Implement @mediabunny/prores extension, add onError callbacks to custom coders, fix visibleRect bug in VideoSample

2026-09-27 02:43:48 +02:00 · 2026-06-29 17:15:10 +02:00
parent af618f014a
commit 8ae0f9d09e
42 changed files with 1074 additions and 451 deletions
@@ -93,6 +93,11 @@ jobs:
          packages/flac-encoder/dist/bundles/mediabunny-flac-encoder.mjs
          packages/flac-encoder/dist/bundles/mediabunny-flac-encoder.min.mjs
          packages/flac-encoder/dist/mediabunny-flac-encoder.d.ts
+          packages/prores/dist/bundles/mediabunny-prores.js
+          packages/prores/dist/bundles/mediabunny-prores.min.js
+          packages/prores/dist/bundles/mediabunny-prores.mjs
+          packages/prores/dist/bundles/mediabunny-prores.min.mjs
+          packages/prores/dist/mediabunny-prores.d.ts
          packages/server/dist/bundles/mediabunny-server.cjs
          packages/server/dist/bundles/mediabunny-server.min.cjs
          packages/server/dist/bundles/mediabunny-server.mjs
@@ -11,3 +11,4 @@ packages/ac3/dist
 packages/aac-encoder/dist
 packages/flac-encoder/dist
 packages/server/dist
+packages/prores/dist
@@ -121,6 +121,7 @@ export default withMermaid({
 						{ text: 'aac-encoder', link: '/guide/extensions/aac-encoder' },
 						{ text: 'ac3', link: '/guide/extensions/ac3' },
 						{ text: 'flac-encoder', link: '/guide/extensions/flac-encoder' },
+						{ text: 'prores', link: '/guide/extensions/prores' },
 					],
 				},
 			],
@@ -26,5 +26,6 @@
    "@mediabunny/mp3-encoder": "Adds MP3 encoder support to Mediabunny.",
    "@mediabunny/ac3": "Adds AC-3/E-AC-3 decoder and encoder support to Mediabunny.",
    "@mediabunny/aac-encoder": "Polyfills AAC encoder support to Mediabunny.",
-    "@mediabunny/flac-encoder": "Adds FLAC encoder support to Mediabunny."
+    "@mediabunny/flac-encoder": "Adds FLAC encoder support to Mediabunny.",
+    "@mediabunny/prores": "Adds Apple ProRes decoder support to Mediabunny."
 }
@@ -0,0 +1,36 @@
+---
+description: The @mediabunny/prores extension provides an extremely fast Apple ProRes decoder for the browser.
+---
+
+# @mediabunny/prores
+
+Browsers have no support for Apple ProRes in their WebCodecs implementations. This extension package provides a decoder for use with Mediabunny, allowing you to decode ProRes directly in the browser at unprecedented speed. It is implemented using Mediabunny's [custom coder API](https://mediabunny.dev/guide/supported-formats-and-codecs#custom-coders) and uses [TurboRes](https://github.com/Vanilagy/turbores), an extremely fast WASM-based ProRes decoder, under the hood.
+
+<a class="!no-underline inline-flex items-center gap-1.5" :no-icon="true" href="https://github.com/Vanilagy/mediabunny/blob/main/packages/prores/README.md">
+	GitHub page
+	<span class="vpi-arrow-right" />
+</a>
+
+## Installation
+
+This library peer-depends on Mediabunny. Install both using npm:
+```bash
+npm install mediabunny @mediabunny/prores
+```
+
+Alternatively, directly include them using a script tag:
+```html
+<script src="mediabunny.js"></script>
+<script src="mediabunny-prores.js"></script>
+```
+
+This will expose the global objects `Mediabunny` and `MediabunnyProres`. Use `mediabunny-prores.d.ts` to provide types for these globals. You can download the built distribution files from the [releases page](https://github.com/Vanilagy/mediabunny/releases).
+
+## Usage
+
+```ts
+import { registerProresDecoder } from '@mediabunny/prores';
+
+registerProresDecoder();
+```
+That's it - Mediabunny now uses the registered ProRes decoder automatically.
@@ -40,6 +40,7 @@ Mediabunny ships with built-in decoders and encoders for all audio PCM codecs, m
 - `'vp8'` - VP8
 - `'vp9'` - VP9
 - `'av1'` - AOMedia Video 1 (AV1)
+- `'prores'` - Apple ProRes [^prores]

 ### Audio codecs

@@ -80,6 +81,7 @@ Not all codecs can be used with all containers. The following table specifies th
 | `'vp8'`        |    ✓     |   ✓   |   ✓   |     ✓     |       |       |       |       |       |       |
 | `'vp9'`        |    ✓     |   ✓   |   ✓   |     ✓     |       |       |       |       |       |       |
 | `'av1'`        |    ✓     |   ✓   |   ✓   |     ✓     |       |       |       |       |       |       |
+| `'prores'`     |    ✓     |   ✓   |   ✓   |           |       |       |       |       |       |       |
 | `'aac'`        |    ✓     |   ✓   |   ✓   |           |       |       |       |   ✓   |       |   ✓   |
 | `'opus'`       |    ✓     |   ✓   |   ✓   |     ✓     |   ✓   |       |       |       |       |       |
 | `'mp3'`        |    ✓     |   ✓   |   ✓   |           |       |   ✓   |       |       |       |   ✓   |
@@ -105,6 +107,7 @@ Not all codecs can be used with all containers. The following table specifies th

 For HLS, the supported codecs depend on the segment format chosen.

+[^prores]: ProRes is not supported by WebCodecs. To decode it, use the [`@mediabunny/prores`](./extensions/prores) extension package.
 [^aac]: In some browsers, AAC encoding is not supported by WebCodecs. You can polyfill it with the [`@mediabunny/aac-encoder`](./extensions/aac-encoder) extension package.
 [^mp3]: MP3 encoding is not supported by WebCodecs. You can polyfill it with the [`@mediabunny/mp3-encoder`](./extensions/mp3-encoder) extension package.
 [^flac]: FLAC encoding is not supported by WebCodecs. You can polyfill it with the [`@mediabunny/flac-encoder`](./extensions/flac-encoder) extension package.
@@ -293,10 +296,13 @@ class {
 	codec: AudioCodec;
 	config: AudioEncoderConfig;
 	onPacket: (packet: EncodedPacket, meta?: EncodedAudioChunkMetadata) => unknown;
+
+	// For both:
+	onError: (error: unknown) => void;
 }
 ```

-`codec` and `config` specify the concrete codec configuration to use, and `onPacket` is a method that your code **must** call for each encoded packet it creates.
+`codec` and `config` specify the concrete codec configuration to use, and `onPacket` is a method that your code **must** call for each encoded packet it creates. `onError` is a method you can call to surface any out-of-band errors that occur outside of the regular method calls (such as from an asynchronous background task); these errors would otherwise go uncaught.

 You **must** implement the following methods in your custom encoder class:
 ```ts
@@ -356,10 +362,13 @@ class {
 	codec: AudioCodec;
 	config: AudioDecoderConfig;
 	onSample: (sample: AudioSample) => unknown;
+
+	// For both:
+	onError: (error: unknown) => void;
 }
 ```

-`codec` and `config` specify the concrete codec configuration to use, and `onSample` is a method that your code **must** call for each video/audio sample it creates.
+`codec` and `config` specify the concrete codec configuration to use, and `onSample` is a method that your code **must** call for each video/audio sample it creates. `onError` is a method you can call to surface any out-of-band errors that occur outside of the regular method calls (such as from an asynchronous background task); these errors would otherwise go uncaught.

 You **must** implement the following methods in your custom decoder class:
 ```ts
@@ -47,6 +47,7 @@ export default tseslint.config(
 			'packages/aac-encoder/build',
 			'packages/flac-encoder/dist',
 			'packages/flac-encoder/build',
+			'packages/prores/dist',
 			'packages/server/dist',
 			'eslint.config.mjs',
 			'docs/.vitepress/cache',
@@ -68,6 +68,7 @@ const compressFile = async (resource: File | string) => {
 				bitrate: QUALITY_VERY_LOW,
 			},
 			audio: {
+				codec: 'opus',
 				bitrate: QUALITY_VERY_LOW,
 			},
 		});
@@ -4,7 +4,6 @@ import {
 	BlobSource,
 	CanvasSink,
 	Input,
-	registerDecoder,
 	UrlSource,
 	WrappedAudioBuffer,
 	WrappedCanvas,
@@ -75,9 +74,6 @@ let volumeMuted = false;

