导入视频资源后的默认图像是个工程图像，非视频预览

Assets/Studio/Scripts/Room/Container/Component/VideoComponent.cs

@@ -32,8 +32,26 @@ namespace ShadowStudio.Model
                 }
                 return moviesPlayer;
             }
+        }
+        void Start()
+        {
+            StartCoroutine(PlayerFirstFrame());
         }
 
+        /// <summary>
+        /// 第一次打开加载时无缩略图，为生成缩略图
+        /// </summary>
+        /// <returns></returns>
+        IEnumerator PlayerFirstFrame()
+        {
+            int temp = 0;
+            yield return new WaitForSeconds(0.3f);
+            while (temp < 2)
+            {
+                playVideoManager();
+                temp++;
+            }
+        }
 
         private void OnTransferSelect(bool isSelect)
         {