AirPlay

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This article is about the software. For the radio term, see Airplay. For other uses, see Airplay (disambiguation).
Not to be confused with FairPlay.
AirPlay
AirPlay logo.png
AirPlay logo
Developer Apple Inc.
Type Wireless Media Streaming
Release date September 1, 2010; November 22, 2010 for iOS systems
Website apple.com/airplay

AirPlay (previously called AirTunes when it was for audio only[1]) is a proprietary protocol stack/suite developed by Apple Inc. that allows wireless streaming of audio, video, and photos, together with related metadata between devices. Originally implemented only in Apple's software and devices, Apple has licensed the AirPlay protocol stack as a third-party software component technology to manufacturer partners for them to use in their products in order to be compatible with Apple's iDevices.

Starting with Apple TV firmware 6.0, the encryption scheme "FairPlay" is enforced and devices not supporting it can't be used.[1]

History[edit]

AirTunes was originally released on June 7, 2004.[2]

The enhancements to the AirTunes technology and the subsequent name change to AirPlay were announced by Apple CEO Steve Jobs at the iPod event on September 1, 2010, and explained thus:

“Now, what is AirPlay? You know what AirTunes is… listen to music from all over your house from your mobile device”, said Jobs. "We’re changing the name of AirTunes to AirPlay, and it’s not just music anymore. You can stream all kinds of media anywhere in your house."[1]

At WWDC 2011, Jobs announced AirPlay Mirroring as a feature in iOS 5 where the user can stream the screen from an iPad 2 to a HDTV wirelessly and securely without the need for cables.[3][4]

Output AirPlay device selection via Remote app for iPhone

Implementations[edit]

There are two types of AirPlay devices: those that send audiovisual content, and those capable of receiving the content and rendering it on displays and speakers.

AirPlay sender devices include computers running iTunes, and iOS devices such as iPhones, iPods, and iPads running iOS 4.2 or greater. OS X Mountain Lion supports display mirroring via AirPlay on systems containing 2nd generation Intel Core processors or later.[5]

AirPlay receiver devices include AirPort Express (which includes an analog and optical SPDIF audio output connector), Apple TV, and third party speakers. With the open source implementations of the AirPlay protocol any computer can now be turned into an AirPlay receiver.[6]

As of iOS 4.3, third-party apps may send compatible audio and video streams over AirPlay.[7] The iTunes Remote app for iOS can be used to control media playback and select streaming devices.[8]

AirPlay wireless technology (receiver mode) is integrated into speaker docks, AV receivers, and stereo systems from companies such as Bose, Yamaha, Philips, Marantz, Bowers & Wilkins, Pioneer, Sony, and Denon.[9] Song titles, artists, album names, elapsed and remaining time, and album artwork can appear on AirPlay-enabled speakers with graphical displays.

Bluetooth devices (headsets, speakers) that support the A2DP profile also appear as AirPlay receivers when paired with an iOS device; Bluetooth is a device-to-device protocol that does not rely on a wireless network access point.

Third-party software implementations[edit]

Senders/Receivers enabling non-Apple software to send/receive media to AirPlay-enabled devices:

AirPlay senders
Name Media type OS Vendor
AirAudio[10] audio only, supports any source Android IsSend Communications
AirBuddy[11] video, photos Android, Google TV, Amazon Fire TV Dipendu Saha
AirFlick[12] OS X Erica Sadun
Airfoil[13] audio only OS X, Windows Rogue Amoeba
AirParrot[14] OS X or Windows screen mirroring OS X (10.6.8+), Windows (XP+) Squirrels
Airstream[15] video, images, audio Cross-platform Christoph Lipautz
audio|acacia[16] audio only Windows (XP+), OS X (10.6+), iOS (5.0+), and Android (4.4+) Plethra
axStream[17] (formerly oAEP) audio only Windows
Beamer[18] video only, supports common codecs OS X Tupil
forked-daapd audio only Linux
Open-Airplay Images (screencast) Cross-platform Open-airplay
Porthole[19] audio only OS X Danger Cove
PulseAudio audio only Linux, default sound system used on most desktop distributions, supports allowing virtually any audio application to use some (no UDP) AirPlay devices
qTunes[20] audio only Java open source
raop_play[21] audio only Linux
TuneBlade[22] audio only Windows Breakfree Audio
WHAALE Multiroom Player[23] audio only iOS (6.0+) WHAALE
AirPlay receivers
Name Media type OS Vendor
AirBuddy[11] audio, video, photos Android, Google TV, Amazon Fire TV Dipendu Saha
Aerodrom[24] audio, video, photos Windows, Windows Media Center funkyf@ctory development
Airfoil Speakers audio only OS X (10.6+), Windows (2000+), iOS (4.0+), Android (2.3+) Rogue Amoeba
AirBubble audio only Android Bubblesoft
AirFloat[25] audio only iOS (removed from App Store[26]) The Famous Software Company
AirMediaPlayer[27] Windows Apostolos Georgiadis
AirPlayer[28] video only Erica Sadun
AirReceiver[29] audio only (Java) Florian Pflug
AirReceiver(Android) audio, video, photos, screen mirroring Android. Google Play
AirServer[30] audio, video, photos, screen mirroring OS X, Windows (Windows more limited feature set currently than on OS X). AirServer
Airtight[31] audio, video, photos Google TV Google Play
Android HiFi audio only Android 2.2+ Android-HiFi
audio|acacia[32] audio only Windows (XP+), OS X (10.6+), iOS (5.0+), and Android (4.4+) Plethra
BananaTV[33] does not support iOS 5 or newer Discontinued as of November 2011
casualShare[34] video, photos OS X Joris Suppers
Freebox AirMedia photos, audio and videos Linux on freebox TV set-top-box and broadband router Free/Iliad
Mirroring360[35] audio, video, photos, screen mirroring OS X, Windows. Splashtop
MythTV[36] audio (with artwork and metadata), video, photos Windows, OS X, Linux
Plex audio, video, photos OS X, Windows, Linux, iOS, Android
Reflector[37] iOS (iPhone 4S+, iPad 2+) screen mirroring OS X (10.6.8+) or Windows (XP+) AirSquirrels
ShairPort[38] audio only OS X, Windows & Linux James Laird
Totem Media Player optional plug-in Linux
TriCaster (XD models)[39] video, photos (hardware) NewTek
Volumio[40] audio only (via shairport) Linux on ARM Embedded Hardware Volumio
XBMC[41] audio, video, photos Windows, OS X, Linux, iOS, Android
X-Mirage[42] audio, video, photos streaming, screen mirroring OS X, Windows. X-Mirage

