Bump patch

.github/workflows/release.yml

@@ -5,6 +5,7 @@ on:
     types: [published]
 
 permissions:
+  id-token: write  # Required for OIDC
   contents: read
 
 jobs:
@@ -14,7 +15,7 @@ jobs:
     permissions: write-all
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
@@ -27,12 +28,15 @@ jobs:
           git push origin release
 
       - name: Set up Node.js
-        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+        uses: actions/setup-node@v4
         with:
           node-version: 22
           cache: 'npm'
           registry-url: https://registry.npmjs.org
 
+      - name: Update npm
+        run: npm install -g npm@latest
+
       - name: Get package.json version
         id: package-json-version
         run: echo "version=v$(cat package.json | jq '.version' --raw-output)" >> $GITHUB_OUTPUT
@@ -58,11 +62,7 @@ jobs:
         run: gh release upload ${{ github.event.release.tag_name }} dist/bundles/mediabunny.cjs dist/bundles/mediabunny.min.cjs dist/bundles/mediabunny.mjs dist/bundles/mediabunny.min.mjs dist/mediabunny.d.ts packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.js packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.min.js packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.mjs packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.min.mjs packages/mp3-encoder/dist/mediabunny-mp3-encoder.d.ts
 
       - name: Publish Mediabunny to npm
-        run: npm publish --provenance --access public
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: npm publish --access public
 
       - name: Publish workspace packages to npm
-        run: npm publish --provenance --access public --workspaces 
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: npm publish --access public --workspaces 

dev/demux.html

@@ -14,7 +14,22 @@
 			source: new Mediabunny.BlobSource(file),
 		});
 
-		console.log(await input.getTracks());
+		const videoTrack = await input.getPrimaryVideoTrack();
+		const sink = new Mediabunny.EncodedPacketSink(videoTrack);
+
+		for await (const packet of sink.packets()) {
+			console.log(packet);
+		}
+
+
+		/*
+		const videoTrack = await input.getPrimaryVideoTrack();
+		const sink = new Mediabunny.EncodedPacketSink(videoTrack);
+
+		for await (const packet of sink.packets()) {
+			console.log(packet);
+		}
+		*/
 
 		/*
 		return;

dev/live.html

@@ -1,6 +1,7 @@
 <button>Go</button>
 
 <script src="../dist/bundles/mediabunny.cjs"></script>
+<script src="../packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.js"></script>
 
 <script type="module">
     function download(blob, filename) {
@@ -12,6 +13,8 @@
 		URL.revokeObjectURL(url);
 	}
 
+	MediabunnyMp3Encoder.registerMp3Encoder();
+
     const button = document.querySelector('button');
     button.addEventListener('click', async () => {
         const stream = await navigator.mediaDevices.getUserMedia({ video: true, audio: true });
@@ -34,7 +37,7 @@
         }
         if (audioTrack) {
             const source = new Mediabunny.MediaStreamAudioTrackSource(audioTrack, {
-                codec: 'aac',
+                codec: 'mp3',
                 bitrate: Mediabunny.QUALITY_MEDIUM
             });
 

