Shairport Sync (as of v4.1 and newer) offers AirPlay 2 support for audio sources on:
- iOS devices,
- Macs from macOS 10.15 (Catalina) onwards,
- HomePod minis,
- and Apple TVs.
-
AirPlay 2 audio for iOS, HomePod mini, AppleTV and Mac players.
- Audio is synchronised with other AirPlay 2 devices.
- Two types of audio are received by Shairport Sync – "Realtime" streams of CD quality ALAC (like "classic" AirPlay) and "Buffered Audio" streams of AAC stereo at 44,100 frames per second.
- The selection of stream type is made by the player.
- Realtime streams generally have a latency of about two seconds. Buffered Audio streams typically have a latency of half a second or less.
- In AirPlay 2 mode, Shairport Sync reverts to "classic" AirPlay when iTunes on macOS or macOS Music plays to multiple speakers and one of more of them is compatible with AirPlay only.
-
Devices running Shairport Sync in AirPlay 2 mode can be added to the Home app.
- No AirPlay 2 for Windows iTunes.
- Remote control facilities are not implemented.
- AirPlay 2 from macOS prior to 10.15 (Catalina) is not supported.
Shairport Sync uses a companion application called NQPTP ("Not Quite PTP")
for timing and synchronisation in AirPlay 2. NQPTP must have exclusive access to ports 319
and 320
.
Lossless and High Definition Lossless material is transcoded to AAC before it reaches Shairport Sync.
AirPlay 2 support needs a slightly more powerful CPU for decoding and synchronisation and more memory for bigger buffers and larger libraries. A system with the power of a Raspberry Pi 2 or Raspberry Pi Zero 2 W, or better, is recommended.
Here are some guidelines:
- Full access, including network capabilities or
root
privileges, to a system at least as powerful as a Raspberry Pi 2 or a Raspberry Pi Zero 2 W. - Ports 319 and 320 must be free to use (i.e. they must not be in use by another service such as a PTP service) and must not be blocked by a firewall.
- An up-to-date system. This is important, as some of the libraries must be the latest available.
- Shairport Sync will not run in AirPlay 2 mode on a Mac because NQPTP, on which it relies, needs ports 319 and 320, which are already used by macOS.
- A version of the FFmpeg library with an AAC decoder capable of decoding Floating Planar --
fltp
-- material. There is a guide here to help you find out if your system has it. - An audio output. The device must be capable of running at 44,100 frames per second. You can use
sps-alsa-explore
to test the suitability of hardware ALSA audio devices on your device. Other backends continue to work as with "classic" Shairport Sync.
- Multiple instances of the AirPlay 2 version of Shairport Sync can not be hosted on the same system. It seems that AirPlay 2 clients are confused by having multiple AirPlay 2 players at the same IP addresses.
- A building guide is available at BUILD.md.