I have already got answer on Facebook! Thanks!

"Sadly, you have to resize your window manually to the original size. Splash PRO EX doesn't support automatic window resizing."

Hi! First of all, sorry for my bad english. :) Is there any option to open video files not always in the same window size? Such as in the Media Player Classic Home Cinema. Splash Pro Ex doesnt keep the original video size. for example: Splash PRO Ex open a 720p video file in the same window size as ...