docs/guide/media-sources.md

@@ -433,4 +433,12 @@ await textSource.add('00:00:00.000 --> 00:00:02.000\nHello there!\n\n');
 await textSource.add('00:00:02.500 --> 00:00:04.000\nChunky chunks.\n\n');
 ```
 
-The chunks have certain constraints: A cue must be fully contained within a chunk and cannot be split across multiple smaller chunks (although a chunk can contain multiple cues). Also, the WebVTT preamble must be added first and all at once.
+The chunks have certain constraints: A cue must be fully contained within a chunk and cannot be split across multiple smaller chunks (although a chunk can contain multiple cues). Also, the WebVTT preamble must be added first and all at once.
+
+::: info
+For QuickTime to display WebVTT subtitles, it typically expects alignment information to be specified:
+```
+00:00:00.000 --> 00:00:02.000 align:center
+This is your last chance.
+```
+:::

examples/live-recording/live-recording.ts

@@ -21,7 +21,7 @@ const context = canvas.getContext('2d', { alpha: false, desynchronized: true })!
 
 const frameRate = 30;
 
-const chunks: Uint8Array[] = [];
+const chunks: Uint8Array<ArrayBuffer>[] = [];
 let recording = false;
 let output: Output;
 let videoSource: CanvasSource;

examples/metadata-extraction/metadata-extraction.ts

@@ -97,7 +97,7 @@ const extractMetadata = (resource: File | string) => {
 				'Lyrics': tags.lyrics,
 				'Comment': tags.comment,
 				'Images': tags.images?.map((image) => {
-					const blob = new Blob([image.data], { type: image.mimeType });
+					const blob = new Blob([image.data.slice()], { type: image.mimeType });
 					const element = new Image();
 					element.src = URL.createObjectURL(blob);
 

package.json

@@ -1,7 +1,7 @@
 {
   "name": "mediabunny",
   "author": "Vanilagy",
-  "version": "1.25.2",
+  "version": "1.25.7",
   "description": "Pure TypeScript media toolkit for reading, writing, and converting media files, directly in the browser.",
   "type": "module",
   "workspaces": [
@@ -70,7 +70,7 @@
     "@eslint/js": "^9.22.0",
     "@fontsource-variable/rubik": "^5.2.6",
     "@fontsource/dm-mono": "^5.2.6",
-    "@microsoft/api-extractor": "^7.52.1",
+    "@microsoft/api-extractor": "^7.55.1",
     "@stylistic/eslint-plugin": "^4.2.0",
     "@tailwindcss/vite": "^4.1.7",
     "@types/markdown-it-footnote": "^3.0.4",
@@ -84,8 +84,8 @@
     "mermaid": "^11.6.0",
     "tailwindcss": "^4.1.7",
     "tsx": "^4.19.4",
-    "typescript": "^5.8.2",
-    "typescript-eslint": "^8.26.1",
+    "typescript": "^5.9.3",
+    "typescript-eslint": "^8.48.0",
     "vite": "^6.3.5",
     "vitepress": "^1.6.3",
     "vitepress-plugin-llms": "^1.5.1",

packages/mp3-encoder/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@mediabunny/mp3-encoder",
   "author": "Vanilagy",
-  "version": "1.25.2",
+  "version": "1.25.7",
   "description": "MP3 encoder extension for Mediabunny, based on LAME.",
   "main": "./dist/bundles/mediabunny-mp3-encoder.mjs",
   "module": "./dist/bundles/mediabunny-mp3-encoder.mjs",

packages/mp3-encoder/src/index.ts

@@ -22,7 +22,7 @@ class Mp3Encoder extends CustomAudioEncoder {
 
 	private buffer = new Uint8Array(2 ** 16);
 	private currentBufferOffset = 0;
-	private currentTimestamp = 0;
+	private currentTimestamp: number | null = null;
 	private chunkMetadata: EncodedAudioChunkMetadata = {};
 
 	static override supports(codec: AudioCodec, config: AudioDecoderConfig): boolean {
@@ -79,6 +79,11 @@ class Mp3Encoder extends CustomAudioEncoder {
 	}
 
 	async encode(audioSample: AudioSample) {
+		if (this.currentTimestamp === null) {
+			// The first sample's timestamp determines where we start
+			this.currentTimestamp = audioSample.timestamp;
+		}
+
 		const sizePerChannel = audioSample.allocationSize({
 			format: 's16-planar',
 			planeIndex: 0,
@@ -123,6 +128,8 @@ class Mp3Encoder extends CustomAudioEncoder {
 	 * these chunks and extract the MP3 frames only when they're complete.
 	 */
 	private digestOutput(bytes: Uint8Array) {
+		assert(this.currentTimestamp !== null);
+
 		const requiredBufferSize = this.currentBufferOffset + bytes.length;
