HOW TO CONFIGURE AIRPLAY ON OS X (MAVERICKS)
In this section I'm going to demonstrate how you connect a MacBook Pro (Mid 2012) Laptop computer to a Sony Bravia 40" Television using a HDMI Cable, Apple TV device and the OS X (Mountain Lion / Mavericks) built-in software called AirPlay whereby the Desktop Screen can then be viewed on the Television. You will need similar hardware and software of course, but not necessary a 40" Sony TV. As long as your TV has a, spare, HDMI Socket you should be okay. My Apple TV is model...
Before you begin you need to make sure your Apple TV device has been set up correctly - Switch ON the black Apple TV device and then connect one end of your HDMI Cable to the back of the black Apple TV device and the other end to a spare HDMI Socket on your HDTV. Switch ON your HDTV and make sure it's now previewing the HDMI Channel associated with the spare HDMI Socket. That channel is normally called HDMI 1 or HDMI 2. You will know when all is well because you should see the Welcome screen of the black Apple TV device. From here, just follow the on-screen set up instructions whereby you will be asked to login with your Apple ID. When you have configured Apple TV, with the Apple ID associated with your MacBook Pro Laptop computer for example, you can then begin the short process of configuring AirPlay.
AirPlay is basically the Apple wireless technically (software) that allows you to stream content (i.e. photos, audio/video files and whatever you see on the Desktop/iPad Screen) between your Computer and Television (or Music Player) via a device such as Apple TV (or AirPort Express). It acts like the middle man, wirelessly streaming content between devices. Apple TV acts a bit like a modem/router in that, with AirPlay being the software, Apple TV is the actual hardware doing the streaming, memory buffering and other dirty work. Apple TV isn't just for the purpose demonstrated in this section. It can also download/stream movies from the internet and download/stream music from an external device, such as a NAS Hard Drive, via iTunes setup.
When the black Apple TV device is switched on, and more importantly configured properly, you will see the AppleTV icon sitting in the menu bar. This doesn't mean AirPlay is instantly communicating with your devices and streaming content. Quite the opposite. AirPlay doesn't communicate with devices, in this case your HDTV and Apple TV, until you click on the APPLE TV menu-item. So at this point, you will not see the content of your desktop screen displayed on your HDTV. You need to click on the APPLE TV menu-item. And even saying this, you should click on the OPEN DISPLAYS PREFERENCES menu-item instead as it will give you more options. Clicking on the APPLE TV menu-item only activates AirPlay whereas clicking on the OPEN DISPLAYS PREFERENCES menu-item allows you to initially configure your device resolutions (screen sizes) and so on.
After clicking on the OPEN DISPLAYS PREFERENCES menu-item the Built-In Display window will open. This is where you can adjust screen brightness and size and activate AirPlay. So first click on the APPLE TV menu-item, belonging to the AIRPLAY DISPLAY drop-down menu located in the bottom-left corner, to active AirPlay. From this point onwards you should now see your desktop screen and its content appear on your HDTV.
By activating AirPlay you are telling it to wirelessly stream the content of your built-in display, which is your computer's desktop screen, onto your HDTV's display (screen). Furthermore, you are telling AirPlay to use a Resolution (Screen Size) that best fits your HDTV in comparison to your Desktop Screen, which basically means you will see a black border on your HDTV when the desktop screen content is streamed (shown on your HDTV) simply because the resolution of your HDTV is far greater than your built-in display (computer screen). Put simply, the desktop screen content will not fill up the entire HD TV screen. There will be a noticeable black border/edge.
If you now click on the AirPlay icon, on the menu bar, you will see that you are indeed using the built-in display (computer screen) as opposed the APPLE TV display that emulates your HDTV screen size. Ignore the technicals if you wish. Just make sure you have your settings set up like those in Fig 1.2 below.
The built-in display (computer screen) is normally set to BEST FOR BUILT-IN DISPLAY by default (normal behaviour) but sometimes this is not the case, for whatever reason(s). If that is the case for you simply click on the radio (circle/dot) button called BEST FOR BUILT-IN DISPLAY and the best possible scree size (resolution) will be used to display the content of your desktop screen.
