Support AirPlay 1 and 2 simultaneously and fix systemd service dependencies

.github/settings.yml

@@ -7,7 +7,7 @@ repository:
   # A URL with more information about the repository
   # homepage: ""
   # A comma-separated list of topics to set on the repository
-  topics: airplay, audio, bluetooth, deploy-rs, dlna, fluidsynth, home-assistant, image, jellyfin, low-latency, music-assistant, midi, multi-room, nix, nixos, pi, pipewire, raspberry, realtime, receiver, rygel, sbc, sd, shairport-sync, snapcast, stereo, synth, synthesizer, upnp, wireplumber,
+  topics: airplay, audio, bluetooth, dlna-upnp, home-assistant, jellyfin, low-latency, music-assistant, midi, multi-room, nixos, pipewire, raspberry-pi, realtime, receiver, snapcast, stereo, synthesizer, wireplumber,
   # Either `true` to make the repository private, or `false` to make it public.
   private: false
   # Either `true` to enable issues for this repository, `false` to disable them.

README.adoc

@@ -44,7 +44,7 @@ endif::[]
 This project is a build of a 2.1 channel receiver based on the Raspberry Pi.
 Out-of-the-box, it takes in audio from the digital optical input.
 The receiver leverages {PipeWire} and {WirePlumber} for the audio routing and session management.
-The software and configuration is built on NixOS and managed through a Nix flake in this repository.
+The software and configuration are built on NixOS and managed through a Nix flake in this repository.
 {Nix} has quite up-to-date software, is extensively customizable, and ensures that builds are reproducible.
 
 .Features
@@ -163,6 +163,7 @@ Installation is done by building a system image which is flashed directly to an
 This can all be built and customized locally with {Nix}.
 Unfortunately, unless you're building this on an aarch64 machine, it will take a significant amount of time to build.
 The initial build probably took about two full days for me.
+I need to tweak the kernel config to avoid building a bunch of unnecessary things, like drivers for AMD and Nouveau GPUs.
 
 . Install an implementation of Nix, such as https://lix.systems[Lix] demonstrated in the following command.
 Enable support for flakes when prompted.
@@ -319,10 +320,57 @@ To make it possible to switch between outputs, I'd need to add a button and some
 
 === AirPlay
 
-https://www.apple.com/airplay/[AirPlay], specifically Airplay 2, is supported via {Shairport-Sync}.
+https://www.apple.com/airplay/[AirPlay] 1 and 2 are supported via {Shairport-Sync}.
+Two instances of Shairport-Sync run simultaneously to provide support for both AirPlay 1 and AirPlay 2.
 It works very nicely.
-AirPlay 1 doesn't appear to work at all, however.
-This may be fixed when `shairport-sync` is updated in NixOS 24.11.
+PipeWire's https://docs.pipewire.org/page_module_raop_discover.html[RAOP Discover module] can be used to automatically discover and stream directly to the Piceiver.
+The following instructions document how to accomplish this.
+
+[NOTE]
+====
+Make sure that the ephemeral port range is open in the firewall on the device from which you are streaming.
+====
+
+. Create the configuration directory for PipeWire for your user.
++
+[,sh]
+----
+mkdir --parents ~/.config/pipewire/pipewire.conf.d
+----
+
+. Configure the RAOP Discover module in a config file fragment.
++
+.~/.config/pipewire/pipewire.conf.d/raop-discover.conf
+[,lua]
+----
+context.modules = [
+{   name = libpipewire-module-raop-discover
+    args = {
+        stream.rules = [
+            {   matches = [
+                    {    raop.ip = "~.*"
+                    }
+                ]
+                actions = {
+                    create-stream = {
+                        stream.props = {
+                            media.class = "Audio/Sink"
+                        }
+                    }
+                }
+            }
+        ]
+    }
+}
+]
+----
+
+. Restart PipeWire.
++
+[,sh]
+----
+systemctl --user restart pipewire
+----
 
 === Bluetooth
 
@@ -434,7 +482,7 @@ The steps here walk through how to do this.
 mkdir --parents ~/.config/pipewire/pipewire.conf.d
 ----
 
-. Drop in and configure the the Snapcast Discover module in a config file fragment.
+. Drop in and configure the Snapcast Discover module in a config file fragment.
 +
 .~/.config/pipewire/pipewire.conf.d/51-snapcast-discover.conf
 [,lua]
@@ -483,11 +531,11 @@ systemctl --user restart pipewire
 
 === Music Assistant
 
-The Piceiver may be integrated with {Music-Assistant} as an external Snapcast server as well as a UPnP/DLNA player provider.
+The Piceiver may be integrated with {Music-Assistant} as an external Snapcast server, an AirPlay playback provider, and a UPnP/DLNA player provider.
 The external Snapcast server option will create a Snapcast stream specific to Music Assistant.
-It may be less disruptive to your Snapcast configuration to use the UPnP/DLNA player provider instead.
-The AirPlay player provider relies on AirPlay 1 and will not work with AirPlay 2 support in shairport-sync enabled.
-It can likewise be incorporated directly in {Home-Assistant} using either the Snapcast or DLNA integrations or directly via Music Assistant.
+This requires manually switching the Snapcast stream back to the default `default` stream after playing anything through Music Assistant, otherwise you'll hear nothing.
+This is a pain, so I recommend using the AirPlay or UPnP/DLNA player providers instead unless you stream everything through Music Assistant.
+The Piceiver can likewise be incorporated directly in {Home-Assistant} using either the Snapcast or DLNA integrations or directly via Music Assistant.
 
