Silverlight+WCF 實戰-網絡象棋最終篇之對戰視頻-下篇[客戶端發送與服務端中轉](六)...

我們發送的視頻，是通過定時器每秒截5張圖發送過去的，每秒鐘將產生5張圖片，因此，圖片壓縮變的相當重要。

因此，找一種圖片壓縮算法，是一種開始：

一開始：是從網上down了個PngEncoder，壓縮160*160的截圖後，圖片大小是40K，看成是4K[因爲看字節時是4後面好多0,看少了一個0]，興奮的我~~~

因此一開始在本地測試是正常的，上到網上就oh..no了。

40K*5，即每秒要發送200K的數據，這樣就等於把2M/200K帶寬給用光了，房東那限制的512K/56K帶寬，就更提不上了~~~

最後：還是用上了大夥普通通用的JpgEncoder，壓縮160*160的截圖後，圖片大小是10K，每秒產生10K*5=50K，56K帶寬剛好夠用了。

1：JpgEncoder下載後內容爲：FJ.Core.dll、JpgEncoder.cs兩個文件。

2：JpgEncoder.cs有一靜態方法，直接可以獲取Stream流：

 public static Stream GetStream(WriteableBitmap bitmap)

3：沒了~~~

ps:具體FJ.Core.dll、JpgEncoder.cs兩個文件可以從下載源碼下找到。

        System.Windows.Threading.DispatcherTimer timer; // 全局定義
          public  MainPage()
        {
            InitializeComponent();
            timer  =   new  System.Windows.Threading.DispatcherTimer();
            timer.Interval  =  TimeSpan.FromSeconds( 0.2 ); // 0.2秒一次，每秒5次
            timer.Tick  +=   new  EventHandler(timer_Tick);          
        }
         void  timer_Tick( object  sender, EventArgs e)
        {
            // 這裏就是發送視頻的代碼了
        }
         private   void  btnSend_Click( object  sender, RoutedEventArgs e)
        {
            timer.Start(); // 點擊發送視頻時，啓動定時器即可
        }

         byte [] content  =   new   byte [ 56   *   1024 ];
         int  length;       
         void  timer_Tick( object  sender, EventArgs e)
        {
            WriteableBitmap img  =   new  WriteableBitmap(canVideo,  null );
            Stream stream  =  JpgEncoder.GetStream(img);  // 獲取壓縮後的流
            length  =  ( int )stream.Length;
            stream.Read(content,  0 , length);
            stream.Close();

            SocketAsyncEventArgs sendEvent  =   new  SocketAsyncEventArgs();
            sendEvent.SetBuffer(content,  0 , length);
            videoSocket.SendAsync(sendEvent); // 這裏只管發送，發送後的結果不管了。
           
            img  =   null ;
        }

namespace  TCPService
{
     class  Program
    {
         public   static  Dictionary < int , ThreadProxy >  soketList; // 房號+顏色值
          static   void  Main( string [] args)
        {
            PolicyServer ps  =   new  PolicyServer(SocketPolicy.Policy); // Silverlight跨域訪問及943端口
             // 主線程監聽
            soketList  =   new  Dictionary < int , ThreadProxy > ();
            Console.WriteLine( " TCPService正在啓動運行 " );
            IPEndPoint ip  =   new  IPEndPoint(IPAddress.Any,  4505 ); // 本地任意IP及4505端口
            Socket mainSocket  =   new  Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            mainSocket.Bind(ip);
            mainSocket.Listen( - 1 );
             while  ( true )
            {
                Socket socket  =  mainSocket.Accept();
                 new  ThreadProxy(socket).Run(); // 收到消息即時處理。

