Fix Linux audio source selection

LivescriptV2.01.py

@@ -976,12 +976,53 @@ def quit_app(self):
 
 
 # --- Background Threads ---
+def is_loopback_microphone(microphone):
+    """Return True for PulseAudio/PipeWire monitor or other loopback sources."""
+    mic_id = str(microphone.id).lower()
+    mic_name = microphone.name.lower()
+    return "monitor" in mic_id or "loopback" in mic_id or "monitor" in mic_name or "loopback" in mic_name
+
+
+def get_loopback_microphone(speaker):
+    """Find the recording source that monitors the given speaker output."""
+    speaker_id = str(speaker.id)
+    candidates = [
+        f"{speaker_id}.monitor",  # PulseAudio/PipeWire monitor source id on Linux.
+        speaker_id,
+        speaker.name,
+        f"Monitor of {speaker.name}",
+    ]
+
+    for candidate in candidates:
+        try:
+            return sc.get_microphone(id=candidate, include_loopback=True)
+        except Exception:
+            pass
+
+    loopbacks = [mic for mic in sc.all_microphones(include_loopback=True) if is_loopback_microphone(mic)]
+    matching_loopbacks = [mic for mic in loopbacks if speaker_id in str(mic.id) or speaker.name in mic.name]
+
+    if matching_loopbacks:
+        return matching_loopbacks[0]
+    if len(loopbacks) == 1:
+        return loopbacks[0]
+
+    available = "\n".join(f"  {mic.name} | id={mic.id}" for mic in sc.all_microphones(include_loopback=True))
+    raise RuntimeError(
+        "Could not find a loopback/monitor microphone for the default speaker.\n"
+        "Available microphones including loopback devices:\n"
+        f"{available}"
+    )
+
+
 def audio_capture_thread(block_size, sample_rate):
     """Captures audio from the default speaker and puts it into a queue."""
     try:
         default_speaker = sc.default_speaker()
         print(f"Using speaker: {default_speaker.name} for audio capture.")
-        with sc.get_microphone(id=str(default_speaker.id), include_loopback=True).recorder(
+        loopback_microphone = get_loopback_microphone(default_speaker)
+        print(f"Using loopback microphone: {loopback_microphone.name} for audio capture.")
+        with loopback_microphone.recorder(
                 samplerate=sample_rate, channels=1, blocksize=int(block_size)
         ) as mic:
             print("Audio recorder started.")
@@ -1107,4 +1148,4 @@ def restart_application():
 
 
 if __name__ == "__main__":
-    main()
+    main()