diff --git a/dev/convert.html b/dev/convert.html
index bc1f9d1..bb9b7a4 100644
--- a/dev/convert.html
+++ b/dev/convert.html
@@ -48,6 +48,7 @@
 			target
 		});
 
+		let ctx = null;
 		const conversion = await Mediabunny.Conversion.init({
 			input: new Mediabunny.Input({
 				formats: Mediabunny.ALL_FORMATS,	
@@ -56,6 +57,8 @@
 			output,
 			audio: (_, n) => ({
 				discard: n > 1,
+				codec: 'aac',
+				//codec: 'opus',
 				/*
 				process: (sample) => {
 					return sample;
@@ -70,7 +73,7 @@
 				//numberOfChannels: 1,
 				//sampleRate: 4000
 				//discard: true
-				//forceTranscode: true,
+				forceTranscode: true,
 			}),
 			/*
 			video: {
@@ -97,6 +100,7 @@
 			},
 			*/
 			video: () => ({
+				//discard: true,
 				/*
 				process: (sample) => {
 					if (!ctx) {
@@ -108,9 +112,11 @@
 						ctx = canvas.getContext('2d');
 					}
 
+					console.log(ctx.canvas.width, ctx.canvas.height);
+
 					ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
-					sample.draw(ctx, 0, 0);
-					ctx.drawImage(watermark, 32, 32);
+					sample.drawWithFit(ctx, { fit: 'fill' });
+					//ctx.drawImage(watermark, 32, 32);
 
 					return ctx.canvas;
 				},
@@ -170,8 +176,8 @@
 				}
 			},
 			trim: {
-				start: 0,
-				end: 10
+				//start: 0,
+				//end: 10
 			},
 		});
 		console.log(conversion);
diff --git a/dev/demux.html b/dev/demux.html
index 1a864a3..c423bfe 100644
--- a/dev/demux.html
+++ b/dev/demux.html
@@ -14,7 +14,21 @@
 			source: new Mediabunny.BlobSource(file),
 		});
 
-		const videoTrack = await input.getPrimaryAudioTrack();
+		const audioTrack = await input.getPrimaryAudioTrack();
+		const sink = new Mediabunny.AudioSampleSink(audioTrack);
+
+		let lastEnd = 0;
+		for await (const sample of sink.samples()) {
+			if (sample.timestamp - lastEnd > 0) {
+				console.warn(sample.timestamp - lastEnd)
+				console.log(sample.timestamp, sample.duration, "diffie", sample.timestamp - lastEnd);
+			}
+
+			lastEnd = sample.timestamp + sample.duration;
+			sample.close();
+		}
+		
+		/*
 		const sink = new Mediabunny.EncodedPacketSink(videoTrack);
 