 === Synthesizer
 

flake.nix

@@ -99,8 +99,9 @@
         mopidy-pipewire-gstreamer-plugin
         rygel-pipewire-gstreamer-plugin
         realtime
-        shairport-sync-airplay2
         unstablePackages
+        unstable-shairport-sync
+        shairport-sync-airplay2
       ];
       pkgsArmCross = import nixpkgs {
         # inherit system;

home-manager/_mixins/services/mopidy/default.nix

@@ -17,8 +17,8 @@ lib.mkIf (lib.elem username installFor && role == "piceiver") {
     ];
     settings = {
       audio = {
-        # todo Investigate buffer time.
-        # buffer_time = 200;
+        # I'm surprised I don't need a value larger than 1ms here.
+        buffer_time = 1; # Must be greater than 0, default from GStreamer is 1000ms
         mixer = "software";
         mixer_volume = 50;
         output = "pipewiresink client-name=Mopidy target-object=snapserver";

home-manager/_mixins/services/rygel/default.nix

@@ -1,6 +1,7 @@
 {
   config,
   lib,
+  osConfig,
   pkgs,
   role,
   username,
@@ -87,24 +88,29 @@ lib.mkIf (lib.elem username installFor && role == "piceiver") {
     "rygel" = {
       Unit = {
         Description = "Rygel DLNA/UPnP Digital Media Renderer";
-        After = [ "wireplumber.service" ];
-        Requires = [ "wireplumber.service" ];
+        After = [
+          "pipewire.service"
+          "wireplumber.service"
+          # The delay from the wireplumber-init service provides enough time for all of the PipeWire nodes to become available.
+          "wireplumber-init.service"
+        ];
+        PartOf = [ "pipewire.service" ];
+        Requires = [ "wireplumber-init.service" ];
+        Wants = [ "wireplumber.service" ];
         X-Restart-Triggers = [
-          "/etc/rygel.conf"
-          "${config.xdg.configHome}/rygel.conf"
+          "${osConfig.environment.etc."rygel.conf".source}"
+          "${config.home.file."${config.xdg.configHome}/rygel.conf".source}"
         ];
       };
       Service = {
         BusName = "org.gnome.Rygel1";
         ExecStart = "${pkgs.gnome.rygel}/bin/rygel";
         Restart = "always";
+        RestartSec = 10;
         Type = "dbus";
       };
       Install = {
-        WantedBy = [
-          "default.target"
-          "wireplumber.service"
-        ];
+        WantedBy = [ "default.target" ];
       };
     };
   };

home-manager/_mixins/services/shairport-sync/default.nix

@@ -1,5 +1,6 @@
 {
   lib,
+  osConfig,
   pkgs,
   role,
   username,
@@ -13,7 +14,7 @@ lib.mkIf (lib.elem username installFor && role == "piceiver") {
     nqptp = {
       Unit = {
         Description = "shairport-sync AirPlay 2 NQPTP server";
-        Before = [ "shairport-sync.service" ];
+        Before = [ "shairport-sync-airplay-2.service" ];
       };
       Service = {
         ExecStart = "${pkgs.nqptp}/bin/nqptp -v";
@@ -23,24 +24,64 @@ lib.mkIf (lib.elem username installFor && role == "piceiver") {
         WantedBy = [ "default.target" ];
       };
     };
-    shairport-sync = {
+    shairport-sync-airplay-2 = {
       Unit = {
-        Description = "shairport-sync AirPlay server";
+        Description = "shairport-sync AirPlay 2 server";
         After = [
           "nqptp.service"
           "pipewire.service"
+          # Start Shairport-Sync for AirPlay 1 first to avoid contention of the same network ports.
+          "shairport-sync-airplay-1.service"
           "wireplumber.service"
+          # The delay from the wireplumber-init service provides enough time for all of the PipeWire nodes to become available.
+          # todo I should probably use a proper `pipewire-ready.target` instead.
+          "wireplumber-init.service"
         ];
+        # This service needs to be restarted whenever PipeWire is.
+        # If it isn't restarted, it will fallback to the combined stereo sink.
+        PartOf = [ "pipewire.service" ];
         Requires = [
           "nqptp.service"
+          "wireplumber-init.service"
+        ];
+        Wants = [
+          "shairport-sync-airplay-1.service"
+          "wireplumber.service"
+        ];
+        X-Restart-Triggers = [ "${osConfig.environment.etc."shairport-sync.conf".source}" ];
+      };
+      Service = {
+        ExecStart = "${pkgs.shairport-sync-airplay-2}/bin/shairport-sync";
+        Restart = "always";
+        RestartSec = 10;
+      };
+      Install = {
+        WantedBy = [ "default.target" ];
+      };
+    };
+    shairport-sync-airplay-1 = {
+      Unit = {
+        Description = "shairport-sync AirPlay 1 server";
+        After = [
           "pipewire.service"
           "wireplumber.service"
+          # The delay from the wireplumber-init service provides enough time for all of the PipeWire nodes to become available.
+          # todo I should probably use a proper `pipewire-ready.target` instead.
+          "wireplumber-init.service"
         ];
-        Wants = [ "wireplumber-init.service" ];
+        # This service needs to be restarted whenever PipeWire is.
+        # If it isn't restarted, it will fallback to the combined stereo sink.
+        PartOf = [ "pipewire.service" ];
+        Requires = [ "wireplumber-init.service" ];
+        Wants = [ "wireplumber.service" ];
+        X-Restart-Triggers = [ "${osConfig.environment.etc."shairport-sync-airplay-1.conf".source}" ];
       };
       Service = {
-        ExecStart = "${pkgs.shairport-sync}/bin/shairport-sync";
+        ExecStart = "${pkgs.shairport-sync}/bin/shairport-sync --configfile=${
+          osConfig.environment.etc."shairport-sync-airplay-1.conf".source
+        }";
         Restart = "always";
+        RestartSec = 10;
       };
       Install = {
         WantedBy = [ "default.target" ];

