Python Ffmpeg Subprocess: Broken Pipe

The following script reads a video with OpenCV, applies a transformation to each frame and attempts to write it with ffmpeg. My problem is, that I don't get ffmpeg working with the

Solution 1:

There is a missing comma after '-vcodec', 'rawvideo'!!!

Took me about an hour to notice...

You should also close stdin and wait before print('Done!'):

pipe.stdin.close()
pipe.wait()