 		if (requiredBufferSize > this.buffer.length) {
 			// Grow the buffer to the required size

src/codec-data.ts

@@ -590,9 +590,7 @@ export const extractNalUnitTypeForHevc = (data: Uint8Array) => {
 };
 
 /** Builds a HevcDecoderConfigurationRecord from an HEVC packet in Annex B format. */
-export const extractHevcDecoderConfigurationRecord = (
-	packetData: Uint8Array,
-) => {
+export const extractHevcDecoderConfigurationRecord = (packetData: Uint8Array) => {
 	try {
 		const nalUnits = findNalUnitsInAnnexB(packetData);
 
@@ -1456,6 +1454,69 @@ export const extractAv1CodecInfoFromPacket = (
 			}
 		}
 
+		// Frame size
+		const frameWidthBitsMinus1 = bitstream.readBits(4);
+		const frameHeightBitsMinus1 = bitstream.readBits(4);
+		const n1 = frameWidthBitsMinus1 + 1;
+		bitstream.skipBits(n1); // max_frame_width_minus_1
+		const n2 = frameHeightBitsMinus1 + 1;
+		bitstream.skipBits(n2); // max_frame_height_minus_1
+
+		// Frame IDs
+		let frameIdNumbersPresentFlag = 0;
+		if (reducedStillPictureHeader) {
+			frameIdNumbersPresentFlag = 0;
+		} else {
+			frameIdNumbersPresentFlag = bitstream.readBits(1);
+		}
+
+		if (frameIdNumbersPresentFlag) {
+			bitstream.skipBits(4); // delta_frame_id_length_minus_2
+			bitstream.skipBits(3); // additional_frame_id_length_minus_1
+		}
+
+		bitstream.skipBits(1); // use_128x128_superblock
+		bitstream.skipBits(1); // enable_filter_intra
+		bitstream.skipBits(1); // enable_intra_edge_filter
+
+		if (!reducedStillPictureHeader) {
+			bitstream.skipBits(1); // enable_interintra_compound
+			bitstream.skipBits(1); // enable_masked_compound
+			bitstream.skipBits(1); // enable_warped_motion
+			bitstream.skipBits(1); // enable_dual_filter
+			const enableOrderHint = bitstream.readBits(1);
+
+			if (enableOrderHint) {
+				bitstream.skipBits(1); // enable_jnt_comp
+				bitstream.skipBits(1); // enable_ref_frame_mvs
+			}
+
+			const seqChooseScreenContentTools = bitstream.readBits(1);
+			let seqForceScreenContentTools = 0;
+
+			if (seqChooseScreenContentTools) {
+				seqForceScreenContentTools = 2; // SELECT_SCREEN_CONTENT_TOOLS
+			} else {
+				seqForceScreenContentTools = bitstream.readBits(1);
+			}
+
+			if (seqForceScreenContentTools > 0) {
+				const seqChooseIntegerMv = bitstream.readBits(1);
+				if (!seqChooseIntegerMv) {
+					bitstream.skipBits(1); // seq_force_integer_mv
+				}
+			}
+
+			if (enableOrderHint) {
+				bitstream.skipBits(3); // order_hint_bits_minus_1
+			}
+		}
+
+		bitstream.skipBits(1); // enable_superres
+		bitstream.skipBits(1); // enable_cdef
+		bitstream.skipBits(1); // enable_restoration
+
+		// color_config()
 		const highBitdepth = bitstream.readBits(1);
 
 		let bitDepth = 8;

src/conversion.ts

@@ -82,10 +82,16 @@ export type ConversionOptions = {
 
 	/** Options to trim the input file. */
 	trim?: {
-		/** The time in the input file in seconds at which the output file should start. Must be less than `end`.  */
-		start: number;
-		/** The time in the input file in seconds at which the output file should end. Must be greater than `start`. */
-		end: number;
+		/**
+		 * The time in the input file in seconds at which the output file should start. Must be less than `end`.
+		 * Defaults to 0 when omitted.
+		 */
+		start?: number;
+		/**
+		 * The time in the input file in seconds at which the output file should end. Must be greater than `start`.
+		 * Defaults to the duration of the input when omitted.
+		 */
+		end?: number;
 	};
 
 	/**
@@ -1509,7 +1515,10 @@ export class Conversion {
 				targetSampleRate,
 				startTime: this._startTimestamp,
 				endTime: this._endTimestamp,
-				onSample: sample => this._registerAudioSample(track, trackOptions, source, sample),
+				onSample: async (sample) => {
+					await this._registerAudioSample(track, trackOptions, source, sample);
+					sample.close();
+				},
 			});
 
 			const sink = new AudioSampleSink(track);
@@ -1521,6 +1530,7 @@ export class Conversion {
 				}
 
 				await resampler.add(sample);
+				sample.close();
 			}
 
 			await resampler.finalize();

src/isobmff/isobmff-boxes.ts

