Bump patch

* Don't overlook potential packets in FLAC bitstream

* Update way of going back

README.md

@@ -39,6 +39,10 @@ Mediabunny is a JavaScript library for reading, writing, and converting media fi
   <a href="https://pqina.nl/pintura/" target="_blank" rel="sponsored">
     <img src="./docs/public/sponsors/pintura-labs.png" width="50" height="50" alt="Pintura Labs">
   </a>
+  &nbsp;&nbsp;&nbsp;&nbsp;
+  <a href="https://ponder.ai/" target="_blank" rel="sponsored">
+    <img src="./docs/public/sponsors/ponder.png" width="50" height="50" alt="Ponder">
+  </a>
 </div>
 
 ### Bronze sponsors

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: 'opus',
+				//codec: 'opus',
 				/*
 				process: (sample) => {
 					return sample;
@@ -97,6 +100,10 @@
 			},
 			*/
 			video: () => ({
+				width: 720,
+				frameRate: 30,
+				bitrate: Mediabunny.QUALITY_VERY_LOW,
+				//discard: true,
 				/*
 				process: (sample) => {
 					if (!ctx) {
@@ -108,9 +115,11 @@
 						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;
 				},
@@ -171,7 +180,7 @@
 			},
 			trim: {
 				start: 0,
-				end: 10
+				end: 20
 			},
 		});
 		console.log(conversion);

dev/demux.html

@@ -14,7 +14,58 @@
 			source: new Mediabunny.BlobSource(file),
 		});
 
-		const videoTrack = await input.getPrimaryVideoTrack();
+		const audioTrack = await input.getPrimaryAudioTrack();
+		const sink = new Mediabunny.EncodedPacketSink(audioTrack);
+
+		for await (const packet of sink.packets()) {
+			console.log(packet.timestamp, packet.duration, packet.type)
+		}
+
+		/*
+		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()) {
+			console.log(packet.timestamp, packet.duration, packet.timestamp + packet.duration);
+
+			if (packet.timestamp > 10) break;
+		}
+		*/
+
+		/*
+		const sink = new Mediabunny.VideoSampleSink(videoTrack);
+
+		for await (const sample of sink.samples()) {
+			console.log(sample.timestamp, sample.duration);
+			sample.close();
+		}
+		*/
+
+		/*
+		const sink = new Mediabunny.EncodedPacketSink(videoTrack);
+
+		for await (const packet of sink.packets()) {
+			console.log(packet.timestamp, packet.timestamp + packet.duration);
+		}
+		*/
+
+
+		/*
 		const sink = new Mediabunny.VideoSampleSink(videoTrack);
 
 		console.log(await videoTrack.getDecoderConfig())
@@ -30,6 +81,7 @@
 		for await (const sample of sink.samples()) {
 			console.log(sample);
 		}
+		*/
 
 		/*
 		let total = 0;

docs/index.md

@@ -98,6 +98,7 @@ const sponsors = {
 	],
 	silver: [
 		{ image: '/sponsors/pintura-labs.png', name: 'Pintura Labs', url: 'https://pqina.nl/pintura/' },
+		{ image: '/sponsors/ponder.png', name: 'Ponder', url: 'https://ponder.ai/' },
 	],
 	bronze: [
 		{ image: '/sponsors/rve.png', name: 'React Video Editor', url: 'https://www.reactvideoeditor.com/' },

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "mediabunny",
-  "version": "1.24.4",
+  "version": "1.24.7",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "mediabunny",
-      "version": "1.24.4",
+      "version": "1.24.7",
       "license": "MPL-2.0",
       "workspaces": [
         "packages/*"
@@ -7749,9 +7749,9 @@
       }
     },
     "node_modules/mediabunny": {
-      "version": "1.24.3",
-      "resolved": "https://registry.npmjs.org/mediabunny/-/mediabunny-1.24.3.tgz",
-      "integrity": "sha512-uQu5lXg6c3z2YUKLimAsem1qYPdGfGziQ5CKaAMJAs0C0NNw5T/Zkn0foPML0gWqQJ5ZeC0wTgCxpiBQY8m1Tw==",
+      "version": "1.24.6",
+      "resolved": "https://registry.npmjs.org/mediabunny/-/mediabunny-1.24.6.tgz",
+      "integrity": "sha512-GODsNvKeig2Zhj2NCABBskVgJS1IMltP0uX/I0ltFksPCHpshreZhJEMwc903YbgdsW3RT7e6uvLX6UtlmeIkQ==",
       "license": "MPL-2.0",
       "peer": true,
       "workspaces": [
@@ -12242,7 +12242,7 @@
     },
     "packages/mp3-encoder": {
       "name": "@mediabunny/mp3-encoder",
-      "version": "1.24.4",
+      "version": "1.24.7",
       "license": "MPL-2.0",
       "devDependencies": {
         "@types/emscripten": "^1.40.1"

package.json

@@ -1,7 +1,7 @@
 {
   "name": "mediabunny",
   "author": "Vanilagy",
-  "version": "1.24.4",
+  "version": "1.24.7",
   "description": "Pure TypeScript media toolkit for reading, writing, and converting media files, directly in the browser.",
   "type": "module",
   "workspaces": [

packages/mp3-encoder/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@mediabunny/mp3-encoder",
   "author": "Vanilagy",
-  "version": "1.24.4",
+  "version": "1.24.7",
   "description": "MP3 encoder extension for Mediabunny, based on LAME.",
   "main": "./dist/bundles/mediabunny-mp3-encoder.mjs",
   "module": "./dist/bundles/mediabunny-mp3-encoder.mjs",

src/codec-data.ts

@@ -229,7 +229,7 @@ const extractNalUnitTypeForAvc = (data: Uint8Array) => {
 };
 
 /** Builds an AvcDecoderConfigurationRecord from an AVC packet in Annex B format. */
-export const extractAvcDecoderConfigurationRecord = (packetData: Uint8Array) => {
+export const extractAvcDecoderConfigurationRecord = (packetData: Uint8Array): AvcDecoderConfigurationRecord | null => {
 	try {
 		const nalUnits = findNalUnitsInAnnexB(packetData);
 
@@ -247,60 +247,27 @@ export const extractAvcDecoderConfigurationRecord = (packetData: Uint8Array) =>
 
 		// Let's get the first SPS for profile and level information
 		const spsData = spsUnits[0]!;
-		const bitstream = new Bitstream(removeEmulationPreventionBytes(spsData));
+		const spsInfo = parseAvcSps(spsData);
+		assert(spsInfo !== null);
 
-		bitstream.skipBits(1); // forbidden_zero_bit
-		bitstream.skipBits(2); // nal_ref_idc
-		const nal_unit_type = bitstream.readBits(5);
+		const hasExtendedData = spsInfo.profileIdc === 100
+			|| spsInfo.profileIdc === 110
+			|| spsInfo.profileIdc === 122
+			|| spsInfo.profileIdc === 144;
 