 /** === INIT LOGIC === */

-import { ProResDecoder } from '../../packages/prores-decoder/src/index.js';
-registerDecoder(ProResDecoder);
-
 const initMediaPlayer = async (resource: File | string) => {
 	try {
 		// First, dispose any ongoing playback:
@@ -1461,6 +1461,10 @@
      "resolved": "packages/mp3-encoder",
      "link": true
    },
+    "node_modules/@mediabunny/prores": {
+      "resolved": "packages/prores",
+      "link": true
+    },
    "node_modules/@mediabunny/server": {
      "resolved": "packages/server",
      "link": true
@@ -12922,6 +12926,21 @@
        "mediabunny": "^1.0.0"
      }
    },
+    "packages/prores": {
+      "name": "@mediabunny/prores",
+      "version": "1.25.8",
+      "license": "MPL-2.0",
+      "devDependencies": {
+        "@types/emscripten": "^1.40.1"
+      },
+      "funding": {
+        "type": "individual",
+        "url": "https://github.com/sponsors/Vanilagy"
+      },
+      "peerDependencies": {
+        "mediabunny": "^1.0.0"
+      }
+    },
    "packages/server": {
      "name": "@mediabunny/server",
      "version": "1.49.0",
@@ -51,7 +51,7 @@
    "docs:dev": "vitepress dev docs",
    "docs:build": "npm run build && npm run docs:generate && vitepress build docs && npm run examples:build && cp dist/mediabunny.d.ts dist-docs/",
    "docs:preview": "vitepress preview docs",
-    "docs:generate": "tsx scripts/generate-api-docs.ts src/index.ts packages/mp3-encoder/src/index.ts packages/ac3/src/index.ts packages/aac-encoder/src/index.ts packages/flac-encoder/src/index.ts packages/server/src/index.ts docs/api-config.json",
+    "docs:generate": "tsx scripts/generate-api-docs.ts src/index.ts packages/mp3-encoder/src/index.ts packages/ac3/src/index.ts packages/aac-encoder/src/index.ts packages/flac-encoder/src/index.ts packages/prores/src/index.ts packages/server/src/index.ts docs/api-config.json",
    "dev": "vite",
    "examples:build": "vite build",
    "fix-build-import-paths": "tsx scripts/add-import-extensions.ts",
@@ -1,46 +0,0 @@
-```bash
-emmake make distclean
-
-emconfigure ./configure \
-    --target-os=none \
-    --arch=x86_32 \
-    --enable-cross-compile \
-    --disable-asm \
-    --disable-x86asm \
-    --disable-inline-asm \
-    --disable-stripping \
-    --disable-programs \
-    --disable-doc \
-    --disable-debug \
-    --disable-all \
-    --disable-everything \
-    --disable-pthreads \
-    --enable-avcodec \
-    --enable-decoder=prores \
-    --cc="emcc" \
-    --cxx=em++ \
-    --ar=emar \
-    --ranlib=emranlib \
-    --extra-cflags="-DNDEBUG -O3 -msimd128"
-
-emmake make
-```
-
-```bash
-export FFMPEG_PATH=/path/to/ffmpeg
-
-emcc src/bridge.c \
-    $FFMPEG_PATH/libavcodec/libavcodec.a \
-    $FFMPEG_PATH/libavutil/libavutil.a \
-    -I$FFMPEG_PATH \
-    -s MODULARIZE=1 \
-    -s EXPORT_ES6=1 \
-    -s SINGLE_FILE=1 \
-    -s ALLOW_MEMORY_GROWTH=1 \
-    -s ENVIRONMENT=web,worker \
-    -s EXPORTED_RUNTIME_METHODS=cwrap,HEAPU8 \
-    -s EXPORTED_FUNCTIONS=_malloc,_free \
-    -msimd128 \
-    -O3 \
-    -o build/prores.js
-```
@@ -1,182 +0,0 @@
-#include <emscripten.h>
-#include <stdio.h>
-#include "libavcodec/avcodec.h"
-#include "libavutil/pixdesc.h"
-#include "libavutil/imgutils.h"
-
-typedef struct {
-	AVCodecContext *codec_ctx;
-	AVPacket *packet;
-	AVFrame *frame;
-	uint8_t *buffer;
-	int buffer_size;
-} DecoderContext;
-
-EMSCRIPTEN_KEEPALIVE
-DecoderContext *init_decoder() {
-	const AVCodec *codec = avcodec_find_decoder(AV_CODEC_ID_PRORES);
-	if (!codec) return NULL;
-
-	AVCodecContext *codec_ctx = avcodec_alloc_context3(codec);
-	if (!codec_ctx) return NULL;
-
-	if (avcodec_open2(codec_ctx, codec, NULL) < 0) {
-		avcodec_free_context(&codec_ctx);
-		return NULL;
-	}
-
-	AVPacket *packet = av_packet_alloc();
-	if (!packet) {
-		avcodec_free_context(&codec_ctx);
-		return NULL;
-	}
-
-	AVFrame *frame = av_frame_alloc();
-	if (!frame) {
-		av_packet_free(&packet);
-		avcodec_free_context(&codec_ctx);
-		return NULL;
-	}
-
-	DecoderContext *ctx = malloc(sizeof(DecoderContext));
-	if (!ctx) {
-		av_frame_free(&frame);
-		av_packet_free(&packet);
-		avcodec_free_context(&codec_ctx);
-		return NULL;
-	}
-
-	ctx->codec_ctx = codec_ctx;
-	ctx->packet = packet;
-	ctx->frame = frame;
-	ctx->buffer = NULL;
-	ctx->buffer_size = 0;
-
-	return ctx;
-}
-
-EMSCRIPTEN_KEEPALIVE
-uint8_t *configure_packet(DecoderContext *ctx, int size) {
-	if (av_new_packet(ctx->packet, size) < 0) {
-		return NULL;
-	}
-
-	ctx->packet->pts = 0;
-	ctx->packet->dts = AV_NOPTS_VALUE;
-	ctx->packet->time_base.num = 1;
-	ctx->packet->time_base.den = 1;
-	ctx->packet->flags = AV_PKT_FLAG_KEY;
-
-	return ctx->packet->data;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int decode_packet(DecoderContext *ctx) {
-	double start = emscripten_get_now();
-
-	int ret = avcodec_send_packet(ctx->codec_ctx, ctx->packet);
-	if (ret < 0) {
-		return ret;
-	}
-
-	double after_send = emscripten_get_now();
-
-	ret = avcodec_receive_frame(ctx->codec_ctx, ctx->frame);
-	if (ret < 0) {
-		return ret;
-	}
-
-	double after_receive = emscripten_get_now();
-
-	// Calculate required buffer size
-	int required_size = av_image_get_buffer_size(
-		ctx->frame->format,
-		ctx->frame->width,
-		ctx->frame->height,
-		1
-	);
-
-	if (required_size < 0) {
-		return required_size;
-	}
-
-	// Reallocate buffer if needed
-	if (ctx->buffer_size < required_size) {
-		free(ctx->buffer);
-		ctx->buffer = malloc(required_size);
-		if (!ctx->buffer) {
-			ctx->buffer_size = 0;
-			return AVERROR(ENOMEM);
-		}
-		ctx->buffer_size = required_size;
-	}
-
-	double after_alloc = emscripten_get_now();
-
-	// Copy frame data to contiguous buffer
-	ret = av_image_copy_to_buffer(
-		ctx->buffer,
-		ctx->buffer_size,
-		(const uint8_t * const *)ctx->frame->data,
-		ctx->frame->linesize,
-		ctx->frame->format,
-		ctx->frame->width,
-		ctx->frame->height,
-		1
-	);
-
-	if (ret < 0) {
-		return ret;
-	}
-
-	double after_copy = emscripten_get_now();
-
-	printf("Timing: send=%.2fms receive=%.2fms alloc=%.2fms copy=%.2fms total=%.2fms\n",
-		after_send - start,
-		after_receive - after_send,
-		after_alloc - after_receive,
-		after_copy - after_alloc,
-		after_copy - start);
-
-	return 0;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_width(DecoderContext *ctx) {
-	return ctx->frame->width;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_height(DecoderContext *ctx) {
-	return ctx->frame->height;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_format(DecoderContext *ctx) {
-	return ctx->frame->format;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_num_planes(DecoderContext *ctx) {
-	return av_pix_fmt_count_planes(ctx->frame->format);
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_linesize(DecoderContext *ctx, int n) {
-	return ctx->frame->linesize[n];
-}
-
-EMSCRIPTEN_KEEPALIVE
-uint8_t *get_frame_data(DecoderContext *ctx, int n) {
-	return ctx->frame->data[n];
-}
-
-EMSCRIPTEN_KEEPALIVE
-uint8_t *get_frame_data_ptr(DecoderContext *ctx) {
-	return ctx->buffer;
-}
-
-EMSCRIPTEN_KEEPALIVE
-int get_frame_data_size(DecoderContext *ctx) {
-	return ctx->buffer_size;
-}
@@ -1,90 +0,0 @@
-import { CustomVideoDecoder, EncodedPacket, MaybePromise, VideoCodec } from 'mediabunny';
-import createModule from '../build/prores';
-import { VideoSample } from 'mediabunny';
-
-type ExtendedEmscriptenModule = EmscriptenModule & {
-	cwrap: typeof cwrap;
-};
-
-export class ProResDecoder extends CustomVideoDecoder {
-	// eslint-disable-next-line @typescript-eslint/no-unused-vars
-	static override supports(codec: VideoCodec, config: VideoDecoderConfig): boolean {
-		return codec === 'prores';
-	}
-
-	module!: ExtendedEmscriptenModule;
-	initDecoder!: () => number;
-	configurePacket!: (ctx: number, size: number) => number;
-	decodePacket!: (ctx: number) => number;
-	getFrameWidth!: (ctx: number) => number;
-	getFrameHeight!: (ctx: number) => number;
-	getFrameFormat!: (ctx: number) => number;
-	getFrameNumPlanes!: (ctx: number) => number;
-	getFrameLinesize!: (ctx: number, n: number) => number;
-	getFrameData!: (ctx: number, n: number) => number;
-	getFrameDataPtr!: (ctx: number) => number;
-	getFrameDataSize!: (ctx: number) => number;
-
-	decoderContextPtr!: number;
-
-	override async init() {
-		console.log('THIS IS BEING CALLED');
-
-		this.module = (await createModule()) as ExtendedEmscriptenModule;
-
-		// Set up the functions
-		this.initDecoder = this.module.cwrap('init_decoder', 'number', []);
-		this.configurePacket = this.module.cwrap('configure_packet', 'number', ['number', 'number']);
-		this.decodePacket = this.module.cwrap('decode_packet', 'number', ['number']);
-		this.getFrameWidth = this.module.cwrap('get_frame_width', 'number', ['number']);
-		this.getFrameHeight = this.module.cwrap('get_frame_height', 'number', ['number']);
-		this.getFrameFormat = this.module.cwrap('get_frame_format', 'number', ['number']);
-		this.getFrameNumPlanes = this.module.cwrap('get_frame_num_planes', 'number', ['number']);
-		this.getFrameLinesize = this.module.cwrap('get_frame_linesize', 'number', ['number', 'number']);
-		this.getFrameData = this.module.cwrap('get_frame_data', 'number', ['number', 'number']);
-		this.getFrameDataPtr = this.module.cwrap('get_frame_data_ptr', 'number', ['number']);
-		this.getFrameDataSize = this.module.cwrap('get_frame_data_size', 'number', ['number']);
-
-		this.decoderContextPtr = this.initDecoder();
-	}
-
-	override decode(packet: EncodedPacket) {
-		const dataPtr = this.configurePacket(this.decoderContextPtr, packet.byteLength);
-		if (dataPtr === 0) {
-			throw new Error('todo');
-		}
-
-		this.module.HEAPU8.set(packet.data, dataPtr);
-
-		console.time();
-		const ret = this.decodePacket(this.decoderContextPtr);
-		console.timeEnd();
-
-		if (ret === 0) {
-			const width = this.getFrameWidth(this.decoderContextPtr);
-			const height = this.getFrameHeight(this.decoderContextPtr);
-			const format = this.getFrameFormat(this.decoderContextPtr);
-			const dataPtr = this.getFrameDataPtr(this.decoderContextPtr);
-			const dataSize = this.getFrameDataSize(this.decoderContextPtr);
-
-			const data = this.module.HEAPU8.subarray(dataPtr, dataPtr + dataSize);
-
-			const sample = new VideoSample(data, {
-				format: 'I422P10' as VideoPixelFormat,
-				codedWidth: width,
-				codedHeight: height,
-				timestamp: packet.timestamp,
-				duration: packet.duration,
-			});
-			this.onSample(sample);
-		}
-	}
-
-	override flush(): MaybePromise<void> {
-		// nada
-	}
-
-	override close(): MaybePromise<void> {
-		// nada
-	}
-}
@@ -0,0 +1,373 @@
+Mozilla Public License Version 2.0
+==================================
+
+1. Definitions
+--------------
+
+1.1. "Contributor"
+    means each individual or legal entity that creates, contributes to
+    the creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+    means the combination of the Contributions of others (if any) used
+    by a Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+    means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+    means Source Code Form to which the initial Contributor has attached
+    the notice in Exhibit A, the Executable Form of such Source Code
+    Form, and Modifications of such Source Code Form, in each case
+    including portions thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+    means
+
+    (a) that the initial Contributor has attached the notice described
+        in Exhibit B to the Covered Software; or
+
+    (b) that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the
+        terms of a Secondary License.
+
+1.6. "Executable Form"
+    means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+    means a work that combines Covered Software with other material, in
+    a separate file or files, that is not Covered Software.
+
+1.8. "License"
+    means this document.
+
+1.9. "Licensable"
+    means having the right to grant, to the maximum extent possible,
+    whether at the time of the initial grant or subsequently, any and
+    all of the rights conveyed by this License.
+
+1.10. "Modifications"
+    means any of the following:
+
+    (a) any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered
+        Software; or
+
+    (b) any new file in Source Code Form that contains any Covered
+        Software.
+
+1.11. "Patent Claims" of a Contributor
+    means any patent claim(s), including without limitation, method,
+    process, and apparatus claims, in any patent Licensable by such
+    Contributor that would be infringed, but for the grant of the
+    License, by the making, using, selling, offering for sale, having
+    made, import, or transfer of either its Contributions or its
+    Contributor Version.
+
+1.12. "Secondary License"
+    means either the GNU General Public License, Version 2.0, the GNU
+    Lesser General Public License, Version 2.1, the GNU Affero General
+    Public License, Version 3.0, or any later versions of those
+    licenses.
+
+1.13. "Source Code Form"
