diff --git a/README.md b/README.md
index b42355e7f..b941c73a6 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,8 @@
+npm run build:win
+
+D:\Development\openscreen\release
+
+
 > [!WARNING]
 > This is very much in beta and might be buggy here and there (but hope you have a good experience!).
 
diff --git a/src/lib/exporter/audioEncoder.ts b/src/lib/exporter/audioEncoder.ts
index 490eed2a9..5af92f7f7 100644
--- a/src/lib/exporter/audioEncoder.ts
+++ b/src/lib/exporter/audioEncoder.ts
@@ -6,8 +6,15 @@ const AUDIO_BITRATE = 128_000;
 const DECODE_BACKPRESSURE_LIMIT = 20;
 const MIN_SPEED_REGION_DELTA_MS = 0.0001;
 
+export type TargetAudioCodec = "aac" | "opus";
+
 export class AudioProcessor {
 	private cancelled = false;
+	private targetCodec: TargetAudioCodec;
+
+	constructor(targetCodec: TargetAudioCodec) {
+		this.targetCodec = targetCodec;
+	}
 
 	/**
 	 * Audio export has two modes:
@@ -132,16 +139,24 @@ export class AudioProcessor {
 		const sampleRate = audioConfig.sampleRate || 48000;
 		const channels = audioConfig.numberOfChannels || 2;
 
-		const encodeConfig: AudioEncoderConfig = {
-			codec: "opus",
-			sampleRate,
-			numberOfChannels: channels,
-			bitrate: AUDIO_BITRATE,
-		};
+		const encodeConfig: AudioEncoderConfig =
+			this.targetCodec === "aac"
+				? {
+						codec: "mp4a.40.2",
+						sampleRate,
+						numberOfChannels: channels,
+						bitrate: AUDIO_BITRATE,
+					}
+				: {
+						codec: "opus",
+						sampleRate,
+						numberOfChannels: channels,
+						bitrate: AUDIO_BITRATE,
+					};
 
 		const encodeSupport = await AudioEncoder.isConfigSupported(encodeConfig);
 		if (!encodeSupport.supported) {
-			console.warn("[AudioProcessor] Opus encoding not supported, skipping audio");
+			console.warn("[AudioProcessor] Audio encoding not supported, skipping audio");
 			for (const frame of decodedFrames) frame.close();
 			return;
 		}
@@ -314,28 +329,7 @@ export class AudioProcessor {
 
 		try {
 			await demuxer.load(file);
-			const audioConfig = (await demuxer.getDecoderConfig("audio")) as AudioDecoderConfig;
-			const reader = (demuxer.read("audio") as ReadableStream<EncodedAudioChunk>).getReader();
-			let isFirstChunk = true;
-
-			try {
-				while (!this.cancelled) {
-					const { done, value: chunk } = await reader.read();
-					if (done || !chunk) break;
-					if (isFirstChunk) {
-						await muxer.addAudioChunk(chunk, { decoderConfig: audioConfig });
-						isFirstChunk = false;
-					} else {
-						await muxer.addAudioChunk(chunk);
-					}
-				}
-			} finally {
-				try {
-					await reader.cancel();
-				} catch {
-					/* reader already closed */
-				}
-			}
+			await this.processTrimOnlyAudio(demuxer, muxer, [], undefined);
 		} finally {
 			try {
 				demuxer.destroy();
diff --git a/src/lib/exporter/muxer.ts b/src/lib/exporter/muxer.ts
index a51123877..8f75f068d 100644
--- a/src/lib/exporter/muxer.ts
+++ b/src/lib/exporter/muxer.ts
@@ -8,17 +8,19 @@ import {
 } from "mediabunny";
 import type { ExportConfig } from "./types";
 
+export type Mp4AudioCodec = "aac" | "opus";
+
 export class VideoMuxer {
 	private output: Output | null = null;
 	private videoSource: EncodedVideoPacketSource | null = null;
 	private audioSource: EncodedAudioPacketSource | null = null;
-	private hasAudio: boolean;
+	private audioCodec: Mp4AudioCodec | null;
 	private target: BufferTarget | null = null;
 	private config: ExportConfig;
 
-	constructor(config: ExportConfig, hasAudio = false) {
+	constructor(config: ExportConfig, audioCodec: Mp4AudioCodec | null = null) {
 		this.config = config;
-		this.hasAudio = hasAudio;
+		this.audioCodec = audioCodec;
 	}
 
 	async initialize(): Promise<void> {
@@ -39,8 +41,8 @@ export class VideoMuxer {
 		});
 
