Because the planets are always rotating, taking long videos won't give you a clear image when stacking frames. Here's a rough guide to the maximum recording time for each of the major planets, including the total time for videos you plan to combine before rotation plays a factor.

 
 
 Acceptable Image Time for Planet Photography 
 
 
Planet
 
Time
 
Combined Video Length
 
 
 
Mars
 
5 Minutes
 
15 Minutes
 
 
 
Jupiter
 
1 Minute
 
3 Minutes
 
 
 
Saturn
 
3 Minutes
 
10 Minute