            }
        }
         public   static   void  WriteLine( string  msg)
        {
            Console.WriteLine(msg);
        }
    }
     class  ThreadProxy
    {
         public  Socket socket;
         public  ThreadProxy(Socket newSocket)
        {
            socket  =  newSocket;
        }
         public   void  Run()
        {
            Thread thread  =   new  Thread( new  ThreadStart(Action));
            thread.Start();
        }
         public   void  Action()
        {
            Program.WriteLine( " 有人來了---- " );
             // 下面開啓處理邏輯
        }
   }
}

         public  Socket socket; // 我方的Socket
        ThreadProxy youThreadProxy; // 對方

        int num;//註冊的編號

         byte [] buffer  =   new   byte [ 30   *   1024 ]; // 緩衝字節30K，簡單說就是用戶10K發送3次，這裏收到滿30K才轉發一次
         bool  firstConn  =   true ; // 是否第一次建立鏈接，首次鏈接都是註冊編號，不發送視頻的；

         private   void  RegSocket( string  key)
        {
            firstConn  =   false ; // 註冊完後，設置下標識
             if  (key.Length  <   10 ) // 字節太多就是圖片流了
            {
                 if  ( int .TryParse(key,  out  num))
                {
                     if  (Program.soketList.ContainsKey(num)) // 之前都有人在了
                       {
                        Program.soketList[num].socket.Close();
                        Program.soketList[num].socket.Dispose();
                        Program.soketList.Remove(num);
                    }
                    Program.soketList.Add(num,  this );
                    Program.WriteLine( " 用戶註冊: "   +  key);
                    FindYouSocket();
                     return ;
                }
            }
        }

        private   void  OnError(ThreadProxy errorProxy, string  errorMsg)
        {
             if  (errorProxy.socket  !=   null )
            {
                errorProxy.socket.Close();
            }
            Console.WriteLine( " 刪除用戶: "   +  errorProxy.num  + " 錯誤信息: " +  errorMsg);
            Program.soketList.Remove(errorProxy.num);
            
        }

        private   void  FindYouSocket()
       {
             int  youNum  =  num  %   2   ==   0   ?  num  -   1  : num  +   1 ;
             if  (Program.soketList.ContainsKey(youNum))
            {
                youThreadProxy  =  Program.soketList[youNum];
            }
         }

        public  ThreadProxy(Socket newSocket)
        {
            socket  =  newSocket;
            socket.SendBufferSize  =  buffer.Length;
            socket.ReceiveBufferSize  =  buffer.Length;
        }
         public   void  Run()
        {
            Thread thread  =   new  Thread( new  ThreadStart(Action));
            thread.Start();
        }
         public   void  Action()
        {
            Program.WriteLine( " 有人來了---- " );
             try
            {
                 while  ( true )
                {
                     if  (socket.Connected)
                    {
                         int  length  =   0 , count  =   0 ;
                         do
                        {
                            System.Threading.Thread.Sleep( 20 ); // 關鍵點,請求太快數據接收不全
                            length  =  socket.Receive(buffer, count, socket.Available,  0 );
                            count  =  count  +  length;

                        }
                         while  (socket.Available  >   0 );

                         if  (count  >   1 )
                        {

                             if  (count  <   4 ) // 小字節，命令字符
                            {
                                 if  (firstConn) // 首次登陸，需要註冊ID
                                {
                                     string  key  =  ASCIIEncoding.ASCII.GetString(buffer,  0 , count);
                                    RegSocket(key);
                                }
                            }
                             else   if  (youThreadProxy  ==   null )
                            {
                                Program.WriteLine( " 沒人接收。。。 " );
                                FindYouSocket();
                            }
                             else   if  (youThreadProxy.canReceive) // 對方允許接收圖片發送
                                {
                                Program.WriteLine( " 圖片來了: "   +  count);
                                 if  (youThreadProxy.socket.Connected)
                                {
                                    Program.WriteLine( " 圖片轉發: "   +  buffer.Length);
                                     try
                                    {
                                        youThreadProxy.socket.Send(buffer, count,  0 );
                                    }
                                     catch (Exception err)
                                    {
                                        OnError(youThreadProxy, err.Message);
                                    }
                                }
                            }
                        }
                    }
                     else
                    {
                        OnError( this , " socket鏈接已關閉 " );
                         break ;
                    }
                }
            }
             catch (Exception err)
            {
                OnError( this ,err.Message);
            }

        }