I could not install ffvideo on OSX Sierra so i decided to work with ffmpeg.
OSX:
brew install ffmpeg
Linux:
apt-get install ffmpeg
Python 3 Code:
import subprocess
video_input_path="/your/video.mp4"
img_output_path="/your/image.jpg"
subprocess.call(['ffmpeg', '-i', video_input_path, '-ss', '00:00:00.000', '-vframes', '1', img_output_path])