airplay or airplay mirroring?
they are 2 different things.
airplay sends the pre-encoded file directly to the aTV.
it can even send the file location to the aTV, and the aTV will download directly, bypassing your phone completely.
airplay mirroring has to
- decode the file
- play it back on your video card
- do a screen capture of that image
- re-encode it
- send it off to the aTV.
All in pretty much real time so the screens stay in sync.
you loose some quality to keep the sync.
it doesn't work well for video playback. It's much more suited for presentations.
if you can see the movie on your phone, iPad, or mac's screen, it's mirroring
if you want to send movies from your mac, look at
airparrot, it lets you stream media files, so it's able to read ahead and encode the file, and will give you a better experience than mirroring.
or if you have lots of media stored on your mac and you have an aTV4, look at
plex, it will index your media, and let you play everything back right on the aTV. (your mac must be running to stream the media)
if you have an aTV2/3 there is an work around called plexconnect, that works pretty well, at least it did a year ago, i haven't used it since the 4 came out. check the plex forums for more info.