AirPort[edit]

Main article: AirPort

AirPlay allows an Apple TV or AirPort-enabled computer with the iTunes music player to send a stream of music to multiple (three to six, in typical conditions) stereos connected to an AirPort Express or Apple TV.[43]

Speakers attached to an AirPort Express or Apple TV can be selected from within the "Remote" iPhone/iPod Touch application, allowing full AirPlay compatibility[44] (see "Remote control" section below).

Protocols[edit]

The AirTunes part of the AirPlay protocol stack uses UDP for streaming audio and is based on the RTSP network control protocol.[45] The streams are transcoded using the Apple Lossless codec with 44100 Hz and 2 channels encrypted with AES, requiring the receiver to have access to the appropriate private key to decrypt the streams.[46] The stream is buffered for approximately 2 seconds before playback begins, resulting in a small delay before audio is output after starting an AirPlay stream.[47]

The protocol supports metadata packets that determine the final output volume on the receiving end. This makes it possible to always send audio data unprocessed at its original full volume, preventing sound quality deterioriaton due to reduction in bit depth and thus sound quality which would otherwise occur if changes in volume were made to the source stream before transmitting. It also makes possible the streaming of one source to multiple targets each with its own volume control.[48]

AirPlay Mirroring[edit]

AirPlay Mirroring is a slightly different technology that allows specific content to be broadcast from a variety of iOS devices and iTunes to a second generation Apple TV. The exact composition of the protocols that AirPlay Mirroring uses have not yet fully been discovered, or reverse-engineered.[4] However, an unofficial AirPlay protocol specification is available.[49] Supported hardware includes the iMac (Mid 2011 or newer), Mac Mini (Mid 2011 or newer), MacBook Air (Mid 2011 or newer), MacBook Pro (Early 2011 or newer), Apple TV (2nd generation or newer), iPhone (4S or newer), iPad (2 or newer), iPad Mini (1 or newer), and the iPod Touch (5th generation)[50]

The AirPort Express' streaming media capabilities use Apple's Remote Audio Output Protocol (RAOP), a proprietary variant of RTSP/RTP. Using WDS-bridging,[51] the AirPort Express can allow AirPlay functionality (as well as Internet access, file and print sharing, etc.) across a larger distance in a mixed environment of wired and up to 10 wireless clients.

Reverse engineering AirTunes and AirPlay[edit]

When the protocol was known as AirTunes, it was reverse-engineered by Jon Lech Johansen in 2004.[46]

On April 8, 2011, James Laird reverse-engineered and released the private key used by the Apple AirPort Express to decrypt incoming audio streams.[52] The release of this key means that third-party software and devices modified to use the key will be able to decrypt and play back or store AirPlay streams.[53] Laird released ShairPort as an example of an audio-only software receiver implementation of AirPlay.[54]

See also[edit]

Notes[edit]

