After this update, API includes one extra param in its response which is the MD5 hash of the HTML5 player file content.

This has been employed to track if the algorithm changes for the current HTML5 player. If it changed, then it will update the algo dictionary.

Even though API has its filter to check the file changes, this is also the responsibility of the client to check the status of the HTML5 player. This is even more critical when the client saved the dictionary in their local environment for faster processing, which is also the expected method to access the API.

MD5 hash of the file can be checked as follows:

/*
 * MD5 hash calculation of the content of the html5 player id en_US-vflr38Js6
 */
md5_file('http://s.ytimg.com/yts/jsbin/html5player-en_US-vflr38Js6/html5player.js');

First check the MD5 hash and match it with the algo dictionary MD5 hash. If both matches then file not changed otherwise make a new API call for the updated dictionary.

API is itself capable of checking the changes if any. Just you have to be aware of the file changes.