This document provides reference information for the YouTube ActionScript 3.0 (AS3) player API.

Note: This documentation was updated in October 2009 to explain how to use AS3 rather than ActionScript 2.0 (AS2).

Contents

Overview

The AS3 API allows users to control the YouTube video players by loading the player into a Flash application and making calls via ActionScript to the player's public API. Calls can be made to play, pause, seek to a certain time in a video, set the volume, mute the player, and other useful functions. The ActionScript API is automatically activated when the player is loaded into another SWF.

Requirements

The end user must have Flash Player 9 or higher installed to view everything correctly.

Getting Started

Use the following URL to load the chromeless player into your application and build your own custom controls in Flash:

http://www.youtube.com/apiplayer?version=3

Once the chromeless player SWF has been loaded, you can use cueVideoById(), loadVideoById(), cueVideoByUrl() or loadVideoByUrl() to load a particular YouTube video.

See the examples below for more detailed information about how to embed a YouTube player SWF into your Flash file.

Operations

The AS3 API is very similar to the JavaScript API, with some small changes to how the player is initialized and some additional functions. For examples of how to initialize and make calls to the player via ActionScript, see the examples below.

Functions

Queueing functions

player.cueVideoById(videoId:String, startSeconds:Number, suggestedQuality:String):Void

Loads the specified video's thumbnail and prepares the player to play the video. The player does not request the FLV until playVideo() or seekTo() is called.

• The required videoId parameter specifies the YouTube Video ID of the video to be played. In YouTube Data API video feeds, the <yt:videoId> tag specifies the ID.
• The optional startSeconds parameter accepts a float/integer and specifies the time from which the video should start playing when playVideo() is called. If you specify a startSeconds value and then call seekTo(), then the player plays from the time specified in the seekTo() call. When the video is cued and ready to play, the player will broadcast a video cued event (5).
• The optional suggestedQuality parameter specifies the suggested playback quality for the video. Please see the definition of the setPlaybackQuality function for more information about playback quality.

player.loadVideoById(videoId:String, startSeconds:Number, suggestedQuality:String):Void

Loads and plays the specified video.

• The required videoId parameter specifies the YouTube Video ID of the video to be played. In YouTube Data API video feeds, the <yt:videoId> tag specifies the ID.
• The optional startSeconds parameter accepts a float/integer. If it is specified, then the video will start from the closest keyframe to the specified time.
• The optional suggestedQuality parameter specifies the suggested playback quality for the video. Please see the definition of the setPlaybackQuality function for more information about playback quality.

player.cueVideoByUrl(mediaContentUrl:String, startSeconds:Number):Void

Loads the specified video's thumbnail and prepares the player to play the video. The player does not request the FLV until playVideo() or seekTo() is called.

• The mediaContentUrl must be a fully qualified YouTube player URL in the format http://www.youtube.com/v/VIDEO_ID. In YouTube Data API video feeds, the url attribute of the <media:content> tag contains a fully qualified player URL when the tag's format attribute has a value of 5.
• startSeconds accepts a float/integer and specifies the time from which the video should start playing when playVideo() is called. If you specify startSeconds and then call seekTo(), then the player plays from the time specified in the seekTo() call. When the video is cued and ready to play, the player will broadcast a video cued event (5).

player.loadVideoByUrl(mediaContentUrl:String, startSeconds:Number):Void

This function, which loads and plays the specified video, has not yet been implemented for the ActionScript 3.0 Player API.

• The mediaContentUrl must be a fully qualified YouTube player URL in the format http://www.youtube.com/v/VIDEO_ID. In YouTube Data API video feeds, the url attribute of the <media:content> tag contains a fully qualified player URL when the tag's format attribute has a value of 5.
• startSeconds accepts a float/integer and specifies the time from which the video should start playing. If startSeconds (number can be a float) is specified, the video will start from the closest keyframe to the specified time.

Loads and plays the specified video.

• The mediaContentUrl must be a fully qualified YouTube player URL in the format http://www.youtube.com/v/VIDEO_ID. In YouTube Data API video feeds, the url attribute of the <media:content> tag contains a fully qualified player URL when the tag's format attribute has a value of 5.
• startSeconds accepts a float/integer and specifies the time from which the video should start playing. If startSeconds (number can be a float) is specified, the video will start from the closest keyframe to the specified time.

