How to measure time-to-first-frame?

The question above is related to the following questions:

• How do I measure my start-up time?

To measure the time-to-first-frame, you need to measure the time difference between the play event and the playing event.

Web SDK

var playEventRegisteredAt;
function playingEventHandler(event) {
  player.removeEventListener('playing', playingEventHandler);
  var timeToFirstFrame = Date.now() - playEventRegisteredAt;
  console.log('Time-to-first-frame:', timeToFirstFrame);
}
function playEventHandler(event) {
  player.removeEventListener('play', playEventHandler);
  playEventRegisteredAt = Date.now();
}
player.addEventListener('playing', playingEventHandler);
player.addEventListener('play', playEventHandler);

Android SDK

long playEventRegisteredAt = 0; // global variable
...
EventListener<PlayingEvent> playingEventHandler = new EventListener<PlayingEvent>() {
    @Override
    public void handleEvent(PlayingEvent playingEvent) {
        tpv.getPlayer().removeEventListener(PlayerEventTypes.PLAYING, this);
        long timeToFirstFrame = System.currentTimeMillis() - playEventRegisteredAt;
        System.out.println("Time-to-first-frame: " + timeToFirstFrame);
    }
};
EventListener<PlayEvent> playEventHandler = new EventListener<PlayEvent>() {
    @Override
    public void handleEvent(PlayEvent playgEvent) {
        tpv.getPlayer().removeEventListener(PlayerEventTypes.PLAY, this);
        playEventRegisteredAt = System.currentTimeMillis();
    }
};
tpv.getPlayer().addEventListener(PlayerEventTypes.PLAYING, playingEventHandler);
tpv.getPlayer().addEventListener(PlayerEventTypes.PLAY, playEventHandler);

iOS/tvOS SDK and Legacy iOS/tvOS SDK (4.12.x)

var playEventRegisteredAt: Date!
...
playingeventlistener = theoplayer.addEventListener(type:
PlayerEventTypes.PLAYING, listener: playingEventHandler)

playeventlistener = theoplayer.addEventListener(type:
PlayerEventTypes.PLAY, listener: playEventHandler)

func playingEventHandler (event : PlayingEvent) {
        theoplayer.removeEventListener(type: PlayerEventTypes.PLAY,  listener: playingeventlistener);

        let components = NSCalendar.current.dateComponents([.second], from: playEventRegisteredAt, to: Date())

        let timeToFirstFrame = components.second

        print("Time-to-first-frame:", timeToFirstFrame!,"second(s)");
}

func playEventHandler(event :PlayEvent) {
        theoplayer.removeEventListener(type: PlayerEventTypes.PLAY,  listener: playeventlistener)
        playEventRegisteredAt = Date()
}

Roku SDK

To measure the time to the first frame, we will use roTimespan. Starting measurement will take place just before setting the source of the player and finishing measurement will occur in "playing" event callback.

<?xml version="1.0" encoding="utf-8" ?>
<component name="TestScene" extends="Scene">
    <interface>
        <function name="callbackOnEventPlayerPlay"/>
        <function name="callbackOnEventPlayerPlaying"/>
    </interface>

    <script type = "text/brightscript" >

        <![CDATA[

        function Init()
            m.player = m.top.findNode("TestPlayer")
            m.player.configuration = {
              "license": "" ' put the THEOplayer license between apostrophes
            }
            m.player.listener = m.top
            m.player.callFunc("addEventListener", m.player.Event.play, "callbackOnEventPlayerPlay")
            m.player.callFunc("addEventListener", m.player.Event.playing, "callbackOnEventPlayerPlaying")
            m._ts = CreateObject("roTimespan")

            setSource()
            m.player.setFocus(true)
            m.player.callFunc("play")
        end function

        function setSource()
            sourceDescription = {
                "sources": [
                    {
                        "src": "http://cdn.theoplayer.com/video/star_wars_episode_vii-the_force_awakens_official_comic-con_2015_reel_(2015)/index.m3u8",
                        "type": "application/x-mpegURL"
                    }
                ]
            }
            m.player.source = sourceDescription
            m.player.source.Live = false
            m.player.source.LiveBoundsPauseBehavior = "pause"
        end function

        function callbackOnEventPlayerPlay(eventData)
            ? "Event <play>: "; eventData
            m._ts.Mark()
        end function

        function callbackOnEventPlayerPlaying(eventData)
            ? "Event <playing>: "; eventData
            ? "Time-to-first-frame: "; m._ts.TotalMilliseconds()
        end function

        ]]>

    </script>

    <children>
	    <THEOsdk:THEOplayer id="TestPlayer"/>
    </children>
</component>