@@ -850,7 +850,7 @@ export const dOps = (trackData: IsobmffAudioTrackData) => {
 	let inputSampleRate = trackData.info.sampleRate;
 	let outputGain = 0;
 	let channelMappingFamily = 0;
-	let channelMappingTable = new Uint8Array(0);
+	let channelMappingTable: Uint8Array<ArrayBufferLike> = new Uint8Array(0);
 
 	// Read preskip and from codec private data from the encoder
 	// https://www.rfc-editor.org/rfc/rfc7845#section-5

src/isobmff/isobmff-demuxer.ts

@@ -2489,11 +2489,8 @@ abstract class IsobmffTrackBacking implements InputTrackBacking {
 		const timestampInTimescale = this.mapTimestampIntoTimescale(timestamp);
 
 		const sampleTable = this.internalTrack.demuxer.getSampleTableForTrack(this.internalTrack);
-		const sampleIndex = getSampleIndexForTimestamp(sampleTable, timestampInTimescale);
-		const keyFrameSampleIndex = sampleIndex === -1
-			? -1
-			: getRelevantKeyframeIndexForSample(sampleTable, sampleIndex);
-		const regularPacket = await this.fetchPacketForSampleIndex(keyFrameSampleIndex, options);
+		const sampleIndex = getKeyframeSampleIndexForTimestamp(sampleTable, timestampInTimescale);
+		const regularPacket = await this.fetchPacketForSampleIndex(sampleIndex, options);
 
 		if (!sampleTableIsEmpty(sampleTable) || !this.internalTrack.demuxer.isFragmented) {
 			// Prefer the non-fragmented packet
@@ -2913,7 +2910,45 @@ const getSampleIndexForTimestamp = (sampleTable: SampleTable, timescaleUnits: nu
 
 		const entry = sampleTable.sampleTimingEntries[index]!;
 		return entry.startIndex
-			+ Math.min(Math.floor((timescaleUnits - entry.startDecodeTimestamp) / entry.delta), entry.count - 1);
+			+ Math.min(
+				Math.floor((timescaleUnits - entry.startDecodeTimestamp) / entry.delta),
+				entry.count - 1,
+			);
+	}
+};
+
+const getKeyframeSampleIndexForTimestamp = (sampleTable: SampleTable, timescaleUnits: number) => {
+	if (!sampleTable.keySampleIndices) {
+		// Every sample is a keyframe
+		return getSampleIndexForTimestamp(sampleTable, timescaleUnits);
+	}
+
+	if (sampleTable.presentationTimestamps) {
+		const index = binarySearchLessOrEqual(
+			sampleTable.presentationTimestamps,
+			timescaleUnits,
+			x => x.presentationTimestamp,
+		);
+		if (index === -1) {
+			return -1;
+		}
+
+		// Walk the samples in presentation order until we find one that's a keyframe
+		for (let i = index; i >= 0; i--) {
+			const sampleIndex = sampleTable.presentationTimestamps[i]!.sampleIndex;
+			const isKeyFrame = binarySearchExact(sampleTable.keySampleIndices, sampleIndex, x => x) !== -1;
+
+			if (isKeyFrame) {
+				return sampleIndex;
+			}
+		}
+
+		return -1;
+	} else {
+		const sampleIndex = getSampleIndexForTimestamp(sampleTable, timescaleUnits);
+
+		const index = binarySearchLessOrEqual(sampleTable.keySampleIndices, sampleIndex, x => x);
+		return sampleTable.keySampleIndices[index] ?? -1;
 	}
 };
 
@@ -3002,15 +3037,6 @@ const getSampleInfo = (sampleTable: SampleTable, sampleIndex: number): SampleInf
 	};
 };
 
-const getRelevantKeyframeIndexForSample = (sampleTable: SampleTable, sampleIndex: number) => {
-	if (!sampleTable.keySampleIndices) {
-		return sampleIndex;
-	}
-
-	const index = binarySearchLessOrEqual(sampleTable.keySampleIndices, sampleIndex, x => x);
-	return sampleTable.keySampleIndices[index] ?? -1;
-};
-
 const getNextKeyframeIndexForSample = (sampleTable: SampleTable, sampleIndex: number) => {
 	if (!sampleTable.keySampleIndices) {
 		return sampleIndex + 1;

src/media-sink.ts

@@ -201,9 +201,10 @@ export class EncodedPacketSink {
 		}
 
 		const packet = await this._track._backing.getKeyPacket(timestamp, options);
-		if (!packet || packet.type === 'delta') {
+		if (!packet) {
 			return packet;
 		}
+		assert(packet.type === 'key');
 
 		const determinedType = await this._track.determinePacketType(packet);
 		if (determinedType === 'delta') {
@@ -235,9 +236,10 @@ export class EncodedPacketSink {
 		}
 
 		const nextPacket = await this._track._backing.getNextKeyPacket(packet, options);
-		if (!nextPacket || nextPacket.type === 'delta') {
+		if (!nextPacket) {
 			return nextPacket;
 		}
+		assert(nextPacket.type === 'key');
 