+    means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+    means an individual or a legal entity exercising rights under this
+    License. For legal entities, "You" includes any entity that
+    controls, is controlled by, or is under common control with You. For
+    purposes of this definition, "control" means (a) the power, direct
+    or indirect, to cause the direction or management of such entity,
+    whether by contract or otherwise, or (b) ownership of more than
+    fifty percent (50%) of the outstanding shares or beneficial
+    ownership of such entity.
+
+2. License Grants and Conditions
+--------------------------------
+
+2.1. Grants
+
+Each Contributor hereby grants You a world-wide, royalty-free,
+non-exclusive license:
+
+(a) under intellectual property rights (other than patent or trademark)
+    Licensable by such Contributor to use, reproduce, make available,
+    modify, display, perform, distribute, and otherwise exploit its
+    Contributions, either on an unmodified basis, with Modifications, or
+    as part of a Larger Work; and
+
+(b) under Patent Claims of such Contributor to make, use, sell, offer
+    for sale, have made, import, and otherwise transfer either its
+    Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+The licenses granted in Section 2.1 with respect to any Contribution
+become effective for each Contribution on the date the Contributor first
+distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+The licenses granted in this Section 2 are the only rights granted under
+this License. No additional rights or licenses will be implied from the
+distribution or licensing of Covered Software under this License.
+Notwithstanding Section 2.1(b) above, no patent license is granted by a
+Contributor:
+
+(a) for any code that a Contributor has removed from Covered Software;
+    or
+
+(b) for infringements caused by: (i) Your and any other third party's
+    modifications of Covered Software, or (ii) the combination of its
+    Contributions with other software (except as part of its Contributor
+    Version); or
+
+(c) under Patent Claims infringed by Covered Software in the absence of
+    its Contributions.
+
+This License does not grant any rights in the trademarks, service marks,
+or logos of any Contributor (except as may be necessary to comply with
+the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+No Contributor makes additional grants as a result of Your choice to
+distribute the Covered Software under a subsequent version of this
+License (see Section 10.2) or under the terms of a Secondary License (if
+permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+Each Contributor represents that the Contributor believes its
+Contributions are its original creation(s) or it has sufficient rights
+to grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+This License is not intended to limit any rights You have under
+applicable copyright doctrines of fair use, fair dealing, or other
+equivalents.
+
+2.7. Conditions
+
+Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
+in Section 2.1.
+
+3. Responsibilities
+-------------------
+
+3.1. Distribution of Source Form
+
+All distribution of Covered Software in Source Code Form, including any
+Modifications that You create or to which You contribute, must be under
+the terms of this License. You must inform recipients that the Source
+Code Form of the Covered Software is governed by the terms of this
+License, and how they can obtain a copy of this License. You may not
+attempt to alter or restrict the recipients' rights in the Source Code
+Form.
+
+3.2. Distribution of Executable Form
+
+If You distribute Covered Software in Executable Form then:
+
+(a) such Covered Software must also be made available in Source Code
+    Form, as described in Section 3.1, and You must inform recipients of
+    the Executable Form how they can obtain a copy of such Source Code
+    Form by reasonable means in a timely manner, at a charge no more
+    than the cost of distribution to the recipient; and
+
+(b) You may distribute such Executable Form under the terms of this
+    License, or sublicense it under different terms, provided that the
+    license for the Executable Form does not attempt to limit or alter
+    the recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+You may create and distribute a Larger Work under terms of Your choice,
+provided that You also comply with the requirements of this License for
+the Covered Software. If the Larger Work is a combination of Covered
+Software with a work governed by one or more Secondary Licenses, and the
+Covered Software is not Incompatible With Secondary Licenses, this
+License permits You to additionally distribute such Covered Software
+under the terms of such Secondary License(s), so that the recipient of
+the Larger Work may, at their option, further distribute the Covered
+Software under the terms of either this License or such Secondary
+License(s).
+
+3.4. Notices
+
+You may not remove or alter the substance of any license notices
+(including copyright notices, patent notices, disclaimers of warranty,
+or limitations of liability) contained within the Source Code Form of
+the Covered Software, except that You may alter any license notices to
+the extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+You may choose to offer, and to charge a fee for, warranty, support,
+indemnity or liability obligations to one or more recipients of Covered
+Software. However, You may do so only on Your own behalf, and not on
+behalf of any Contributor. You must make it absolutely clear that any
+such warranty, support, indemnity, or liability obligation is offered by
+You alone, and You hereby agree to indemnify every Contributor for any
+liability incurred by such Contributor as a result of warranty, support,
+indemnity or liability terms You offer. You may include additional
+disclaimers of warranty and limitations of liability specific to any
+jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+---------------------------------------------------
+
+If it is impossible for You to comply with any of the terms of this
+License with respect to some or all of the Covered Software due to
+statute, judicial order, or regulation then You must: (a) comply with
+the terms of this License to the maximum extent possible; and (b)
+describe the limitations and the code they affect. Such description must
+be placed in a text file included with all distributions of the Covered
+Software under this License. Except to the extent prohibited by statute
+or regulation, such description must be sufficiently detailed for a
+recipient of ordinary skill to be able to understand it.
+
+5. Termination
+--------------
+
+5.1. The rights granted under this License will terminate automatically
+if You fail to comply with any of its terms. However, if You become
+compliant, then the rights granted under this License from a particular
+Contributor are reinstated (a) provisionally, unless and until such
+Contributor explicitly and finally terminates Your grants, and (b) on an
+ongoing basis, if such Contributor fails to notify You of the
+non-compliance by some reasonable means prior to 60 days after You have
+come back into compliance. Moreover, Your grants from a particular
+Contributor are reinstated on an ongoing basis if such Contributor
+notifies You of the non-compliance by some reasonable means, this is the
+first time You have received notice of non-compliance with this License
+from such Contributor, and You become compliant prior to 30 days after
+Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+infringement claim (excluding declaratory judgment actions,
+counter-claims, and cross-claims) alleging that a Contributor Version
+directly or indirectly infringes any patent, then the rights granted to
+You by any and all Contributors for the Covered Software under Section
+2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all
+end user license agreements (excluding distributors and resellers) which
+have been validly granted by You or Your distributors under this License
+prior to termination shall survive termination.
+
+************************************************************************
+*                                                                      *
+*  6. Disclaimer of Warranty                                           *
+*  -------------------------                                           *
+*                                                                      *
+*  Covered Software is provided under this License on an "as is"       *
+*  basis, without warranty of any kind, either expressed, implied, or  *
+*  statutory, including, without limitation, warranties that the       *
+*  Covered Software is free of defects, merchantable, fit for a        *
+*  particular purpose or non-infringing. The entire risk as to the     *
+*  quality and performance of the Covered Software is with You.        *
+*  Should any Covered Software prove defective in any respect, You     *
+*  (not any Contributor) assume the cost of any necessary servicing,   *
+*  repair, or correction. This disclaimer of warranty constitutes an   *
+*  essential part of this License. No use of any Covered Software is   *
+*  authorized under this License except under this disclaimer.         *
+*                                                                      *
+************************************************************************
+
+************************************************************************
+*                                                                      *
+*  7. Limitation of Liability                                          *
+*  --------------------------                                          *
+*                                                                      *
+*  Under no circumstances and under no legal theory, whether tort      *
+*  (including negligence), contract, or otherwise, shall any           *
+*  Contributor, or anyone who distributes Covered Software as          *
+*  permitted above, be liable to You for any direct, indirect,         *
+*  special, incidental, or consequential damages of any character      *
+*  including, without limitation, damages for lost profits, loss of    *
+*  goodwill, work stoppage, computer failure or malfunction, or any    *
+*  and all other commercial damages or losses, even if such party      *
+*  shall have been informed of the possibility of such damages. This   *
+*  limitation of liability shall not apply to liability for death or   *
+*  personal injury resulting from such party's negligence to the       *
+*  extent applicable law prohibits such limitation. Some               *
+*  jurisdictions do not allow the exclusion or limitation of           *
+*  incidental or consequential damages, so this exclusion and          *
+*  limitation may not apply to You.                                    *
+*                                                                      *
+************************************************************************
+
+8. Litigation
+-------------
+
+Any litigation relating to this License may be brought only in the
+courts of a jurisdiction where the defendant maintains its principal
+place of business and such litigation shall be governed by laws of that
+jurisdiction, without reference to its conflict-of-law provisions.
+Nothing in this Section shall prevent a party's ability to bring
+cross-claims or counter-claims.
+
+9. Miscellaneous
+----------------
+
+This License represents the complete agreement concerning the subject
+matter hereof. If any provision of this License is held to be
+unenforceable, such provision shall be reformed only to the extent
+necessary to make it enforceable. Any law or regulation which provides
+that the language of a contract shall be construed against the drafter
+shall not be used to construe this License against a Contributor.
+
+10. Versions of the License
+---------------------------
+
+10.1. New Versions
+
+Mozilla Foundation is the license steward. Except as provided in Section
+10.3, no one other than the license steward has the right to modify or
+publish new versions of this License. Each version will be given a
+distinguishing version number.
+
+10.2. Effect of New Versions
+
+You may distribute the Covered Software under the terms of the version
+of the License under which You originally received the Covered Software,
+or under the terms of any subsequent version published by the license
+steward.
+
+10.3. Modified Versions
+
+If you create software not governed by this License, and you want to
+create a new license for such software, you may create and use a
+modified version of this License if you rename the license and remove
+any references to the name of the license steward (except to note that
