QMediaPlayer 类

成员函数文档编制

QMediaPlayer:: QMediaPlayer ( QObject * parent = nullptr, QMediaPlayer::Flags flags = Flags())

Construct a QMediaPlayer instance parented to parent and with flags .

[virtual] QMediaPlayer:: ~QMediaPlayer ()

Destroys the player object.

[signal] void QMediaPlayer:: audioAvailableChanged ( bool available )

Signals the availability of audio content has changed to available .

注意： 通知信号为特性 audioAvailable .

[signal] void QMediaPlayer:: audioRoleChanged ( QAudio::Role role )

Signals that the audio role of the media player has changed.

This function was introduced in Qt 5.6.

注意： 通知信号为特性 audioRole .

[override virtual] QMultimedia::AvailabilityStatus QMediaPlayer:: availability () const

Reimplemented from QMediaObject::availability ().

[signal] void QMediaPlayer:: bufferStatusChanged ( int percentFilled )

Signal the amount of the local buffer filled as a percentage by percentFilled .

注意： 通知信号为特性 bufferStatus .

[signal] void QMediaPlayer:: currentMediaChanged (const QMediaContent & media )

Signals that the current playing content has been changed to media .

注意： 通知信号为特性 currentMedia .

另请参阅 currentMedia () 和 mediaChanged ().

QNetworkConfiguration QMediaPlayer:: currentNetworkConfiguration () const

Returns the current network access point in use. If a default contructed QNetworkConfiguration is returned this feature is not available or that none of the current supplied configurations are in use.

[signal] void QMediaPlayer:: customAudioRoleChanged (const QString & role )

Signals that the audio role of the media player has changed.

This function was introduced in Qt 5.11.

注意： 通知信号为特性 customAudioRole .

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

Signal the duration of the content has changed to duration , expressed in milliseconds.

注意： 通知信号为特性 duration .

QMediaPlayer::Error QMediaPlayer:: error () const

Returns the current error state.

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

Signals that an error condition has occurred.

注意： Signal 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(mediaPlayer, QOverload<QMediaPlayer::Error>::of(&QMediaPlayer::error),
    [=](QMediaPlayer::Error error){ /* ... */ });
							

另请参阅 errorString ().

[static] QMultimedia::SupportEstimate QMediaPlayer:: hasSupport (const QString & mimeType , const QStringList & codecs = QStringList(), QMediaPlayer::Flags flags = Flags())

Returns the level of support a media player has for a mimeType and a set of codecs .

flags argument allows additional requirements such as performance indicators to be specified.

[signal] void QMediaPlayer:: mediaChanged (const QMediaContent & media )

Signals that the media source has been changed to media .

注意： 通知信号为特性 media .

另请参阅 media () 和 currentMediaChanged ().

[signal] void QMediaPlayer:: mediaStatusChanged ( QMediaPlayer::MediaStatus status )

Signals that the status of the current media has changed.

注意： 通知信号为特性 mediaStatus .

另请参阅 mediaStatus ().

const QIODevice *QMediaPlayer:: mediaStream () const

Returns the stream source of media data.

This is only valid if a stream was passed to setMedia ().

另请参阅 setMedia ().

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

Signal the mute state has changed to muted .

注意： 通知信号为特性 muted .

[signal] void QMediaPlayer:: networkConfigurationChanged (const QNetworkConfiguration & configuration )

Signal that the active in use network access point has been changed to configuration and all subsequent network access will use this configuration .

[slot] void QMediaPlayer:: pause ()

Pause playing the current source.

[slot] void QMediaPlayer:: play ()

Start or resume playing the current source.

[signal] void QMediaPlayer:: playbackRateChanged ( qreal rate )

Signals the playbackRate has changed to rate .

注意： 通知信号为特性 playbackRate .

[signal] void QMediaPlayer:: positionChanged ( qint64 position )

Signal the position of the content has changed to position , expressed in milliseconds.

注意： 通知信号为特性 position .

[signal] void QMediaPlayer:: seekableChanged ( bool seekable )

Signals the seekable status of the player object has changed.

注意： 通知信号为特性 seekable .