home-manager/_mixins/services/snapclient/default.nix

@@ -10,8 +10,7 @@ let
   snapcastFlags =
     [
       "--logsink system"
-      # todo I'm not sure the best buffer time here, but it may need tweaked. pulse:buffer_time=100
-      "--player pulse"
+      "--player pulse:buffer_time=10" # Minimum is 10ms, default is 100ms
     ]
     ++ lib.optionals (role == "piceiver") [
       "--host ::1"
@@ -26,23 +25,26 @@ lib.mkIf (lib.elem username installFor) {
       Unit = {
         Description = "Snapcast client";
         After = [
+          "pipewire.service"
           "pipewire-pulse.service"
           "wireplumber.service"
+          # The wireplumber-init service ensures the volume is set correctly before playback starts.
+          "wireplumber-init.service"
         ];
-        Requires = [
-          "pipewire-pulse.service"
+        PartOf = [ "pipewire-pulse.service" ];
+        Requires = [ "wireplumber-init.service" ];
+        Wants = [
+          "pipewire.service"
           "wireplumber.service"
         ];
       };
       Service = {
         ExecStart = "${pkgs.snapcast}/bin/snapclient " + builtins.toString snapcastFlags;
         Restart = "always";
+        RestartSec = 10;
       };
       Install = {
-        WantedBy = [
-          "default.target"
-          "wireplumber.service"
-        ];
+        WantedBy = [ "default.target" ];
       };
     };
   };

home-manager/_mixins/services/wireplumber-init/default.nix

@@ -1,5 +1,6 @@
 {
   lib,
+  osConfig,
   pkgs,
   role,
   username,
@@ -11,8 +12,7 @@ let
     if role == "piceiver" then
       "${pkgs.initialize-wireplumber}/bin/initialize-wireplumber.nu"
     else
-      # todo Keep in sync with the version in NixOs PipeWire config.
-      "${pkgs.unstable.wireplumber}/bin/wpctl set-volume @DEFAULT_AUDIO_SINK@ 80%";
+      "${osConfig.services.pipewire.wireplumber.package}/bin/wpctl set-volume @DEFAULT_AUDIO_SINK@ 80%";
 in
 lib.mkIf (lib.elem username installFor) {
   systemd.user = {
@@ -22,9 +22,15 @@ lib.mkIf (lib.elem username installFor) {
           Description = "Initialize WirePlumber default devices and volumes";
           After = [ "wireplumber.service" ];
           Requires = [ "wireplumber.service" ];
+          X-Restart-Triggers = lib.optionals (role == "piceiver") [
+            "${pkgs.initialize-wireplumber}/bin/initialize-wireplumber.nu"
+          ];
         };
         Service = {
+          # Sleep for 5 seconds to give PipeWire a chance to initialize?
+          ExecStartPre = "${pkgs.coreutils}/bin/sleep 5";
           ExecStart = script;
+          # RemainAfterExit = true;
           Type = "oneshot";
         };
       };

lychee.toml

@@ -1,5 +1,8 @@
-# Due to rate limiting from gnu.org
-accept = [429]
+exclude = [
+  # These websites return 403 forbidden codes for GitHub runners.
+  '^https://www\.digikey\.com',
+  '^https://www\.raspberrypi\.com',
+]
 
 cache = true
 exclude_path = [".direnv/", "result/"]