Is there an infinity setting when shooting videos?

[dolts007]

Hi

I have upgraded at last from a Galaxy S to the S4 and when i used the Galaxy S for shooting videos i never had any blurry vids. Now i get them all the time even though the AF button is showing on the screen. Is there an infinity setting i can use to override the AF as i just used it at a family party and the playback looks awful with people going in and out of focus.

If there isnt does anyone know of a good video app that could overcome the problem?

Thanks in advance for any help