 		const determinedType = await this._track.determinePacketType(nextPacket);
 		if (determinedType === 'delta') {
@@ -474,9 +476,6 @@ export abstract class BaseMediaSampleSink<
 			const packetSink = this._createPacketSink();
 			const keyPacket = await packetSink.getKeyPacket(startTimestamp, { verifyKeyPackets: true })
 				?? await packetSink.getFirstPacket();
-			if (!keyPacket) {
-				return;
-			}
 
 			let currentPacket: EncodedPacket | null = keyPacket;
 
@@ -498,7 +497,7 @@ export abstract class BaseMediaSampleSink<
 				}
 			}
 
-			const packets = packetSink.packets(keyPacket, endPacket);
+			const packets = packetSink.packets(keyPacket ?? undefined, endPacket);
 			await packets.next(); // Skip the start packet as we already have it
 
 			while (currentPacket && !ended && !this._track.input._disposed) {
@@ -2127,11 +2126,14 @@ export class AudioBufferSink {
 
 	/** @internal */
 	_audioSampleToWrappedArrayBuffer(sample: AudioSample): WrappedAudioBuffer {
-		return {
+		const result: WrappedAudioBuffer = {
 			buffer: sample.toAudioBuffer(),
 			timestamp: sample.timestamp,
 			duration: sample.duration,
 		};
+
+		sample.close();
+		return result;
 	}
 
 	/**

src/media-source.ts

@@ -1356,21 +1356,27 @@ class AudioEncoderWrapper {
 					(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,
-					});
+				if (this.lastEndSampleIndex === null) {
+					this.lastEndSampleIndex = endSampleIndex;
+				} else {
+					const sampleDiff = startSampleIndex - this.lastEndSampleIndex;
 
-					await this.add(fillSample, true); // Recursive call
+					if (sampleDiff >= 64) {
+						// The gap is big enough, let's add a correction sample
+						const fillSample = new AudioSample({
+							data: new Float32Array(sampleDiff * audioSample.numberOfChannels),
+							format: 'f32-planar',
+							sampleRate: audioSample.sampleRate,
+							numberOfChannels: audioSample.numberOfChannels,
+							numberOfFrames: sampleDiff,
+							timestamp: this.lastEndSampleIndex / audioSample.sampleRate,
+						});
+
+						await this.add(fillSample, true); // Recursive call
+					}
+
+					this.lastEndSampleIndex += audioSample.numberOfFrames;
 				}
-
-				this.lastEndSampleIndex = endSampleIndex;
 			}
 
 			if (this.customEncoder) {

src/misc.ts

@@ -157,20 +157,20 @@ export const writeBits = (bytes: Uint8Array, start: number, end: number, value:
 export const toUint8Array = (source: AllowSharedBufferSource): Uint8Array => {
 	if (source.constructor === Uint8Array) { // We want a true Uint8Array, not something that extends it like Buffer
 		return source;
-	} else if (source instanceof ArrayBuffer) {
-		return new Uint8Array(source);
-	} else {
+	} else if (ArrayBuffer.isView(source)) {
 		return new Uint8Array(source.buffer, source.byteOffset, source.byteLength);
+	} else {
+		return new Uint8Array(source);
 	}
 };
 
-export const toDataView = (source: AllowSharedBufferSource) => {
+export const toDataView = (source: AllowSharedBufferSource): DataView => {
 	if (source.constructor === DataView) {
 		return source;
-	} else if (source instanceof ArrayBuffer) {
-		return new DataView(source);
-	} else {
+	} else if (ArrayBuffer.isView(source)) {
 		return new DataView(source.buffer, source.byteOffset, source.byteLength);
+	} else {
+		return new DataView(source);
 	}
 };
 

src/sample.ts

@@ -21,6 +21,54 @@ import {
 
 polyfillSymbolDispose();
 
+type FinalizationRegistryValue = {
+	type: 'video';
+	data: VideoFrame | OffscreenCanvas | Uint8Array;
+} | {
+	type: 'audio';
+	data: AudioData | Uint8Array;
+};
+
+// Let's manually handle logging the garbage collection errors that are typically logged by the browser. This way, they
+// also kick for audio samples (which is normally not the case), making sure any incorrect code is quickly caught.
+let lastVideoGcErrorLog = -Infinity;
+let lastAudioGcErrorLog = -Infinity;
+let finalizationRegistry: FinalizationRegistry<FinalizationRegistryValue> | null = null;
+if (typeof FinalizationRegistry !== 'undefined') {
+	finalizationRegistry = new FinalizationRegistry<FinalizationRegistryValue>((value) => {
