I have been using the excellent AirParrot program to stream from my computer to my Apple TV. Mostly because there is no App for Showtime Anywhere on the Roku, iPad or Apple TV that will stream to the Apple TV or Roku. AirParrot allows us with older Macs to activate AirPlay streaming, and does a pretty good job of it, allow you to stream your screen or an individual app or window (the most useful for ShowTime anywhere, if you pop out just the video, so you just see the top bar of the browser window and the video) and it streams sound as well. This is great, and I will likely still keep the program around, just uninstalled (so I can re-install when I need it).
The reason I am keeping it uninstalled is it has been causing some issues with my sound on my MacPro. Specifically I was losing the 3 physical hardware settings in my Sound control panel. And I run my sound out through a Digital Out to an Emotiva DAC, but have lately had no sound options. Sometimes running Diskwarrior seemed to help, but as of today nothing was bringing them back, so I removed Airparrot and it’s installed plug ins (they have a removal tool that I could not find on their web site, though it talks about it, but when I tweeted them they quickly gave me the link http://t.co/bFYfDNoaFN, though I used the awesome Find Any File [and it is $7.99 in the app store] while holding down option to really find anything, and was able to remove the program and it’s installed file ) and after a restart my sound settings were all back. And hopefully they will stay that way!