Flash/Flex学习笔记(24)：摄像头/麦克风的视频/音量指示器
在一些实时视频或视频分享应用中，需要动态显示麦克风的音量大小，或者检测视频是不是正在播放，这里演示一种简单的音量指示器
1.先写一个指示器类
其实就是一个根据百分比来填充的矩形
?package {
?import flash.display.Sprite;
//音量指示器(by 菩提树下的杨过 http://yjmyzz.cnblogs.com/)
?public class Indicator extends Sprite {
private var _w:uint;
?private var _h:uint;
?private var _bColor:uint;
?private var _bgColor:uint;
?private var _fColor:uint;
?private var _current:Number;
?public function Indicator(w:uint=150,h:uint=15,borderColor:uint=0x000000,bgColor:uint=0xffffff,fillColor:uint=0xff6600,current:Number=0.3):void {
//trace("Indicator");
?this._w=w;
?this._h=h;
?this._bColor=borderColor;
?this._bgColor=bgColor;
this._fColor=fillColor;
?this._current=current;
?if (_current>=1) {
?_current=1;
} else if (_current<=0) {
?_current=0;
?}
?init();??}
?
public function set Current(v:Number):void {
_current=v;
?if (_current>=1) {
?_current=1;
} else if (_current<=0) {
?_current=0;
?}???????????
?init();
}
?public function get Current():Number {
?return (_current);
}
private function init():void {
?graphics.clear();
?graphics.lineStyle(1,_bColor);
//先画背景色
?graphics.beginFill(_bgColor);
?graphics.drawRect(-1*_w/2,-1*_h/2,_w,_h);
?graphics.endFill();
?//再画当前值
?graphics.lineStyle(1,_bColor,0);
graphics.beginFill(_fColor);
var _per:Number=_w*_current;
graphics.drawRect(-1*_w/2 +0.5 ,-1*_h/2 +0.5,_per,_h-1);
?graphics.endFill();
}
?}
?}
2.如何获取音量大小以及监测摄像头直播状态
音量大小可以通过activityLevel属性获得，但摄像头的画面变化程度却无法直接获取，但每当摄像头画面有活动时ACTIVITY事件将被触发，所以可在该事件中监测最后一次活动的时间与当前时间做比较，从而判断画面有多久没有变化了。
?var videoInd:Indicator=new Indicator(100,10,0x000000,0xffffff);
?var audioInd:Indicator=new Indicator(100,10,0x000000,0xffffff);
?addChild(videoInd);
addChild(audioInd);
?//初始化视频/音频指示器位置
?videoInd.x=stage.stageWidth/2 + 30;
?videoInd.y=-100;
?audioInd.x=stage.stageWidth/2 + 30;
?audioInd.y=-100;
?txtMsg.y = stage.stageHeight/2 - txtMsg.height/2;
?txtMsg.width = stage.stageWidth;
var cam:Camera;
?var mic:Microphone;
?var video:Video;
?var videoIsWorked=false;
?var lastVideoActiveData:Date = new Date();
?var timer:Timer = new Timer(100,20);//每隔100ms检测摄像头状态，一共检测20次
?function startCheckVideo() {
?cam=Camera.getCamera();
?if (cam==null) {
?txtMsg.text="未安装摄像头!";
?return;
?}
?cam.addEventListener(StatusEvent.STATUS, statusHandler);????
?cam.addEventListener(ActivityEvent.ACTIVITY,camActivityHandler);
?video=new Video(cam.width,cam.height);
3 //trace("视频宽度：" + cam.width + "，视频高度：" + cam.height);
?video.height = 120;
?video.width = 160;
?video.x=stage.stageWidth/2-video.width/2;
?video.y=10;
video.attachCamera(cam);//执行这句时，flash才会弹出摄像头是否允许使用提示框???
?}
?//摄像头有活动时，被触发
?function camActivityHandler(e:ActivityEvent) {??
?//trace("camActivityHandler：" + new Date().toString());
?if (!videoIsWorked) {???????????
?timer.addEventListener(TimerEvent.TIMER,TimerHandler);
?timer.addEventListener(TimerEvent.TIMER_COMPLETE,timerCompleteHandler);
?timer.start();??????
?}???
lastVideoActiveData = new Date();//记录本次视频活动时间???
?}
?//回调函数
?function TimerHandler(e:TimerEvent):void {??
?txtMsg.text="摄像头视频获取中..." ;
?if (cam.currentFPS>0) {??????
?timer.stop();???????????
?addChild(video);//加载到当前舞台中??
?videoInd.y=video.y+video.height+10;
?audioInd.y=videoInd.y + videoInd.height + 10;
?txtVideo.text = "视频状态："
?txtVideo.y = videoInd.y - 8
?txtVideo.x = videoInd.x - videoInd.width -20 ;?????
?txtAudio.text = "音频状态："
?txtAudio.y = audioInd.y - 8
?txtAudio.x = audioInd.x - audioInd.width -20 ;
?if (txtMsg!=null) {
?removeChild(txtMsg);
?}
?videoIsWorked=true; //摄像头工作正常???????
?this.addEventListener(Event.ENTER_FRAME,EnterFrameHandler);?????
?}???
}
function timerCompleteHandler(e:TimerEvent):void{
?txtMsg.text="设备无法使用(有可能被占用)";???????????????
}
//用户选择"同意"或"不允许"使用摄像头时触发
?function statusHandler(e:StatusEvent) {?
?if (e.code=="Camera.Muted") {
txtMsg.text="您不允许使用摄像头!";
?} else if (e.code == "Camera.Unmuted") {
?txtMsg.text="摄像头视频获取中...";
?camActivityHandler(null);//重要：在release模式下，webCam的Activity事件不会自动触发(Adobe的bug?)，所以要显式手动调用一次
}
?}
?//开始检测麦克风
?function startCheckAudio():void{
?mic = Microphone.getMicrophone();
?mic.setLoopBack(true);//将采集到的声音回发到扬声器（否则自己听不到自己的声音，不方便测试）
?}
function EnterFrameHandler(e:Event):void{???
var curDate:Date = new Date();??
var _timeSpan:Number = curDate.time - lastVideoActiveData.time;?
?if (_timeSpan >= 30 * 1000){
?trace("您的视频已经超过30秒没动静了!");
?videoInd.Current = 0;
?} else{
?videoInd.Current = Math.random() * 0.1;//视频指示器
}???
?if (mic!=null){
audioInd.Current = 0.05 + mic.activityLevel/100;//音量指示器?????
?}
?}
?txtMsg.text="正在检测摄像头...";
?startCheckVideo();
?startCheckAudio();
