netstream.publish仅保存网络摄像头视频5秒+ flex 4.6和AMS

Question

我是felx和FMS（AMS）的新手。我想在用户允许访问该程序并将其保存在Flash Media Server上后录制网络摄像头视频。这是我正在使用的代码：

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx"
               minWidth="955" minHeight="600">
    <fx:Script>
        <![CDATA[

            import mx.controls.Alert;
            import mx.events.FlexEvent;

            private var camLive:Camera = Camera.getCamera();
            private var nc:NetConnection;
            private var ns:NetStream; 

        protected function video_d_creationCompleteHandler(event:FlexEvent):void
            {   
                if (camLive) {                  
                    nc=new NetConnection();
                    nc.connect("rtmp://00.00.0000.000/test");
                    nc.addEventListener(NetStatusEvent.NET_STATUS, netStatusHandler);

                } else {
                    Alert.show("You don't seem to have a camera.");
                }
            }

            private  function netStatusHandler(event:NetStatusEvent):void {
                var code:String = event.info.code;  
                    if (code == "NetConnection.Connect.Success") {                      
                        ns=new NetStream(nc);
                        ns.attachCamera(camLive);                       
                        ns.publish("foobar", "record");                     
                    }
                    else{    
                        trace(code);   
                    }  
            }

        ]]>
    </fx:Script>

    <s:Panel title="Video">
        <s:VideoDisplay id="vDisplay" width="400" height="300"
                        creationComplete="video_d_creationCompleteHandler(event)"/>
    </s:Panel>  
</s:Application>

有两个问题： 1）我无法在vDisplay中看到我的网络摄像头视图，基本上vDispaly是一个空白帧。我该怎么解决？ 2）它只能以FLV格式在FMS上保存5秒的网络摄像头视频。我想将记录时间增加到至少20分钟。

任何提示都表示赞赏。