+such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+Licenses
+
+If You choose to distribute Source Code Form that is Incompatible With
+Secondary Licenses under the terms of this version of the License, the
+notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+-------------------------------------------
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular
+file, then You may include the notice in a location (such as a LICENSE
+file in a relevant directory) where a recipient would be likely to look
+for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+---------------------------------------------------------
+
+  This Source Code Form is "Incompatible With Secondary Licenses", as
+  defined by the Mozilla Public License, v. 2.0.
@@ -0,0 +1,44 @@
+# @mediabunny/prores
+
+[![](https://img.shields.io/npm/v/@mediabunny/prores)](https://www.npmjs.com/package/@mediabunny/prores)
+[![](https://img.shields.io/bundlephobia/minzip/@mediabunny/prores)](https://bundlephobia.com/package/@mediabunny/prores)
+[![](https://img.shields.io/npm/dm/@mediabunny/prores)](https://www.npmjs.com/package/@mediabunny/prores)
+[![](https://img.shields.io/discord/1390044844285497344?logo=discord&label=Discord)](https://discord.gg/hmpkyYuS4U)
+
+<div align="center">
+    <img src="../../docs/public/mediabunny-logo.svg" width="180" height="180">
+</div>
+
+Browsers have no support for Apple ProRes in their WebCodecs implementations. This extension package provides a decoder for use with [Mediabunny](https://github.com/Vanilagy/mediabunny), allowing you to decode ProRes directly in the browser at unprecedented speed. It is implemented using Mediabunny's [custom coder API](https://mediabunny.dev/guide/supported-formats-and-codecs#custom-coders) and uses [TurboRes](https://github.com/Vanilagy/turbores), an extremely fast WASM-based ProRes decoder, under the hood.
+
+> This package, like the rest of Mediabunny, is enabled by its [sponsors](https://mediabunny.dev/#sponsors) and their donations. If you've derived value from this package, please consider [leaving a donation](https://github.com/sponsors/Vanilagy)! 💘
+
+## Installation
+
+This library peer-depends on Mediabunny. Install both using npm:
+```bash
+npm install mediabunny @mediabunny/prores
+```
+
+Alternatively, directly include them using a script tag:
+```html
+<script src="mediabunny.js"></script>
+<script src="mediabunny-prores.js"></script>
+```
+
+This will expose the global objects `Mediabunny` and `MediabunnyProres`. Use `mediabunny-prores.d.ts` to provide types for these globals. You can download the built distribution files from the [releases page](https://github.com/Vanilagy/mediabunny/releases).
+
+## Usage
+
+```ts
+import { registerProresDecoder } from '@mediabunny/prores';
+
+registerProresDecoder();
+```
+That's it - Mediabunny now uses the registered ProRes decoder automatically.
+
+For all the ways of using Mediabunny, refer to its [guide](https://mediabunny.dev/guide/introduction).
+
+## Building and development
+
+The complete JavaScript package can be built alongside the rest of Mediabunny by running `npm run build` in Mediabunny's root.
@@ -0,0 +1,37 @@
+{
+  "$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
+  "mainEntryPointFilePath": "dist/modules/src/index.d.ts",
+  "bundledPackages": [],
+  "compiler": {},
+  "apiReport": {
+    "enabled": false
+  },
+  "docModel": {
+    "enabled": false
+  },
+  "dtsRollup": {
+    "enabled": true,
+	"untrimmedFilePath": "dist/mediabunny-prores.d.ts"
+  },
+  "tsdocMetadata": {
+	"enabled": false
+  },
+  "messages": {
+    "compilerMessageReporting": {
+      "default": {
+        "logLevel": "warning"
+      }
+    },
+    "extractorMessageReporting": {
+      "default": {
+        "logLevel": "warning"
+      }
+    },
+    "tsdocMessageReporting": {
+      "default": {
+        "logLevel": "warning"
+      }
+    }
+  },
+	"newlineKind": "lf"
+}
@@ -1,15 +1,15 @@
 {
-  "name": "@mediabunny/prores-decoder",
+  "name": "@mediabunny/prores",
  "author": "Vanilagy",
-  "version": "1.25.8",
-  "description": "MP3 encoder extension for Mediabunny, based on LAME.",
-  "main": "./dist/bundles/mediabunny-mp3-encoder.mjs",
-  "module": "./dist/bundles/mediabunny-mp3-encoder.mjs",
+  "version": "1.49.0",
+  "description": "Apple ProRes decoder extension for Mediabunny, based on TurboRes.",
+  "main": "./dist/bundles/mediabunny-prores.mjs",
+  "module": "./dist/bundles/mediabunny-prores.mjs",
  "types": "./dist/modules/src/index.d.ts",
  "exports": {
    "types": "./dist/modules/src/index.d.ts",
-    "import": "./dist/bundles/mediabunny-mp3-encoder.mjs",
-    "require": "./dist/bundles/mediabunny-mp3-encoder.mjs"
+    "import": "./dist/bundles/mediabunny-prores.mjs",
+    "require": "./dist/bundles/mediabunny-prores.mjs"
  },
  "files": [
    "README.md",
@@ -19,32 +19,38 @@
    "src"
  ],
  "sideEffects": false,
+  "browser": {
+    "node:worker_threads": false,
+    "node:os": false
+  },
  "license": "MPL-2.0",
  "repository": {
    "type": "git",
    "url": "git+https://github.com/Vanilagy/mediabunny.git",
-    "directory": "packages/mp3-encoder"
+    "directory": "packages/prores"
  },
  "bugs": {
    "url": "https://github.com/Vanilagy/mediabunny/issues"
  },
-  "homepage": "https://mediabunny.dev/guide/extensions/mp3-encoder",
+  "homepage": "https://mediabunny.dev/guide/extensions/prores",
  "funding": {
    "type": "individual",
    "url": "https://github.com/sponsors/Vanilagy"
  },
-  "peerDependencies": {
-    "mediabunny": "^1.0.0"
+  "dependencies": {
+    "turbores": "^1.0.0"
  },
-  "devDependencies": {
-    "@types/emscripten": "^1.40.1"
+  "peerDependencies": {
+    "mediabunny": "^1.49.0"
  },
  "keywords": [
-    "mp3",
-    "encoding",
+    "prores",
+    "apple-prores",
+    "decoding",
    "codec",
    "mediabunny",
-    "lame",
+    "turbores",
+    "video",
    "browser",
    "wasm",
    "polyfill"
@@ -0,0 +1,212 @@
+/*!
+ * Copyright (c) 2026-present, Vanilagy and contributors
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { CustomVideoDecoder, EncodedPacket, Logging, registerDecoder, VideoCodec, VideoSample } from 'mediabunny';
+import { Decoder, Frame, PixelFormat, PIXEL_FORMATS, FilledFrame } from 'turbores';
+import {
+	assert,
+	isWebKit,
+} from '../../../src/misc';
+import { type ProresFourCc } from '../../../src/codec';
+
+const PRORES_LOADED_SYMBOL = Symbol.for('@mediabunny/prores loaded');
+if ((globalThis as Record<symbol, unknown>)[PRORES_LOADED_SYMBOL]) {
+	Logging._error(
+		'[WARNING]\n@mediabunny/prores was loaded twice.'
+		+ ' This will likely cause the decoder not to work correctly.'
+		+ ' Check if multiple dependencies are importing different versions of @mediabunny/prores,'
+		+ ' or if something is being bundled incorrectly.',
+	);
+}
+(globalThis as Record<symbol, unknown>)[PRORES_LOADED_SYMBOL] = true;
+
+class ProresDecoder extends CustomVideoDecoder {
+	private decoder: Decoder | null = null;
+	private framePool: Frame[] = [];
+
+	// eslint-disable-next-line @typescript-eslint/no-unused-vars
+	static override supports(codec: VideoCodec, config: VideoDecoderConfig): boolean {
+		return codec === 'prores';
+	}
+
+	/** @internal */
+	static _supportedVideoFrameFormats: PixelFormat[] | null = null;
+
+	/** @internal */
+	static _determineSupportedVideoFrameFormats() {
+		const result: PixelFormat[] = [];
+		const data = new Uint8Array(32);
+
+		for (const format of PIXEL_FORMATS) {
+			try {
+				const frame = new VideoFrame(data, {
+					format: format as VideoPixelFormat,
+					codedWidth: 2,
+					codedHeight: 2,
+					timestamp: 0,
+					duration: 0,
+				});
+				frame.close();
+
+				result.push(format);
+			} catch {
+				// Format is not supported
+			}
+		}
+
+		return result;
+	}
+
+	async init() {
+		if (typeof VideoFrame !== 'undefined') {
+			// Not all VideoFrame implementations support all pixel formats, therefore let's determine the supported set
+			ProresDecoder._supportedVideoFrameFormats ??= ProresDecoder._determineSupportedVideoFrameFormats();
+		}
+
+		const decoder = await Decoder.create({
+			proresFourCc: this.config.codec as ProresFourCc,
+			useSharedMemory: Decoder.canUseSharedMemory(),
+			allowedOutputFormats: ProresDecoder._supportedVideoFrameFormats ?? undefined,
+		});
+		if (decoder instanceof Error) {
+			throw decoder;
+		}
+
+		this.decoder = decoder;
+	}
+
+	async decode(packet: EncodedPacket) {
+		assert(this.decoder);
+
+		if (this.decoder.useSharedMemory) {
+			await this.runDecode(packet);
+		} else {
+			while (this.decoder.decodeQueueSize >= this.decoder.concurrency) {
+				await this.decoder.dequeued;
+			}
+
+			void this.runDecode(packet)
+				.catch(error => this.onError(error));
+		}
+	}
+
+	private async runDecode(packet: EncodedPacket) {
+		assert(this.decoder);
+
+		let frame: Frame;
+		if (this.framePool.length > 0) {
+			frame = this.framePool.shift()!;
+		} else {
+			frame = new Frame();
+		}
+
+		const result = await this.decoder.decode(packet.data, frame);
+		this.framePool.push(frame);
+
+		if (result instanceof Error) {
+			throw result;
+		}
+
+		if (result.visibleHeight < result.codedHeight && isWebKit()) {
+			// WebKit has (had) a bug with displaying height-trimmed YUV frames, so we must compact the frame data a
+			// little https://bugs.webkit.org/show_bug.cgi?id=317524
+			this.trimCodedHeightToVisibleHeight(result);
+		}
+
+		const sample = new VideoSample(result.frameData, {
+			format: result.pixelFormat,
+			codedWidth: result.codedWidth,
+			codedHeight: result.codedHeight,
+			visibleRect: {
+				left: 0,
+				top: 0,
+				width: result.visibleWidth,
+				height: result.visibleHeight,
+			},
+			timestamp: packet.timestamp,
+			duration: packet.duration,
+			colorSpace: {
+				primaries: result.colorPrimariesString as VideoColorPrimaries | undefined,
+				matrix: result.colorMatrixString as VideoMatrixCoefficients | undefined,
+				transfer: result.colorTransferString as VideoTransferCharacteristics | undefined,
+				fullRange: result.colorRangeFull,
+			},
+		});
+		this.onSample(sample);
+	}
+
+	private trimCodedHeightToVisibleHeight(result: FilledFrame) {
+		const bytesPerSample = result.pixelFormat.includes('P') ? 2 : 1;
+		const subWidth = result.pixelFormat.includes('444') ? 1 : 2;
+		const subHeight = result.pixelFormat.includes('420') ? 2 : 1;
+
+		const chromaCodedWidth = result.codedWidth / subWidth;
+		const chromaCodedHeight = result.codedHeight / subHeight;
+		const chromaVisibleHeight = Math.ceil(result.visibleHeight / subHeight);
+
+		const lumaCodedPixels = result.codedWidth * result.codedHeight;
+		const lumaVisiblePixels = result.codedWidth * result.visibleHeight;
+		const chromaCodedPixels = chromaCodedWidth * chromaCodedHeight;
+		const chromaVisiblePixels = chromaCodedWidth * chromaVisibleHeight;
+
+		// U
+		result.frameData.set(
+			result.frameData.subarray(
+				bytesPerSample * lumaCodedPixels,
+				bytesPerSample * (lumaCodedPixels + chromaCodedPixels),
+			),
+			bytesPerSample * lumaVisiblePixels,
+		);
+		// V
+		result.frameData.set(
+			result.frameData.subarray(
+				bytesPerSample * (lumaCodedPixels + chromaCodedPixels),
+				bytesPerSample * (lumaCodedPixels + 2 * chromaCodedPixels),
+			),
+			bytesPerSample * (lumaVisiblePixels + chromaVisiblePixels),
+		);
+
+		result.codedHeight = result.visibleHeight;
+	}
+
+	async flush() {
+		assert(this.decoder);
+
+		while (this.decoder.decodeQueueSize > 0) {
+			await this.decoder.dequeued;
+		}
+	}
+
+	async close() {
+		assert(this.decoder);
+
+		await this.decoder.close();
+
+		for (const frame of this.framePool) {
+			frame.clear();
+		}
+	}
+}
+
+let registered = false;
+
+/**
+ * Registers an Apple ProRes decoder which Mediabunny will then use automatically when applicable. Make sure to call
+ * this function before starting any decoding task.
+ *
+ * @group \@mediabunny/prores
+ * @public
+ */
+export const registerProresDecoder = () => {
+	if (registered) {
+		return;
+	}
+	registered = true;
+
+	registerDecoder(ProresDecoder);
+};
@@ -1,7 +1,7 @@
 {
-	"extends": "../../../tsconfig.json",
+	"extends": "../../tsconfig.json",
 	"compilerOptions": {
-		"outDir": "../dist/modules",
+		"outDir": "./dist/modules",
 		"declaration": true,
 		"declarationMap": true,
 		"stripInternal": true,
@@ -11,13 +11,13 @@
 		"module": "nodenext",
 		"allowJs": true,
 		"paths": {
-			"mediabunny": ["../../../src/index.ts"],
+			"mediabunny": ["../../src/index.ts"],
 		},
 	},
 	"include": [
-		"**/*",
+		"./src/**/*",
 	],
 	"references": [
-        { "path": "../../../src" }
+        { "path": "../../src" }
    ]
 }
@@ -0,0 +1,4 @@
+{
+    "$schema": "https://developer.microsoft.com/json-schemas/tsdoc/v0/tsdoc.schema.json",
+    "extends": ["../../tsdoc.json"]
+}
@@ -375,6 +375,7 @@ export class NodeAvVideoEncoder extends CustomVideoEncoder {
 					hevcCodecInfo: null,
 					vp9CodecInfo: null,
 					av1CodecInfo: null,
+					proresFormat: null,
 				});