Playback controls and player settings

Playing a video

player.playVideo():Void

Plays the currently cued/loaded video.

player.pauseVideo():Void

Pauses the currently playing video.

player.stopVideo():Void

Stops the current video. This function also closes the NetStream object and cancels the loading of the video. Once stopVideo() is called, a video cannot be resumed without reloading the player or loading a new video (chromeless player only). When calling stopVideo(), the player broadcasts an end event (0).

player.seekTo(seconds, allowSeekAhead):Void

Seeks to the specified time of the video in seconds. The allowSeekAhead determines whether or not the player will make a new request to the server if seconds is beyond the currently loaded video data. Note that seekTo() will look for the closest keyframe before the seconds specified. This means that sometimes the play head may seek to just before the requested time, usually no more than ~2 seconds.

player.clearVideo():Void

Clears the video display. This function is useful if you want to clear the video remnant after calling stopVideo(). Note that this function has been deprecated in the ActionScript 3.0 Player API.

Changing the player volume

player.mute():Void

Mutes the player.

player.unMute():Void

Unmutes the player.

player.isMuted():Boolean

Returns true if the player is muted, false if not.

player.setVolume(volume):Void

Sets the volume. Accepts an integer between 0 and 100.

player.getVolume():Number

Returns the player's current volume, an integer between 0 and 100. Note that getVolume() will return the volume even if the player is muted.

Setting the player size

player.setSize(width:Number, height:Number):Void

Sets the size in pixels of the player. This method should be used instead of setting the width and height properties of the MovieClip. Note that this method does not constrain the proportions of the video player, so you will need to maintain a 4:3 aspect ratio. The default size of the chromeless SWF when loaded into another SWF is 320px by 240px and the default size of the embedded player SWF is 480px by 385px.

Playback status

player.getVideoBytesLoaded():Number

Returns the number of bytes loaded for the current video.

player.getVideoBytesTotal():Number

Returns the size in bytes of the currently loaded/playing video.

player.getVideoStartBytes():Number

Returns the number of bytes the video file started loading from. Example scenario: the user seeks ahead to a point that hasn't loaded yet, and the player makes a new request to play a segment of the video that hasn't loaded yet.

player.getPlayerState():Number

Returns the state of the player. Possible values are unstarted (-1), ended (0), playing (1), paused (2), buffering (3), video cued (5).

player.getCurrentTime():Number

Returns the elapsed time in seconds since the video started playing.

Playback quality

player.getPlaybackQuality():String

This function retrieves the actual video quality of the current video. It returns undefined if there is no current video. Possible return values are hd720, large, medium and small.

player.setPlaybackQuality(suggestedQuality:String):Void

This function sets the suggested video quality for the current video. The function causes the video to reload at its current position in the new quality. If the playback quality does change, it will only change for the video being played.

Calling this function does not guarantee that the playback quality will actually change. If the playback quality does change, it will only change for the video being played. At that time, the onPlaybackQualityChange event will fire, and your code should respond to the event rather than the fact that it called the setPlaybackQuality function.

The suggestedQuality parameter value can be small, medium, large, hd720 or default. Setting the parameter value to default instructs YouTube to select the most appropriate playback quality, which will vary for different users, videos, systems and other playback conditions.

When you suggest a playback quality for a video, the suggested quality will only be in effect for that video. You should select a playback quality that corresponds to the size of your video player. For example, if your page displays a 640px by 360px video player, a medium quality video will actually look better than a large quality video. The following list shows recommended playback quality levels for different player sizes:

• Quality level small: Player resolution less than 640px by 360px.
• Quality level medium: Minimum player resolution of 640px by 360px.
• Quality level large: Minimum player resolution of 854px by 480px.
• Quality level hd720: Minimum player resolution of 1280px by 720px.
• Quality level default: YouTube selects the appropriate playback quality. This setting effectively reverts the quality level to the default state and nullifies any previous efforts to set playback quality using the cueVideoById, loadVideoById or setPlaybackQuality functions.

If you call the setPlaybackQuality function with a suggestedQuality level that is not available for the video, then the quality will be set to the next lowest level that is available. For example, if you request a quality level of large, and that is unavailable, then the playback quality will be set to medium (as long as that quality level is available).

In addition, setting suggestedQuality to a value that is not a recognized quality level is equivalent to setting suggestedQuality to default.

player.getAvailableQualityLevels():Array

This function returns the set of quality formats in which the current video is available. You could use this function to determine whether the video is available in a higher quality than the user is viewing, and your player could display a button or other element to let the user adjust the quality.

The function returns an array of strings ordered from highest to lowest quality. Possible array element values are hd720, large, medium and small. This function returns an empty array if there is no current video.

Your client should not automatically switch to use the highest (or lowest) quality video or to any unknown format name. YouTube could expand the list of quality levels to include formats that may not be appropriate in your player context. Similarly, YouTube could remove quality options that would be detrimental to the user experience. By ensuring that your client only switches to known, available formats, you can ensure that your client's performance will not be affected by either the introduction of new quality levels or the removal of quality levels that are not appropriate for your player context.

