From 89ad5d1dcaaaef95841a87e815334b0a33d2305e Mon Sep 17 00:00:00 2001
From: codex <codex@example.local>
Date: Wed, 10 Jun 2026 22:37:29 +0200
Subject: [PATCH] Add local microphone volume meter

---
 public/app.js     | 103 +++++++++++++++++++++++++++++++++++++++++++++-
 public/index.html |   7 ++++
 public/styles.css |  29 +++++++++++++
 3 files changed, 137 insertions(+), 2 deletions(-)

diff --git a/public/app.js b/public/app.js
index f93a58b..083a01d 100644
--- a/public/app.js
+++ b/public/app.js
@@ -25,6 +25,8 @@ const cameraButton = document.querySelector("#camera-button");
 const micButton = document.querySelector("#mic-button");
 const shareButton = document.querySelector("#share-button");
 const announceButton = document.querySelector("#announce-button");
+const selfMicVolumeInput = document.querySelector("#self-mic-volume");
+const selfMicMeter = document.querySelector("#self-mic-meter");
 const announcementDialog = document.querySelector("#announcement-dialog");
 const announcementForm = document.querySelector("#announcement-form");
 const announcementInput = document.querySelector("#announcement-input");
@@ -35,6 +37,7 @@ const nameStorageKey = "kkkmeet.displayName";
 const clientIdStorageKey = "kkkmeet.clientId";
 const cameraStorageKey = "kkkmeet.cameraDeviceId";
 const micStorageKey = "kkkmeet.micDeviceId";
+const micVolumeStorageKey = "kkkmeet.selfMicVolume";
 const watchHeightStorageKey = "kkkmeet.watchPanelHeight";
 const watchCollapsedStorageKey = "kkkmeet.watchPanelCollapsed";
 const rtcConfig = {
@@ -44,6 +47,12 @@ const rtcConfig = {
 let peerId = "";
 let displayName = "";
 let localStream;
+let localProcessedAudioTrack;
+let localMicSourceNode;
+let localMicGainNode;
+let localMicAnalyserNode;
+let localMicDestination;
+let micMeterAnimationFrame = 0;
 let screenStream;
 let localPresentationTile;
 let events;
@@ -682,6 +691,7 @@ async function ensureLocalStream() {
     localStream = await navigator.mediaDevices.getUserMedia(mediaConstraints());
   }
   localVideo.srcObject = localStream;
+  rebuildLocalMicGraph(localStream.getAudioTracks()[0]);
   await refreshDeviceLists();
   return localStream;
 }
@@ -728,6 +738,81 @@ async function refreshDeviceLists() {
   );
 }
 
+function savedSelfMicVolume() {
+  const saved = Number(localStorage.getItem(micVolumeStorageKey));
+  return Number.isFinite(saved) ? clamp(saved, 0, 200) : 100;
+}
+
+function setSelfMicVolume(value) {
+  const normalizedVolume = clamp(Number(value) || 0, 0, 200);
+  selfMicVolumeInput.value = String(normalizedVolume);
+  localStorage.setItem(micVolumeStorageKey, String(normalizedVolume));
+  if (localMicGainNode) {
+    localMicGainNode.gain.value = normalizedVolume / 100;
+  }
+}
+
+function stopMicMeter() {
+  if (micMeterAnimationFrame) {
+    cancelAnimationFrame(micMeterAnimationFrame);
+    micMeterAnimationFrame = 0;
+  }
+  selfMicMeter.value = 0;
+}
+
+function startMicMeter() {
+  stopMicMeter();
+  if (!localMicAnalyserNode) return;
+
+  const samples = new Uint8Array(localMicAnalyserNode.fftSize);
+  const tick = () => {
+    localMicAnalyserNode.getByteTimeDomainData(samples);
+    let sum = 0;
+    for (const sample of samples) {
+      const centered = (sample - 128) / 128;
+      sum += centered * centered;
+    }
+    selfMicMeter.value = Math.min(1, Math.sqrt(sum / samples.length) * 3);
+    micMeterAnimationFrame = requestAnimationFrame(tick);
+  };
+  tick();
+}
+
+function rebuildLocalMicGraph(track) {
+  localMicSourceNode?.disconnect();
+  localMicGainNode?.disconnect();
+  localMicAnalyserNode?.disconnect();
+  stopMicMeter();
+
+  localProcessedAudioTrack?.stop();
+  localProcessedAudioTrack = undefined;
+  localMicSourceNode = undefined;
+  localMicGainNode = undefined;
+  localMicAnalyserNode = undefined;
+  localMicDestination = undefined;
+
+  if (!track) return;
+
+  const context = ensureAudioContext();
+  const sourceStream = new MediaStream([track]);
+  localMicSourceNode = context.createMediaStreamSource(sourceStream);
+  localMicGainNode = context.createGain();
+  localMicAnalyserNode = context.createAnalyser();
+  localMicAnalyserNode.fftSize = 256;
+  localMicDestination = context.createMediaStreamDestination();
+  localMicSourceNode.connect(localMicGainNode);
+  localMicGainNode.connect(localMicAnalyserNode);
+  localMicGainNode.connect(localMicDestination);
+  localProcessedAudioTrack = localMicDestination.stream.getAudioTracks()[0];
+  localProcessedAudioTrack.enabled = track.enabled;
+  setSelfMicVolume(selfMicVolumeInput.value);
+  startMicMeter();
+}
+
+function outboundAudioTrack() {
+  return localProcessedAudioTrack || localStream?.getAudioTracks()[0];
+}
+
 async function replaceLocalTrack(kind, deviceId) {
   if (!deviceId) return;
 
