diff --git "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/birds_concat.mp4" "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/birds_concat.mp4"
index ef911ca7848d0a5d451cfd34f30f5d8a10ca172e..efd897df50ea7ed6f2f3c075e656b4bda5c03cf3 100644
Binary files "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/birds_concat.mp4" and "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/birds_concat.mp4" differ
diff --git "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.md" "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.md"
index 13d7118710891c102127b4628bc1637ee9e41af0..e63ec94d393f851548ba9e3110f5cc8b8cc46c1d 100644
--- "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.md"
+++ "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.md"
@@ -8,7 +8,7 @@
 这是合影的效果：
 <object width="500" height="300" data="./birds_concat.mp4"></object>
 
-基本的实现代码如下：
+基本的实现代码如下，合影每10帧采样一次：
 
 ```python
 import numpy as np
@@ -20,6 +20,7 @@ if __name__ == '__main__':
     out = ...
     # TODO(You): 请在此正确创建待保存的目标mp4文件`out`
 
+    i = 0
     while(cap.isOpened()):
 
         ret, bird_frame = cap.read()
@@ -33,7 +34,9 @@ if __name__ == '__main__':
         )
 
         cv2.imshow('bird_concat_frame', bird_concat_frame)
-        out.write(bird_concat_frame)
+        if i % 10 == 0:
+            out.write(bird_concat_frame)
+        i += 1
         if cv2.waitKey(1) & 0xFF == ord('q'):
             break
 
diff --git "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.py" "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.py"
index 655b4476ac03196fd4248f4d4406f3cc013f60e1..1bd7079a2a3ee2ee08f0a3aaac5f4ab442b2e62b 100644
--- "a/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.py"
+++ "b/data/1.OpenCV\345\210\235\351\230\266/1.OpenCV\345\237\272\347\241\200/4.IO\344\270\216GUI/video_read_write.py"
@@ -15,6 +15,7 @@ if __name__ == '__main__':
         (width*2, height)
     )
 
+    i = 0
     while(cap.isOpened()):
 
         ret, bird_frame = cap.read()
@@ -28,7 +29,9 @@ if __name__ == '__main__':
         )
 
         cv2.imshow('bird_concat_frame', bird_concat_frame)
-        out.write(bird_concat_frame)
+        if i % 10 == 0:
+            out.write(bird_concat_frame)
+        i += 1
         if cv2.waitKey(1) & 0xFF == ord('q'):
             break