 				if (!expectsAnnexB) {
@@ -450,6 +451,7 @@ export class NodeAvVideoEncoder extends CustomVideoEncoder {
 					hevcCodecInfo: null,
 					vp9CodecInfo: null,
 					av1CodecInfo: null,
+					proresFormat: null,
 				});
 			}
 		} else if (this.codec === 'vp9') {
@@ -467,6 +469,7 @@ export class NodeAvVideoEncoder extends CustomVideoEncoder {
 					hevcCodecInfo: null,
 					vp9CodecInfo,
 					av1CodecInfo: null,
+					proresFormat: null,
 				});
 			}
 		} else if (this.codec === 'av1') {
@@ -484,6 +487,7 @@ export class NodeAvVideoEncoder extends CustomVideoEncoder {
 					hevcCodecInfo: null,
 					vp9CodecInfo: null,
 					av1CodecInfo,
+					proresFormat: null,
 				});
 			}
 		} else {
@@ -9,6 +9,7 @@ rm -rf packages/mp3-encoder/dist
 rm -rf packages/ac3/dist
 rm -rf packages/aac-encoder/dist
 rm -rf packages/flac-encoder/dist
+rm -rf packages/prores/dist
 rm -rf packages/server/dist

 # Ensure license headers on all source files
@@ -20,6 +21,7 @@ tsc -p packages/mp3-encoder
 tsc -p packages/ac3
 tsc -p packages/aac-encoder
 tsc -p packages/flac-encoder
+tsc -p packages/prores
 tsc -p packages/server

 # Generate the root again, now with internals properly stripped
@@ -39,6 +41,7 @@ api-extractor run -c packages/mp3-encoder/api-extractor.json
 api-extractor run -c packages/ac3/api-extractor.json
 api-extractor run -c packages/aac-encoder/api-extractor.json
 api-extractor run -c packages/flac-encoder/api-extractor.json
+api-extractor run -c packages/prores/api-extractor.json
 api-extractor run -c packages/server/api-extractor.json

 # Checks that all symbols are documented
@@ -47,6 +50,7 @@ tsx scripts/check-docblocks.ts packages/mp3-encoder/dist/mediabunny-mp3-encoder.
 tsx scripts/check-docblocks.ts packages/ac3/dist/mediabunny-ac3.d.ts
 tsx scripts/check-docblocks.ts packages/aac-encoder/dist/mediabunny-aac-encoder.d.ts
 tsx scripts/check-docblocks.ts packages/flac-encoder/dist/mediabunny-flac-encoder.d.ts
+tsx scripts/check-docblocks.ts packages/prores/dist/mediabunny-prores.d.ts
 tsx scripts/check-docblocks.ts packages/server/dist/mediabunny-server.d.ts

 # Checks that API docs are generatable
@@ -58,4 +62,5 @@ echo 'export as namespace MediabunnyMp3Encoder;' >> packages/mp3-encoder/dist/me
 echo 'export as namespace MediabunnyAc3;' >> packages/ac3/dist/mediabunny-ac3.d.ts
 echo 'export as namespace MediabunnyAacEncoder;' >> packages/aac-encoder/dist/mediabunny-aac-encoder.d.ts
 echo 'export as namespace MediabunnyFlacEncoder;' >> packages/flac-encoder/dist/mediabunny-flac-encoder.d.ts
+echo 'export as namespace MediabunnyProres;' >> packages/prores/dist/mediabunny-prores.d.ts
 echo 'export as namespace MediabunnyServer;' >> packages/server/dist/mediabunny-server.d.ts
@@ -223,6 +223,24 @@ const flacEncoderVariants = await createVariants(
 	},
 );

