diff --git a/multi_Thread/ledThreads/2020_08_14.md b/multi_Thread/ledThreads/2020_08_14.md
index 037bdbb52b8959dddd58face041ab54949401b99..1949d972e7a6f6c3cff42aba6fd00e6b2eefe623 100644
--- a/multi_Thread/ledThreads/2020_08_14.md
+++ b/multi_Thread/ledThreads/2020_08_14.md
@@ -97,17 +97,19 @@ Makefile이 생성된 후, make를 입력하여 응용 프로그램을 생성하
 ####  3-1) ./main
 
 
-<iframe width="560" height="315" src="https://www.youtube.com/embed/NfKf4ip-5uo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+<video source src = "./0.mp4" controls>
+</video>
 <br><br>
 
 ####  3-2) ./main 1 5
 
-<iframe width="560" height="315" src="https://www.youtube.com/embed/UKGIucKDOBQ" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
-
+<video source src = "./1.mp4" controls>
+</video>
 ####  3-2) ./main 2 7
 
-<iframe width="560" height="315" src="https://www.youtube.com/embed/5sroLUnva3o" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
-
+<video source src = "./2.mp4" controls>
+</video>
 ####  3-2) ./main 3 6
 
-<iframe width="560" height="315" src="https://www.youtube.com/embed/z_3D1bgHnQE" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
\ No newline at end of file
+<video source src = "./3.mp4" controls>
+</video>
\ No newline at end of file