-		if (nal_unit_type !== 7) { // SPS NAL unit type is 7
-			console.error('Invalid SPS NAL unit type');
-			return null;
-		}
-
-		const profile_idc = bitstream.readAlignedByte();
-		const constraint_flags = bitstream.readAlignedByte();
-		const level_idc = bitstream.readAlignedByte();
-
-		const record: AvcDecoderConfigurationRecord = {
+		return {
 			configurationVersion: 1,
-			avcProfileIndication: profile_idc,
-			profileCompatibility: constraint_flags,
-			avcLevelIndication: level_idc,
+			avcProfileIndication: spsInfo.profileIdc,
+			profileCompatibility: spsInfo.constraintFlags,
+			avcLevelIndication: spsInfo.levelIdc,
 			lengthSizeMinusOne: 3, // Typically 4 bytes for length field
 			sequenceParameterSets: spsUnits,
 			pictureParameterSets: ppsUnits,
-			chromaFormat: null,
-			bitDepthLumaMinus8: null,
-			bitDepthChromaMinus8: null,
-			sequenceParameterSetExt: null,
+			chromaFormat: hasExtendedData ? spsInfo.chromaFormatIdc : null,
+			bitDepthLumaMinus8: hasExtendedData ? spsInfo.bitDepthLumaMinus8 : null,
+			bitDepthChromaMinus8: hasExtendedData ? spsInfo.bitDepthChromaMinus8 : null,
+			sequenceParameterSetExt: hasExtendedData ? spsExtUnits : null,
 		};
-
-		if (
-			profile_idc === 100
-			|| profile_idc === 110
-			|| profile_idc === 122
-			|| profile_idc === 144
-		) {
-			readExpGolomb(bitstream); // seq_parameter_set_id
-
-			const chroma_format_idc = readExpGolomb(bitstream);
-
-			if (chroma_format_idc === 3) {
-				bitstream.skipBits(1); // separate_colour_plane_flag
-			}
-
-			const bit_depth_luma_minus8 = readExpGolomb(bitstream);
-
-			const bit_depth_chroma_minus8 = readExpGolomb(bitstream);
-
-			record.chromaFormat = chroma_format_idc;
-			record.bitDepthLumaMinus8 = bit_depth_luma_minus8;
-			record.bitDepthChromaMinus8 = bit_depth_chroma_minus8;
-			record.sequenceParameterSetExt = spsExtUnits;
-		}
-
-		return record;
 	} catch (error) {
 		console.error('Error building AVC Decoder Configuration Record:', error);
 		return null;
@@ -377,6 +344,206 @@ export const serializeAvcDecoderConfigurationRecord = (record: AvcDecoderConfigu
 	return new Uint8Array(bytes);
 };
 
+/** Deserializes an AvcDecoderConfigurationRecord from the format specified in Section 5.3.3.1 of ISO 14496-15. */
+export const deserializeAvcDecoderConfigurationRecord = (data: Uint8Array): AvcDecoderConfigurationRecord | null => {
+	try {
+		const view = toDataView(data);
+		let offset = 0;
+
+		// Read header
+		const configurationVersion = view.getUint8(offset++);
+		const avcProfileIndication = view.getUint8(offset++);
+		const profileCompatibility = view.getUint8(offset++);
+		const avcLevelIndication = view.getUint8(offset++);
+		const lengthSizeMinusOne = view.getUint8(offset++) & 0x03;
+
+		const numOfSequenceParameterSets = view.getUint8(offset++) & 0x1F;
+
+		// Read SPS
+		const sequenceParameterSets: Uint8Array[] = [];
+		for (let i = 0; i < numOfSequenceParameterSets; i++) {
+			const length = view.getUint16(offset, false);
+			offset += 2;
+
+			sequenceParameterSets.push(data.subarray(offset, offset + length));
+			offset += length;
+		}
+
+		const numOfPictureParameterSets = view.getUint8(offset++);
+
+		// Read PPS
+		const pictureParameterSets: Uint8Array[] = [];
+		for (let i = 0; i < numOfPictureParameterSets; i++) {
+			const length = view.getUint16(offset, false);
+			offset += 2;
+
+			pictureParameterSets.push(data.subarray(offset, offset + length));
+			offset += length;
+		}
+
+		const record: AvcDecoderConfigurationRecord = {
+			configurationVersion,
+			avcProfileIndication,
+			profileCompatibility,
+			avcLevelIndication,
+			lengthSizeMinusOne,
+			sequenceParameterSets,
+			pictureParameterSets,
+			chromaFormat: null,
+			bitDepthLumaMinus8: null,
+			bitDepthChromaMinus8: null,
+			sequenceParameterSetExt: null,
+		};
+
+		// Check if there are extended profile fields
+		if (
+			(
+				avcProfileIndication === 100
+				|| avcProfileIndication === 110
+				|| avcProfileIndication === 122
+				|| avcProfileIndication === 144
+			)
+			&& offset + 4 <= data.length
+		) {
+			const chromaFormat = view.getUint8(offset++) & 0x03;
+			const bitDepthLumaMinus8 = view.getUint8(offset++) & 0x07;
+			const bitDepthChromaMinus8 = view.getUint8(offset++) & 0x07;
+			const numOfSequenceParameterSetExt = view.getUint8(offset++);
+
+			record.chromaFormat = chromaFormat;
+			record.bitDepthLumaMinus8 = bitDepthLumaMinus8;
+			record.bitDepthChromaMinus8 = bitDepthChromaMinus8;
+
+			// Read SPS Ext
+			const sequenceParameterSetExt: Uint8Array[] = [];
+			for (let i = 0; i < numOfSequenceParameterSetExt; i++) {
+				const length = view.getUint16(offset, false);
+				offset += 2;
+
+				sequenceParameterSetExt.push(data.subarray(offset, offset + length));
+				offset += length;
+			}
+
+			record.sequenceParameterSetExt = sequenceParameterSetExt;
+		}
+
+		return record;
+	} catch (error) {
+		console.error('Error deserializing AVC Decoder Configuration Record:', error);
+		return null;
+	}
+};
+
+export type AvcSpsInfo = {
+	profileIdc: number;
+	constraintFlags: number;
+	levelIdc: number;
+	frameMbsOnlyFlag: number;
+	chromaFormatIdc: number | null;
+	bitDepthLumaMinus8: number | null;
+	bitDepthChromaMinus8: number | null;
+};
+
+/** Parses an AVC SPS (Sequence Parameter Set) to extract basic information. */
+export const parseAvcSps = (sps: Uint8Array): AvcSpsInfo | null => {
+	try {
+		const bitstream = new Bitstream(removeEmulationPreventionBytes(sps));
+
+		bitstream.skipBits(1); // forbidden_zero_bit
+		bitstream.skipBits(2); // nal_ref_idc
+		const nalUnitType = bitstream.readBits(5);
+
+		if (nalUnitType !== 7) { // SPS NAL unit type is 7
+			return null;
+		}
+
+		const profileIdc = bitstream.readAlignedByte();
+		const constraintFlags = bitstream.readAlignedByte();
+		const levelIdc = bitstream.readAlignedByte();
+
+		readExpGolomb(bitstream); // seq_parameter_set_id
+
+		let chromaFormatIdc: number | null = null;
+		let bitDepthLumaMinus8: number | null = null;
+		let bitDepthChromaMinus8: number | null = null;
+
+		// Handle high profile chroma_format_idc
+		if (
+			profileIdc === 100
+			|| profileIdc === 110
+			|| profileIdc === 122
+			|| profileIdc === 244
+			|| profileIdc === 44
+			|| profileIdc === 83
+			|| profileIdc === 86
+			|| profileIdc === 118
+			|| profileIdc === 128
+		) {
+			chromaFormatIdc = readExpGolomb(bitstream);
+			if (chromaFormatIdc === 3) {
+				bitstream.skipBits(1); // separate_colour_plane_flag
+			}
+			bitDepthLumaMinus8 = readExpGolomb(bitstream);
+			bitDepthChromaMinus8 = readExpGolomb(bitstream);
+			bitstream.skipBits(1); // qpprime_y_zero_transform_bypass_flag
+			const seqScalingMatrixPresentFlag = bitstream.readBits(1);
+			if (seqScalingMatrixPresentFlag) {
+				for (let i = 0; i < (chromaFormatIdc !== 3 ? 8 : 12); i++) {
+					const seqScalingListPresentFlag = bitstream.readBits(1);
+					if (seqScalingListPresentFlag) {
+						const sizeOfScalingList = i < 6 ? 16 : 64;
+						let lastScale = 8;
+						let nextScale = 8;
+						for (let j = 0; j < sizeOfScalingList; j++) {
+							if (nextScale !== 0) {
+								const deltaScale = readSignedExpGolomb(bitstream);
+								nextScale = (lastScale + deltaScale + 256) % 256;
+							}
+							lastScale = nextScale === 0 ? lastScale : nextScale;
+						}
+					}
+				}
+			}
+		}
+
+		readExpGolomb(bitstream); // log2_max_frame_num_minus4
+
+		const picOrderCntType = readExpGolomb(bitstream);
+		if (picOrderCntType === 0) {
+			readExpGolomb(bitstream); // log2_max_pic_order_cnt_lsb_minus4
+		} else if (picOrderCntType === 1) {
+			bitstream.skipBits(1); // delta_pic_order_always_zero_flag
+			readSignedExpGolomb(bitstream); // offset_for_non_ref_pic
+			readSignedExpGolomb(bitstream); // offset_for_top_to_bottom_field
+			const numRefFramesInPicOrderCntCycle = readExpGolomb(bitstream);
+			for (let i = 0; i < numRefFramesInPicOrderCntCycle; i++) {
+				readSignedExpGolomb(bitstream); // offset_for_ref_frame[i]
+			}
+		}
+
+		readExpGolomb(bitstream); // max_num_ref_frames
+		bitstream.skipBits(1); // gaps_in_frame_num_value_allowed_flag
+
+		readExpGolomb(bitstream); // pic_width_in_mbs_minus1
+		readExpGolomb(bitstream); // pic_height_in_map_units_minus1
+
+		const frameMbsOnlyFlag = bitstream.readBits(1);
+
+		return {
+			profileIdc,
+			constraintFlags,
+			levelIdc,
+			frameMbsOnlyFlag,
+			chromaFormatIdc,
+			bitDepthLumaMinus8,
+			bitDepthChromaMinus8,
+		};
+	} catch (error) {
+		console.error('Error parsing AVC SPS:', error);
+		return null;
+	}
+};
+
 // Data specified in ISO 14496-15
 export type HevcDecoderConfigurationRecord = {
 	configurationVersion: number;

