Fix macOS Sidecar microphone duplication

electron/native/ScreenCaptureKitRecorder.swift

@@ -528,8 +528,35 @@ final class ScreenCaptureRecorder: NSObject, SCStreamOutput, SCStreamDelegate {
 		]
 	}
 
+	private static func isLikelyDisplayAudioDevice(_ device: AVCaptureDevice) -> Bool {
+		let normalizedName = device.localizedName
+			.trimmingCharacters(in: .whitespacesAndNewlines)
+			.lowercased()
+		if normalizedName.isEmpty {
+			return false
+		}
+
+		let microphoneTokens = ["mic", "microphone", "headset", "airpods", "airpods max"]
+		let mentionsMicrophone = microphoneTokens.contains { normalizedName.contains($0) }
+		if normalizedName.contains("sidecar") {
+			return !mentionsMicrophone
+		}
+
+		if normalizedName.contains("continuity") && !mentionsMicrophone {
+			return true
+		}
+
+		let displayRouteTokens = ["display", "monitor", "screen", "hdmi", "airplay"]
+		let audioOutputTokens = ["audio", "speaker", "output"]
+		let mentionsDisplayRoute = displayRouteTokens.contains { normalizedName.contains($0) }
+		let mentionsAudioOutput = audioOutputTokens.contains { normalizedName.contains($0) }
+		return mentionsDisplayRoute && mentionsAudioOutput && !mentionsMicrophone
+	}
+
 	private static func resolveMicrophoneCaptureDeviceID(config: CaptureConfig) -> String? {
-		let audioDevices = AVCaptureDevice.devices(for: .audio)
+		let audioDevices = AVCaptureDevice.devices(for: .audio).filter {
+			!isLikelyDisplayAudioDevice($0)
+		}
 
 		if let microphoneLabel = config.microphoneLabel?.trimmingCharacters(in: .whitespacesAndNewlines), !microphoneLabel.isEmpty {
 			if let matchedDevice = audioDevices.first(where: { $0.localizedName == microphoneLabel }) {

src/hooks/useMicrophoneDevices.test.ts

@@ -0,0 +1,58 @@
+import { describe, expect, it } from "vitest";
+
+import {
+	getAvailableMicrophoneDevices,
+	isLikelyDisplayAudioInputLabel,
+} from "./useMicrophoneDevices";
+
+describe("isLikelyDisplayAudioInputLabel", () => {
+	it("filters Sidecar and display-audio routes", () => {
+		expect(isLikelyDisplayAudioInputLabel("Sidecar Display Audio")).toBe(true);
+		expect(isLikelyDisplayAudioInputLabel("LG HDR 4K Display Audio")).toBe(true);
+		expect(isLikelyDisplayAudioInputLabel("AirPlay Receiver Audio")).toBe(true);
+	});
+
+	it("keeps real microphones even when the label mentions a display", () => {
+		expect(isLikelyDisplayAudioInputLabel("Studio Display Microphone")).toBe(false);
+		expect(isLikelyDisplayAudioInputLabel("MacBook Pro Microphone")).toBe(false);
+		expect(isLikelyDisplayAudioInputLabel("AirPods Max Microphone")).toBe(false);
+	});
+});
+
+describe("getAvailableMicrophoneDevices", () => {
+	it("excludes likely display-audio endpoints from the microphone list", () => {
+		const devices = getAvailableMicrophoneDevices([
+			{
+				deviceId: "default",
+				groupId: "builtin-group",
+				kind: "audioinput",
+				label: "MacBook Pro Microphone",
+			},
+			{
+				deviceId: "sidecar",
+				groupId: "sidecar-group",
+				kind: "audioinput",
+				label: "Sidecar Display Audio",
+			},
+			{
+				deviceId: "studio-display",
+				groupId: "display-group",
+				kind: "audioinput",
+				label: "Studio Display Microphone",
+			},
+		] satisfies MediaDeviceInfo[]);
+
+		expect(devices).toEqual([
+			{
+				deviceId: "default",
+				groupId: "builtin-group",
+				label: "MacBook Pro Microphone",
+			},
+			{
+				deviceId: "studio-display",
+				groupId: "display-group",
+				label: "Studio Display Microphone",
+			},
+		]);
+	});
+});

src/hooks/useMicrophoneDevices.ts

@@ -6,6 +6,48 @@ export interface MicrophoneDevice {
 	groupId: string;
 }
 
+type AudioInputDeviceLike = Pick<MediaDeviceInfo, "deviceId" | "groupId" | "kind" | "label">;
+
+const DISPLAY_AUDIO_ROUTE_TOKENS = ["display", "monitor", "screen", "hdmi", "airplay"];
+const AUDIO_OUTPUT_TOKENS = ["audio", "speaker", "output"];
+const MICROPHONE_TOKENS = ["mic", "microphone", "headset", "airpods", "airpods max"];
+
+export function isLikelyDisplayAudioInputLabel(label: string): boolean {
+	const normalizedLabel = label.trim().toLowerCase();
+	if (!normalizedLabel) {
+		return false;
+	}
+
+	const mentionsMicrophone = MICROPHONE_TOKENS.some((token) => normalizedLabel.includes(token));
+	if (normalizedLabel.includes("sidecar")) {
+		return !mentionsMicrophone;
+	}
+
+	if (normalizedLabel.includes("continuity") && !mentionsMicrophone) {
+		return true;
+	}
+
+	const mentionsDisplayRoute = DISPLAY_AUDIO_ROUTE_TOKENS.some((token) =>
+		normalizedLabel.includes(token),
+	);
+	const mentionsAudioOutput = AUDIO_OUTPUT_TOKENS.some((token) =>
+		normalizedLabel.includes(token),
+	);
+
+	return mentionsDisplayRoute && mentionsAudioOutput && !mentionsMicrophone;
+}
+
+export function getAvailableMicrophoneDevices(devices: AudioInputDeviceLike[]): MicrophoneDevice[] {
+	return devices
+		.filter((device) => device.kind === "audioinput")
+		.filter((device) => !isLikelyDisplayAudioInputLabel(device.label))
+		.map((device) => ({
+			deviceId: device.deviceId,
+			label: device.label || `Microphone ${device.deviceId.slice(0, 8)}`,
+			groupId: device.groupId,
+		}));
+}
+
 let hasRequestedMicrophoneLabels = false;
 