+		const now = Date.now();
+
+		if (value.type === 'video') {
+			if (now - lastVideoGcErrorLog >= 1000) {
+				// This error is annoying but oh so important
+				console.error(
+					`A VideoSample was garbage collected without first being closed. For proper resource management,`
+					+ ` make sure to call close() on all your VideoSamples as soon as you're done using them.`,
+				);
+
+				lastVideoGcErrorLog = now;
+			}
+
+			if (typeof VideoFrame !== 'undefined' && value.data instanceof VideoFrame) {
+				value.data.close(); // Prevent the browser error since we're logging our own
+			}
+		} else {
+			if (now - lastAudioGcErrorLog >= 1000) {
+				console.error(
+					`An AudioSample was garbage collected without first being closed. For proper resource management,`
+					+ ` make sure to call close() on all your AudioSamples as soon as you're done using them.`,
+				);
+
+				lastAudioGcErrorLog = now;
+			}
+
+			if (typeof AudioData !== 'undefined' && value.data instanceof AudioData) {
+				value.data.close();
+			}
+		}
+	});
+}
+
 /**
  * Metadata used for VideoSample initialization.
  * @group Samples
@@ -133,7 +181,11 @@ export class VideoSample implements Disposable {
 		data: VideoFrame | CanvasImageSource | AllowSharedBufferSource,
 		init?: VideoSampleInit,
 	) {
-		if (data instanceof ArrayBuffer || ArrayBuffer.isView(data)) {
+		if (
+			data instanceof ArrayBuffer
+			|| (typeof SharedArrayBuffer !== 'undefined' && data instanceof SharedArrayBuffer)
+			|| ArrayBuffer.isView(data)
+		) {
 			if (!init || typeof init !== 'object') {
 				throw new TypeError('init must be an object.');
 			}
@@ -265,6 +317,8 @@ export class VideoSample implements Disposable {
 		} else {
 			throw new TypeError('Invalid data type: Must be a BufferSource or CanvasImageSource.');
 		}
+
+		finalizationRegistry?.register(this, { type: 'video', data: this._data }, this);
 	}
 
 	/** Clones this video sample. */
@@ -313,6 +367,8 @@ export class VideoSample implements Disposable {
 			return;
 		}
 
+		finalizationRegistry?.unregister(this);
+
 		if (isVideoFrame(this._data)) {
 			this._data.close();
 		} else {
@@ -955,6 +1011,8 @@ export class AudioSample implements Disposable {
 
 			this._data = dataBuffer;
 		}
+
+		finalizationRegistry?.register(this, { type: 'audio', data: this._data }, this);
 	}
 
 	/** Returns the number of bytes required to hold the audio sample's data as specified by the given options. */
@@ -1116,9 +1174,8 @@ export class AudioSample implements Disposable {
 				}
 			}
 		} else {
-			// Branch for Uint8Array data (non-AudioData)
 			const uint8Data = this._data;
-			const srcView = new DataView(uint8Data.buffer, uint8Data.byteOffset, uint8Data.byteLength);
+			const srcView = toDataView(uint8Data);
 
 			const srcFormat = this.format;
 			const readFn = getReadFunction(srcFormat);
@@ -1188,6 +1245,8 @@ export class AudioSample implements Disposable {
 			return;
 		}
 
+		finalizationRegistry?.unregister(this);
+
 		if (isAudioData(this._data)) {
 			this._data.close();
 		} else {
@@ -1250,7 +1309,9 @@ export class AudioSample implements Disposable {
 				numberOfFrames: this.numberOfFrames,
 				numberOfChannels: this.numberOfChannels,
 				timestamp: this.microsecondTimestamp,
-				data: this._data,
+				data: this._data.buffer instanceof ArrayBuffer
+					? this._data.buffer
+					: this._data.slice(), // In the case of SharedArrayBuffer, convert to ArrayBuffer
 			});
 		}
 	}

src/source.ts

@@ -102,10 +102,17 @@ export class BufferSource extends Source {
 	/** @internal */
 	_onreadCalled = false;
 
-	/** Creates a new {@link BufferSource} backed the specified `ArrayBuffer` or `ArrayBufferView`. */
-	constructor(buffer: ArrayBuffer | ArrayBufferView) {
-		if (!(buffer instanceof ArrayBuffer) && !ArrayBuffer.isView(buffer)) {
-			throw new TypeError('buffer must be an ArrayBuffer or ArrayBufferView.');
+	/**
+	 * Creates a new {@link BufferSource} backed by the specified `ArrayBuffer`, `SharedArrayBuffer`,
+	 * or `ArrayBufferView`.
+	 */
+	constructor(buffer: AllowSharedBufferSource) {
