How to programmatically select a video track quality
This article describes how you can use the API to select a video track quality. If you select a specific quality, you overrule the ABR algorithm.
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 toggle a specific video quality.
SDKs
| Web SDK | Android SDK | iOS SDK | tvOS SDK | Android TV SDK | Chromecast SDK |
|---|---|---|---|---|---|
| Yes | Yes | Yes | Yes | Yes | Yes |
Code examples
The code examples below show how to implement selecting video track qualities across SDKs.
Web SDK
The Web SDK leverages the MediaTrack API.
// enable a specific video track quality
player.videoTracks[0].targetQuality =
player.videoTracks[0].qualities[indexOfRequestedVideoTrackQuality];
// do ABR on a set of qualities
player.videoTracks[0].targetQuality = [
player.videoTracks[0].qualities[indexOfRequestedVideoTrackQuality1],
player.videoTracks[0].qualities[indexOfRequestedVideoTrackQuality2]
];
// set to default ABR algorithm
player.videoTracks[0].targetQuality = null;
Android (TV) SDK
The Android SDK leverages the MediaTrack API.
// enable a specific video track quality
theoplayer.getPlayer().getVideoTracks().getItem(0).setTargetQuality(theoplayer.getPlayer().getVideoTracks().getItem(0).getQualities().getItem(indexOfRequestedVideoTrackQuality));
// do ABR on a set of qualities
ArrayList<VideoQuality> selectedVideoQualities = new ArrayList<>();
selectedVideoQualities.add(theoplayer.getPlayer().getVideoTracks().getItem(0).getQualities().getItem(0));
selectedVideoQualities.add(theoplayer.getPlayer().getVideoTracks().getItem(0).getQualities().getItem(1));
theoplayer.getPlayer().getVideoTracks().getItem(0).setTargetQualities(selectedVideoQualities); // ABR algorithm only executed to qualities belonging to selectedVideoQualities
// set to default ABR algorithm
theoplayer.getPlayer().getVideoTracks().getItem(0).setTargetQualities(Collections.emptyList());
iOS (/tvOS) SDK
The iOS SDK leverages the ABR API. The underlying AVFoundation stack, which THEOplayer has to use, brings along the technical limitation that you cannot select a specific video quality. Instead, you can set a maximum resolution or bitrate.
// set preferred peak bitrate
self.theoplayer.abr.preferredPeakBitRate = 200000
// self.theoplayer.abr.preferredPeakBitRate = nil // removes any bitrate limitation
// preferredMaximumResolution supported starting from iOS 11 and above
// self.theoplayer.abr.preferredMaximumResolution = CGSize(width: 1280, height: 720)
// self.theoplayer.abr.preferredMaximumResolution = CGSize.zero // removes any resolution limitation
Remarks
- A related article on building a Chromeless UI is located at How to build a Chromeless UI.