Cannot capture video from file or camera

[toseef-ahmd]

I'm trying to use this code with python 3.5.3. I have installed all dependencies but the code won't run. It keeps waiting for a while and exits with the statement " capture failed". The trace back leads me to the line 84 which is as follows:
if ret == False: print("Capture Error") break

can you please help me solve this issue?