@@ -755,10 +840,14 @@ async function replaceLocalTrack(kind, deviceId) {
     localStream.addTrack(newTrack);
   }
 
+  if (kind === "audio") {
+    rebuildLocalMicGraph(newTrack);
+  }
+
   if (kind === "audio" || !screenStream) {
     for (const { connection } of peers.values()) {
       const sender = connection.getSenders().find((item) => item.track?.kind === kind);
-      await sender?.replaceTrack(newTrack);
+      await sender?.replaceTrack(kind === "audio" ? outboundAudioTrack() : newTrack);
     }
   }
 
@@ -917,7 +1006,7 @@ async function sendRoomEvent(payload) {
 }
 
 function outboundTracks() {
-  const audioTracks = localStream?.getAudioTracks() || [];
+  const audioTracks = [outboundAudioTrack()].filter(Boolean);
   const videoTrack = screenStream?.getVideoTracks()[0] || localStream?.getVideoTracks()[0];
   return [...audioTracks, videoTrack].filter(Boolean);
 }
@@ -1119,6 +1208,9 @@ function setTrackEnabled(kind, enabled) {
   localStream?.getTracks().forEach((track) => {
     if (track.kind === kind) track.enabled = enabled;
   });
+  if (kind === "audio" && localProcessedAudioTrack) {
+    localProcessedAudioTrack.enabled = enabled;
+  }
 }
 
 function updateToggleButton(button, enabled, enabledLabel, disabledLabel) {
@@ -1313,6 +1405,10 @@ micButton.addEventListener("click", () => {
   setTrackEnabled("audio", enabled);
 });
 
+selfMicVolumeInput.addEventListener("input", () => {
+  setSelfMicVolume(selfMicVolumeInput.value);
+});
+
 cameraSelect.addEventListener("change", () => {
   replaceLocalTrack("video", cameraSelect.value).catch((error) => {
     console.error(error);
@@ -1371,6 +1467,9 @@ shareButton.addEventListener("click", async () => {
   }
 });
 
+selfMicVolumeInput.value = String(savedSelfMicVolume());
+selfMicMeter.value = 0;
+
 const savedName = localStorage.getItem(nameStorageKey);
 if (savedName) {
   setDisplayName(savedName);
diff --git a/public/index.html b/public/index.html
index 195ab7c..8850c1d 100644
--- a/public/index.html
+++ b/public/index.html
@@ -111,6 +111,13 @@
           <div class="control-actions" aria-label="Call controls">
             <button id="share-button" type="button">Share Screen</button>
             <button id="announce-button" type="button">Announce</button>
+            <div class="self-mic-control" aria-label="Local microphone volume">
+              <label>
+                <span>Mic</span>
+                <input id="self-mic-volume" type="range" min="0" max="200" step="1" />
+              </label>
+              <meter id="self-mic-meter" min="0" max="1" low="0.15" high="0.65" optimum="0.45"></meter>
+            </div>
           </div>
         </div>
         <article class="self-preview">
diff --git a/public/styles.css b/public/styles.css
index df9f6bd..1b68a25 100644
--- a/public/styles.css
+++ b/public/styles.css
@@ -607,6 +607,35 @@ button[aria-pressed="false"] {
   font-size: 13px;
 }
 
+.self-mic-control {
+  display: grid;
+  grid-template-columns: minmax(120px, 160px) 56px;
+  align-items: end;
+  gap: 8px;
+  min-width: 190px;
+}
+
+.self-mic-control label {
+  display: grid;
+  grid-template-rows: 12px 18px;
+  gap: 5px;
+  color: #aeb7c3;
+  font-size: 11px;
+  font-weight: 650;
+}
+
+.self-mic-control input {
+  width: 100%;
+  height: 18px;
+  padding: 0;
+}
+
+.self-mic-control meter {
+  width: 56px;
+  height: 18px;
+  align-self: end;
+}
+
 .self-preview {
   position: relative;
   overflow: hidden;