get video fps using FFProbe
This will print the video FPS:
ffprobe -v error -select_streams v -of default=noprint_wrappers=1:nokey=1 -show_entries stream=r_frame_rate file.mp4
You can simply run this also, to get the video FPS, this will work on linux machines.
ffprobe -v quiet -show_streams -select_streams v:0 INPUT |grep "r_frame_rate"