+const proresVariants = await createVariants(
+	'packages/prores/src/index.ts',
+	'MediabunnyProres',
+	'packages/prores/dist/bundles/mediabunny-prores',
+	'js', // The bundles are purely for the browser, not for Node (due to the peer dependecy)
+	{
+		plugins: [
+			PluginExternalGlobal.externalGlobalPlugin({
+				mediabunny: 'Mediabunny',
+			}),
+		],
+	},
+	{
+		external: ['mediabunny'],
+		platform: 'node', // To retain the Node imports
+	},
+);
+
 const serverVariants = await createVariants(
 	'packages/server/src/index.ts',
 	'MediabunnyServer',
@@ -246,6 +264,7 @@ const contexts = [
 	...ac3Variants,
 	...aacEncoderVariants,
 	...flacEncoderVariants,
+	...proresVariants,
 	...serverVariants,
 ];

@@ -16,6 +16,9 @@ tsc -p packages/aac-encoder
 rm -rf packages/flac-encoder/dist/modules
 tsc -p packages/flac-encoder

+rm -rf packages/prores/dist/modules
+tsc -p packages/prores
+
 rm -rf packages/server/dist/modules
 tsc -p packages/server

@@ -40,6 +40,7 @@ checkDirectory(path.join(__dirname, '..', 'packages', 'mp3-encoder', 'src'));
 checkDirectory(path.join(__dirname, '..', 'packages', 'ac3', 'src'));
 checkDirectory(path.join(__dirname, '..', 'packages', 'flac-encoder', 'src'));
 checkDirectory(path.join(__dirname, '..', 'packages', 'aac-encoder', 'src'));
+checkDirectory(path.join(__dirname, '..', 'packages', 'prores', 'src'));
 checkDirectory(path.join(__dirname, '..', 'packages', 'server', 'src'));

 if (missingFiles.length > 0) {
@@ -224,7 +224,8 @@ export const PRORES_FOURCCS = [
 	'apcn', // ProRes 422 Standard Definition
 	'apcs', // ProRes 422 LT
 	'apco', // ProRes 422 Proxy
-];
+] as const;
+export type ProresFourCc = typeof PRORES_FOURCCS[number];

 export const buildVideoCodecString = (codec: VideoCodec, width: number, height: number, bitrate: number) => {
 	if (codec === 'avc') {
@@ -359,7 +360,7 @@ export const extractVideoCodecString = (trackInfo: {
 	hevcCodecInfo: HevcDecoderConfigurationRecord | null;
 	vp9CodecInfo: Vp9CodecInfo | null;
 	av1CodecInfo: Av1CodecInfo | null;
-	proresFormat: string | null;
+	proresFormat: ProresFourCc | null;
 }) => {
 	const {
 		codec,
@@ -946,7 +947,7 @@ export const validateVideoChunkMetadata = (metadata: EncodedVideoChunkMetadata |

 		if (!PRORES_FOURCCS.some(x => metadata.decoderConfig!.codec === x)) {
 			throw new TypeError(
-				'Video chunk metadata decoder configuration codec string for ProRes must be one of the valid ProRes'
+				`Video chunk metadata decoder configuration codec string for ProRes must be one of the valid ProRes`
 				+ ` four-character codes: ${PRORES_FOURCCS.join(', ')}.`,
 			);
 		}
@@ -27,6 +27,8 @@ export abstract class CustomVideoDecoder {
 	readonly config!: VideoDecoderConfig;
 	/** The callback to call when a decoded VideoSample is available. */
 	readonly onSample!: (sample: VideoSample) => unknown;
+	/** The callback to call to surface out-of-band errors that can't be surfaced through the main methods. */
+	readonly onError!: (error: unknown) => undefined;

 	/** Returns true if and only if the decoder can decode the given codec configuration. */
 	// eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -57,6 +59,8 @@ export abstract class CustomAudioDecoder {
 	readonly config!: AudioDecoderConfig;
 	/** The callback to call when a decoded AudioSample is available. */
 	readonly onSample!: (sample: AudioSample) => unknown;
+	/** The callback to call to surface out-of-band errors that can't be surfaced through the main methods. */
+	readonly onError!: (error: unknown) => undefined;

 	/** Returns true if and only if the decoder can decode the given codec configuration. */
 	// eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -87,6 +91,8 @@ export abstract class CustomVideoEncoder {
 	readonly config!: VideoEncoderConfig;
 	/** The callback to call when an EncodedPacket is available. */
 	readonly onPacket!: (packet: EncodedPacket, meta?: EncodedVideoChunkMetadata) => unknown;
+	/** The callback to call to surface out-of-band errors that can't be surfaced through the main methods. */
+	readonly onError!: (error: unknown) => undefined;

 	/** Returns true if and only if the encoder can encode the given codec configuration. */
 	// eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -117,6 +123,8 @@ export abstract class CustomAudioEncoder {
 	readonly config!: AudioEncoderConfig;
 	/** The callback to call when an EncodedPacket is available. */
 	readonly onPacket!: (packet: EncodedPacket, meta?: EncodedAudioChunkMetadata) => unknown;
+	/** The callback to call to surface out-of-band errors that can't be surfaced through the main methods. */
+	readonly onError!: (error: unknown) => undefined;

 	/** Returns true if and only if the encoder can encode the given codec configuration. */
 	// eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -549,20 +549,20 @@ export class Quality {
 	/** @internal */
 	_toVideoBitrate(codec: VideoCodec, width: number, height: number) {
 		const pixels = width * height;
+		const referencePixels = 1920 * 1080;
+		const referenceBitrate = 3_000_000;
+		const scaleFactor = Math.pow(pixels / referencePixels, 0.95); // Slight non-linear scaling
+		const baseBitrate = referenceBitrate * scaleFactor;

-		const codecEfficiencyFactors = {
+		const codecEfficiencyFactors: Record<VideoCodec, number> = {
 			avc: 1.0, // H.264/AVC (baseline)
 			hevc: 0.6, // H.265/HEVC (~40% more efficient than AVC)
 			vp9: 0.6, // Similar to HEVC
 			av1: 0.4, // ~60% more efficient than AVC
 			vp8: 1.2, // Slightly less efficient than AVC
+			prores: 220_000_000 / referenceBitrate, // Apple ProRes white paper claims 220 Mbps for 1080p 422 HQ @30Hz
 		};

-		const referencePixels = 1920 * 1080;
-		const referenceBitrate = 3000000;
-		const scaleFactor = Math.pow(pixels / referencePixels, 0.95); // Slight non-linear scaling
-		const baseBitrate = referenceBitrate * scaleFactor;
-
 		const codecAdjustedBitrate = baseBitrate * codecEfficiencyFactors[codec];
 		const finalBitrate = codecAdjustedBitrate * this._factor;

@@ -19,6 +19,7 @@ import {
 	PCM_AUDIO_CODECS,
 	PcmAudioCodec,
 	PRORES_FOURCCS,
+	ProresFourCc,
 	VideoCodec,
 } from '../codec';
 import {
@@ -148,7 +149,7 @@ type InternalTrack = {
 		hevcCodecInfo: HevcDecoderConfigurationRecord | null;
 		vp9CodecInfo: Vp9CodecInfo | null;
 		av1CodecInfo: Av1CodecInfo | null;
-		proresFormat: string | null;
+		proresFormat: ProresFourCc | null;
 	};
 } | {
 	info: {
@@ -1096,9 +1097,9 @@ export class IsobmffDemuxer extends Demuxer {
 							track.info.codec = 'vp9';
 						} else if (codecName === 'av01') {
 							track.info.codec = 'av1';
-						} else if (PRORES_FOURCCS.includes(lowercaseBoxName)) {
+						} else if ((PRORES_FOURCCS as readonly string[]).includes(lowercaseBoxName)) {
 							track.info.codec = 'prores';
-							track.info.proresFormat = lowercaseBoxName;
+							track.info.proresFormat = lowercaseBoxName as ProresFourCc;
 						} else if (codecName === null) {
 							Logging._warn(`Unknown encrypted video codec due to missing frma box.`);
 						} else {
@@ -3347,7 +3348,10 @@ class IsobmffVideoTrackBacking extends IsobmffTrackBacking implements InputVideo
 	}

 	async canBeTransparent() {
-		return false;
+		return this.internalTrack.info.codec === 'prores' && (
+			this.internalTrack.info.proresFormat === 'ap4h'
+			|| this.internalTrack.info.proresFormat === 'ap4x'
+		);
 	}

 	async getDecoderConfig(): Promise<VideoDecoderConfig | null> {
@@ -21,6 +21,7 @@ import {
 	MediaCodec,
 	OPUS_SAMPLE_RATE,
 	PRORES_FOURCCS,
+	ProresFourCc,
 	VideoCodec,
 } from '../codec';
 import { Demuxer } from '../demuxer';
@@ -216,6 +217,7 @@ type InternalTrack = {
 			codecDescription: Uint8Array | null;
 			colorSpace: VideoColorSpaceInit | null;
 			alphaMode: boolean;
+			proresFormat: ProresFourCc | null;
 		}
 		| {
 			type: 'audio';
@@ -1084,10 +1086,12 @@ export class MatroskaDemuxer extends Demuxer {
 								? textDecoder.decode(this.currentTrack.codecPrivate)
 								: '';

-							if (PRORES_FOURCCS.includes(format)) {
+							if ((PRORES_FOURCCS as readonly string[]).includes(format)) {
 								this.currentTrack.info.codec = 'prores';
+								this.currentTrack.info.proresFormat = format as ProresFourCc;
 							} else {
-								// We don't support ProRes RAW yet
+								// Either an invalid string or ProRes RAW, which we don't support yet (it's a
+								// different codec).
 							}
 						}