Retrieving video information

player.getDuration():Number

Returns the duration in seconds of the currently playing video. Note that getDuration() will return 0 until the video's metadata is loaded, which normally happens just after the video starts playing.

player.getVideoUrl():String

Returns the YouTube.com URL for the currently loaded/playing video.

player.getVideoEmbedCode():String

Returns the embed code for the currently loaded/playing video.

Adding an event listener

player.addEventListener(event:String, listener):Void

Adds a listener function for the specified event. The listener is a string of a function name if you are using the JavaScript API and is a reference to a function if you are using the ActionScript API.

Special Functions

The ActionScript specific API calls are listed below:

player.destroy():Void

This function, which has not yet been implemented for the AS3 Player API, destroys the player instance. This method should be called before unloading the player SWF from your parent SWF.

Important: You should always call player.destroy() to unload a YouTube player. This function will close the NetStream object and stop additional videos from downloading after the player has been unloaded. If your code contains additional references to the player SWF, you also need to destroy those references separately when you unload the player.

Events

onStateChange

This event is fired whenever the player's state changes. Possible values are unstarted (-1), ended (0), playing (1), paused (2), buffering (3), video cued (5). When the SWF is first loaded it will broadcast an unstarted (-1) event. When the video is cued and ready to play it will broadcast a video cued event (5).

onPlaybackQualityChange

This event is fired whenever the video playback quality changes. For example, if you call the setPlaybackQuality(suggestedQuality) function, this event will fire if the playback quality actually changes. Your code should respond to the event and should not assume that the quality will automatically change when the setPlaybackQuality(suggestedQuality) function is called. Similarly, your code should not assume that playback quality will only change as a result of an explicit call to setPlaybackQuality or any other function that allows you to set a suggested playback quality.

The value that the event broadcasts is the new playback quality. Possible values are "small", "medium", "large" and "hd720".

onError

This event is fired when an error in the player occurs. The possible error codes are 100, 101, and 150. The 100 error code is broadcast when the video requested is not found. This occurs when a video has been removed (for any reason), or it has been marked as private. The 101 error code is broadcast when the video requested does not allow playback in the embedded players. The error code 150 is the same as 101, it's just 101 in disguise!

Examples

Loading the player SWF

The AS3 API uses a different initialization sequence than the AS2 player. Whereas the AS2 player uses the isPlayerLoaded() function to determine when the player is loaded, initialized and ready to receive API calls, the AS3 player uses a more robust event system. The sample code below demonstrates how to load and initialize the AS3 API player:

// This will hold the API player instance once it is initialized.
var player:Object;

var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.INIT, onLoaderInit);
loader.load(new URLRequest("http://www.youtube.com/apiplayer?version=3"));

function onLoaderInit(event:Event):void {
    addChild(loader);
    loader.content.addEventListener("onReady", onPlayerReady);
    loader.content.addEventListener("onError", onPlayerError);
    loader.content.addEventListener("onStateChange", onPlayerStateChange);
    loader.content.addEventListener("onPlaybackQualityChange", 
        onVideoPlaybackQualityChange);
}

function onPlayerReady(event:Event):void {
    // Event.data contains the event parameter, which is the Player API ID 
    trace("player ready:", Object(event).data);

    // Once this event has been dispatched by the player, we can use
    // cueVideoById, loadVideoById, cueVideoByUrl and loadVideoByUrl
    // to load a particular YouTube video.
    player = loader.content;
}

function onPlayerError(event:Event):void {
    // Event.data contains the event parameter, which is the error code
    trace("player error:", Object(event).data);
}

function onPlayerStateChange(event:Event):void {
    // Event.data contains the event parameter, which is the new player state
    trace("player state:", Object(event).data);
}

function onVideoPlaybackQualityChange(event:Event):void {
    // Event.data contains the event parameter, which is the new video quality
    trace("video quality:", Object(event).data);
}

Determining the state of a quality toggle button

The sample code below demonstrates how YouTube determines the status of its quality toggle button, which lets users select a different playback quality based on available quality levels for a video.

var qualityLevels:Array = getAvailableQualityLevels()
// qualityLevels may be undefined if the API function does not exist, 
// in which case this conditional is false
if (qualityLevels.length > 1) {

    var highestQuality:String = qualityLevels[0]
    if (highestQuality begins with "hd") {
        // Brand quality toggle button as HD.
    } else {
        // Brand quality toggle button as HQ.
        // The highest available quality is shown, but it is not HD video.
    }

    var quality:String = getPlaybackQuality();
    if (quality == 'small' || quality == 'medium') {
        // The user is not watching the highest quality available 
        // can can toggle to a higher quality.
    } else {
        // The user is watching the highest quality available 
        // and can toggle to a lower quality.
    }

} else {
    // Hide the toggle button because there is no current video or
    // there is only one quality available.
}

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