 		// Create audio source if needed
-		if (this.hasAudio) {
-			this.audioSource = new EncodedAudioPacketSource("opus");
+		if (this.audioCodec) {
+			this.audioSource = new EncodedAudioPacketSource(this.audioCodec);
 			this.output.addAudioTrack(this.audioSource);
 		}
 
diff --git a/src/lib/exporter/videoExporter.ts b/src/lib/exporter/videoExporter.ts
index d0affd17c..7a477f893 100644
--- a/src/lib/exporter/videoExporter.ts
+++ b/src/lib/exporter/videoExporter.ts
@@ -1,3 +1,4 @@
+import type { WebDemuxer } from "web-demuxer";
 import type {
 	AnnotationRegion,
 	CropRegion,
@@ -10,12 +11,13 @@ import type {
 import { AsyncVideoFrameQueue } from "./asyncVideoFrameQueue";
 import { AudioProcessor } from "./audioEncoder";
 import { FrameRenderer } from "./frameRenderer";
-import { VideoMuxer } from "./muxer";
+import { type Mp4AudioCodec, VideoMuxer } from "./muxer";
 import { StreamingVideoDecoder } from "./streamingDecoder";
 import type { ExportConfig, ExportProgress, ExportResult } from "./types";
 
 const ENCODER_STALL_TIMEOUT_MS = 15_000;
 const ENCODER_FLUSH_TIMEOUT_MS = 20_000;
+const AUDIO_BITRATE = 128_000;
 
 interface VideoExporterConfig extends ExportConfig {
 	videoUrl: string;
@@ -66,6 +68,40 @@ export class VideoExporter {
 		this.config = config;
 	}
 
+	private async pickAudioCodec(demuxer: WebDemuxer | null): Promise<Mp4AudioCodec | null> {
+		if (!demuxer) return null;
+
+		let audioConfig: AudioDecoderConfig;
+		try {
+			audioConfig = (await demuxer.getDecoderConfig("audio")) as AudioDecoderConfig;
+		} catch {
+			return null;
+		}
+
+		const sampleRate = audioConfig.sampleRate || 48000;
+		const channels = audioConfig.numberOfChannels || 2;
+
+		const aacConfig: AudioEncoderConfig = {
+			codec: "mp4a.40.2",
+			sampleRate,
+			numberOfChannels: channels,
+			bitrate: AUDIO_BITRATE,
+		};
+		const aacSupport = await AudioEncoder.isConfigSupported(aacConfig);
+		if (aacSupport.supported) return "aac";
+
+		const opusConfig: AudioEncoderConfig = {
+			codec: "opus",
+			sampleRate,
+			numberOfChannels: channels,
+			bitrate: AUDIO_BITRATE,
+		};
+		const opusSupport = await AudioEncoder.isConfigSupported(opusConfig);
+		if (opusSupport.supported) return "opus";
+
+		return null;
+	}
+
 	async export(): Promise<ExportResult> {
 		const encoderPreferences = this.getEncoderPreferences();
 		let lastError: Error | null = null;
@@ -153,7 +189,14 @@ export class VideoExporter {
 			await this.initializeEncoder(encoderPreference);
 
 			const hasAudio = videoInfo.hasAudio;
-			const muxer = new VideoMuxer(this.config, hasAudio);
+			const audioCodec = hasAudio ? await this.pickAudioCodec(streamingDecoder.getDemuxer()) : null;
+			if (hasAudio && !audioCodec) {
+				throw new Error(
+					"Source has audio, but no supported audio encoder was found for MP4 export.",
+				);
+			}
+
+			const muxer = new VideoMuxer(this.config, audioCodec);
 			this.muxer = muxer;
 			await muxer.initialize();
 
@@ -335,11 +378,11 @@ export class VideoExporter {
 				phase: "finalizing",
 			});
 
-			if (hasAudio && !this.cancelled) {
+			if (audioCodec && !this.cancelled) {
 				const demuxer = streamingDecoder.getDemuxer();
 				if (demuxer) {
 					console.log("[VideoExporter] Processing audio track...");
-					this.audioProcessor = new AudioProcessor();
+					this.audioProcessor = new AudioProcessor(audioCodec);
 					await this.audioProcessor.process(
 						demuxer,
 						muxer,
diff --git a/vitest.config.ts b/vitest.config.ts
index ea60216f4..9108f6991 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -6,6 +6,7 @@ export default defineConfig({
 		globals: true,
 		environment: "jsdom",
 		include: ["src/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}"],
+		exclude: ["src/**/*.browser.test.{ts,tsx}"],
 	},
 	resolve: {
 		alias: {