fix(lotus): restart the shared mic sampler only when the LiveKit rooms change (#45)

observeLocalMicSample$ switchMapped on every allConnections$ emission,
which re-emits far more often than the set of rooms changes. Each one
stopped the clone, closed the AudioContext and emitted null, and the
null reset the muted-speech gate, so the "You're muted" nudge could
never stay true long enough to fire. Map to the room list and only
restart when it actually changes.

Fixes #45

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

embedded/web/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lotusguild/element-call-embedded",
-  "version": "0.25.0-lotus.22",
+  "version": "0.25.0-lotus.24",
   "files": [
     "README.md",
     "LICENSE-AGPL-3.0",

src/lotus/lotusAudioOutput.test.ts

@@ -0,0 +1,24 @@
+/*
+Copyright 2026 Lotus Guild
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { expect, test } from "vitest";
+
+import { audioOutputList } from "./lotusAudioOutput";
+import { type AudioOutputDeviceLabel } from "../state/MediaDevices";
+
+test("audioOutputList labels every kind of output (cinny #310)", () => {
+  const m = new Map<string, AudioOutputDeviceLabel>([
+    ["", { type: "default", name: "Speakers" }],
+    ["a1", { type: "name", name: "Headset" }],
+    ["a2", { type: "number", number: 3 }],
+  ]);
+  expect(audioOutputList(m)).toEqual([
+    { id: "", label: "Default (Speakers)" },
+    { id: "a1", label: "Headset" },
+    { id: "a2", label: "Output 3" },
+  ]);
+});

src/lotus/lotusAudioOutput.ts

@@ -8,7 +8,12 @@ Please see LICENSE in the repository root for full details.
 import { type IWidgetApiRequest } from "matrix-widget-api";
 import { logger } from "matrix-js-sdk/lib/logger";
 
-import { type MediaDevices } from "../state/MediaDevices";
+import { combineLatest } from "rxjs";
+
+import {
+  type AudioOutputDeviceLabel,
+  type MediaDevices,
+} from "../state/MediaDevices";
 import { widget } from "../widget";
 import { LotusWidgetActions } from "./lotusActions";
 import { lotusSendToHost } from "./lotusWidget";
@@ -19,6 +24,10 @@ import { lotusSendToHost } from "./lotusWidget";
  * selects the output; the fork answers each change (and the initial state)
  * with `io.lotus.audio_output_state { deviceId, available: [{id,label}] }`.
  * No effect unless the host sends the action. Returns a teardown function.
+ *
+ * [cinny #310] Browsers hash deviceIds per frame/origin, so the host can't
+ * use ids from its own enumerateDevices(); it builds its menu from
+ * `available` here, whose ids are valid in this frame.
  */
 export function startLotusAudioOutput(mediaDevices: MediaDevices): () => void {
   const w = widget;
@@ -33,9 +42,13 @@ export function startLotusAudioOutput(mediaDevices: MediaDevices): () => void {
   };
   w.lazyActions.on(LotusWidgetActions.SetAudioOutput, handler);
 
-  const sub = mediaDevices.audioOutput.selected$.subscribe((selected) => {
+  const sub = combineLatest([
+    mediaDevices.audioOutput.available$,
+    mediaDevices.audioOutput.selected$,
+  ]).subscribe(([available, selected]) => {
     lotusSendToHost(LotusWidgetActions.AudioOutputState, {
       deviceId: selected?.id ?? null,
+      available: audioOutputList(available),
     });
   });
 
@@ -44,3 +57,29 @@ export function startLotusAudioOutput(mediaDevices: MediaDevices): () => void {
     w.lazyActions.off(LotusWidgetActions.SetAudioOutput, handler);
   };
 }
+
+/** The output list as `{id, label}` for the host's menu (#310). */
+export function audioOutputList(
+  available: Map<string, AudioOutputDeviceLabel>,
+): { id: string; label: string }[] {
+  return [...available].map(([id, l]) => {
+    let label: string;
+    switch (l.type) {
+      case "name":
+        label = l.name;
+        break;
+      case "number":
+        label = `Output ${l.number}`;
+        break;
+      case "default":
+        label = l.name ? `Default (${l.name})` : "Default";
+        break;
+      case "speaker":
+        label = "Speaker";
+        break;
+      default:
+        label = "Earpiece";
+    }
+    return { id, label };
+  });
+}

src/lotus/lotusMicLevel.test.ts

@@ -7,7 +7,7 @@ Please see LICENSE in the repository root for full details.
 
 import { describe, expect, it } from "vitest";
 
-import { MicLevelQuantizer } from "./lotusMicLevel";
+import { MicLevelQuantizer, sameRooms } from "./lotusMicLevel";
 
 describe("MicLevelQuantizer", () => {
   it("maps RMS to 0–3 bars", () => {
@@ -35,3 +35,14 @@ describe("MicLevelQuantizer", () => {
     expect(q.push(0)).toBe(0);
   });
 });
+
+describe("sameRooms (EC #45)", () => {
+  it("compares rooms by identity and order", () => {
+    const a = {};
+    const b = {};
+    expect(sameRooms([a, b], [a, b])).toBe(true);
+    expect(sameRooms([a], [a, b])).toBe(false);
+    expect(sameRooms([a, b], [b, a])).toBe(false);
+    expect(sameRooms([{}], [{}])).toBe(false);
+  });
+});

src/lotus/lotusMicLevel.ts

@@ -46,6 +46,10 @@ const micPublication = (
     : null;
 };
 
+/** Pure: the same LiveKit rooms, in the same order (by identity). */
+export const sameRooms = <T>(a: readonly T[], b: readonly T[]): boolean =>
+  a.length === b.length && a.every((r, i) => r === b[i]);
+
 const samplers = new WeakMap<
   CallViewModel,
   Observable<LocalMicSample | null>
@@ -62,10 +66,15 @@ export function observeLocalMicSample$(
   const cached = samplers.get(vm);
   if (cached) return cached;
   const sampler$ = vm.allConnections$.pipe(
+    map((data) => data.getConnections().map((c) => c.livekitRoom)),
+    // [EC #45] allConnections$ re-emits far more often than the set of
+    // LiveKit rooms changes; restarting the tap each time closed the
+    // AudioContext ~1×/s and emitted null, which reset the muted-speech
+    // gate so the "You're muted" nudge could never fire.
+    distinctUntilChanged(sameRooms),
     switchMap(
-      (data) =>
+      (rooms) =>
         new Observable<LocalMicSample | null>((subscriber) => {
-          const rooms = data.getConnections().map((c) => c.livekitRoom);
           let ctx: AudioContext | null = null;
           let clone: MediaStreamTrack | null = null;
           let timer: ReturnType<typeof setInterval> | undefined;