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;
@@ -621,6 +624,54 @@ export const parseAacAudioSpecificConfig = (bytes: Uint8Array | null): AacAudioS
 	};
 };
 
+export const buildAacAudioSpecificConfig = (config: {
+	objectType: number;
+	sampleRate: number;
+	numberOfChannels: number;
+}) => {
+	let frequencyIndex = aacFrequencyTable.indexOf(config.sampleRate);
+	let customSampleRate: number | null = null;
+
+	if (frequencyIndex === -1) {
+		frequencyIndex = 15;
+		customSampleRate = config.sampleRate;
+	}
+
+	const channelConfiguration = aacChannelMap.indexOf(config.numberOfChannels);
+	if (channelConfiguration === -1) {
+		throw new TypeError(`Unsupported number of channels: ${config.numberOfChannels}`);
+	}
+
+	let bitCount = 5 + 4 + 4;
+	if (config.objectType >= 32) {
+		bitCount += 6;
+	}
+	if (frequencyIndex === 15) {
+		bitCount += 24;
+	}
+
+	const byteCount = Math.ceil(bitCount / 8);
+	const bytes = new Uint8Array(byteCount);
+	const bitstream = new Bitstream(bytes);
+
+	if (config.objectType < 32) {
+		bitstream.writeBits(5, config.objectType);
+	} else {
+		bitstream.writeBits(5, 31);
+		bitstream.writeBits(6, config.objectType - 32);
+	}
+
+	bitstream.writeBits(4, frequencyIndex);
+
+	if (frequencyIndex === 15) {
+		bitstream.writeBits(24, customSampleRate!);
+	}
+
+	bitstream.writeBits(4, channelConfiguration);
+
+	return bytes;
+};
+
 export const OPUS_SAMPLE_RATE = 48_000;
 
 const PCM_CODEC_REGEX = /^pcm-([usf])(\d+)+(be)?$/;

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';
@@ -1039,6 +1043,7 @@ export class Conversion {
 								duration: 1 / frameRate,
 							});
 							await this._registerVideoSample(track, trackOptions, source, sample);
+							sample.close();
 						}
 					};
 
@@ -1075,12 +1080,11 @@ export class Conversion {
 							duration: frameRate !== undefined ? 1 / frameRate : duration,
 						});
 						await this._registerVideoSample(track, trackOptions, source, sample);
+						sample.close();
 
 						if (frameRate !== undefined) {
 							lastCanvas = canvas;
 							lastCanvasTimestamp = adjustedSampleTimestamp;
-						} else {
-							sample.close();
 						}
 					}
 