 		for await (const packet of sink.packets()) {
@@ -22,6 +36,7 @@
 
 			if (packet.timestamp > 10) break;
 		}
+		*/
 
 		/*
 		const sink = new Mediabunny.VideoSampleSink(videoTrack);
diff --git a/package-lock.json b/package-lock.json
index 271da7e..e991436 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "mediabunny",
-  "version": "1.24.5",
+  "version": "1.24.6",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "mediabunny",
-      "version": "1.24.5",
+      "version": "1.24.6",
       "license": "MPL-2.0",
       "workspaces": [
         "packages/*"
@@ -7749,9 +7749,9 @@
       }
     },
     "node_modules/mediabunny": {
-      "version": "1.24.4",
-      "resolved": "https://registry.npmjs.org/mediabunny/-/mediabunny-1.24.4.tgz",
-      "integrity": "sha512-dpWYBPTtMg152yNLXZQ7xb6hsXdYbKp9EuK8qq4npS+SZ08FVc1XHlXYhrOm31T+tUVJKgm95Yaqy69wTpZP9Q==",
+      "version": "1.24.5",
+      "resolved": "https://registry.npmjs.org/mediabunny/-/mediabunny-1.24.5.tgz",
+      "integrity": "sha512-4Sd5x8WXQiuDKZcJDAiQjyD0Lg/cg9p+dBShCM02F1pMvKdB9R6+WHZ9NFCFSqViVPX2fYSu95ZIpBUg9+TwTQ==",
       "license": "MPL-2.0",
       "peer": true,
       "workspaces": [
@@ -12242,7 +12242,7 @@
     },
     "packages/mp3-encoder": {
       "name": "@mediabunny/mp3-encoder",
-      "version": "1.24.5",
+      "version": "1.24.6",
       "license": "MPL-2.0",
       "devDependencies": {
         "@types/emscripten": "^1.40.1"
diff --git a/package.json b/package.json
index 3b11949..acc0a8c 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "mediabunny",
   "author": "Vanilagy",
-  "version": "1.24.5",
+  "version": "1.24.6",
   "description": "Pure TypeScript media toolkit for reading, writing, and converting media files, directly in the browser.",
   "type": "module",
   "workspaces": [
diff --git a/packages/mp3-encoder/package.json b/packages/mp3-encoder/package.json
index b7d133b..64bc7ab 100644
--- a/packages/mp3-encoder/package.json
+++ b/packages/mp3-encoder/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@mediabunny/mp3-encoder",
   "author": "Vanilagy",
-  "version": "1.24.5",
+  "version": "1.24.6",
   "description": "MP3 encoder extension for Mediabunny, based on LAME.",
   "main": "./dist/bundles/mediabunny-mp3-encoder.mjs",
   "module": "./dist/bundles/mediabunny-mp3-encoder.mjs",
diff --git a/src/codec.ts b/src/codec.ts
index a396e70..b9414fd 100644
--- a/src/codec.ts
+++ b/src/codec.ts
@@ -337,6 +337,7 @@ export const extractVideoCodecString = (trackInfo: {
 	codec: VideoCodec | null;
 	codecDescription: Uint8Array | null;
 	colorSpace: VideoColorSpaceInit | null;
+	avcType: 1 | 3 | null;
 	avcCodecInfo: AvcDecoderConfigurationRecord | null;
 	hevcCodecInfo: HevcDecoderConfigurationRecord | null;
 	vp9CodecInfo: Vp9CodecInfo | null;
@@ -345,6 +346,8 @@ export const extractVideoCodecString = (trackInfo: {
 	const { codec, codecDescription, colorSpace, avcCodecInfo, hevcCodecInfo, vp9CodecInfo, av1CodecInfo } = trackInfo;
 
 	if (codec === 'avc') {
+		assert(trackInfo.avcType !== null);
+
 		if (avcCodecInfo) {
 			const bytes = new Uint8Array([
 				avcCodecInfo.avcProfileIndication,
@@ -352,14 +355,14 @@ export const extractVideoCodecString = (trackInfo: {
 				avcCodecInfo.avcLevelIndication,
 			]);
 
-			return `avc1.${bytesToHexString(bytes)}`;
+			return `avc${trackInfo.avcType}.${bytesToHexString(bytes)}`;
 		}
 
 		if (!codecDescription || codecDescription.byteLength < 4) {
 			throw new TypeError('AVC decoder description is not provided or is not at least 4 bytes long.');
 		}
 
-		return `avc1.${bytesToHexString(codecDescription.subarray(1, 4))}`;
+		return `avc${trackInfo.avcType}.${bytesToHexString(codecDescription.subarray(1, 4))}`;
 	} else if (codec === 'hevc') {
 		let generalProfileSpace: number;
 		let generalProfileIdc: number;
diff --git a/src/conversion.ts b/src/conversion.ts
index abf820a..0cabe1a 100644
--- a/src/conversion.ts
+++ b/src/conversion.ts
@@ -182,7 +182,8 @@ export type ConversionVideoOptions = {
 	 * corrections.
 	 *
 	 * Must return a {@link VideoSample} or a `CanvasImageSource`, an array of them, or `null` for dropping the frame.
-	 * When non-timestamped data is returned, the timestamp and duration from the source sample will be used.
+	 * When non-timestamped data is returned, the timestamp and duration from the source sample will be used. Rotation
+	 * metadata of the returned sample will be ignored.
 	 *
 	 * This function can also be used to manually resize frames. When doing so, you should signal the post-process
 	 * dimensions using the `processedWidth` and `processedHeight` fields, which enables the encoder to better know what
@@ -873,7 +874,10 @@ export class Conversion {
 			|| trackOptions.process !== undefined;
 		let needsRerender = width !== originalWidth
 			|| height !== originalHeight
-			|| (totalRotation !== 0 && !outputSupportsRotation)
+			// TODO This is suboptimal: Forcing a rerender when both rotation and process are set is not
+			// performance-optimal, but right now there's no other way because we can't change the track rotation
+			// metadata after the output has already started. Should be possible with API changes in v2, though!
+			|| (totalRotation !== 0 && (!outputSupportsRotation || trackOptions.process !== undefined))
 			|| !!crop;
 
 		const alpha = trackOptions.alpha ?? 'discard';
diff --git a/src/flac/flac-demuxer.ts b/src/flac/flac-demuxer.ts
index 5248394..4303fd4 100644
--- a/src/flac/flac-demuxer.ts
+++ b/src/flac/flac-demuxer.ts
@@ -328,11 +328,13 @@ export class FlacDemuxer extends Demuxer {
 
 			const nextByte = readU8(slice);
 			if (nextByte === 0xff) {
+				const positionBeforeReading = slice.filePos;
+
 				const byteAfterNextByte = readU8(slice);
 
 				const expected = this.blockingBit === 1 ? 0b1111_1001 : 0b1111_1000;
 				if (byteAfterNextByte !== expected) {
-					slice.skip(-1);
+					slice.filePos = positionBeforeReading;
 					continue;
 				}
 