+		if (
+			!(buffer instanceof ArrayBuffer)
+			&& !(typeof SharedArrayBuffer !== 'undefined' && buffer instanceof SharedArrayBuffer)
+			&& !ArrayBuffer.isView(buffer)
+		) {
+			throw new TypeError('buffer must be an ArrayBuffer, SharedArrayBuffer, or ArrayBufferView.');
 		}
 
 		super();
@@ -234,12 +241,7 @@ export class BlobSource extends Source {
 				const { done, value } = await reader.read();
 				if (done) {
 					this._orchestrator.forgetWorker(worker);
-
-					if (worker.currentPos < worker.targetPos) { // I think this `if` should always hit?
-						throw new Error('Blob reader stopped unexpectedly before all requested data was read.');
-					}
-
-					break;
+					throw new Error('Blob reader stopped unexpectedly before all requested data was read.');
 				}
 
 				if (worker.aborted) {
@@ -441,7 +443,7 @@ export class UrlSource extends Source {
 		let fileSize: number;
 
 		if (response.status === 206) {
-			fileSize = this._getPartialLengthFromRangeResponse(response);
+			fileSize = this._getTotalLengthFromRangeResponse(response);
 			worker = this._orchestrator.createWorker(0, Math.min(fileSize, URL_SOURCE_MIN_LOAD_AMOUNT));
 		} else {
 			// Server probably returned a 200.
@@ -515,14 +517,6 @@ export class UrlSource extends Source {
 				);
 			}
 
-			const length = this._getPartialLengthFromRangeResponse(response);
-			const required = worker.targetPos - worker.currentPos;
-			if (length < required) {
-				throw new Error(
-					`HTTP response unexpectedly too short: Needed at least ${required} bytes, got only ${length}.`,
-				);
-			}
-
 			if (!response.body) {
 				throw new Error(
 					'Missing HTTP response body stream. The used fetch function must provide the response body as a'
@@ -568,16 +562,17 @@ export class UrlSource extends Source {
 				const { done, value } = readResult;
 
 				if (done) {
-					this._orchestrator.forgetWorker(worker);
-
-					if (worker.currentPos < worker.targetPos) {
-						throw new Error(
-							'Response stream reader stopped unexpectedly before all requested data was read.',
-						);
+					if (worker.currentPos >= worker.targetPos) {
+						// All data was delivered, we're good
+						this._orchestrator.forgetWorker(worker);
+						worker.running = false;
+						return;
 					}
 
-					worker.running = false;
-					return;
+					// The response stopped early, before the target. This can happen if server decides to cap range
+					// requests arbitrarily, even if the request had an uncapped end. In this case, let's fetch the rest
+					// of the data using a new request.
+					break;
 				}
 
 				this.onread?.(worker.currentPos, worker.currentPos + value.length);
@@ -597,25 +592,23 @@ export class UrlSource extends Source {
 	}
 
 	/** @internal */
-	private _getPartialLengthFromRangeResponse(response: Response) {
+	private _getTotalLengthFromRangeResponse(response: Response) {
 		const contentRange = response.headers.get('Content-Range');
 		if (contentRange) {
 			const match = /\/(\d+)/.exec(contentRange);
 			if (match) {
 				return Number(match[1]);
-			} else {
-				throw new Error(`Invalid Content-Range header: ${contentRange}`);
 			}
+		}
+
+		const contentLength = response.headers.get('Content-Length');
+		if (contentLength) {
+			return Number(contentLength);
 		} else {
-			const contentLength = response.headers.get('Content-Length');
-			if (contentLength) {
-				return Number(contentLength);
-			} else {
-				throw new Error(
-					'Partial HTTP response (status 206) must surface either Content-Range or'
-					+ ' Content-Length header.',
-				);
-			}
+			throw new Error(
+				'Partial HTTP response (status 206) must surface either Content-Range or'
+				+ ' Content-Length header.',
+			);
 		}
 	}
 

src/target.ts

@@ -62,7 +62,7 @@ export type StreamTargetChunk = {
 	/** The operation type. */
 	type: 'write'; // This ensures automatic compatibility with FileSystemWritableFileStream
 	/** The data to write. */
-	data: Uint8Array;
+	data: Uint8Array<ArrayBuffer>;
 	/** The byte offset in the output file at which to write the data. */
