Sound.loadCompressedDataFromByteArray

前不久Adobe发布了Flash Player 11的release版本, Flash Player 11 带来了很多新特性, 最最红火的就是Stage3D了,但是这里讲的是这个版本的另一个新特性, 直接播放MP3数据 Sound.loadCompressedDataFromByteArray.
以往我们要播放一个mp3,必须要有一个路径才能播放, 每次想要将声音文件缓存起来,就不方便.现在Flash 提供了直接播放bytearray的API,那么就方便多了。

Sound.loadCompressedDataFromByteArray带来的便利

• 直接播放bytearray,而不再需要url地址.
• 可以方便的播放音频片段,而不必加载完整的mp3文件.
• 结合URLStream类,可以方便的实现边听边存功能.
• 可以对保存的音乐进行加密,从而保护版权. 目前只想到以上几点,不过结合这个API肯定能做更多的事。

使用FlahsPlayer11的新特性注意事项

一定要在编译器选项里添加 -swf-version=13 . 否则会运行时报错,找不到相关的API。
在FlashDevelop里设置：
Project菜单 => Properties..子菜单, 打开 Properties面板。
Compiler Options选项卡 => Additional Compiler Options。
输入 -swf-version=13 ， 一路确定着出来就行了。

FlashDevelop里设置Flashplayer11编译器选项

在FlashBuilder里设置：
Project菜单 => Properties..子菜单, 打开 Properties面板。
Flex编译器选项 => 附加的编译器参数。
添加 -swf-version=13 ，一路确定着出来就行了。

FlashBuilder里设置Flashplayer11编译器选项

示例

请确保声卡驱动已经安装好，并且能播放声音。

源代码

package
{
    import fl.controls.TextInput;
    import fl.events.ComponentEvent;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.IOErrorEvent;
    import flash.events.ProgressEvent;
    import flash.events.SecurityErrorEvent;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.net.URLRequest;
    import flash.net.URLStream;
    import flash.text.TextField;
    import flash.utils.ByteArray;
    import flash.utils.setTimeout;

    /**
     * Sound.loadCompressedDataFromByteArray
     * @author lite3
     * @link http://www.litefeel.com
     */
    [SWF(width = 600, height = 170)]
    public class Main extends Sprite
    {
        private const SOUND_URL:String = "http://www.sqcbbs.net/data/attachment/forum/music/suyan.mp3";

        private var sound:Sound;
        private var stream:URLStream;

        private var isPlaying:Boolean;
        private var sc:SoundChannel;

        private var txt:TextField;
        private var input:TextInput;

        public function Main():void
        {
            initUI();

            sound = new Sound();
            stream = new URLStream();
            stream.addEventListener(Event.COMPLETE, streamHandler);
            stream.addEventListener(ProgressEvent.PROGRESS, streamHandler);
            stream.addEventListener(IOErrorEvent.IO_ERROR, streamHandler);
            stream.addEventListener(SecurityErrorEvent.SECURITY_ERROR, streamHandler);

            var url:String = loaderInfo.parameters.soundURL ? loaderInfo.parameters.soundURL : SOUND_URL;
            input.text = url;
            loadSound(null);
            input.addEventListener(ComponentEvent.ENTER, loadSound);
        }

        private function loadSound(e:ComponentEvent):void
        {
            if (!input.text) return;

            if (sc != null)
            {
                sc.removeEventListener(Event.SOUND_COMPLETE, soundCompleteHandler);
                sc.stop();
                sc = null;
            }
            try {
                stream.close();
            }catch (e:Error) { }

            stream.load(new URLRequest(input.text));
            showText("开始加载");
        }

        private function streamHandler(e:Event):void
        {
            switch(e.type)
            {
                case Event.COMPLETE :
                    showText("加载完成,播放中...");
                    var byte:ByteArray = new ByteArray();
                    stream.readBytes(byte, 4000, stream.bytesAvailable/10);
                    sound.loadCompressedDataFromByteArray(byte, byte.length/2);
                    playSound();
                    break;

                case ProgressEvent.PROGRESS :
                    showText("加载进度:" + ProgressEvent(e).bytesLoaded + "/" + ProgressEvent(e).bytesTotal);
                    break;

                case IOErrorEvent.IO_ERROR :
                    showText("加载失败");
                    break;

                case SecurityErrorEvent.SECURITY_ERROR :
                    showText("安全沙箱限制,不能从目标网站加载数据");
                    break;
            }
        }

        private function playSound():void
        {
            isPlaying = true;
            showText("isPlaying: " +isPlaying);

            sc = sound.play();
            sc.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler);
        }

        private function soundCompleteHandler(e:Event):void
        {
            isPlaying = false;
            showText("isPlaying: " +isPlaying);
            setTimeout(playSound, 1000);
        }

        private function showText(text:String):void
        {
            txt.text = text;
        }

        private function initUI():void
        {
            txt = new TextField();
            txt.mouseEnabled = false;
            txt.text = "Sound.loadCompressedDataFromByteArray For Flash Player 11";
            txt.width = 600;
            txt.height = txt.textHeight + 4;
            txt.mouseEnabled = false;
            txt.autoSize = "center";
            txt.y = 10;
            addChild(txt);

            txt = new TextField();
            txt.text = "请输入MP3地址并回车,以更换MP3.";
            txt.mouseEnabled = false;
            txt.width = txt.textWidth + 4;
            txt.height = txt.textHeight + 4;
            txt.x = 10;
            txt.y = 100;
            addChild(txt);

            input = new TextInput();
            input.width = 550;
            input.x = 10;
            input.y = 120;
            addChild(input);

            txt = new TextField();
            txt.mouseEnabled = false;
            txt.width = 300;
            txt.height = 40;
            txt.x = 100;
            txt.y = 50;
            addChild(txt);
        }
    }
}