Discover media performance metrics in AVFoundation

6:27 - AVMetric Publishers

public protocol AVMetricEventStreamPublisher 
{
	func metrics<MetricType: AVMetricEvent>(forType metricType: MetricType.Type) -> AVMetrics<MetricType>

	func allMetrics() -> AVMetrics<AVMetricEvent>
}

extension AVPlayerItem : AVMetricEventStreamPublisher

6:50 - Example showing how to obtain likely to keep up and summary metrics from AVPlayerItem - Swift

let playerItem : AVPlayerItem = ...
			
let ltkuMetrics = item.metrics(forType: AVMetricPlayerItemLikelyToKeepUpEvent.self)
let summaryMetrics = item.metrics(forType: AVMetricPlayerItemPlaybackSummaryEvent.self)
		
for await (metricEvent, publisher) in ltkuMetrics.chronologicalMerge(with: summaryMetrics) 
{
	// send metricEvent to server
}

7:26 - Example showing how to obtain likely to keep up and summary metrics from AVPlayerItem - Objective-C

AVPlayerItem *item = ...
	
AVMetricEventStream *eventStream = [AVMetricEventStream eventStream];
id<AVMetricEventStreamSubscriber> subscriber = [[MyMetricSubscriber alloc] init];
[eventStream setSubscriber:subscriber queue:mySerialQueue]

[eventStream subscribeToMetricEvent:[AVMetricPlayerItemLikelyToKeepUpEvent class]];
[eventStream subscribeToMetricEvent:[AVMetricPlayerItemPlaybackSummaryEvent class]];

[eventStream addPublisher:item];