I converted my DVD's to MP 4's & saved them to my PC and an external hard drive. When I right click on the movie, I have the option to cast to either one of my Roku's.
So, I guess, my answer would be yes you can. I was intrigued with the idea that I could cast it so I did try it with one of my movies and it worked, although I did not see an option for pausing or stopping the movie without going to the computer. Unfortunately the PC is in another room. An easier way to get around that, I found, is to take my portable external hard drive & plug it into my Roku. Works Great! Hope this is helpful.
WD - My Passport 3TB External USB 3.0/2.0 Portable Hard Drive - Black/Silver
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