When you click on the OPEN DISPLAY PREFERENCES menu-item (Fig 1.0 above) two windows actually open. One for the built-in display (Fig 1.3 above) and one for the Apple TV display (below). This allows you to instantly see what screen size is being used when desktop screen content is being streamed (displayed) on your HDTV. In other words, is the AirPlay software going to stream your desktop content on to your HDTV at BEST FOR APPLE TV size, at 720p or 1080p. That's partly up to you and partly determined by the capabilities of your hardware. For example, on my equipment I can change the settings on the Apple TV window to BEST FOR APPLE TV, 1080p 720p or 2560 x 1440.
At the moment (Fig 1.4 below) the Apple TV window is stating that the desktop screen content will be streamed, and optimised, using the screen size 1024 x 800 as set by the SCALED setting of the built-in display (Fig 1.3 above). Or put another way; the HDTV will display the desktop screen content at a resolution (screen size) of 1024 x 800.
If I change the settings on the Built-In Display window (below) so that the built-in display is optimised for the Apple TV display (screen size) the streamed desktop screen content will fill the entire HDTV screen. In other words, if you want to view the content of your desktop screen as a computer screen on your HDTV just leave the built-in display settings as OPTIMISED FOR - BUILT-IN DISPLAY, but if you want to view the content of your desktop screen as a full size desktop on your HDTV, so your HDTV screen now looks like a computer screen, change the setting to OPTIMISED FOR - APPLE TV.
It's difficult to express some of these settings in action without the use of a video tutorial for example. Meaning, just play around with the above settings to see what is and isn't possible using your particular equipment and screen sizes (resolutions). The only real settings you need to test and change are the OPTIMISED FOR setting together with the screen size setting. As you change these settings you will notice the difference on your HDTV. Experiment in other words!
MIRROR BUILT-IN DISPLAY - If this setting is ticked in the menu bar (Fig 1.2 above) the content of your desktop screen (or iPad screen) will be streamed to your HDTV too. And if it's switched off (unticked) it means the content of your desktop screen (or iPad screen) will not be streamed to your HDTV - You will only be able to see your desktop content (or iPad content) on their relevant screens but not on your HDTV screen - Your HDTV screen will be black.
EXTEND DESKTOP - If this setting is ticked your HDTV will display a blank desktop with only the menu bar available plus the currently opened app. This feature (setting) is meant for slideshow and presentation purposes (i.e. you want to utilise the whole screen) and furthermore really meant for those with a second (extended) HDTV/Monitor Screen whereby they can switch between them using apps such as Final Cut. Ignore the technicals here! Just use the standard ("normal") MIRROR BUILT-IN DISPLAY setting instead.
MATCH DESKTOP SIZE - If this is set to BUILT-IN DISPLAY your HDTV will have a bordered edge (scaled down version of your apple mac desktop screen or iPad screen), as mentioned above, because it is only matching the screen size of your built-in display (computer screen). If the APPLE TV setting is ticked instead your desktop content will fill the HDTV screen (see above).
There is a lot of talk on the internet about cheaper HDMI Cables being of the same quality as the commercially branded ones, but just like computers crash due to wrongly programmed software you cannot always guarantee every single HDMI Cable will work with your specific equipment and its configuration.
For example, I originally had a £20 Philips HDMI Cable that I bought years ago with my Sony Bravia 40" TV and Sony DVD/HD Recorder. It produces 1080p perfectly. Recently I decided to buy a Sony HDMI Cable to marry up the brands (which I normally do, but years ago couldn't find a Sony HDMI Cable....or it was around but too expensive). Anyway, the Sony HDMI Cable also produces 1080p perfectly. Finally, I bought a cheap £6 HDMI Cable from the local computer market only to find it doesn't produce a 1080p signal. It only produces 720p. Now this could just of been a bad cable, so my advice to you is try and test the HDMI Cable you are thinking of buying, with your specific equipment, before deciding to purchase it. Also, pay around £20 for it, but now more than that. I bought my Sony HDMI Cable from Argos.
For more information about HDMI, Apple TV and Screen Resolutions search the internet, but also read this 720p vs 1080i article and the comments on this AVForums post to get a better understanding of the things mentioned in this section.