Frist you want to any video hide
1.go to your gallery of file manager
2 go to your video folder
3 select your video
4 then Rename this video exm...If your file name hinde song.mp4 you delect the last character 4 now save hinde song.mp
5 now this video can't show in your gallery or video player
note: If you want to see this video again Rename this video and just add last chatacter 4 ok