The VideoPlaybackQuality interface's totalVideoFrames read-only property returns the total number of video frames that have been displayed or dropped since the media was loaded.

The total number of frames that the <video> element has displayed or dropped since the media was loaded into it. Essentially, this is the number of frames the element would have presented had no problems occurred.

This value is reset when the media is reloaded or replaced.

This example calls getVideoPlaybackQuality() to obtain a VideoPlaybackQuality object, then determines what percentage of frames have been lost by either corruption or being dropped. If that exceeds 10% (0.1), a function called lostFramesThresholdExceeded() is called to, perhaps, update a quality indicator to show an increase in frame loss.

const videoElem = document.getElementById("my_vid");
const quality = videoElem.getVideoPlaybackQuality();

if (
  (quality.corruptedVideoFrames + quality.droppedVideoFrames) /
    quality.totalVideoFrames >
  0.1
) {
  lostFramesThresholdExceeded();
}

A similar algorithm might be used to attempt to switch to a lower-resolution video that requires less bandwidth, in order to avoid dropping frames.

• The HTMLVideoElement.getVideoPlaybackQuality() method for constructing and returning this interface.