How to stream FROM Windows 8.1 TO Apple TV

Is is possible to stream audio or, better yet, audiovisual, from my Windows 8.1 PC to my Apple TV WITHOUT using iTunes? Don't get me wrong, streaming from iTunes works great (at least for audio). But I wouid like to mirror or at least stream YouTube and other non-iTunes sources from my PC to my Apple TV.

Home sharing is on and homegroup and Bonjour are both on/enabled.

What precise steps on my PC must I take to make this work?