Mp3播放器频谱——官方帮助文档

import flash.display.Sprite;
import flash.display.Graphics;
import flash.events.Event;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.media.SoundMixer;
import flash.net.URLRequest;
import flash.utils.ByteArray;
import flash.text.TextField;


SoundMixer_computeSpectrumExample();

function SoundMixer_computeSpectrumExample() {
	var snd:Sound = new Sound();
	var req:URLRequest=new URLRequest("喜剧之王.mp3");
	snd.load(req);

	var channel:SoundChannel;
	channel=snd.play();
	addEventListener(Event.ENTER_FRAME, onEnterFrame);
	channel.addEventListener(Event.SOUND_COMPLETE, onPlaybackComplete);
}

function onEnterFrame(event:Event):void {
	var bytes:ByteArray = new ByteArray();
	const PLOT_HEIGHT:int=200;
	const CHANNEL_LENGTH:int=256;

	SoundMixer.computeSpectrum(bytes, false, 0);

	var g:Graphics=this.graphics;

	g.clear();

	g.lineStyle(0, 0x6600CC);
	g.beginFill(0x6600CC);
	g.moveTo(0, PLOT_HEIGHT);

	var n:Number=0;

	for (var i:int = 0; i < CHANNEL_LENGTH; i++) {
		n = (bytes.readFloat() * PLOT_HEIGHT);
		g.lineTo(i * 2, PLOT_HEIGHT - n);
	}

	g.lineTo(CHANNEL_LENGTH * 2, PLOT_HEIGHT);
	g.endFill();

	g.lineStyle(0, 0xCC0066);
	g.beginFill(0xCC0066, 0.5);
	g.moveTo(CHANNEL_LENGTH * 2, PLOT_HEIGHT);

	for (i = CHANNEL_LENGTH; i > 0; i--) {
		n = (bytes.readFloat() * PLOT_HEIGHT);
		g.lineTo(i * 2, PLOT_HEIGHT - n);
	}

	g.lineTo(0, PLOT_HEIGHT);
	g.endFill();
}

function onPlaybackComplete(event:Event):void {
	removeEventListener(Event.ENTER_FRAME, onEnterFrame);
}