This jsbin takes the following queryString parameters:

userAction    - Play video on user action (uses click event by default)
videoFromFile - Play an mp4 file in the video element instead of a user media stream
delay         - Play video after specified milliseconds (0 by default)

Examples:
?                                    - Play user media without delay
?delay                               - Play user media with 0ms delay
?videoFromFile&delay                 - Play a file after 0ms delay
?userAction=click&videoFromFile      - Play a file on click event
?userAction=touchstart&videoFromFile - Play a file on touchstart event