fix mic meter and distribute participant positions

public/audio-manager.js

@@ -6,6 +6,7 @@ export class AudioManager {
     this.source = null;
     this.gainNode = null;
     this.analyser = null;
+    this.meterSink = null;
     this.meterData = new Float32Array(1024);
     this.gain = Number(localStorage.getItem('voicepoc.micGain') || 1);
   }
@@ -25,20 +26,24 @@ export class AudioManager {
     this.gainNode.gain.value = this.gain;
     this.analyser = this.context.createAnalyser();
     this.analyser.fftSize = 1024;
+    this.meterSink = this.context.createGain();
+    this.meterSink.gain.value = 0;
     const destination = this.context.createMediaStreamDestination();
     this.source.connect(this.gainNode).connect(this.analyser);
+    // Keep the analyser alive without sending the microphone to the speakers.
+    this.analyser.connect(this.meterSink).connect(this.context.destination);
     this.gainNode.connect(destination);
     this.outputStream = destination.stream;
     return this.outputStream;
   }
 
   detachInput() {
-    for (const node of [this.source, this.gainNode, this.analyser]) {
+    for (const node of [this.source, this.gainNode, this.analyser, this.meterSink]) {
       try { node?.disconnect(); } catch {}
     }
     this.outputStream?.getTracks().forEach((track) => track.stop());
     this.rawStream?.getTracks().forEach((track) => track.stop());
-    this.source = this.gainNode = this.analyser = null;
+    this.source = this.gainNode = this.analyser = this.meterSink = null;
     this.outputStream = this.rawStream = null;
   }