hello, i record video in gta v but i want apply sweetfx on video any method to do that ?

You can use https://obsproject.com/ and run your game in borderless window mode. Set the software not to broadcast instead to direct file and you can see the applied effect on the recording.

if you want to apply the effects to a video http://forums.guru3d.com/showpost.php?p=4986317&postcount=327 then use obs to record the played video