Diff being reverted:
diff --git a/cnc/index.mdwn b/cnc/index.mdwn
index 5a5f994..8062752 100644
--- a/cnc/index.mdwn
+++ b/cnc/index.mdwn
@@ -99,6 +99,6 @@ and toggle the step outputs for the axes that are not there yet. To get a
 delay between toggles, I use the `_delay_us` function from avr-gcc; you
 could use the `delayMicroseconds` function in the Arduino library instead.
 
-[[!img cnc-home.png size="1280x720" alt="Video" link="cnc-home.mp4"]]
+[[!img cnc-home.png size="1280x720" alt="Video" link="cnc-home.mkv"]]
 
 Source code: [02-home.c](02-home.c.html)