Cropping the video and removing the black portion I know that the below command will crop 25 from top and bottom 

ffplay -i input.mp4 -vf "crop=in_w:in_h-50"


However I just want to crop 25 from bottom(not top).
Also How can i remove the black portion in the output so that the output video appears as full screen?

EDIT

Here is the screenshot of the black portion after crop



Before crop
Use

ffplay -i input.mp4 -vf "crop=in_w:in_h-25:0:0"


If you're watching this full screen, then the display will show black bars if the resized video is not the same aspect ratio as your monitor. To achieve that, you'll have to crop horizontally as well. If your crop X pixels vertically, you'll have to crop (16/9)*X pixels horizontally.

To do this, use

(left and right)

ffplay -i input.mp4 -vf "crop=in_w-25*16/9:in_h-25:(ow-iw)/2:0"


(right only)

ffplay -i input.mp4 -vf "crop=in_w-25*16/9:in_h-25:0:0"