Yeah, sorry, this is definitely not how Latin really sounded. Somebody in the YT comments describes the video as "Polish with Latin words" and I can confirm it.
Linguists have been able to piece together how Latin was pronounced at various periods in time, although we (of course) don't know every nuance of local variations in grammar & pronunciation.
This guy's blog does a really good job of describing the development & evolution of the English language. http://historyofenglishpodcast.com/2013/08/05/episode-16-the-rise- of-rome-and-latin/
Because Latin is a part of the history of the English language, he has several episodes about Ancient Greek, Latin, and so on. (My link goes to one of the Latin episodes.)