src/encode.ts

@@ -115,9 +115,15 @@ export type VideoEncodingAdditionalOptions = {
 	 * format that supports transparency (such as WebM or Matroska).
 	 */
 	alpha?: 'discard' | 'keep';
-	/** Configures the bitrate mode. */
+	/** Configures the bitrate mode; defaults to `'variable'`. */
 	bitrateMode?: 'constant' | 'variable';
-	/** The latency mode used by the encoder; controls the performance-quality tradeoff. */
+	/**
+	 * The latency mode used by the encoder; controls the performance-quality tradeoff.
+	 *
+	 * - `'quality'` (default): The encoder prioritizes quality over latency, and no frames can be dropped.
+	 * - `'realtime'`: The encoder prioritizes low latency over quality, and may drop frames if the encoder becomes
+	 * overloaded to keep up with real-time requirements.
+	 */
 	latencyMode?: 'quality' | 'realtime';
 	/**
 	 * The full codec string as specified in the WebCodecs Codec Registry. This string must match the codec
@@ -125,7 +131,8 @@ export type VideoEncodingAdditionalOptions = {
 	 */
 	fullCodecString?: string;
 	/**
-	 * A hint that configures the hardware acceleration method of this codec. This is best left on `'no-preference'`.
+	 * A hint that configures the hardware acceleration method of this codec. This is best left on `'no-preference'`,
+	 * the default.
 	 */
 	hardwareAcceleration?: 'no-preference' | 'prefer-hardware' | 'prefer-software';
 	/**
@@ -403,31 +410,31 @@ export class Quality {
  * @group Encoding
  * @public
  */
-export const QUALITY_VERY_LOW = new Quality(0.3);
+export const QUALITY_VERY_LOW = /* #__PURE__ */ new Quality(0.3);
 /**
  * Represents a low media quality.
  * @group Encoding
  * @public
  */
-export const QUALITY_LOW = new Quality(0.6);
+export const QUALITY_LOW = /* #__PURE__ */ new Quality(0.6);
 /**
  * Represents a medium media quality.
  * @group Encoding
  * @public
  */
-export const QUALITY_MEDIUM = new Quality(1);
+export const QUALITY_MEDIUM = /* #__PURE__ */ new Quality(1);
 /**
  * Represents a high media quality.
  * @group Encoding
  * @public
  */
-export const QUALITY_HIGH = new Quality(2);
+export const QUALITY_HIGH = /* #__PURE__ */ new Quality(2);
 /**
  * Represents a very high media quality.
  * @group Encoding
  * @public
  */
-export const QUALITY_VERY_HIGH = new Quality(4);
+export const QUALITY_VERY_HIGH = /* #__PURE__ */ new Quality(4);
 
 /**
  * Checks if the browser is able to encode the given codec.

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;
 					}
 				}

src/flac/flac-muxer.ts

@@ -28,7 +28,7 @@ import {
 	readCodedNumber,
 } from './flac-misc';
 
-const FLAC_HEADER = new Uint8Array([0x66, 0x4c, 0x61, 0x43]); // 'fLaC'
+const FLAC_HEADER = /* #__PURE__ */ new Uint8Array([0x66, 0x4c, 0x61, 0x43]); // 'fLaC'
 const STREAMINFO_SIZE = 38;
 const STREAMINFO_BLOCK_SIZE = 34;
 

src/input-format.ts

@@ -481,56 +481,56 @@ export class AdtsInputFormat extends InputFormat {
  * @group Input formats
  * @public
  */
-export const MP4 = new Mp4InputFormat();
+export const MP4 = /* #__PURE__ */ new Mp4InputFormat();
 /**
  * QuickTime File Format input format singleton.
  * @group Input formats
  * @public
  */
-export const QTFF = new QuickTimeInputFormat();
+export const QTFF = /* #__PURE__ */ new QuickTimeInputFormat();
 /**
  * Matroska input format singleton.
  * @group Input formats
  * @public
  */
-export const MATROSKA = new MatroskaInputFormat();
+export const MATROSKA = /* #__PURE__ */ new MatroskaInputFormat();
 /**
  * WebM input format singleton.
  * @group Input formats
  * @public
  */
-export const WEBM = new WebMInputFormat();
+export const WEBM = /* #__PURE__ */ new WebMInputFormat();
 /**
  * MP3 input format singleton.
  * @group Input formats
  * @public
  */
-export const MP3 = new Mp3InputFormat();
+export const MP3 = /* #__PURE__ */ new Mp3InputFormat();
 /**
  * WAVE input format singleton.
  * @group Input formats
  * @public
  */
-export const WAVE = new WaveInputFormat();
+export const WAVE = /* #__PURE__ */ new WaveInputFormat();
 /**
  * Ogg input format singleton.
  * @group Input formats
  * @public
  */
-export const OGG = new OggInputFormat();
+export const OGG = /* #__PURE__ */ new OggInputFormat();
 /**
  * ADTS input format singleton.
  * @group Input formats
  * @public
  */
-export const ADTS = new AdtsInputFormat();
+export const ADTS = /* #__PURE__ */ new AdtsInputFormat();
 
 /**
  * FLAC input format singleton.
  * @group Input formats
  * @public
  */
-export const FLAC = new FlacInputFormat();
+export const FLAC = /* #__PURE__ */ new FlacInputFormat();
 
 /**
  * List of all input format singletons. If you don't need to support all input formats, you should specify the

src/isobmff/isobmff-boxes.ts

@@ -135,8 +135,8 @@ export class IsobmffBoxWriter {
 	}
 }
 
-const bytes = new Uint8Array(8);
-const view = new DataView(bytes.buffer);
+const bytes = /* #__PURE__ */ new Uint8Array(8);
+const view = /* #__PURE__ */ new DataView(bytes.buffer);
 
 const u8 = (value: number) => {
 	return [(value % 0x100 + 0x100) % 0x100];
@@ -243,7 +243,7 @@ const rotationMatrix = (rotationInDegrees: number): TransformationMatrix => {
 		0, 0, 1,
 	];
 };
-const IDENTITY_MATRIX = rotationMatrix(0);
+const IDENTITY_MATRIX = /* #__PURE__ */ rotationMatrix(0);
 
 const matrixToBytes = (matrix: TransformationMatrix) => {
 	return [
@@ -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> = {

src/isobmff/isobmff-demuxer.ts

@@ -51,13 +51,13 @@ import {
 	MATRIX_COEFFICIENTS_MAP_INVERSE,
 	normalizeRotation,
 	roundToMultiple,
-	roundToPrecision,
 	Rotation,
 	textDecoder,
 	TransformationMatrix,
 	TRANSFER_CHARACTERISTICS_MAP_INVERSE,
 	UNDETERMINED_LANGUAGE,
 	toDataView,
+	roundIfAlmostInteger,
 } from '../misc';
 import { EncodedPacket, PLACEHOLDER_DATA } from '../packet';
 import { buildIsobmffMimeType } from './isobmff-misc';
@@ -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') {
@@ -2385,7 +2388,7 @@ abstract class IsobmffTrackBacking implements InputTrackBacking {
 		// Do a little rounding to catch cases where the result is very close to an integer. If it is, it's likely
 		// that the number was originally an integer divided by the timescale. For stability, it's best
 		// to return the integer in this case.
-		return roundToPrecision(timestamp * this.internalTrack.timescale, 14) + this.internalTrack.editListOffset;
+		return roundIfAlmostInteger(timestamp * this.internalTrack.timescale) + this.internalTrack.editListOffset;
 	}
 
 	async getPacket(timestamp: number, options: PacketRetrievalOptions) {

src/matroska/ebml.ts

@@ -463,7 +463,7 @@ export class EBMLWriter {
 
 export const MAX_VAR_INT_SIZE = 8;
 export const MIN_HEADER_SIZE = 2; // 1-byte ID and 1-byte size
-export const MAX_HEADER_SIZE = 2 * MAX_VAR_INT_SIZE; // 8-byte ID and 8-byte size
+export const MAX_HEADER_SIZE = /* #__PURE__ */ 2 * MAX_VAR_INT_SIZE; // 8-byte ID and 8-byte size
 
