QMediaRecorder 类

QMediaRecorder 类用于媒体内容的录制。 更多...

头: #include <QMediaRecorder>
qmake: QT += multimedia
继承: QObject and QMediaBindableInterface
继承者:

QAudioRecorder

公共类型

enum Error { NoError, ResourceError, FormatError, OutOfSpaceError }
enum State { StoppedState, RecordingState, PausedState }
enum Status { UnavailableStatus, UnloadedStatus, LoadingStatus, LoadedStatus, StartingStatus, …, FinalizingStatus }

特性

公共函数

QMediaRecorder (QMediaObject * mediaObject , QObject * parent = nullptr)
virtual ~QMediaRecorder ()
QUrl actualLocation () const
QString audioCodecDescription (const QString & codec ) const
QAudioEncoderSettings audioSettings () const
QMultimedia::AvailabilityStatus availability () const
QStringList availableMetaData () const
QString containerDescription (const QString & format ) const
QString containerFormat () const
qint64 duration () const
QMediaRecorder::Error error () const
QString errorString () const
bool isAvailable () const
bool isMetaDataAvailable () const
bool isMetaDataWritable () const
bool isMuted () const
QVariant metaData (const QString & key ) const
QUrl outputLocation () const
void setAudioSettings (const QAudioEncoderSettings & settings )
void setContainerFormat (const QString & container )
void setEncodingSettings (const QAudioEncoderSettings & audio , const QVideoEncoderSettings & video = QVideoEncoderSettings(), const QString & container = QString())
void setMetaData (const QString & key , const QVariant & value )
bool setOutputLocation (const QUrl & location )
void setVideoSettings (const QVideoEncoderSettings & settings )
QMediaRecorder::State state () const
QMediaRecorder::Status status () const
QStringList supportedAudioCodecs () const
QList<int> supportedAudioSampleRates (const QAudioEncoderSettings & settings = QAudioEncoderSettings(), bool * continuous = nullptr) const
QStringList supportedContainers () const
QList<qreal> supportedFrameRates (const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = nullptr) const
QList<QSize> supportedResolutions (const QVideoEncoderSettings & settings = QVideoEncoderSettings(), bool * continuous = nullptr) const
QStringList supportedVideoCodecs () const
QString videoCodecDescription (const QString & codec ) const
QVideoEncoderSettings videoSettings () const
qreal volume () const

重实现公共函数

virtual QMediaObject * mediaObject () const override

公共槽

void pause ()
void record ()
void setMuted (bool muted )
void setVolume (qreal volume )
void stop ()

信号

void actualLocationChanged (const QUrl & location )
void availabilityChanged (QMultimedia::AvailabilityStatus availability )
void availabilityChanged (bool available )
void durationChanged (qint64 duration )
void error (QMediaRecorder::Error error )
void metaDataAvailableChanged (bool available )
void metaDataChanged (const QString & key , const QVariant & value )
void metaDataChanged ()
void metaDataWritableChanged (bool writable )
void mutedChanged (bool muted )
void stateChanged (QMediaRecorder::State state )
void statusChanged (QMediaRecorder::Status status )
void volumeChanged (qreal volume )

详细描述

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 QCamera .

recorder = new QMediaRecorder(camera);
QAudioEncoderSettings audioSettings;
audioSettings.setCodec("audio/amr");
audioSettings.setQuality(QMultimedia::HighQuality);
recorder->setAudioSettings(audioSettings);
recorder->setOutputLocation(QUrl::fromLocalFile(fileName));
recorder->record();
					

另请参阅 QAudioRecorder .

成员类型文档编制

enum QMediaRecorder:: Error

常量 描述
QMediaRecorder::NoError 0 没有错误。
QMediaRecorder::ResourceError 1 设备未就绪 (或不可用)。
QMediaRecorder::FormatError 2 不支持当前格式。
QMediaRecorder::OutOfSpaceError 3 设备没有剩余空间。

enum QMediaRecorder:: State

常量 描述
QMediaRecorder::StoppedState 0 The recorder is not active. If this is the state after recording then the actual created recording has finished being written to the final location and is ready on all platforms except on Android. On Android, due to platform limitations, there is no way to be certain that the recording has finished writing to the final location.
QMediaRecorder::RecordingState 1 请求录制。
QMediaRecorder::PausedState 2 录制器暂停。

enum QMediaRecorder:: Status

常量 描述
QMediaRecorder::UnavailableStatus 0 The recorder is not available or not supported by connected media object.
QMediaRecorder::UnloadedStatus 1 The recorder is avilable but not loaded.
QMediaRecorder::LoadingStatus 2 The recorder is initializing.
QMediaRecorder::LoadedStatus 3 The recorder is initialized and ready to record media.
QMediaRecorder::StartingStatus 4 Recording is requested but not active yet.
QMediaRecorder::RecordingStatus 5 Recording is active.
QMediaRecorder::PausedStatus 6 Recording is paused.
QMediaRecorder::FinalizingStatus 7 Recording is stopped with media being finalized.

特性文档编制

actualLocation : const QUrl

此特性保持最后媒体内容的实际位置。

The actual location is usually available after recording starts, and reset when new location is set or new recording starts.

访问函数:

QUrl actualLocation () const

通知程序信号:

void actualLocationChanged (const QUrl & location )

duration : const qint64

此特性保持录制媒体的持续时间 (以毫秒为单位)。

访问函数:

qint64 duration () const

通知程序信号:

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.

访问函数:

bool isMetaDataAvailable () const

通知程序信号:

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.

访问函数:

bool isMetaDataWritable () const

通知程序信号:

void metaDataWritableChanged (bool writable )

muted : bool

This property holds whether a recording audio stream is muted.