[slot] void QMediaPlayer:: setMedia (const QMediaContent & media , QIODevice * stream = nullptr)

Sets the current media source.

若 stream is supplied; media data will be read from it instead of resolving the media source. In this case the media source may still be used to resolve additional information about the media such as mime type. The stream must be open and readable.

Setting the media to a null QMediaContent will cause the player to discard all information relating to the current media source and to cease all I/O operations related to that media.

注意： This function returns immediately after recording the specified source of the media. It does not wait for the media to finish loading and does not check for errors. Listen for the mediaStatusChanged () 和 error () signals to be notified when the media is loaded and when an error occurs during loading.

Since Qt 5.12.2, the url scheme gst-pipeline provides custom pipelines for the GStreamer backend.

player = new QMediaPlayer;
player->setMedia(QUrl("gst-pipeline: videotestsrc ! autovideosink"));
player->play();
							

If the pipeline contains a video sink element named qtvideosink , current QVideoWidget can be used to render the video.

If the pipeline contains appsrc element, it will be used to push data from stream .

QImage img("images/qt-logo.png");
img = img.convertToFormat(QImage::Format_ARGB32);
QByteArray ba(reinterpret_cast<const char *>(img.bits()), img.sizeInBytes());
QBuffer buffer(&ba);
buffer.open(QIODevice::ReadOnly);
player = new QMediaPlayer;
player->setMedia(QUrl("gst-pipeline: appsrc blocksize=4294967295 ! \
    video/x-raw,format=BGRx,framerate=30/1,width=200,height=147 ! \
    coloreffects preset=heat ! videoconvert ! video/x-raw,format=I420 ! jpegenc ! rtpjpegpay ! \
    udpsink host=127.0.0.1 port=5000"), &buffer);
player->play();
QMediaPlayer *receiver = new QMediaPlayer;
videoWidget = new QVideoWidget;
receiver->setVideoOutput(videoWidget);
receiver->setMedia(QUrl("gst-pipeline: udpsrc port=5000 ! \
    application/x-rtp,encoding-name=JPEG,payload=26 ! rtpjpegdepay ! jpegdec ! \
    xvimagesink name=qtvideosink"));
receiver->play();
// Content will be shown in this widget.
videoWidget->show();
							

注意： Setter 函数为特性 media .

另请参阅 media ().

[slot] void QMediaPlayer:: setNetworkConfigurations (const QList < QNetworkConfiguration > & configurations )

Sets the network access points for remote media playback. configurations contains, in ascending preferential order, a list of configuration that can be used for network access.

This will invalidate the choice of previous configurations.

void QMediaPlayer:: setVideoOutput ( QVideoWidget * output )

Attach a QVideoWidget video output to the media player.

If the media player has already video output attached, it will be replaced with a new one.

void QMediaPlayer:: setVideoOutput ( QGraphicsVideoItem * output )

Attach a QGraphicsVideoItem video output to the media player.

If the media player has already video output attached, it will be replaced with a new one.

void QMediaPlayer:: setVideoOutput ( QAbstractVideoSurface * surface )

Sets a video surface as the video output of a media player.

If a video output has already been set on the media player the new surface will replace it.

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

Signal the state of the Player object has changed.

注意： 通知信号为特性 state .

[slot] void QMediaPlayer:: stop ()

Stop playing, and reset the play position to the beginning.

QList < QAudio::Role > QMediaPlayer:: supportedAudioRoles () const

Returns a list of supported audio roles.

If setting the audio role is not supported, an empty list is returned.

This function was introduced in Qt 5.6.

另请参阅 audioRole .

QStringList QMediaPlayer:: supportedCustomAudioRoles () const

Returns a list of supported custom audio roles. An empty list may indicate that the supported custom audio roles aren't known. The list may not be complete.

This function was introduced in Qt 5.11.

另请参阅 customAudioRole .

[signal] void QMediaPlayer:: videoAvailableChanged ( bool videoAvailable )

Signal the availability of visual content has changed to videoAvailable .

注意： 通知信号为特性 videoAvailable .

[signal] void QMediaPlayer:: volumeChanged ( int volume )

Signal the playback volume has changed to volume .

注意： 通知信号为特性 volume .