diff --git a/JianGongYun/TRTC/LiveClassroom.cs b/JianGongYun/TRTC/LiveClassroom.cs
index 0fbb45c..a37b75b 100644
--- a/JianGongYun/TRTC/LiveClassroom.cs
+++ b/JianGongYun/TRTC/LiveClassroom.cs
@@ -18,6 +18,7 @@ using System.Collections.Concurrent;
 using System.Windows.Data;
 using System.Drawing;
 using System.Diagnostics;
+using System.Runtime.InteropServices;
 
 namespace JianGongYun.TRTC
 {
@@ -50,11 +51,11 @@ namespace JianGongYun.TRTC
         /// <summary>
         /// 摄像头帧
         /// </summary>
-        public static VideoFrameEntity MainFrame = new VideoFrameEntity();
+        public static Mat MainFrame = new Mat();
         /// <summary>
         /// 屏幕帧
         /// </summary>
-        public static VideoFrameEntity SubFrame = new VideoFrameEntity();
+        public static Mat SubFrame = new Mat();
         /// <summary>
         /// 背景帧
         /// </summary>
@@ -171,10 +172,8 @@ namespace JianGongYun.TRTC
                         //sw.Restart();
                         lock (MainFrame)
                         {
-                            MainFrame.Width = w;
-                            MainFrame.Height = h;
-                            MainFrame.Data = new byte[data.Length];
-                            Buffer.BlockCopy(data, 0, MainFrame.Data, 0, data.Length);
+                            MainFrame.Create(h, w, MatType.CV_8UC4);
+                            Marshal.Copy(data, 0, MainFrame.Data, data.Length);
                         }
                         //sw.Stop();
                         //Debug.Print("main" + sw.ElapsedMilliseconds.ToString());
@@ -215,20 +214,18 @@ namespace JianGongYun.TRTC
                 var view = AddCustomVideoView(parent, CurrentClassroomEntity.TeacherId, TRTCVideoStreamType.TRTCVideoStreamTypeSub, true);
                 if (liveWinMode.IsLive)
                 {
-                    //Stopwatch sw = new Stopwatch();
+                    Stopwatch sw = new Stopwatch();
                     //VideoRecordTask(view, TRTCVideoStreamType.TRTCVideoStreamTypeSub);
                     view.OnRenderVideoFrameHandler += (data, w, h) =>
                     {
-                        //sw.Restart();
+                        sw.Restart();
                         lock (SubFrame)
                         {
-                            SubFrame.Width = w;
-                            SubFrame.Height = h;
-                            SubFrame.Data = new byte[data.Length];
-                            Buffer.BlockCopy(data, 0, SubFrame.Data, 0, data.Length);
+                            SubFrame.Create(h, w, MatType.CV_8UC4);
+                            Marshal.Copy(data, 0, SubFrame.Data, data.Length);
                         }
-                        //sw.Stop();
-                        //Debug.Print("sub" + sw.ElapsedMilliseconds.ToString());
+                        sw.Stop();
+                        Debug.Print("sub" + sw.ElapsedMilliseconds.ToString());
                     };
                 }
                 return view;
diff --git a/JianGongYun/TRTC/Models/VideoFrameEntity.cs b/JianGongYun/TRTC/Models/VideoFrameEntity.cs
deleted file mode 100644
index 8d031e2..0000000
--- a/JianGongYun/TRTC/Models/VideoFrameEntity.cs
+++ /dev/null
@@ -1,15 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace JianGongYun.TRTC.Models
-{
-    public class VideoFrameEntity
-    {
-        public byte[] Data { get; set; } = null;
-        public int Width { get; set; } = 0;
-        public int Height { get; set; } = 0;
-
-
-    }
-}
diff --git a/JianGongYun/TRTC/ViewModels/LiveWindowViewModel.cs b/JianGongYun/TRTC/ViewModels/LiveWindowViewModel.cs
index 0a4c399..d00f300 100644
--- a/JianGongYun/TRTC/ViewModels/LiveWindowViewModel.cs
+++ b/JianGongYun/TRTC/ViewModels/LiveWindowViewModel.cs
@@ -10,6 +10,8 @@ using System.Linq;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using System.Windows.Threading;
+using System.Windows;
+using System.Windows.Controls;
 
