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Version: 10.3.0

How to programmatically detect video track quality changes

This article describes how you can use the API to detect video track quality changes.

The VideoTrack API, which is a sub-API of the MediaTrack API, can be used to implement this functionality. Implementing this functionality is a common use-case for developers who want to build their own UI to visualize the available video track qualities.

SDKs​

Web SDKAndroid SDKiOS SDKtvOS SDKAndroid TV SDKChromecast SDK
YesYesYesYesYesYes

Code examples​

The code examples below how to implement the detection of video track qualities across SDK.

Web SDK​

The Web SDK leverages the MediaTrack API.

// detect video tracks being added to the player
player.videoTracks.addEventListener('addtrack', function (e0) {
  // detect quality changes of a track
  e0.track.addEventListener('activequalitychanged', function (e1) {
    console.log('activequalitychanged event detected!', e1);
  });
});
Android (TV) SDK​

The Android SDK leverages the MediaTrack API.

EventListener<AddTrackEvent> handleAddTrackEvent = new EventListener<AddTrackEvent>() {
    EventListener<ActiveQualityChangedEvent> handleActiveQualityChangedEvent = new EventListener<ActiveQualityChangedEvent>() {
        @Override
        public void handleEvent(ActiveQualityChangedEvent activeQualityChangedEvent) {
            System.out.println("activequalitychanged event detected! " + activeQualityChangedEvent.getQuality().toString());
        }
    };
    @Override
    public void handleEvent(AddTrackEvent addTrackEvent) {
        addTrackEvent.getTrack().addEventListener(VideoTrackEventTypes.ACTIVEQUALITYCHANGEDEVENT, handleActiveQualityChangedEvent);
    }
};
tpv.getPlayer().getVideoTracks().addEventListener(VideoTrackListEventTypes.ADDTRACK, handleAddTrackEvent);
iOS (/tvOS) SDK​
player.videoTracks.addEventListener(type: VideoTrackListEventTypes.ADD_TRACK, listener: { addTrackEvent in
    guard let videoTrack = addTrackEvent.track as? VideoTrack else { return }
    videoTrack.addEventListener(type: MediaTrackEventTypes.ACTIVE_QUALITY_CHANGED, listener: { qualityChangeEvent in
        let quality = qualityChangeEvent.quality
        var msg = "Quality changed: bandwidth = \(quality.bandwidth)"
        if let videoQuality = quality as? VideoQuality {
            msg.append(", width = \(videoQuality.width), height = \(videoQuality.height)")
        }
        print(msg)
    })
})

Remarks​