@@ -345,7 +347,7 @@ export class FlacDemuxer extends Demuxer {
 				});
 
 				if (!nextFrameHeader) {
-					slice.skip(-1);
+					slice.filePos = positionBeforeReading;
 					continue;
 				}
 
@@ -355,14 +357,14 @@ export class FlacDemuxer extends Demuxer {
 				if (this.blockingBit === 0) {
 					// Case A: If the stream is fixed block size, this is the frame number, which increments by 1
 					if (nextFrameHeader.num - frameHeader.num !== 1) {
-						slice.skip(-1);
+						slice.filePos = positionBeforeReading;
 						continue;
 					}
 				} else {
 					// Case B: If the stream is variable block size, this is the sample number, which increments by
 					// amount of samples in a frame.
 					if (nextFrameHeader.num - frameHeader.num !== frameHeader.blockSize) {
-						slice.skip(-1);
+						slice.filePos = positionBeforeReading;
 						continue;
 					}
 				}
diff --git a/src/isobmff/isobmff-boxes.ts b/src/isobmff/isobmff-boxes.ts
index 96900d0..d7a5a38 100644
--- a/src/isobmff/isobmff-boxes.ts
+++ b/src/isobmff/isobmff-boxes.ts
@@ -577,7 +577,7 @@ export const stsd = (trackData: IsobmffTrackData) => {
 
 	if (trackData.type === 'video') {
 		sampleDescription = videoSampleDescription(
-			VIDEO_CODEC_TO_BOX_NAME[trackData.track.source._codec],
+			videoCodecToBoxName(trackData.track.source._codec, trackData.info.decoderConfig.codec),
 			trackData,
 		);
 	} else if (trackData.type === 'audio') {
@@ -1572,12 +1572,14 @@ const dataStringBoxLong = (value: string) => {
 	]);
 };
 
-const VIDEO_CODEC_TO_BOX_NAME: Record<VideoCodec, string> = {
-	avc: 'avc1',
-	hevc: 'hvc1',
-	vp8: 'vp08',
-	vp9: 'vp09',
-	av1: 'av01',
+const videoCodecToBoxName = (codec: VideoCodec, fullCodecString: string) => {
+	switch (codec) {
+		case 'avc': return fullCodecString.startsWith('avc3') ? 'avc3' : 'avc1';
+		case 'hevc': return 'hvc1';
+		case 'vp8': return 'vp08';
+		case 'vp9': return 'vp09';
+		case 'av1': return 'av01';
+	}
 };
 
 const VIDEO_CODEC_TO_CONFIGURATION_BOX: Record<VideoCodec, (trackData: IsobmffVideoTrackData) => Box | null> = {
diff --git a/src/isobmff/isobmff-demuxer.ts b/src/isobmff/isobmff-demuxer.ts
index e1d047c..124c7b1 100644
--- a/src/isobmff/isobmff-demuxer.ts
+++ b/src/isobmff/isobmff-demuxer.ts
@@ -126,6 +126,7 @@ type InternalTrack = {
 		codec: VideoCodec | null;
 		codecDescription: Uint8Array | null;
 		colorSpace: VideoColorSpaceInit | null;
+		avcType: 1 | 3 | null;
 		avcCodecInfo: AvcDecoderConfigurationRecord | null;
 		hevcCodecInfo: HevcDecoderConfigurationRecord | null;
 		vp9CodecInfo: Vp9CodecInfo | null;
@@ -836,6 +837,7 @@ export class IsobmffDemuxer extends Demuxer {
 						codec: null,
 						codecDescription: null,
 						colorSpace: null,
+						avcType: null,
 						avcCodecInfo: null,
 						hevcCodecInfo: null,
 						vp9CodecInfo: null,
@@ -890,8 +892,9 @@ export class IsobmffDemuxer extends Demuxer {
 					const lowercaseBoxName = sampleBoxInfo.name.toLowerCase();
 
