QMediaPlayer Class

Member Function Documentation

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

Construct a QMediaPlayer instance parented to parent and with flags.

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

Signals the availability of audio content has changed to available.

Note: Notifier signal for property audioAvailable.

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

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

Note: Notifier signal for property audioRole.

This function was introduced in Qt 5.6.

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

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

Note: Notifier signal for property bufferStatus.

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

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

Note: Notifier signal for property currentMedia.

See also currentMedia() and mediaChanged().

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

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

Note: Notifier signal for property customAudioRole.

This function was introduced in Qt 5.11.

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

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

Note: Notifier signal for property duration.

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

Signals that an error condition 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(mediaPlayer, QOverload<QMediaPlayer::Error>::of(&QMediaPlayer::error),
    [=](QMediaPlayer::Error error){ /* ... */ });

See also errorString().

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

Signals that the media source has been changed to media.

Note: Notifier signal for property media.

See also media() and currentMediaChanged().

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

Signals that the status of the current media has changed.

Note: Notifier signal for property mediaStatus.

See also mediaStatus().

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

Signal the mute state has changed to muted.

Note: Notifier signal for property muted.

[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.

Note: Notifier signal for property playbackRate.

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

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

Note: Notifier signal for property position.

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

Signals the seekable status of the player object has changed.

Note: Notifier signal for property seekable.

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

Sets the current media source.

If a stream is supplied; media data will be read from it instead of resolving the media source. In this case the url should be provided to resolve additional information about the media such as mime type. The stream must be open and readable. For macOS the stream should be also seekable.

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.

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 QAbstractVideoSurface is used as the video output, qtvideosink can be used as a video sink element directly in the pipeline. After that the surface will receive the video frames in QAbstractVideoSurface::present().

class Surface : public QAbstractVideoSurface
{
public:
    Surface(QObject *p) : QAbstractVideoSurface(p) { }
    QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType) const override
    {
        // Make sure that the driver supports this pixel format.
        return QList<QVideoFrame::PixelFormat>() << QVideoFrame::Format_YUYV;
    }

    // Video frames are handled here.
    bool present(const QVideoFrame &) override { return true; }
};

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

If QVideoWidget is used as the video output and the pipeline contains a video sink element named qtvideosink, current QVideoWidget will be used to render the video.

player = new QMediaPlayer;
videoWidget = new QVideoWidget;
videoWidget->show();
player->setVideoOutput(videoWidget);
player->setMedia(QUrl("gst-pipeline: videotestsrc ! xvimagesink name=\"qtvideosink\""));
player->play();

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();

Note: Setter function for property media.

See also media().

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

Signal the state of the Player object has changed.

Note: Notifier signal for property state.

[slot] void QMediaPlayer::stop()

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

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

Signal the availability of visual content has changed to videoAvailable.

Note: Notifier signal for property videoAvailable.

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

Signal the playback volume has changed to volume.

Note: Notifier signal for property volume.

[virtual] QMediaPlayer::~QMediaPlayer()

Destroys the player object.

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

Reimplements: QMediaObject::availability() const.

QMediaPlayer::Error QMediaPlayer::error() const

Returns the current error state.

[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.

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

const QIODevice *QMediaPlayer::mediaStream() const

Returns the stream source of media data.

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

See also setMedia().

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.

void QMediaPlayer::setVideoOutput(const QVector<QAbstractVideoSurface *> &surfaces)

Sets multiple video surfaces as the video output of a media player. This allows the media player to render video frames on different surfaces.

All video surfaces must support at least one shared QVideoFrame::PixelFormat.

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

This function was introduced in Qt 5.15.

See also QAbstractVideoSurface::supportedPixelFormats.

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.

See also 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.

See also customAudioRole.