  1. ^ a b c Brownlee, John (September 1, 2010). "September iPod Event: In iOS 4.2, AirTunes Becomes AirPlay". Cult of Mac. Cultomedia. Retrieved April 11, 2011. 
  2. ^ "Apple Unveils AirPort Express for Mac & PC Users". Apple.com. June 7, 2004. Retrieved April 12, 2012. 
  3. ^ "iOS5 – AirPlay Mirroring for iPad 2". Apple. Retrieved April 12, 2012. 
  4. ^ a b http://www.aorensoftware.com/blog/2011/08/20/exploring-airplay-mirroring-internals/ Exploring Airplay Mirroring Internals
  5. ^ "About AirPlay Mirroring in OS X Mountain Lion". Apple. Retrieved 6 August 2012. 
  6. ^ "How-To: Turn your Raspberry Pi into a AirPlay receiver to stream music from your iPhone". Raspberry Pi HQ. Retrieved Sep 4, 2013. 
  7. ^ Rose, Michael. "iOS 4.3 spotlight: AirPlay improvements and 720p playback". TUAW. AOL. Retrieved May 5, 2011. 
  8. ^ "Apple.com – iTunes Remote". 
  9. ^ Grobart, Sam (November 22, 2010). "Understanding AirPlay in Apple’s iOS 4.2". The New York Times. Retrieved April 11, 2011. 
  10. ^ "AirAudio - AirPlay/DLNA/Chrome". IsSend Communications. Retrieved August 6, 2014. 
  11. ^ a b "Share your beautiful photos, video & music with your friends and family on the big screen TV using AirBuddy App for Android.". Retrieved August 11, 2014. 
  12. ^ "Index of /ftp/AirPlay". Ericasadun.com. Retrieved April 12, 2012. 
  13. ^ "Airfoil | Select Your Operating System". Rogue Amoeba. Retrieved April 12, 2012. 
  14. ^ "AirParrot". 
  15. ^ "Airstream at GitHub". Christoph Lipautz. Retrieved June 23, 2014. 
  16. ^ "Multimedia Distribution & Automation". Plethra. Retrieved April 12, 2012. 
  17. ^ "Airport Express Streamer (oAEP)". Oaep.codeplex.com. Retrieved April 12, 2012. 
  18. ^ "Beamer for Mac - Play any movie file directly via Apple TV". Tupil. Retrieved May 18, 2012. 
  19. ^ "Porthole". 
  20. ^ "qTunes". Retrieved January 19, 2012. 
  21. ^ "Apple Airport Express Client Player". Raop-play.sourceforge.net. December 16, 2005. Retrieved April 12, 2012. 
  22. ^ "TuneBlade". 
  23. ^ "WHAALE". 
  24. ^ "Aerodrom". Retrieved March 26, 2013. 
  25. ^ "AirFloat – Turn your iPhone into an AirPlay speaker!". 
  26. ^ "AirFloat has been removed from App Store". 
  27. ^ "Technology and Science: AirMediaPlayer for Windows". Apogeorgiadis.blogspot.com.au. Retrieved April 12, 2012. 
  28. ^ "AirPlayer". ericasadun.com. Retrieved April 12, 2012. 
  29. ^ "AirReceiver". Retrieved June 10, 2011. 
  30. ^ "AirServer". Retrieved February 14, 2012. 
  31. ^ "Airtight is Airplay for Your Google TV". Retrieved March 6, 2012. 
  32. ^ "audiolacacia". Retrieved November 3, 2013. 
  33. ^ "Banana TV". Retrieved February 14, 2012. 
  34. ^ "casualShare". Retrieved January 9, 2013. 
  35. ^ "Mirroring360". Retrieved June 20, 2014. 
  36. ^ "MythTV 0.27 Changelog". 
  37. ^ "Reflector". 
  38. ^ "ShairPort". James Laird. Retrieved 26 March 2013. 
  39. ^ "NewTek TriCaster". Retrieved October 1, 2011. 
  40. ^ "Volumio 1.4 is out". Retrieved August 5, 2014. 
  41. ^ "XBMC 11.0 Eden Changelog". Retrieved April 9, 2012. 
  42. ^ "X-Mirage". Retrieved February 14, 2012. 
  43. ^ "Apple TV: Using AirPlay". Apple. November 20, 2008. Retrieved March 12, 2009. 
  44. ^ "iTunes Remote". Apple.com. September 13, 2011. Retrieved April 12, 2012. 
  45. ^ Donenfeld, Jason A. "AirTunes 2 Protocol". ZX2C4. Retrieved April 11, 2011. 
  46. ^ a b Hanselmann, Michael (December 16, 2008). "Add Remote Audio Output Protocol stream output plugin". http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=bc9a84781306ab22d2facc636a2f82eb6ba2abd3.
  47. ^ "Preventing audio delays while watching videos with Airfoil". Rogue Amoeba. Retrieved Aug 18, 2012. 
  48. ^ ""How are volume changes applied to an Airplay audio stream?" at Quora". Quora/Bjørn van Raaij. Retrieved June 11, 2013. 
  49. ^ "Unofficial AirPlay Protocol Specification". nto.github.com. May 29, 2012. Retrieved May 29, 2012. 
  50. ^ http://www.apple.com/osx/specs/.  Missing or empty |title= (help)
  51. ^ "Apple WDS Setup". Support.apple.com. February 11, 2011. Retrieved April 12, 2012. 
  52. ^ Laird, James (April 8, 2011). "RAOP/Airtunes". vlc-devel mailing list. http://mailman.videolan.org/pipermail/vlc-devel/2011-April/079148.html.
  53. ^ Cheng, Jacqui (April 11, 2011). "ShairPort emulates AirPort Express to receive AirPlay streams". Ars Technica. Retrieved April 11, 2011. 
  54. ^ Laird, James (April 11, 2011). "ShairPort 0.02 released". Archived from the original on April 27, 2011. Retrieved April 11, 2011. 

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