 export const readVarIntSize = (slice: FileSlice) => {
 	const firstByte = readU8(slice);

src/matroska/matroska-demuxer.ts

@@ -43,7 +43,7 @@ import {
 	MATRIX_COEFFICIENTS_MAP_INVERSE,
 	normalizeRotation,
 	Rotation,
-	roundToPrecision,
+	roundIfAlmostInteger,
 	TRANSFER_CHARACTERISTICS_MAP_INVERSE,
 	UNDETERMINED_LANGUAGE,
 } from '../misc';
@@ -61,7 +61,6 @@ import {
 	readElementHeader,
 	readElementId,
 	readFloat,
-	readSignedInt,
 	readUnsignedInt,
 	readVarInt,
 	resync,
@@ -137,7 +136,6 @@ type ClusterBlock = {
 	timestamp: number;
 	duration: number;
 	isKeyFrame: boolean;
-	referencedTimestamps: number[];
 	data: Uint8Array;
 	lacing: BlockLacing;
 	decoded: boolean;
@@ -230,7 +228,7 @@ const METADATA_ELEMENTS = [
 	{ id: EBMLId.Tracks, flag: 'tracksSeen' },
 	{ id: EBMLId.Cues, flag: 'cuesSeen' },
 ] as const;
-const MAX_RESYNC_LENGTH = 10 * 2 ** 20; // 10 MiB
+const MAX_RESYNC_LENGTH = /* #__PURE__ */ 10 * 2 ** 20; // 10 MiB
 
 export class MatroskaDemuxer extends Demuxer {
 	reader: Reader;
@@ -649,21 +647,15 @@ export class MatroskaDemuxer extends Demuxer {
 			// This must hold, as track datas only get created if a block for that track is encountered
 			assert(trackData.blocks.length > 0);
 
-			let blockReferencesExist = false;
 			let hasLacedBlocks = false;
 
 			for (let i = 0; i < trackData.blocks.length; i++) {
 				const block = trackData.blocks[i]!;
 				block.timestamp += cluster.timestamp;
 
-				blockReferencesExist ||= block.referencedTimestamps.length > 0;
 				hasLacedBlocks ||= block.lacing !== BlockLacing.None;
 			}
 
-			if (blockReferencesExist) {
-				trackData.blocks = sortBlocksByReferences(trackData.blocks);
-			}
-
 			trackData.presentationTimestamps = trackData.blocks
 				.map((block, i) => ({ timestamp: block.timestamp, blockIndex: i }))
 				.sort((a, b) => a.timestamp - b.timestamp);
@@ -844,13 +836,13 @@ export class MatroskaDemuxer extends Demuxer {
 
 			blocks.splice(blockIndex, 1); // Remove the original block
 
+			const blockDuration = originalBlock.duration || frameCount * (track.defaultDuration ?? 0);
+
 			// Now, let's insert each frame as its own block
 			for (let i = 0; i < frameCount; i++) {
 				const frameSize = frameSizes[i]!;
 				const frameData = readBytes(slice, frameSize);
 
-				const blockDuration = originalBlock.duration || (frameCount * (track.defaultDuration ?? 0));
-
 				// Distribute timestamps evenly across the block duration
 				const frameTimestamp = originalBlock.timestamp + (blockDuration * i / frameCount);
 				const frameDuration = blockDuration / frameCount;
@@ -859,7 +851,6 @@ export class MatroskaDemuxer extends Demuxer {
 					timestamp: frameTimestamp,
 					duration: frameDuration,
 					isKeyFrame: originalBlock.isKeyFrame,
-					referencedTimestamps: originalBlock.referencedTimestamps,
 					data: frameData,
 					lacing: BlockLacing.None,
 					decoded: true,
@@ -1383,9 +1374,17 @@ export class MatroskaDemuxer extends Demuxer {
 				const relativeTimestamp = readI16Be(slice);
 
 				const flags = readU8(slice);
-				const isKeyFrame = !!(flags & 0x80);
 				const lacing = (flags >> 1) & 0x3 as BlockLacing; // If the block is laced, we'll expand it later
 
+				let isKeyFrame = !!(flags & 0x80);
+				if (trackData.track.info?.type === 'audio' && trackData.track.info.codec) {
+					// Some files don't mark their audio packets as key packets (I'm looking at you, Firefox). But, we
+					// can fix this in most cases: if we recognize the codec of the track, then we know every packet is
+					// necessarily a key packet, no matter what the container says.
+					// https://github.com/Vanilagy/mediabunny/issues/192
+					isKeyFrame = true;
+				}
+
 				const blockData = readBytes(slice, size - (slice.filePos - dataStartPos));
 				const hasDecodingInstructions = trackData.track.decodingInstructions.length > 0;
 
@@ -1393,7 +1392,6 @@ export class MatroskaDemuxer extends Demuxer {
 					timestamp: relativeTimestamp, // We'll add the cluster's timestamp to this later
 					duration: 0, // Will set later
 					isKeyFrame,
-					referencedTimestamps: [],
 					data: blockData,
 					lacing,
 					decoded: !hasDecodingInstructions,
@@ -1406,13 +1404,7 @@ export class MatroskaDemuxer extends Demuxer {
 
 				this.readContiguousElements(slice.slice(dataStartPos, size));
 
-				if (this.currentBlock) {
-					for (let i = 0; i < this.currentBlock.referencedTimestamps.length; i++) {
-						this.currentBlock.referencedTimestamps[i]! += this.currentBlock.timestamp;
-					}
-
-					this.currentBlock = null;
-				}
+				this.currentBlock = null;
 			}; break;
 
 			case EBMLId.Block: {
@@ -1436,7 +1428,6 @@ export class MatroskaDemuxer extends Demuxer {
 					timestamp: relativeTimestamp, // We'll add the cluster's timestamp to this later
 					duration: 0, // Will set later
 					isKeyFrame: true,
-					referencedTimestamps: [],
 					data: blockData,
 					lacing,
 					decoded: !hasDecodingInstructions,
@@ -1487,11 +1478,8 @@ export class MatroskaDemuxer extends Demuxer {
 				if (!this.currentBlock) break;
 
 				this.currentBlock.isKeyFrame = false;
-
-				const relativeTimestamp = readSignedInt(slice, size);
-
-				// We'll offset this by the block's timestamp later
-				this.currentBlock.referencedTimestamps.push(relativeTimestamp);
+				// We ignore the actual value here, we just use the reference as an indicator for "not a key frame".
+				// This is in line with FFmpeg's behavior.
 			}; break;
 
 			case EBMLId.Tag: {
@@ -1886,7 +1874,7 @@ abstract class MatroskaTrackBacking implements InputTrackBacking {
 		// Do a little rounding to catch cases where the result is very close to an integer. If it is, it's likely
 		// that the number was originally an integer divided by the timescale. For stability, it's best
 		// to return the integer in this case.
-		return roundToPrecision(timestamp * this.internalTrack.segment.timestampFactor, 14);
+		return roundIfAlmostInteger(timestamp * this.internalTrack.segment.timestampFactor);
 	}
 
