To start video
var videoURL = $('#playerID').prop('src');
videoURL += "&autoplay=1";
$('#playerID').prop('src',videoURL);
To stop video
var videoURL = $('#playerID').prop('src');
videoURL = videoURL.replace("&autoplay=1", "");
$('#playerID').prop('src','');
$('#playerID').prop('src',videoURL);
You may want to replace "&autoplay=1" with "?autoplay=1" incase there are no additional parameters
works for both vimeo and youtube on FF & Chrome