 namespace JianGongYun.TRTC.ViewModels
 {
@@ -130,6 +132,8 @@ namespace JianGongYun.TRTC.ViewModels
                 if (PropertyChanged != null)
                 {
                     PropertyChanged(this, new PropertyChangedEventArgs("CameraRunning"));
+                    PropertyChanged(this, new PropertyChangedEventArgs("MainSmallWrapStyle"));
+                    PropertyChanged(this, new PropertyChangedEventArgs("MainBigWrapStyle"));
                 }
             }
             get
@@ -150,6 +154,8 @@ namespace JianGongYun.TRTC.ViewModels
                 if (PropertyChanged != null)
                 {
                     PropertyChanged(this, new PropertyChangedEventArgs("ScreenRunning"));
+                    PropertyChanged(this, new PropertyChangedEventArgs("MainSmallWrapStyle"));
+                    PropertyChanged(this, new PropertyChangedEventArgs("MainBigWrapStyle"));
                 }
             }
             get
@@ -305,5 +311,37 @@ namespace JianGongYun.TRTC.ViewModels
             }
         }
 
+        #region 只有摄像头，则画面放大并居中
+        public Style MainBigWrapStyle
+        {
+            get
+            {
+                var style = new Style(typeof(Grid));
+                if (CameraRunning && ScreenRunning)
+                {
+                    style.Setters.Add(new Setter { Property = FrameworkElement.HorizontalAlignmentProperty, Value = HorizontalAlignment.Right });
+                }
+                return style;
+            }
+        }
+        public Style MainSmallWrapStyle
+        {
+            get
+            {
+                var style = new Style(typeof(Border));
+                if (CameraRunning &&ScreenRunning)
+                {
+                    style.Setters.Add(new Setter { Property = FrameworkElement.HorizontalAlignmentProperty, Value = HorizontalAlignment.Right });
+                    style.Setters.Add(new Setter { Property = FrameworkElement.VerticalAlignmentProperty, Value = VerticalAlignment.Bottom });
+                    style.Setters.Add(new Setter { Property = Border.BorderThicknessProperty, Value = new Thickness(1) });
+                    style.Setters.Add(new Setter { Property = Border.MarginProperty, Value = new Thickness(0, 0, 20, 20) });
+                    style.Setters.Add(new Setter { Property = Border.WidthProperty, Value = 150d });
+                    style.Setters.Add(new Setter { Property = Border.HeightProperty, Value = 150d });
+                }
+                return style;
+            }
+        }
+        #endregion
+
     }
 }
diff --git a/JianGongYun/TRTC/Windows/LiveWindow.xaml b/JianGongYun/TRTC/Windows/LiveWindow.xaml
index 77e129d..a2f59df 100644
--- a/JianGongYun/TRTC/Windows/LiveWindow.xaml
+++ b/JianGongYun/TRTC/Windows/LiveWindow.xaml
@@ -170,9 +170,13 @@
                         <!--屏幕预览容器-->
                         <Grid x:Name="AfterLiveSubViewWrap" Width="{Binding ElementName=AfterLivePanel,Path=ActualWidth}" Height="{Binding ElementName=AfterLivePanel,Path=ActualHeight}" Canvas.Top="0" Canvas.Left="0"></Grid>
                         <!--摄像头预览容器-->
-                        <Border Visibility="{Binding CameraRunning, Converter={StaticResource VisibilityOfBool}}" Width="150" Height="150" BorderThickness="1" BorderBrush="#efefef" Canvas.Bottom="20" Canvas.Right="20">
-                            <Grid x:Name="AfterLiveViewWrap"></Grid>
-                        </Border>
+                        <Grid Width="{Binding ElementName=AfterLivePanel,Path=ActualWidth}" Height="{Binding ElementName=AfterLivePanel,Path=ActualHeight}" Canvas.Top="0" Canvas.Left="0">
+                            <Grid Style="{Binding MainBigWrapStyle}" Width="{Binding ElementName=AfterLivePanel,Path=ActualHeight}">
+                                <Border Style="{Binding MainSmallWrapStyle}" Visibility="{Binding CameraRunning, Converter={StaticResource VisibilityOfBool}}" BorderBrush="#efefef">
+                                    <Grid x:Name="AfterLiveViewWrap"></Grid>
+                                </Border>
+                            </Grid>
+                        </Grid>
                     </Canvas>
                 </Grid>
             </Canvas>