 					if (track.info.type === 'video') {
-						if (lowercaseBoxName === 'avc1') {
+						if (lowercaseBoxName === 'avc1' || lowercaseBoxName === 'avc3') {
 							track.info.codec = 'avc';
+							track.info.avcType = lowercaseBoxName === 'avc1' ? 1 : 3;
 						} else if (lowercaseBoxName === 'hvc1' || lowercaseBoxName === 'hev1') {
 							track.info.codec = 'hevc';
 						} else if (lowercaseBoxName === 'vp08') {
diff --git a/src/matroska/matroska-demuxer.ts b/src/matroska/matroska-demuxer.ts
index e964bef..1992205 100644
--- a/src/matroska/matroska-demuxer.ts
+++ b/src/matroska/matroska-demuxer.ts
@@ -2319,6 +2319,7 @@ class MatroskaVideoTrackBacking extends MatroskaTrackBacking implements InputVid
 					codec: this.internalTrack.info.codec,
 					codecDescription: this.internalTrack.info.codecDescription,
 					colorSpace: this.internalTrack.info.colorSpace,
+					avcType: 1, // We don't know better (or do we?) so just assume 'avc1'
 					avcCodecInfo: this.internalTrack.info.codec === 'avc' && firstPacket
 						? extractAvcDecoderConfigurationRecord(firstPacket.data)
 						: null,
diff --git a/src/media-source.ts b/src/media-source.ts
index 86989a2..c2b4a6b 100644
--- a/src/media-source.ts
+++ b/src/media-source.ts
@@ -1294,6 +1294,8 @@ class AudioEncoderWrapper {
 	private customEncoderCallSerializer = new CallSerializer();
 	private customEncoderQueueSize = 0;
 
+	private lastEndSampleIndex: number | null = null;
+
 	/**
 	 * Encoders typically throw their errors "out of band", meaning asynchronously in some other execution context.
 	 * However, we want to surface these errors to the user within the normal control flow, so they don't go uncaught.
@@ -1342,6 +1344,35 @@ class AudioEncoderWrapper {
 			}
 			assert(this.encoderInitialized);
 
+			// Handle padding of gaps with silence to avoid audio drift over time, like in
+			// https://github.com/Vanilagy/mediabunny/issues/176
+			// TODO An open question is how encoders deal with the first AudioData having a non-zero timestamp, and with
+			// AudioDatas that have an overlapping timestamp range.
+			{
+				const startSampleIndex = Math.round(
+					audioSample.timestamp * audioSample.sampleRate,
+				);
+				const endSampleIndex = Math.round(
+					(audioSample.timestamp + audioSample.duration) * audioSample.sampleRate,
+				);
+
+				if (this.lastEndSampleIndex !== null && startSampleIndex > this.lastEndSampleIndex) {
+					const sampleCount = startSampleIndex - this.lastEndSampleIndex;
+					const fillSample = new AudioSample({
+						data: new Float32Array(sampleCount * audioSample.numberOfChannels),
+						format: 'f32-planar',
+						sampleRate: audioSample.sampleRate,
+						numberOfChannels: audioSample.numberOfChannels,
+						numberOfFrames: sampleCount,
+						timestamp: this.lastEndSampleIndex / audioSample.sampleRate,
+					});
+
+					await this.add(fillSample, true); // Recursive call
+				}
+
+				this.lastEndSampleIndex = endSampleIndex;
+			}
+
 			if (this.customEncoder) {
 				this.customEncoderQueueSize++;
 
diff --git a/src/sample.ts b/src/sample.ts
index 805aebe..35d7800 100644
--- a/src/sample.ts
+++ b/src/sample.ts
@@ -552,7 +552,6 @@ export class VideoSample implements Disposable {
 			dHeight,
 		);
 
-		// Restore the previous transformation state
 		context.restore();
 	}
 
@@ -644,6 +643,8 @@ export class VideoSample implements Disposable {
 			dy = (canvasHeight - newHeight) / 2;
 		}
 
+		context.save();
+
 		const aspectRatioChange = rotation % 180 === 0 ? 1 : newWidth / newHeight;
 		context.translate(canvasWidth / 2, canvasHeight / 2);
 		context.rotate(rotation * Math.PI / 180);
@@ -655,6 +656,8 @@ export class VideoSample implements Disposable {
 		// Important that we don't use .draw() here since that would take rotation into account, but we wanna handle it
 		// ourselves here
 		context.drawImage(this.toCanvasImageSource(), sx, sy, sWidth, sHeight, dx, dy, newWidth, newHeight);
+
+		context.restore();
 	}
 
 	/** @internal */