 	position: number;
 };

src/writer.ts

@@ -190,7 +190,7 @@ const MAX_CHUNKS_AT_ONCE = 2;
 interface Chunk {
 	start: number;
 	written: ChunkSection[];
-	data: Uint8Array;
+	data: Uint8Array<ArrayBuffer>;
 	shouldFlush: boolean;
 }
 
@@ -281,7 +281,7 @@ export class StreamTargetWriter extends Writer {
 		const chunks: {
 			start: number;
 			size: number;
-			data?: Uint8Array;
+			data?: Uint8Array<ArrayBuffer>;
 		}[] = [];
 		const sorted = [...this.sections].sort((a, b) => a.start - b.start);
 

test/browser/flac.test.ts

@@ -19,7 +19,7 @@ test('can decode samples from a FLAC file', async () => {
 
 	const sink = new AudioSampleSink(track);
 
-	const sample = await sink.getSample(1);
+	using sample = await sink.getSample(1);
 	assert(sample);
 	expect(sample.timestamp).toBe(0.9287981859410431);
 });

test/browser/transparency.test.ts

@@ -21,7 +21,7 @@ test('Can decode transparent video', async () => {
 	expect(await videoTrack.canBeTransparent()).toBe(true);
 
 	const sink = new VideoSampleSink(videoTrack);
-	const sample = (await sink.getSample(0.5))!;
+	using sample = (await sink.getSample(0.5))!;
 
 	expect(sample.format).toContain('A'); // Probably RGBA
 	expect(sample.hasAlpha).toBe(true);
@@ -47,10 +47,10 @@ test('Can decode faulty transparent video and behaves gracefully', async () => {
 
 	const sink = new VideoSampleSink(videoTrack);
 
-	const startSample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
+	using startSample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
 	expect(startSample.format).toContain('A');
 
-	const secondSample = (await sink.getSample(secondKeyPacket.timestamp))!;
+	using secondSample = (await sink.getSample(secondKeyPacket.timestamp))!;
 	expect(secondSample.format).not.toContain('A'); // There was no alpha key frame for this one
 	expect(secondSample.hasAlpha).toBe(false);
 });
@@ -164,7 +164,7 @@ test('Can encode transparent video', async () => {
 
 	const sink = new VideoSampleSink(videoTrack);
 
-	const firstSample = (await sink.getSample(0))!;
+	using firstSample = (await sink.getSample(0))!;
 	expect(firstSample.format).toContain('A');
 
 	probeContext.clearRect(0, 0, probeCanvas.width, probeCanvas.height);
@@ -201,7 +201,7 @@ test('Can encode video with alternating transparency', async () => {
 	await output.start();
 
 	for (let i = 0; i < 64; i++) {
-		const sample = new VideoSample(new Uint8Array(640 * 480 * 4), {
+		using sample = new VideoSample(new Uint8Array(640 * 480 * 4), {
 			format: i % 2 ? 'RGBX' : 'RGBA',
 			codedWidth: 640,
 			codedHeight: 480,
@@ -235,7 +235,7 @@ test('Can encode video with alternating transparency', async () => {
 	const sampleSink = new VideoSampleSink(videoTrack);
 
 	i = 0;
-	for await (const sample of sampleSink.samples()) {
+	for await (using sample of sampleSink.samples()) {
 		if (i % 2) {
 			expect(sample.format).not.toContain('A');
 		} else {
@@ -299,7 +299,7 @@ test('Can transmux transparent video, discards alpha by default', async () => {
 	expect(await videoTrack.canBeTransparent()).toBe(false);
 
 	const sink = new VideoSampleSink(videoTrack);
-	const sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
+	using sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
 	expect(sample.hasAlpha).toBe(false);
 });
 
@@ -331,7 +331,7 @@ test('Can transmux transparent video, can keep alpha', async () => {
 	expect(await videoTrack.canBeTransparent()).toBe(true);
 
 	const sink = new VideoSampleSink(videoTrack);
-	const sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
+	using sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
 	expect(sample.format).toContain('A');
 	expect(sample.hasAlpha).toBe(true);
 });
@@ -370,7 +370,7 @@ test('Can reencode transparent video, keeping alpha', async () => {
 	expect(videoTrack.displayWidth).toBe(320);
 
 	const sink = new VideoSampleSink(videoTrack);
-	const sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
+	using sample = (await sink.getSample(await videoTrack.getFirstTimestamp()))!;
 	expect(sample.format).toContain('A');
 	expect(sample.hasAlpha).toBe(true);
 });