it's possible, but you're better off getting a dvd player for the TV... You can try AirParrot if you wish. It's good for screen mirroring and using the TV as a second monitor, but when you add sound to the mix, it becomes very laggy.
Westgarth Realty wrote:
I have purchased a movie on DVD. How do I play that movie on my Mac, but watch it on the big screen TV using Apple TV?
Not currently possible.
It might be possible when Mountain Lion OS comes out as that may support Airplay, but we have no idea if there will be restrictions on what can be streamed.
There are two steps to getting this done.
1) You must have purchased the DVD. DVDs are encrypted to protect the content from being copied. It is not legal to decrypt the contents. The Internet has many articles on how to copy the content for personal use.
2) Use an open source application like Handbrake to reformat the contents to run on the AppleTV.