访问函数:

bool isMuted () const
void setMuted (bool muted )

通知程序信号:

void mutedChanged (bool muted )

outputLocation : QUrl

此特性保持媒体内容的目的地位置。

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.

访问函数:

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

state : const QMediaRecorder::State

此特性保持媒体录制器的当前状态。

The state property represents the user request and is changed synchronously during record (), pause () 或 stop () calls. Recorder state may also change asynchronously when recording fails.

访问函数:

QMediaRecorder::State state () const

通知程序信号:

void stateChanged (QMediaRecorder::State state )

status : const QMediaRecorder::Status

This property holds the current status of the media recorder.

The status is changed asynchronously and represents the actual status of media recorder.

访问函数:

QMediaRecorder::Status status () const

通知程序信号:

void statusChanged (QMediaRecorder::Status status )

volume : qreal

This property holds the current recording audio volume.

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

默认音量为 1.0 .

UI volume controls should usually be scaled nonlinearly. For example, using a logarithmic scale will produce linear changes in perceived loudness, which is what a user would normally expect from a volume control. See QAudio::convertVolume () 了解更多细节。

访问函数:

qreal volume () const
void setVolume (qreal volume )

通知程序信号:

void volumeChanged (qreal volume )

成员函数文档编制

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

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

The parent 会被传递给 QMediaObject .

[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.

注意: 通知程序信号对于特性 actualLocation .

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

Signals that the service availability has changed to availability .

注意: 信号 availabilityChanged 在此类中被重载。通过使用函数指针句法连接到此信号,Qt 提供用于获得如此范例展示的函数指针的方便帮助程序:

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

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

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

注意: 信号 availabilityChanged 在此类中被重载。通过使用函数指针句法连接到此信号,Qt 提供用于获得如此范例展示的函数指针的方便帮助程序:

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

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

信号 duration of the recorded media has changed.

注意: 通知程序信号对于特性 duration .

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

Signals that an error has occurred.

注意: 信号 error 在此类中被重载。通过使用函数指针句法连接到此信号,Qt 提供用于获得如此范例展示的函数指针的方便帮助程序:

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

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

信号 available state of a media object's meta-data has changed.

注意: 通知程序信号对于特性 metaDataAvailable .

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

Signal the changes of one meta-data element value 采用给定 key .

注意: 信号 metaDataChanged 在此类中被重载。通过使用函数指针句法连接到此信号,Qt 提供用于获得如此范例展示的函数指针的方便帮助程序:

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

[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.

注意: 信号 metaDataChanged 在此类中被重载。通过使用函数指针句法连接到此信号,Qt 提供用于获得如此范例展示的函数指针的方便帮助程序:

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

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

信号 writable state of a media object's meta-data has changed.

注意: 通知程序信号对于特性 metaDataWritable .

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

信号 muted state has changed. If true the recording is being muted.

注意: 通知程序信号对于特性 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 ()

开始录制。

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

若录制失败 error () signal is emitted with recorder state being reset back to QMediaRecorder::StoppedState .

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

Signals that a media recorder's state 已改变。

注意: 通知程序信号对于特性 state .

[slot] void QMediaRecorder:: stop ()

Stop recording.

The recorder state is changed to QMediaRecorder::StoppedState .

[虚拟] QMediaRecorder:: ~QMediaRecorder ()

销毁媒体录制器对象。

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.

另请参阅 setAudioSettings () 和 setEncodingSettings ().

QMultimedia::AvailabilityStatus QMediaRecorder:: availability () const

Returns the availability of this functionality.

另请参阅 availabilityChanged ().

QStringList QMediaRecorder:: availableMetaData () const

返回元数据的可用键列表。

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

Returns a description of a container format .

QString QMediaRecorder:: containerFormat () const

Returns the selected container format.

另请参阅 setContainerFormat ().

QMediaRecorder::Error QMediaRecorder:: error () const

返回当前错误状态。

另请参阅 errorString ().

QString QMediaRecorder:: errorString () const

返回描述当前错误状态的字符串。

另请参阅 error ().

bool QMediaRecorder:: isAvailable () const

Returns true if media recorder service ready to use.

另请参阅 availabilityChanged ().

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

重实现: QMediaBindableInterface::mediaObject () const.

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

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

返回的值关联元数据 key .

另请参阅 setMetaData ().

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.

另请参阅 audioSettings (), videoSettings (),和 containerFormat ().

void QMediaRecorder:: setContainerFormat (const QString & container )

Sets the media container 格式。

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.

另请参阅 audioSettings (), videoSettings (),和 containerFormat ().

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

设置 audio and video encoder settings and container 格式。

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.

另请参阅 audioSettings (), videoSettings (),和 containerFormat ().

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

设置 value for a meta-data key .

注意: 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.

另请参阅 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.

另请参阅 audioSettings (), videoSettings (),和 containerFormat ().

QMediaRecorder::State QMediaRecorder:: state () const

Returns the current media recorder state.

注意: Getter function for property state.

另请参阅 QMediaRecorder::State .

QMediaRecorder::Status QMediaRecorder:: status () const

Returns the current media recorder status.

注意: getter 函数对于特性 status。

另请参阅 QMediaRecorder::Status .

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 被设为 true,否则 * continuous 被设为 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 被设为 true,否则 * continuous 被设为 false。

另请参阅 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 被设为 true,否则 * continuous 被设为 false。

另请参阅 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 .

另请参阅 setEncodingSettings ().

QVideoEncoderSettings QMediaRecorder:: videoSettings () const

Returns the video encoder settings being used.

另请参阅 setVideoSettings () 和 setEncodingSettings ().