QMediaPlayer Class

player = new QMediaPlayer;
audioOutput = new QAudioOutput;
player->setAudioOutput(audioOutput);
connect(player, &QMediaPlayer::positionChanged, this, &MediaExample::positionChanged);
player->setSource(QUrl::fromLocalFile("/Users/me/Music/coolsong.mp3"));
audioOutput->setVolume(50);
player->play();

Property Documentation

activeAudioTrack : int

Returns the currently active audio track.

By default, the first available audio track will be chosen.

Set index to -1 to disable all audio tracks.

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activeSubtitleTrack : int

Returns the currently active subtitle track.

Set index to -1 to disable subtitles.

Subtitles are disabled by default.

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activeVideoTrack : int

Returns the currently active video track.

By default, the first available audio track will be chosen.

Set index to -1 to disable all video tracks.

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[since 6.8] audioBufferOutput : QAudioBufferOutput*

This property holds the output audio buffer used by the media player.

Sets an audio buffer output to the media player.

If QAudioBufferOutput is specified and the media source contains an audio stream, the media player, it will emit the signal QAudioBufferOutput::audioBufferReceived with audio buffers containing decoded audio data. At the end of the audio stream, QMediaPlayer emits an empty QAudioBuffer.

QMediaPlayer emits outputs audio buffers at the same time as it pushes the matching data to the audio output if it's specified. However, the sound can be played with a small delay due to audio bufferization.

The format of emitted audio buffers is taken from the specified output or from the matching audio stream if the output returns an invalid format. Emitted audio data is not scaled depending on the current playback rate.

Potential use cases of utilizing QAudioBufferOutput with QMediaPlayer might be:

• Audio visualization. If the playback rate of the media player is not 1, you may scale the output image dimensions, or image update interval according to the requirements of the visualizer.
• Any AI sound processing, e.g. voice recognition.
• Sending the data to external audio output. Playback rate changing, synchronization with video, and manual flushing on stoping and seeking should be considered. We don't recommend using the audio buffer output for this purpose unless you have a strong reason for this.

This property was introduced in Qt 6.8.

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audioOutput : QAudioOutput*

This property holds the audio output device used by the media player.

The current audio output to be used when playing back media. Setting a new audio output will replace the currently used output.

Setting this property to nullptr will disable any audio output.

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[read-only] audioTracks : const QList<QMediaMetaData>

Lists the set of available audio tracks inside the media.

The QMediaMetaData returned describes the properties of individual tracks.

Different audio tracks can for example contain audio in different languages.

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[read-only] bufferProgress : const float

This property holds the percentage of the temporary buffer filled before playback begins or resumes, from 0. (empty) to 1. (full).

When the player object is buffering; this property holds the percentage of the temporary buffer that is filled. The buffer will need to reach 100% filled before playback can start or resume, at which time mediaStatus() will return BufferedMedia or BufferingMedia. If the value is anything lower than 100, mediaStatus() will return StalledMedia.

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See also mediaStatus().

[read-only] duration : const qint64

This property holds the duration of the current media.

The value is the total playback time in milliseconds of the current media. The value may change across the life time of the QMediaPlayer object and may not be available when initial playback begins, connect to the durationChanged() signal to receive status notifications.

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[read-only] error : const Error

This property holds a string describing the last error condition.

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See also error().

[read-only] errorString : const QString

This property holds a string describing the current error condition in more detail.

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[read-only] hasAudio : const bool

This property holds whether the media contains audio.

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[read-only] hasVideo : const bool

This property holds whether the media contains video.

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loops : int

Determines how often the media is played before the player stops. Set to QMediaPlayer::Infinite to loop the current media file forever.

The default value is 1. Setting this property to 0 has no effect.

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[read-only] mediaStatus : const MediaStatus

This property holds the status of the current media stream.

The stream status describes how the playback of the current stream is progressing.

By default this property is QMediaPlayer::NoMedia

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[read-only] metaData : const QMediaMetaData

Returns meta data for the current media used by the media player.

Meta data can contain information such as the title of the video or its creation date.

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playbackRate : qreal

This property holds the playback rate of the current media.

This value is a multiplier applied to the media's standard playback rate. By default this value is 1.0, indicating that the media is playing at the standard speed. Values higher than 1.0 will increase the playback speed, while values between 0.0 and 1.0 results in slower playback. Negative playback rates are not supported.

Not all playback services support change of the playback rate. It is framework defined as to the status and quality of audio and video while fast forwarding or rewinding.

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[read-only] playbackState : const PlaybackState

Returns the PlaybackState.

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See also playing.

[read-only, since 6.5] playing : const bool

This property holds whether the media is playing.

This property was introduced in Qt 6.5.

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See also playbackState and PlayingState.

position : qint64

This property holds the playback position of the current media.

The value is the current playback position, expressed in milliseconds since the beginning of the media. Periodically changes in the position will be indicated with the positionChanged() signal.

If the seekable property is true, this property can be set to milliseconds.

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[read-only] seekable : const bool

This property holds the seek-able status of the current media

If seeking is supported this property will be true; false otherwise. The status of this property may change across the life time of the QMediaPlayer object, use the seekableChanged signal to monitor changes.

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source : QUrl

This property holds the active media source being used by the player object.

The player object will use the QUrl for selection of the content to be played.

By default this property has a null QUrl.

Setting this property to a null QUrl 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.

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See also QUrl.

[read-only] subtitleTracks : const QList<QMediaMetaData>

Lists the set of available subtitle tracks inside the media.

The QMediaMetaData returned describes the properties of individual tracks.

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videoOutput : QObject*

This property holds the video output to be used by the media player.

A media player can only have one video output attached, so setting this property will replace the previously connected video output.

Setting this property to nullptr will disable video output.

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[read-only] videoTracks : const QList<QMediaMetaData>

Lists the set of available video tracks inside the media.

The QMediaMetaData returned describes the properties of individual tracks.

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