Wired: The Hidden Secrets of Apple’s AirPlay
Posted on November 23, 2010 by kelly maddox
Wired has a good article about Apple’s new revolutionary AirPlay feature in iOS 4.2.
The iOS 4.2 update brings one really big new feature to the iPhone, iPad and iPod Touch: AirPlay. IPad users might be overjoyed with folders and support for background processes, but the real star is the new music and video-streaming function. It will change the way you consume your media, and it will justify all the AirPort Express units you have dotted around your home. But first, how does it work?
You’ll need a device running iOS 4.2, and at least one of the following: an AirPort Express, a v2 AppleTV, a third-party AirPlay-ready speaker, or a Bluetooth audio device. Using it is as easy as you’d expect when Apple controls the whole infrastructure. In any app that uses the standard media-controls (iPod, Video, Spotify, YouTube) you will see a new symbol, a rectangle being penetrated from underneath by a triangle. Tap this and a menu pops up showing available devices.
From this menu, you simply pick where you want to send the media currently playing on your iDevice and, after a couple seconds buffering the signal, it starts. Audio will play anywhere, and video and/or audio will play on the AppleTV (not every video app is yet working – YouTube in Safari, for instance, sends only audio, while the YouTube app works as expected).
And that’s it. Thanks to background processes, you can switch away from the music or video app and read a book or surf the web. The stream continues, uninterrupted. The background stream can be controlled from the standard iOS 4 places: Double-tap the home button and swipe right to bring up the media controls to play, pause, skip or adjust volume. On the iPad you’ll also see the currently-playing app’s icon in this view. If your iDevice is locked, a double-tap will bring up the controls overlaid on the lock-screen, and both these shortcuts also give access to the AirPlay icon and menu.
Another handy trick is that you can adjust the volume using the hardware volume keys on the iDevice while the display is still sleeping.
One little-known extra is that any paired Bluetooth audio devices also show up in the same AirPlay menu. Tapping one switches the audio stream to that device, with one just difference: Bluetooth streaming starts instantly, without the two-second buffer required by Wi-Fi. If the speaker has media controls, then these buttons will allow you to play/pause and skip music without touching the iPhone in your pocket.
AirPlay also works from iTunes, although not as well as it does from an iOS device. While your iPhone will sync an on-screen movie with streamed audio, iTunes will let you select an AirPlay destination, but it will play the soundtrack locally. It will let you choose multiple sources, however (although not Bluetooth), while iOS devices can send to just one place at a time.
That’s pretty much it, apart from one oddity. If you’re streaming music to, say, an AirPort Express and then start playing, say, Angry Birds, then the game’s soundtrack will also be piped to the speakers. This could be a neat feature, but the sound suffers the same two-second delay, lagging behind the on-screen action. This seems to be a bug, and is inconsistent. Perhaps it is caused by apps that have yet to be updated to be iOS 4.2 compatible.
AirPlay really is a big deal, and you should expect to see it built-in to more and more third-party speakers and components in the future. Not only does it give you an instant, multi-room audio setup without a computer, it also turns your iPhone into a pocket home-theater.