Audio Router

router.py

@@ -0,0 +1,142 @@
+#!/usr/bin/env python3
+import json
+import signal
+import time
+
+import jack
+import yaml
+import paho.mqtt.client as mqtt
+
+
+CONFIG_FILE = "config.yaml"
+
+
+class JackRouter:
+    def __init__(self):
+        with open(CONFIG_FILE, "r") as f:
+            self.cfg = yaml.safe_load(f)
+
+        self.client = jack.Client("AudioRouter")
+        self.mode = "mute_all"
+        self.base_topic = self.cfg["mqtt"]["base_topic"].rstrip("/")
+
+    def connect(self, src, dst):
+        try:
+            if not self.client.get_all_connections(dst).count(src):
+                self.client.connect(src, dst)
+                print(f"Connected: {src} -> {dst}")
+        except jack.JackError as e:
+            print(f"Connect failed: {src} -> {dst}: {e}")
+
+    def disconnect(self, src, dst):
+        try:
+            self.client.disconnect(src, dst)
+            print(f"Disconnected: {src} -> {dst}")
+        except jack.JackError:
+            pass
+
+    def clear_routes(self):
+        all_routes = self.cfg["routes"]
+
+        for route in all_routes.values():
+            source = self.cfg["ports"][route["source"]]
+            output = self.cfg["ports"][route["output"]]
+
+            pairs = [
+                (source["left"], output["left"]),
+                (source["right"], output["right"]),
+            ]
+
+            for src, dst in pairs:
+                self.disconnect(src, dst)
+
+    def routes_for_mode(self, mode):
+        preset = self.cfg["presets"].get(mode)
+
+        if preset is None:
+            return None
+
+        resolved_routes = []
+
+        for route_name, enabled in preset.items():
+            if not enabled:
+                continue
+
+            route = self.cfg["routes"][route_name]
+
+            source_name = route["source"]
+            output_name = route["output"]
+
+            source = self.cfg["ports"][source_name]
+            output = self.cfg["ports"][output_name]
+
+            resolved_routes.append((source["left"], output["left"]))
+            resolved_routes.append((source["right"], output["right"]))
+
+        return resolved_routes
+
+    def set_mode(self, mode):
+        routes = self.routes_for_mode(mode)
+        if routes is None:
+            print(f"Unknown mode: {mode}")
+            return False
+
+        print(f"Setting mode: {mode}")
+        self.clear_routes()
+
+        for src, dst in routes:
+            self.connect(src, dst)
+
+        self.mode = mode
+        return True
+
+    def state(self):
+        return {
+            "mode": self.mode,
+            "running": True,
+            "timestamp": int(time.time()),
+        }
+
+
+def main():
+    router = JackRouter()
+
+    mqtt_cfg = router.cfg["mqtt"]
+    client = mqtt.Client()
+
+    def publish_state():
+        client.publish(f"{router.base_topic}/state", json.dumps(router.state()), retain=True)
+        client.publish(f"{router.base_topic}/mode/state", router.mode, retain=True)
+
+    def on_connect(client, userdata, flags, rc):
+        print(f"MQTT connected: {rc}")
+        client.subscribe(f"{router.base_topic}/mode/set")
+        router.set_mode("aux_only")
+        publish_state()
+
+    def on_message(client, userdata, msg):
+        mode = msg.payload.decode().strip()
+        print(f"MQTT received: {msg.topic} = {mode}")
+
+        if router.set_mode(mode):
+            publish_state()
+
+    def shutdown(*args):
+        print("Stopping router...")
+        router.set_mode("mute_all")
+        publish_state()
+        raise SystemExit
+
+    signal.signal(signal.SIGINT, shutdown)
+    signal.signal(signal.SIGTERM, shutdown)
+
+    client.on_connect = on_connect
+    client.on_message = on_message
+
+    with router.client:
+        client.connect(mqtt_cfg["host"], int(mqtt_cfg["port"]), 60)
+        client.loop_forever()
+
+
+if __name__ == "__main__":
+    main()