 export function useMicrophoneDevices(enabled: boolean = true, preferredDeviceId?: string) {
@@ -29,28 +71,20 @@ export function useMicrophoneDevices(enabled: boolean = true, preferredDeviceId?
 				setError(null);
 
 				let allDevices = await navigator.mediaDevices.enumerateDevices();
-				let audioInputs = allDevices
-					.filter((device) => device.kind === "audioinput")
-					.map((device) => ({
-						deviceId: device.deviceId,
-						label: device.label || `Microphone ${device.deviceId.slice(0, 8)}`,
-						groupId: device.groupId,
-					}));
+				let audioInputs = getAvailableMicrophoneDevices(allDevices);
+				const rawAudioInputs = allDevices.filter(
+					(device): device is MediaDeviceInfo => device.kind === "audioinput",
+				);
 
 				const needsLabelPermission =
-					audioInputs.length > 0 && audioInputs.every((device) => !device.label.trim());
+					rawAudioInputs.length > 0 &&
+					rawAudioInputs.every((device) => !device.label.trim());
 
 				if (needsLabelPermission && !hasRequestedMicrophoneLabels) {
 					hasRequestedMicrophoneLabels = true;
 					permissionStream = await navigator.mediaDevices.getUserMedia({ audio: true });
 					allDevices = await navigator.mediaDevices.enumerateDevices();
-					audioInputs = allDevices
-						.filter((device) => device.kind === "audioinput")
-						.map((device) => ({
-							deviceId: device.deviceId,
-							label: device.label || `Microphone ${device.deviceId.slice(0, 8)}`,
-							groupId: device.groupId,
-						}));
+					audioInputs = getAvailableMicrophoneDevices(allDevices);
 				}
 
 				if (mounted) {

src/hooks/useScreenRecorder.ts

@@ -8,6 +8,7 @@ import {
 	selectRecordingMimeType,
 	selectWebcamRecordingMimeType,
 } from "./recordingMimeType";
+import { getAvailableMicrophoneDevices } from "./useMicrophoneDevices";
 
 const TARGET_FRAME_RATE = 60;
 const TARGET_WIDTH = 3840;
@@ -380,13 +381,11 @@ async function createAudioInputDeviceSnapshot(): Promise<
 	}
 
 	const devices = await navigator.mediaDevices.enumerateDevices();
-	const audioInputs = devices
-		.filter((device) => device.kind === "audioinput")
-		.map((device) => ({
-			deviceId: device.deviceId,
-			...(device.groupId ? { groupId: device.groupId } : {}),
-			label: device.label,
-		}));
+	const audioInputs = getAvailableMicrophoneDevices(devices).map((device) => ({
+		deviceId: device.deviceId,
+		...(device.groupId ? { groupId: device.groupId } : {}),
+		label: device.label,
+	}));
 
 	return audioInputs.length > 0 ? audioInputs : null;
 }
@@ -1521,12 +1520,15 @@ export function useScreenRecorder(): UseScreenRecorderReturn {
 			if (useNativeMacScreenCapture || useNativeWindowsCapture) {
 				// Resolve the selected mic label for native capture backends.
 				let micLabel: string | undefined;
+				let resolvedMicrophoneDeviceId = microphoneDeviceId;
 				if (microphoneEnabled) {
 					try {
 						const devices = await navigator.mediaDevices.enumerateDevices();
-						const mic = devices.find(
-							(d) => d.deviceId === microphoneDeviceId && d.kind === "audioinput",
+						const availableMicrophones = getAvailableMicrophoneDevices(devices);
+						const mic = availableMicrophones.find(
+							(device) => device.deviceId === microphoneDeviceId,
 						);
+						resolvedMicrophoneDeviceId = mic?.deviceId;
 						micLabel = mic?.label || undefined;
 					} catch {
 						// Fall through — native process will use the default mic
@@ -1538,7 +1540,7 @@ export function useScreenRecorder(): UseScreenRecorderReturn {
 					{
 						capturesSystemAudio: systemAudioEnabled,
 						capturesMicrophone: microphoneEnabled,
-						microphoneDeviceId,
+						microphoneDeviceId: resolvedMicrophoneDeviceId,
 						microphoneLabel: micLabel,
 					},
 				);
@@ -1589,7 +1591,7 @@ export function useScreenRecorder(): UseScreenRecorderReturn {
 						console.info("Using browser microphone processing for this recording.");
 						try {
 							const microphoneConstraints = createProcessedMicrophoneConstraints(
-								microphoneDeviceId,
+								resolvedMicrophoneDeviceId,
 								browserMicrophoneProfile.current,
 							);
 							micFallbackRequestedConstraints.current = microphoneConstraints;