 	async getPacket(timestamp: number, options: PacketRetrievalOptions) {
@@ -2319,6 +2307,7 @@ 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,
@@ -2379,43 +2368,3 @@ class MatroskaAudioTrackBacking extends MatroskaTrackBacking implements InputAud
 		};
 	}
 }
-
-/** Sorts blocks such that referenced blocks come before the blocks that reference them. */
-const sortBlocksByReferences = (blocks: ClusterBlock[]) => {
-	const timestampToBlock = new Map<number, ClusterBlock>();
-
-	for (let i = 0; i < blocks.length; i++) {
-		const block = blocks[i]!;
-		timestampToBlock.set(block.timestamp, block);
-	}
-
-	const processedBlocks = new Set<ClusterBlock>();
-	const result: ClusterBlock[] = [];
-
-	const processBlock = (block: ClusterBlock) => {
-		if (processedBlocks.has(block)) {
-			return;
-		}
-
-		// Marking the block as processed here already; prevents this algorithm from dying on cycles
-		processedBlocks.add(block);
-
-		for (let j = 0; j < block.referencedTimestamps.length; j++) {
-			const timestamp = block.referencedTimestamps[j]!;
-			const otherBlock = timestampToBlock.get(timestamp);
-			if (!otherBlock) {
-				continue;
-			}
-
-			processBlock(otherBlock);
-		}
-
-		result.push(block);
-	};
-
-	for (let i = 0; i < blocks.length; i++) {
-		processBlock(blocks[i]!);
-	}
-
-	return result;
-};

src/matroska/matroska-muxer.ts

@@ -65,8 +65,8 @@ import { EncodedPacket } from '../packet';
 import { parseOpusIdentificationHeader } from '../codec-data';
 import { AttachedFile } from '../tags';
 
-const MIN_CLUSTER_TIMESTAMP_MS = -(2 ** 15);
-const MAX_CLUSTER_TIMESTAMP_MS = 2 ** 15 - 1;
+const MIN_CLUSTER_TIMESTAMP_MS = /* #__PURE__ */ -(2 ** 15);
+const MAX_CLUSTER_TIMESTAMP_MS = /* #__PURE__ */ 2 ** 15 - 1;
 const APP_NAME = 'Mediabunny';
 const SEGMENT_SIZE_BYTES = 6;
 const CLUSTER_SIZE_BYTES = 5;

src/media-sink.ts

@@ -8,10 +8,12 @@
 
 import { parsePcmCodec, PCM_AUDIO_CODECS, PcmAudioCodec, VideoCodec, AudioCodec } from './codec';
 import {
+	deserializeAvcDecoderConfigurationRecord,
 	determineVideoPacketType,
 	extractHevcNalUnits,
 	extractNalUnitTypeForHevc,
 	HevcNalUnitType,
+	parseAvcSps,
 } from './codec-data';
 import { CustomVideoDecoder, customVideoDecoders, CustomAudioDecoder, customAudioDecoders } from './custom-coder';
 import { InputDisposedError } from './input';
@@ -24,15 +26,17 @@ import {
 	getInt24,
 	getUint24,
 	insertSorted,
+	isChromium,
 	isFirefox,
 	isNumber,
-	isSafari,
+	isWebKit,
 	last,
 	mapAsyncGenerator,
 	promiseWithResolvers,
 	Rotation,
 	toAsyncIterator,
 	toDataView,
+	toUint8Array,
 	validateAnyIterable,
 } from './misc';
 import { EncodedPacket } from './packet';
@@ -872,6 +876,22 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 				}
 			};
 
+			if (codec === 'avc' && this.decoderConfig.description && isChromium()) {
+				// Chromium has/had a bug with playing interlaced AVC (https://issues.chromium.org/issues/456919096)
+				// which can be worked around by requesting that software decoding be used. So, here we peek into the
+				// AVC description, if present, and switch to software decoding if we find interlaced content.
+				const record = deserializeAvcDecoderConfigurationRecord(toUint8Array(this.decoderConfig.description));
+				if (record && record.sequenceParameterSets.length > 0) {
+					const sps = parseAvcSps(record.sequenceParameterSets[0]!);
+					if (sps && sps.frameMbsOnlyFlag === 0) {
+						this.decoderConfig = {
+							...this.decoderConfig,
+							hardwareAcceleration: 'prefer-software',
+						};
+					}
+				}
+			}
+
 			this.decoder = new VideoDecoder({
 				output: (frame) => {
 					try {
@@ -882,7 +902,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 				},
 				error: onError,
 			});
-			this.decoder.configure(decoderConfig);
+			this.decoder.configure(this.decoderConfig);
 		}
 	}
 
@@ -918,7 +938,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 		} else {
 			assert(this.decoder);
 
-			if (!isSafari()) {
+			if (!isWebKit()) {
 				insertSorted(this.inputTimestamps, packet.timestamp, x => x);
 			}
 
@@ -1049,7 +1069,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 
 	/** Handler for the WebCodecs VideoDecoder for ironing out browser differences. */
 	sampleHandler(sample: VideoSample) {
-		if (isSafari()) {
+		if (isWebKit()) {
 			// For correct B-frame handling, we don't just hand over the frames directly but instead add them to
 			// a queue, because we want to ensure frames are emitted in presentation order. We flush the queue
 			// each time we receive a frame with a timestamp larger than the highest we've seen so far, as we
@@ -1137,7 +1157,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 			this.alphaRaslSkipped = false;
 		}
 
-		if (isSafari()) {
+		if (isWebKit()) {
 			for (const sample of this.sampleQueue) {
 				this.finalizeAndEmitSample(sample);
 			}

src/media-source.ts

@@ -9,6 +9,8 @@
 import {
 	AUDIO_CODECS,
 	AudioCodec,
+	buildAacAudioSpecificConfig,
+	parseAacAudioSpecificConfig,
 	parsePcmCodec,
 	PCM_AUDIO_CODECS,
 	PcmAudioCodec,
@@ -24,9 +26,11 @@ import {
 	CallSerializer,
 	clamp,
 	isFirefox,
+	last,
 	promiseWithResolvers,
 	setInt24,
 	setUint24,
+	toUint8Array,
 } from './misc';
 import { Muxer } from './muxer';
 import { SubtitleParser } from './subtitles';
@@ -1290,6 +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.
@@ -1338,6 +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++;
 
