sane-cast: support casting audio

hosts/common/programs/assorted.nix

@@ -1079,7 +1079,8 @@ in
     sane-cast.sandbox.method = "bunpen";
     sane-cast.sandbox.net = "clearnet";
     sane-cast.sandbox.autodetectCliPaths = "existingFile";
-    sane-cast.suggestedPrograms = [ "go2tv" ];
+    sane-cast.sandbox.whitelistAudio = true;  #< for blast audio casting
+    sane-cast.suggestedPrograms = [ "blast-ugjka" "go2tv" ];
 
     sane-die-with-parent.sandbox.enable = false;  #< it's a launcher; can't sandbox
 

hosts/common/programs/pipewire/20-virtual.conf

@@ -7,6 +7,11 @@
 # based on: <repo:pipewire/pipewire:src/daemon/filter-chain/source-duplicate-FL.conf>
 # but modified:
 # - duplicate both FL *and* FR
+# - don't pipe inputs into outputs
+#   this effectively creates a filter who's output is always silence.
+#   blast still works because it grabs from the monitor, not the output.
+#   better would be to make a sink (a "virtual sink", a "null sink", or a "loopback"), which has no output at *all*,
+#   but i couldn't get that to actually work (e.g. it doesn't show up in PavuControl, or it does but still forwards audio)
 
 context.modules = [
   { name = libpipewire-module-filter-chain
@@ -40,8 +45,8 @@ context.modules = [
         links = [
           # we can only tee from nodes, not inputs so we need
           # to copy the inputs and then tee.
-          { output = "copyIL:Out" input = "copyOL:In" }
-          { output = "copyIR:Out" input = "copyOR:In" }
+          # { output = "copyIL:Out" input = "copyOL:In" }
+          # { output = "copyIR:Out" input = "copyOR:In" }
         ]
         inputs  = [ "copyIL:In" "copyIR:In" ]
         outputs = [ "copyOL:Out" "copyOR:Out" ]

pkgs/additional/sane-cast/default.nix

@@ -1,7 +1,7 @@
 { static-nix-shell }:
 static-nix-shell.mkPython3 {
   pname = "sane-cast";
-  pkgs = [ "go2tv" ];
+  pkgs = [ "blast-ugjka" "go2tv" ];
   srcRoot = ./.;
 }
 

pkgs/additional/sane-cast/sane-cast

@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#!nix-shell -i python3 -p go2tv -p python3
+#!nix-shell -i python3 -p blast-ugjka -p go2tv -p python3
 # vim: set filetype=python :
 """
 cast media (local video or audio files) to a device on the same network
@@ -13,6 +13,7 @@ from enum import Enum
 import argparse
 import logging
 import os
+import socket
 import subprocess
 import tempfile
 
@@ -125,6 +126,31 @@ class Go2TvDriver:
 
         os.execvp("go2tv", cli_args)
 
+class BlastDriver:
+    def cast_to(self, dev: Device) -> None:
+        blast_args = [
+            "blast",
+            # "blast.monitor" source will create a new output, or we can do that in pipewire config for better predictability.
+            "-source", "effect_input.virtual.monitor",
+            "-device", dev.model,
+            "-ip", get_ranked_ip_addrs()[0],
+        ]
+        if dev.compat != Compat.RenameToMp4:
+            blast_args += [ "-usewav" ];
+
+        os.execvp("blast", blast_args)
+
+def get_ranked_ip_addrs():
+    """
+    return the IP addresses most likely to be LAN addresses
+    based on: <https://stackoverflow.com/a/1267524>
+    """
+    _name, _aliases, static_addrs = socket.gethostbyname_ex(socket.gethostname())
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.connect(("1", 53))
+    con_addr, _port = s.getsockname()
+    return sorted(set(static_addrs + [ con_addr ]), key=lambda a: (a.startswith("127"), a))
+
 def filter_devices(devices: list[Device], filter: str) -> list[Device]:
     return [d for d in devices if d.matches(filter)]
 
@@ -179,13 +205,14 @@ def main():
     parser.add_argument("--verbose", action="store_true", help="more logging")
     parser.add_argument("--always-ask", action="store_true", help="always ask which device to cast to, regardless how many are available")
     parser.add_argument("--device", help="filter devices based on if this string is contained in their name (case-insensitive)")
-    parser.add_argument("media", help="file or URL to send to the DLNA device")
+    parser.add_argument("media", nargs="?", help="file or URL to send to the DLNA device. empty to case just an audio stream")
 
     args = parser.parse_args()
 
     if args.verbose:
         logger.setLevel(logging.DEBUG)
 
+    blast = BlastDriver()
     go2tv = Go2TvDriver()
     devices = go2tv.scan_devices()
 
@@ -197,7 +224,10 @@ def main():
     if dev is None or args.always_ask:
         dev = ask_device(devices)
     if dev:
-        go2tv.cast_to(dev, args.media)
+        if args.media:
+            go2tv.cast_to(dev, args.media)
+        else:
+            blast.cast_to(dev)
 
 if __name__ == "__main__":
     main()