How to capture screencast video and root not required? I found a lot of solution to make a screencast on Android but each time the root is mandatory.

Does anyone have the solution without root?
Well, the reason Screencast and similar apps require root permission is that the video data has to be accessed using the administrative privileges (i.e. roots access)

But you can always use an app such as No Root Screen Recorder to video record your screen. But the problem with this option is that you have to connect your device to a windows computer in order to capture. 

This is the only option which is available to given you have no root access.