder::State

Constant Value Description
QMediaRecorder::StoppedState 0 The recorder is not active.
QMediaRecorder::RecordingState 1 The recorder is currently active and producing data.
QMediaRecorder::PausedState 2 The recorder is paused.

Property Documentation

duration : const qint64

This property holds the recorded media duration in milliseconds.

This property was introduced in Qt Mobility 1.0.

Access functions:

qint64 duration () const

Notifier signal:

void durationChanged ( qint64 duration )

metaDataAvailable : const bool

This property holds whether access to a media object's meta-data is available.

If this is true there is meta-data available, otherwise there is no meta-data available.

This property was introduced in Qt Mobility 1.0.

Access functions:

bool isMetaDataAvailable () const

Notifier signal:

void metaDataAvailableChanged ( bool available )

metaDataWritable : const bool

This property holds whether a media object's meta-data is writable.

If this is true the meta-data is writable, otherwise the meta-data is read-only.

This property was introduced in Qt Mobility 1.0.

Access functions:

bool isMetaDataWritable () const

Notifier signal:

void metaDataWritableChanged ( bool writable )

muted : bool

This property holds whether a recording audio stream is muted.

This property was introduced in Qt Mobility 1.0.

Access functions:

bool isMuted () const
void setMuted ( bool muted )

Notifier signal:

void mutedChanged ( bool muted )

outputLocation : QUrl

This property holds the destination location of media content.

Setting the location can fail, for example when the service supports only local file system locations but a network URL was passed. If the service does not support media recording this setting the output location will always fail.

The location can be relative or empty; in this case the recorder uses the system specific place and file naming scheme. After recording has stated, QMediaRecorder::outputLocation() returns the actual output location.

This property was introduced in Qt Mobility 1.0.

Access functions:

QUrl outputLocation () const
bool setOutputLocation ( const QUrl & location )

Member Function Documentation

QMediaRecorder::QMediaRecorder ( QMediaObject * mediaObject, QObject * parent = 0 )

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

The parent is passed to QMediaObject.

This function was introduced in Qt Mobility 1.0.

QMediaRecorder::~QMediaRecorder ()

Destroys a media recorder object.

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

Returns a description of an audio codec.

This function was introduced in Qt Mobility 1.0.

QAudioEncoderSettings QMediaRecorder::audioSettings () const

Returns the audio encoder settings being used.

This function was introduced in Qt Mobility 1.0.

See also setEncodingSettings().

QtMultimediaKit::AvailabilityError QMediaRecorder::availabilityError () const

Returns the availability error code.

This function was introduced in Qt Mobility 1.0.

QStringList QMediaRecorder::availableExtendedMetaData () const

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

This function was introduced in Qt Mobility 1.0.

QList<QtMultimediaKit::MetaData> QMediaRecorder::availableMetaData () const

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

This function was introduced in Qt Mobility 1.0.

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

Returns a description of a container format mimeType.

This function was introduced in Qt Mobility 1.0.

QString QMediaRecorder::containerMimeType () const

Returns the MIME type of the selected container format.

This function was introduced in Qt Mobility 1.0.

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

Signals that the duration of the recorded media has changed.

This function was introduced in Qt Mobility 1.0.

Error QMediaRecorder::error () const

Returns the current error state.

This function was introduced in Qt Mobility 1.0.

See also errorString().

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

Signals that an error has occurred.

This function was introduced in Qt Mobility 1.0.

QString QMediaRecorder::errorString () const

Returns a string describing the current error state.

This function was introduced in Qt Mobility 1.0.

See also error().

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

Returns the value associated with a meta-data key.

The naming and type of extended meta-data is not standardized, so the values and meaning of keys may vary between backends.

This function was introduced in Qt Mobility 1.0.

See also setExtendedMetaData().

bool QMediaRecorder::isAvailable () const

Returns true if media recorder service ready to use.

This function was introduced in Qt Mobility 1.0.

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

Reimplemented from QMediaBindableInterface::mediaObject().

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

This function was introduced in Qt Mobility 1.0.

QVariant QMediaRecorder::metaData ( QtMultimediaKit::MetaData key ) const

Returns the value associated with a meta-data key.

This function was introduced in Qt Mobility 1.0.

See also setMetaData().

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

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

This function was introduced in Qt Mobility 1.0.

void QMediaRecorder::metaDataChanged () [signal]

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

This function was introduced in Qt Mobility 1.0.

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

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

This function was introduced in Qt Mobility 1.0.

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

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

This function was introduced in Qt Mobility 1.0.

void QMediaRecorder::pause () [slot]

Pause recording.

This function was introduced in Qt Mobility 1.0.

void QMediaRecorder::record () [slot]

Start recording.

This is an asynchronous call, with signal stateCahnged(QMediaRecorder::RecordingState) being emitted when recording started, otherwise the error() signal is emitted.

This function was introduced in Qt Mobility 1.0.

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

Sets the audio and video encoder settings and container format MIME type.

If some parameters are not specified, or null settings are passed, the encoder will choose default encoding parameters, depending on media source properties. While setEncodingSettings is optional, the backend can preload encoding pipeline to improve recording startup time.

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

This function was introduced in Qt Mobility 1.0.

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

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

Sets a value for a meta-data key.

The naming and type of extended meta-data is not standardized, so the values and meaning of keys may vary between backends.

This function was introduced in Qt Mobility 1.0.

See also extendedMetaData().

void QMediaRecorder::setMetaData ( QtMultimediaKit::MetaData 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.

This function was introduced in Qt Mobility 1.0.

See also metaData().

State QMediaRecorder::state () const

Returns the current media recorder state.

This function was introduced in Qt Mobility 1.0.

See also QMediaRecorder::State.

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

Signals that a media recorder's state has changed.

This function was introduced in Qt Mobility 1.0.

void QMediaRecorder::stop () [slot]

Stop recording.

This function was introduced in Qt Mobility 1.0.

QStringList QMediaRecorder::supportedAudioCodecs () const

Returns a list of supported audio codecs.

This function was introduced in Qt Mobility 1.0.

QList<int> QMediaRecorder::supportedAudioSampleRates ( const QAudioEncoderSettings & settings = QAudioEncoderSettings(), bool * continuous = 0 ) 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.

This function was introduced in Qt Mobility 1.0.

QStringList QMediaRecorder::supportedContainers () const

Returns a list of MIME types of supported container formats.

This function was introduced in Qt Mobility 1.0.

QList<qreal> QMediaRecorder::supportedFrameRates ( const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = 0 ) 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.

This function was introduced in Qt Mobility 1.0.

See also QVideoEncoderSettings::frameRate().

QList<QSize> QMediaRecorder::supportedResolutions ( const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = 0 ) 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.

This function was introduced in Qt Mobility 1.0.

See also QVideoEncoderSettings::resolution().

QStringList QMediaRecorder::supportedVideoCodecs () const

Returns a list of supported video codecs.

This function was introduced in Qt Mobility 1.0.

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

Returns a description of a video codec.

This function was introduced in Qt Mobility 1.0.

See also setEncodingSettings().

QVideoEncoderSettings QMediaRecorder::videoSettings () const

Returns the video encoder settings being used.

This function was introduced in Qt Mobility 1.0.

See also setEncodingSettings().

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