@@ -1515,6 +1550,32 @@ class AudioEncoderWrapper {
 
 				this.encoder = new AudioEncoder({
 					output: (chunk, meta) => {
+						// WebKit emits an invalid description for AAC (https://bugs.webkit.org/show_bug.cgi?id=302253),
+						// which we try to detect here. If detected, we'll provide our own description instead, derived
+						// from the codec string and audio parameters.
+						if (this.encodingConfig.codec === 'aac' && meta?.decoderConfig) {
+							let needsDescriptionOverwrite = false;
+							if (!meta.decoderConfig.description || meta.decoderConfig.description.byteLength < 2) {
+								needsDescriptionOverwrite = true;
+							} else {
+								const audioSpecificConfig = parseAacAudioSpecificConfig(
+									toUint8Array(meta.decoderConfig.description),
+								);
+
+								needsDescriptionOverwrite = audioSpecificConfig.objectType === 0;
+							}
+
+							if (needsDescriptionOverwrite) {
+								const objectType = Number(last(encoderConfig.codec.split('.')));
+
+								meta.decoderConfig.description = buildAacAudioSpecificConfig({
+									objectType,
+									numberOfChannels: meta.decoderConfig.numberOfChannels,
+									sampleRate: meta.decoderConfig.sampleRate,
+								});
+							}
+						}
+
 						const packet = EncodedPacket.fromEncodedChunk(chunk);
 
 						this.encodingConfig.onEncodedPacket?.(packet, meta);

src/misc.ts

@@ -174,8 +174,8 @@ export const toDataView = (source: AllowSharedBufferSource) => {
 	}
 };
 
-export const textDecoder = new TextDecoder();
-export const textEncoder = new TextEncoder();
+export const textDecoder = /* #__PURE__ */ new TextDecoder();
+export const textEncoder = /* #__PURE__ */ new TextEncoder();
 
 export const isIso88591Compatible = (text: string) => {
 	for (let i = 0; i < text.length; i++) {
@@ -201,7 +201,7 @@ export const COLOR_PRIMARIES_MAP = {
 	bt2020: 9, // ITU-R BT.202
 	smpte432: 12, // SMPTE EG 432-1
 };
-export const COLOR_PRIMARIES_MAP_INVERSE = invertObject(COLOR_PRIMARIES_MAP);
+export const COLOR_PRIMARIES_MAP_INVERSE = /* #__PURE__ */ invertObject(COLOR_PRIMARIES_MAP);
 
 export const TRANSFER_CHARACTERISTICS_MAP = {
 	'bt709': 1, // ITU-R BT.709
@@ -211,7 +211,7 @@ export const TRANSFER_CHARACTERISTICS_MAP = {
 	'pq': 16, // Rec. ITU-R BT.2100-2 perceptual quantization (PQ) system
 	'hlg': 18, // Rec. ITU-R BT.2100-2 hybrid loggamma (HLG) system
 };
-export const TRANSFER_CHARACTERISTICS_MAP_INVERSE = invertObject(TRANSFER_CHARACTERISTICS_MAP);
+export const TRANSFER_CHARACTERISTICS_MAP_INVERSE = /* #__PURE__ */ invertObject(TRANSFER_CHARACTERISTICS_MAP);
 
 export const MATRIX_COEFFICIENTS_MAP = {
 	'rgb': 0, // Identity
@@ -220,7 +220,7 @@ export const MATRIX_COEFFICIENTS_MAP = {
 	'smpte170m': 6, // SMPTE 170M
 	'bt2020-ncl': 9, // ITU-R BT.2020-2 (non-constant luminance)
 };
-export const MATRIX_COEFFICIENTS_MAP_INVERSE = invertObject(MATRIX_COEFFICIENTS_MAP);
+export const MATRIX_COEFFICIENTS_MAP_INVERSE = /* #__PURE__ */ invertObject(MATRIX_COEFFICIENTS_MAP);
 
 export type RequiredNonNull<T> = {
 	[K in keyof T]-?: NonNullable<T[K]>;
@@ -486,9 +486,14 @@ export const clamp = (value: number, min: number, max: number) => {
 
 export const UNDETERMINED_LANGUAGE = 'und';
 
-export const roundToPrecision = (value: number, digits: number) => {
-	const factor = 10 ** digits;
-	return Math.round(value * factor) / factor;
+export const roundIfAlmostInteger = (value: number) => {
+	const rounded = Math.round(value);
+
+	if (Math.abs(value / rounded - 1) < 10 * Number.EPSILON) {
+		return rounded;
+	} else {
+		return value;
+	}
 };
 
 export const roundToMultiple = (value: number, multiple: number) => {
@@ -510,7 +515,7 @@ export const isIso639Dash2LanguageCode = (x: string) => {
 };
 
 // Since the result will be truncated, add a bit of eps to compensate for floating point errors
-export const SECOND_TO_MICROSECOND_FACTOR = 1e6 * (1 + Number.EPSILON);
+export const SECOND_TO_MICROSECOND_FACTOR = /* #__PURE__ */ 1e6 * (1 + Number.EPSILON);
 
 /**
  * Sets all keys K of T to be required.
@@ -658,22 +663,14 @@ export class CallSerializer {
 	}
 }
 
-let isSafariCache: boolean | null = null;
-export const isSafari = () => {
-	if (isSafariCache !== null) {
-		return isSafariCache;
+let isWebKitCache: boolean | null = null;
+export const isWebKit = () => {
+	if (isWebKitCache !== null) {
+		return isWebKitCache;
 	}
 
-	const result = !!(
-		typeof navigator !== 'undefined'
-		&& navigator.vendor?.match(/apple/i)
-		&& !navigator.userAgent?.match(/crios/i)
-		&& !navigator.userAgent?.match(/fxios/i)
-		&& !navigator.userAgent?.match(/Opera|OPT\//)
-	);
-
-	isSafariCache = result;
-	return result;
+	// This even returns true for WebKit-wrapping browsers such as Chrome on iOS
+	return isWebKitCache = !!(typeof navigator !== 'undefined' && navigator.vendor?.match(/apple/i));
 };
 
 let isFirefoxCache: boolean | null = null;
@@ -685,6 +682,15 @@ export const isFirefox = () => {
 	return isFirefoxCache = typeof navigator !== 'undefined' && navigator.userAgent?.includes('Firefox');
 };
 
+let isChromiumCache: boolean | null = null;
+export const isChromium = () => {
+	if (isChromiumCache !== null) {
+		return isChromiumCache;
+	}
+
+	return isChromiumCache = !!(typeof navigator !== 'undefined' && navigator.vendor?.includes('Google Inc'));
+};
+
 /**
  * T or a promise that resolves to T.
  * @group Miscellaneous

src/muxer.ts

@@ -46,21 +46,21 @@ export abstract class Muxer {
 
 	private trackTimestampInfo = new WeakMap<OutputTrack, {
 		maxTimestamp: number;
-		maxTimestampBeforeLastKeyFrame: number;
+		maxTimestampBeforeLastKeyPacket: number;
 	}>();
 
-	protected validateAndNormalizeTimestamp(track: OutputTrack, timestampInSeconds: number, isKeyFrame: boolean) {
+	protected validateAndNormalizeTimestamp(track: OutputTrack, timestampInSeconds: number, isKeyPacket: boolean) {
 		timestampInSeconds += track.source._timestampOffset;
 
 		let timestampInfo = this.trackTimestampInfo.get(track);
 		if (!timestampInfo) {
-			if (!isKeyFrame) {
-				throw new Error('First frame must be a key frame.');
+			if (!isKeyPacket) {
+				throw new Error('First packet must be a key packet.');
 			}
 
 			timestampInfo = {
 				maxTimestamp: timestampInSeconds,
-				maxTimestampBeforeLastKeyFrame: timestampInSeconds,
+				maxTimestampBeforeLastKeyPacket: timestampInSeconds,
 			};
 			this.trackTimestampInfo.set(track, timestampInfo);
 		}
@@ -69,15 +69,15 @@ export abstract class Muxer {
 			throw new Error(`Timestamps must be non-negative (got ${timestampInSeconds}s).`);
 		}
 