@@ -1182,6 +1186,7 @@ export class MatroskaDemuxer extends Demuxer {
 						codecDescription: null,
 						colorSpace: null,
 						alphaMode: false,
+						proresFormat: null,
 					};
 				} else if (type === 2) {
 					this.currentTrack.info = {
@@ -2447,7 +2452,12 @@ class MatroskaVideoTrackBacking extends MatroskaTrackBacking implements InputVid
 	}

 	async canBeTransparent() {
-		return this.internalTrack.info.alphaMode;
+		return this.internalTrack.info.alphaMode || (
+			this.internalTrack.info.codec === 'prores' && (
+				this.internalTrack.info.proresFormat === 'ap4h'
+				|| this.internalTrack.info.proresFormat === 'ap4x'
+			)
+		);
 	}

 	async getDecoderConfig(): Promise<VideoDecoderConfig | null> {
@@ -2489,9 +2499,7 @@ class MatroskaVideoTrackBacking extends MatroskaTrackBacking implements InputVid
 					av1CodecInfo: this.internalTrack.info.codec === 'av1' && firstPacket
 						? extractAv1CodecInfoFromPacket(firstPacket.data)
 						: null,
-					proresFormat: this.internalTrack.info.codec === 'prores' && this.internalTrack.codecPrivate
-						? textDecoder.decode(this.internalTrack.codecPrivate)
-						: null,
+					proresFormat: this.internalTrack.info.proresFormat,
 				}),
 				codedWidth: this.internalTrack.info.width,
 				codedHeight: this.internalTrack.info.height,
@@ -333,7 +333,8 @@ export class EncodedPacketSink {
 		// This stores errors that are "out of band" in the sense that they didn't occur in the normal flow of this
 		// method but instead in a different context. This error should not go unnoticed and must be bubbled up to
 		// the consumer.
-		let outOfBandError = null as Error | null;
+		let outOfBandError = null as unknown;
+		let hasOutOfBandError = false;

 		const timestamps: number[] = [];
 		// The queue should always be big enough to hold 1 second worth of packets
@@ -364,9 +365,10 @@ export class EncodedPacketSink {

 			ended = true;
 			onQueueNotEmpty();
-		})().catch((error: Error) => {
-			if (!outOfBandError) {
+		})().catch((error) => {
+			if (!hasOutOfBandError) {
 				outOfBandError = error;
+				hasOutOfBandError = true;
 				onQueueNotEmpty();
 			}
 		});
@@ -380,7 +382,7 @@ export class EncodedPacketSink {
 						throw new InputDisposedError();
 					} else if (terminated) {
 						return { value: undefined, done: true };
-					} else if (outOfBandError) {
+					} else if (hasOutOfBandError) {
 						throw outOfBandError;
 					} else if (packetQueue.length > 0) {
 						const value = packetQueue.shift()!;
@@ -423,7 +425,7 @@ abstract class DecoderWrapper<
 > {
 	constructor(
 		public onSample: (sample: MediaSample) => unknown,
-		public onError: (error: Error) => unknown,
+		public onError: (error: unknown) => unknown,
 	) {}

 	abstract getDecodeQueueSize(): number;
@@ -446,7 +448,7 @@ export abstract class BaseMediaSampleSink<
 	/** @internal */
 	abstract _createDecoder(
 		onSample: (sample: MediaSample) => unknown,
-		onError: (error: Error) => unknown
+		onError: (error: unknown) => unknown
 	): Promise<DecoderWrapper<MediaSample>>;
 	/** @internal */
 	abstract _createPacketSink(): EncodedPacketSink;
@@ -472,7 +474,8 @@ export abstract class BaseMediaSampleSink<
 		// This stores errors that are "out of band" in the sense that they didn't occur in the normal flow of this
 		// method but instead in a different context. This error should not go unnoticed and must be bubbled up to
 		// the consumer.
-		let outOfBandError = null as Error | null;
+		let outOfBandError = null as unknown;
+		let hasOutOfBandError = false;

 		const packetRetrievalOptions: PacketRetrievalOptions = {
 			...options,
@@ -518,8 +521,9 @@ export abstract class BaseMediaSampleSink<
 					({ promise: queueNotEmpty, resolve: onQueueNotEmpty } = promiseWithResolvers());
 				}
 			}, (error) => {
-				if (!outOfBandError) {
+				if (!hasOutOfBandError) {
 					outOfBandError = error;
+					hasOutOfBandError = true;
 					onQueueNotEmpty();
 				}
 			});
@@ -572,9 +576,10 @@ export abstract class BaseMediaSampleSink<

 			decoderIsFlushed = true;
 			onQueueNotEmpty(); // To unstuck the generator
-		})().catch((error: Error) => {
-			if (!outOfBandError) {
+		})().catch((error) => {
+			if (!hasOutOfBandError) {
 				outOfBandError = error;
+				hasOutOfBandError = true;
 				onQueueNotEmpty();
 			}
 		});
@@ -595,7 +600,7 @@ export abstract class BaseMediaSampleSink<
 						throw new InputDisposedError();
 					} else if (terminated) {
 						return { value: undefined, done: true };
-					} else if (outOfBandError) {
+					} else if (hasOutOfBandError) {
 						closeSamples();
 						throw outOfBandError;
 					} else if (sampleQueue.length > 0) {
@@ -645,7 +650,8 @@ export abstract class BaseMediaSampleSink<
 		// This stores errors that are "out of band" in the sense that they didn't occur in the normal flow of this
 		// method but instead in a different context. This error should not go unnoticed and must be bubbled up to
 		// the consumer.
-		let outOfBandError = null as Error | null;
+		let outOfBandError = null as unknown;
+		let hasOutOfBandError = false;

 		const pushToQueue = (sample: MediaSample | null) => {
 			sampleQueue.push(sample);
@@ -687,8 +693,9 @@ export abstract class BaseMediaSampleSink<
 					sample.close();
 				}
 			}, (error) => {
-				if (!outOfBandError) {
+				if (!hasOutOfBandError) {
 					outOfBandError = error;
+					hasOutOfBandError = true;
 					onQueueNotEmpty();
 				}
 			});
@@ -792,9 +799,10 @@ export abstract class BaseMediaSampleSink<

 			decoderIsFlushed = true;
 			onQueueNotEmpty(); // To unstuck the generator
-		})().catch((error: Error) => {
-			if (!outOfBandError) {
+		})().catch((error) => {
+			if (!hasOutOfBandError) {
 				outOfBandError = error;
+				hasOutOfBandError = true;
 				onQueueNotEmpty();
 			}
 		});
@@ -814,7 +822,7 @@ export abstract class BaseMediaSampleSink<
 						throw new InputDisposedError();
 					} else if (terminated) {
 						return { value: undefined, done: true };
-					} else if (outOfBandError) {
+					} else if (hasOutOfBandError) {
 						closeSamples();
 						throw outOfBandError;
 					} else if (sampleQueue.length > 0) {
@@ -882,7 +890,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {

 	constructor(
 		onSample: (sample: VideoSample) => unknown,
-		onError: (error: Error) => unknown,
+		onError: (error: unknown) => unknown,
 		public codec: VideoCodec,
 		public decoderConfig: VideoDecoderConfig,
 		public rotation: Rotation,
@@ -906,8 +914,14 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {

 				this.finalizeAndEmitSample(sample);
 			};
+			// @ts-expect-error It's technically readonly
+			this.customDecoder.onError = (error) => {
+				onError(error);
+			};

-			void this.customDecoderCallSerializer.call(() => this.customDecoder!.init());
+			void this.customDecoderCallSerializer
+				.call(() => this.customDecoder!.init())
+				.catch(error => onError(error));
 		} else {
 			const colorHandler = (frame: VideoFrame) => {
 				this.frameHandlerSerializer.call(async () => {
@@ -920,7 +934,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 					} else {
 						this.colorQueue.push(frame);
 					}
-				}).catch((error: Error) => this.onError(error));
+				}).catch(error => this.onError(error));
 			};

 			if (codec === 'avc' && this.decoderConfig.description && isChromium()) {
@@ -946,7 +960,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 					try {
 						colorHandler(frame);
 					} catch (error) {
-						this.onError(error as Error);
+						this.onError(error);
 					}
 				},
 				error: (error) => {
@@ -984,7 +998,8 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 			this.customDecoderQueueSize++;
 			void this.customDecoderCallSerializer
 				.call(() => this.customDecoder!.decode(packet))
-				.then(() => this.customDecoderQueueSize--);
+				.catch(error => this.onError(error))
+				.finally(() => this.customDecoderQueueSize--);
 		} else {
 			assert(this.decoder);

@@ -1074,7 +1089,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 					}

 					this.alphaDecoderQueueSize--;
-				}).catch((error: Error) => this.onError(error));
+				}).catch(error => this.onError(error));
 			};

 			const stack = new Error('Decoding error').stack;
@@ -1084,7 +1099,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 					try {
 						alphaHandler(frame);
 					} catch (error) {
-						this.onError(error as Error);
+						this.onError(error);
 					}
 				},
 				error: (error) => {
@@ -1813,7 +1828,7 @@ export class VideoSampleSink extends BaseMediaSampleSink<VideoSample> {
 	/** @internal */
 	async _createDecoder(
 		onSample: (sample: VideoSample) => unknown,
-		onError: (error: Error) => unknown,
+		onError: (error: unknown) => unknown,
 	) {
 		if (!(await this._track.canDecode())) {
 			throw new Error(
@@ -2215,7 +2230,7 @@ class AudioDecoderWrapper extends DecoderWrapper<AudioSample> {

 	constructor(
 		onSample: (sample: AudioSample) => unknown,
-		onError: (error: Error) => unknown,
+		onError: (error: unknown) => unknown,
 		codec: AudioCodec,
 		decoderConfig: AudioDecoderConfig,
 	) {
@@ -2271,8 +2286,14 @@ class AudioDecoderWrapper extends DecoderWrapper<AudioSample> {

 				sampleHandler(sample);
 			};
+			// @ts-expect-error It's technically readonly
+			this.customDecoder.onError = (error) => {
+				onError(error);
+			};

