manewcActionscript Snippets

Sound.length -> Measuring the time length of a sound object

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For one of my projects I encountered an issue where I was unable to retrieve how long my sound object was. I needed to know how long the song that was loaded was in order to display a playing progress bar. I found out that because of the way I was instantiating my variables, this was causing an issue with the sound object. Here is a bit of code to exemplify finding the length of a externally loaded .mp3 file:

package
{
	import flash.display.Sprite;
	import flash.net.URLLoader;
	import flash.net.URLRequest;
	import flash.text.TextField;
	import flash.text.TextFieldAutoSize;
	import flash.text.TextFieldType;
	import flash.text.TextFormat;
	import flash.media.Sound;
	import flash.media.SoundChannel;
	import flash.events.Event;

	public class MP3Player extends Sprite
	{
		private var s:Sound;
		private var channel:SoundChannel;
		private var loadTime:Number;
		private var loadPercent:uint;
		private var playLoadTime:Number;
		private var playbackPercent:uint;
		private var output:TextField;

		public function MP3Player()
		{
			Output();
			playSong();
		}

		public function playSong():void
		{
			// create a new sound
			s = new Sound();
			// load the mp3
			s.load(new URLRequest("/path/to/mp3/file/*.mp3"));
			// play the music
			channel = s.play();

			addEventListener(Event.ENTER_FRAME, SoundPlayingHandler);
		}

		private function SoundPlayingHandler(e:Event):void
		{
			var totalBytes = s.bytesTotal;
			loadTime = s.bytesLoaded / totalBytes;
            loadPercent = Math.round(loadTime * 100);

			var playLoadTime:Number = s.bytesLoaded / s.bytesTotal;
			var estimatedLength:int = Math.ceil(s.length / (playLoadTime));
			var playbackPercent:uint = Math.round(100 * (channel.position / estimatedLength));

			output.text = "Length of Song: " + (Math.round(((estimatedLength / 1000) / 60) * 100) / 100) + "\nPlaying " +  playbackPercent + "%\nLoading " + loadPercent + "%";
		}

		// UI elements
		public function Output():void
		{
			// Small Black Text Formatting
			var smallBlackFormat:TextFormat = new TextFormat();
			smallBlackFormat.font = "Arial";
			smallBlackFormat.color = 0x000000;
            smallBlackFormat.size = 10;
            smallBlackFormat.underline = false;

        	// output TextField
        	output = new TextField();
			output.defaultTextFormat = smallBlackFormat;
        	addChild(output);
        	output.width = 700;
            output.height = 200;
			output.x = 0;
        	output.y = 0;
            output.multiline = true;
            output.wordWrap = true;
            output.border = true;
            output.background = true;
			output.text = "DEBUGGING:\n";
        }

	}
}

Friday, May 2nd, 2008 at 8:28 am and is filed under Actionscript 3, Audio. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.