-		if (isKeyFrame) {
-			timestampInfo.maxTimestampBeforeLastKeyFrame = timestampInfo.maxTimestamp;
+		if (isKeyPacket) {
+			timestampInfo.maxTimestampBeforeLastKeyPacket = timestampInfo.maxTimestamp;
 		}
 
-		if (timestampInSeconds < timestampInfo.maxTimestampBeforeLastKeyFrame) {
+		if (timestampInSeconds < timestampInfo.maxTimestampBeforeLastKeyPacket) {
 			throw new Error(
-				`Timestamps cannot be smaller than the highest timestamp of the previous GOP (a GOP begins with a key`
-				+ ` frame and ends right before the next key frame). Got ${timestampInSeconds}s, but highest timestamp`
-				+ ` is ${timestampInfo.maxTimestampBeforeLastKeyFrame}s.`,
+				`Timestamps cannot be smaller than the largest timestamp of the previous GOP (a GOP begins with a key`
+				+ ` packet and ends right before the next key packet). Got ${timestampInSeconds}s, but largest`
+				+ ` timestamp is ${timestampInfo.maxTimestampBeforeLastKeyPacket}s.`,
 			);
 		}
 

src/ogg/ogg-demuxer.ts

@@ -19,7 +19,7 @@ import {
 	binarySearchLessOrEqual,
 	findLast,
 	last,
-	roundToPrecision,
+	roundIfAlmostInteger,
 	toDataView,
 	UNDETERMINED_LANGUAGE,
 } from '../misc';
@@ -577,7 +577,7 @@ class OggAudioTrackBacking implements InputAudioTrackBacking {
 			return this.getPacketSequential(timestamp, options);
 		}
 
-		const timestampInSamples = roundToPrecision(timestamp * this.internalSampleRate, 14);
+		const timestampInSamples = roundIfAlmostInteger(timestamp * this.internalSampleRate);
 		if (timestampInSamples === 0) {
 			// Fast path for timestamp 0 - avoids binary search when playing back from the start
 			return this.getFirstPacket(options);
@@ -910,7 +910,7 @@ class OggAudioTrackBacking implements InputAudioTrackBacking {
 		const release = await this.sequentialScanMutex.acquire(); // Requires exclusivity because we write to a cache
 
 		try {
-			const timestampInSamples = roundToPrecision(timestamp * this.internalSampleRate, 14);
+			const timestampInSamples = roundIfAlmostInteger(timestamp * this.internalSampleRate);
 			timestamp = timestampInSamples / this.internalSampleRate;
 
 			const index = binarySearchLessOrEqual(

src/ogg/ogg-reader.ts

@@ -11,7 +11,7 @@ import { OGGS } from './ogg-misc';
 
 export const MIN_PAGE_HEADER_SIZE = 27;
 export const MAX_PAGE_HEADER_SIZE = 27 + 255;
-export const MAX_PAGE_SIZE = MAX_PAGE_HEADER_SIZE + 255 * 255;
+export const MAX_PAGE_SIZE = /* #__PURE__ */ MAX_PAGE_HEADER_SIZE + 255 * 255;
 
 export type Page = {
 	headerStartPos: number;

src/packet.ts

@@ -8,7 +8,7 @@
 
 import { SECOND_TO_MICROSECOND_FACTOR } from './misc';
 
-export const PLACEHOLDER_DATA = new Uint8Array(0);
+export const PLACEHOLDER_DATA = /* #__PURE__ */ new Uint8Array(0);
 
 /**
  * The type of a packet. Key packets can be decoded without previous packets, while delta packets depend on previous
@@ -126,7 +126,10 @@ export class EncodedPacket {
 		}
 	}
 
-	/** If this packet is a metadata-only packet. Metadata-only packets don't contain their packet data. */
+	/**
+	 * If this packet is a metadata-only packet. Metadata-only packets don't contain their packet data. They are the
+	 * result of retrieving packets with {@link PacketRetrievalOptions.metadataOnly} set to `true`.
+	 */
 	get isMetadataOnly() {
 		return this.data === PLACEHOLDER_DATA;
 	}

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 */

src/source.ts

@@ -12,6 +12,7 @@ import {
 	binarySearchLessOrEqual,
 	closedIntervalsOverlap,
 	isNumber,
+	isWebKit,
 	MaybePromise,
 	mergeRequestInit,
 	promiseWithResolvers,
@@ -209,7 +210,14 @@ export class BlobSource extends Source {
 	private async _runWorker(worker: ReadWorker) {
 		let reader = this._readers.get(worker);
 		if (reader === undefined) {
-			if ('stream' in this._blob) {
+			// https://github.com/Vanilagy/mediabunny/issues/184
+			// WebKit has critical bugs with blob.stream():
+			// - WebKitBlobResource error 1 when streaming large files
+			// - Memory buildup and reload loops on iOS (network process crashes)
+			// - ReadableStream stalls under backpressure (especially video)
+			// Affects Safari and all iOS browsers (Chrome, Firefox, etc.).
+			// Use arrayBuffer() fallback for WebKit browsers.
+			if ('stream' in this._blob && !isWebKit()) {
 				// Get a reader of the blob starting at the required offset, and then keep it around
 				const slice = this._blob.slice(worker.currentPos);
 				reader = slice.stream().getReader();
@@ -261,7 +269,7 @@ export class BlobSource extends Source {
 	}
 }
 
-const URL_SOURCE_MIN_LOAD_AMOUNT = 0.5 * 2 ** 20; // 0.5 MiB
+const URL_SOURCE_MIN_LOAD_AMOUNT = /* #__PURE__ */ 0.5 * 2 ** 20; // 0.5 MiB
 const DEFAULT_RETRY_DELAY
 	= ((previousAttempts, error, src) => {
 		// Check if this could be a CORS error. If so, we cannot recover from it and

src/writer.ts

@@ -89,8 +89,8 @@ export abstract class Writer {
 	}
 }
 
-const ARRAY_BUFFER_INITIAL_SIZE = 2 ** 16;
-const ARRAY_BUFFER_MAX_SIZE = 2 ** 32;
+const ARRAY_BUFFER_INITIAL_SIZE = /* #__PURE__ */ 2 ** 16;
+const ARRAY_BUFFER_MAX_SIZE = /* #__PURE__ */ 2 ** 32;
 
 export class BufferTargetWriter extends Writer {
 	private pos = 0;
@@ -184,7 +184,7 @@ export class BufferTargetWriter extends Writer {
 	}
 }
 
-const DEFAULT_CHUNK_SIZE = 2 ** 24;
+const DEFAULT_CHUNK_SIZE = /* #__PURE__ */ 2 ** 24;
 const MAX_CHUNKS_AT_ONCE = 2;
 
 interface Chunk {