-			void this.customDecoderCallSerializer.call(() => this.customDecoder!.init());
+			void this.customDecoderCallSerializer
+				.call(() => this.customDecoder!.init())
+				.catch(error => onError(error));
 		} else {
 			const stack = new Error('Decoding error').stack;

@@ -2281,7 +2302,7 @@ class AudioDecoderWrapper extends DecoderWrapper<AudioSample> {
 					try {
 						sampleHandler(new AudioSample(data));
 					} catch (error) {
-						this.onError(error as Error);
+						this.onError(error);
 					}
 				},
 				error: (error) => {
@@ -2307,7 +2328,8 @@ class AudioDecoderWrapper extends DecoderWrapper<AudioSample> {
 			this.customDecoderQueueSize++;
 			void this.customDecoderCallSerializer
 				.call(() => this.customDecoder!.decode(packet))
-				.then(() => this.customDecoderQueueSize--);
+				.catch(error => this.onError(error))
+				.finally(() => this.customDecoderQueueSize--);
 		} else {
 			assert(this.decoder);

@@ -2357,7 +2379,7 @@ class PcmAudioDecoderWrapper extends DecoderWrapper<AudioSample> {

 	constructor(
 		onSample: (sample: AudioSample) => unknown,
-		onError: (error: Error) => unknown,
+		onError: (error: unknown) => unknown,
 		public decoderConfig: AudioDecoderConfig,
 	) {
 		super(onSample, onError);
@@ -2547,7 +2569,7 @@ export class AudioSampleSink extends BaseMediaSampleSink<AudioSample> {
 	/** @internal */
 	async _createDecoder(
 		onSample: (sample: AudioSample) => unknown,
-		onError: (error: Error) => unknown,
+		onError: (error: unknown) => unknown,
 	) {
 		if (!(await this._track.canDecode())) {
 			throw new Error(
@@ -265,10 +265,18 @@ class VideoEncoderWrapper {
 	 * However, we want to surface these errors to the user within the normal control flow, so they don't go uncaught.
 	 * So, we keep track of the encoder error and throw it as soon as we get the chance.
 	 */
-	private error: Error | null = null;
-	private closed = false;
+	private error: unknown = null;
+	private errorSet = false;
+
+	private setError(error: unknown) {
+		if (!this.errorSet) {
+			this.error = error;
+			this.errorSet = true;
+		}
+	}

 	private lastMuxerPromise: Promise<void> = Promise.resolve();
+	private closed = false;

 	constructor(private source: VideoSource, private encodingConfig: VideoEncodingConfig) {}

@@ -492,9 +500,9 @@ class VideoEncoderWrapper {

 					const promise = this.customEncoderCallSerializer
 						.call(() => this.customEncoder!.encode(clonedSample, finalEncodeOptions))
-						.then(() => this.customEncoderQueueSize--)
-						.catch((error: Error) => this.error ??= error)
+						.catch((error: unknown) => this.setError(error))
 						.finally(() => {
+							this.customEncoderQueueSize--;
 							clonedSample.close();
 						});

@@ -641,9 +649,13 @@ class VideoEncoderWrapper {
 					this.lastMuxerPromise
 						= this.muxer!.addEncodedVideoPacket(this.source._connectedTrack!, packet, meta)
 							.catch((error) => {
-								this.error ??= error;
+								this.setError(error);
 							});
 				};
+				// @ts-expect-error It's technically readonly
+				this.customEncoder.onError = (error) => {
+					this.setError(error);
+				};

 				await this.customEncoder.init();
 			} else {
@@ -746,7 +758,7 @@ class VideoEncoderWrapper {
 					this.lastMuxerPromise
 						= this.muxer!.addEncodedVideoPacket(this.source._connectedTrack!, packet, meta)
 							.catch((error) => {
-								this.error ??= error;
+								this.setError(error);
 							});

 					this.emittedEncoderPackets++;
@@ -791,7 +803,7 @@ class VideoEncoderWrapper {
 					},
 					error: (error) => {
 						error.stack = stack; // Provide a more useful stack trace, the default one sucks
-						this.error ??= error;
+						this.setError(error);
 					},
 				});
 				this.encoder.configure(encoderConfig);
@@ -827,7 +839,7 @@ class VideoEncoderWrapper {
 						},
 						error: (error) => {
 							error.stack = stack; // Provide a more useful stack trace
-							this.error ??= error;
+							this.setError(error);
 						},
 					});
 					this.alphaEncoder.configure(encoderConfig);
@@ -899,7 +911,7 @@ class VideoEncoderWrapper {
 	}

 	checkForEncoderError() {
-		if (this.error) {
+		if (this.errorSet) {
 			throw this.error;
 		}
 	}
@@ -2043,7 +2055,16 @@ class AudioEncoderWrapper {
 	 * However, we want to surface these errors to the user within the normal control flow, so they don't go uncaught.
 	 * So, we keep track of the encoder error and throw it as soon as we get the chance.
 	 */
-	private error: Error | null = null;
+	private error: unknown = null;
+	private errorSet = false;
+
+	private setError(error: unknown) {
+		if (!this.errorSet) {
+			this.error = error;
+			this.errorSet = true;
+		}
+	}
+
 	private lastMuxerPromise: Promise<void> = Promise.resolve();
 	private closed = false;

@@ -2222,9 +2243,9 @@ class AudioEncoderWrapper {

 				const promise = this.customEncoderCallSerializer
 					.call(() => this.customEncoder!.encode(clonedSample))
-					.then(() => this.customEncoderQueueSize--)
-					.catch((error: Error) => this.error ??= error)
+					.catch((error: unknown) => this.setError(error))
 					.finally(() => {
+						this.customEncoderQueueSize--;
 						clonedSample.close();
 					});

@@ -2365,9 +2386,13 @@ class AudioEncoderWrapper {
 					this.lastMuxerPromise
 						= this.muxer!.addEncodedAudioPacket(this.source._connectedTrack!, packet, meta)
 							.catch((error) => {
-								this.error ??= error;
+								this.setError(error);
 							});
 				};
+				// @ts-expect-error It's technically readonly
+				this.customEncoder.onError = (error) => {
+					this.setError(error);
+				};

 				await this.customEncoder.init();
 			} else if ((PCM_AUDIO_CODECS as readonly string[]).includes(this.encodingConfig.codec)) {
@@ -2431,12 +2456,12 @@ class AudioEncoderWrapper {
 						this.lastMuxerPromise
 							= this.muxer!.addEncodedAudioPacket(this.source._connectedTrack!, packet, meta)
 								.catch((error) => {
-									this.error ??= error;
+									this.setError(error);
 								});
 					},
 					error: (error) => {
 						error.stack = stack; // Provide a more useful stack trace
-						this.error ??= error;
+						this.setError(error);
 					},
 				});
 				this.encoder.configure(encoderConfig);
@@ -2587,7 +2612,7 @@ class AudioEncoderWrapper {
 	}

 	checkForEncoderError() {
-		if (this.error) {
+		if (this.errorSet) {
 			throw this.error;
 		}
 	}
@@ -2959,7 +2984,7 @@ type MediaStreamTrackProcessorWorkerMessage = {
 } | {
 	type: 'error';
 	trackId: number;
-	error: Error;
+	error: unknown;
 };

 type MediaStreamTrackProcessorControllerMessage = {
@@ -3018,7 +3043,7 @@ const mediaStreamTrackProcessorWorkerCode = () => {

 				processor.readable.pipeTo(consumer, {
 					signal: abortController.signal,
-				}).catch((error: Error) => {
+				}).catch((error: unknown) => {
 					// Handle AbortError silently
 					if (error instanceof DOMException && error.name === 'AbortError') return;

@@ -3138,7 +3163,9 @@ export class TextSubtitleSource extends SubtitleSource {
 	/** @internal */
 	private _parser: SubtitleParser;
 	/** @internal */
-	private _error: Error | null = null;
+	private _error: unknown = null;
+	/** @internal */
+	private _errorSet = false;
 	/** @internal */
 	private _lastMuxerPromise: Promise<void> = Promise.resolve();

@@ -3152,7 +3179,7 @@ export class TextSubtitleSource extends SubtitleSource {
 				this._lastMuxerPromise
 					= this._connectedTrack!.output._muxer.addSubtitleCue(this._connectedTrack!, cue, metadata)
 						.catch((error) => {
-							this._error ??= error;
+							this._setError(error);
 						});
 			},
 		});
@@ -3178,9 +3205,17 @@ export class TextSubtitleSource extends SubtitleSource {
 		return this._lastMuxerPromise; // Allow the writer to apply backpressure
 	}

+	/** @internal */
+	private _setError(error: unknown) {
+		if (!this._errorSet) {
+			this._error = error;
+			this._errorSet = true;
+		}
+	}
+
 	/** @internal */
 	_checkForError() {
-		if (this._error) {
+		if (this._errorSet) {
 			throw this._error;
 		}
 	}
@@ -589,6 +589,7 @@ export class MpegTsDemuxer extends Demuxer {
 									hevcCodecInfo: elementaryStream.info.hevcCodecInfo,
 									vp9CodecInfo: null,
 									av1CodecInfo: null,
+									proresFormat: null,
 								}),
 								codedWidth: elementaryStream.info.width,
 								codedHeight: elementaryStream.info.height,
@@ -423,16 +423,13 @@ export class VideoSample implements Disposable {
 				);
 			}

-			this._data = init._doNotCopy
-				? toUint8Array(data)
-				: toUint8Array(data).slice(); // Copy it
-			this._layout = init.layout ?? createDefaultPlaneLayout(init.format, init.codedWidth!, init.codedHeight!);
-
 			this.format = init.format;
 			this.rotation = init.rotation ?? 0;
 			this.timestamp = init.timestamp!;
 			this.duration = init.duration ?? 0;

+			const layout = init.layout ?? createDefaultPlaneLayout(init.format, init.codedWidth!, init.codedHeight!);
+
 			let colorSpaceInit = init.colorSpace ?? null;
 			if (colorSpaceInit === null) {
 				if (
@@ -457,8 +454,6 @@ export class VideoSample implements Disposable {
 				}
 			}

-			this.colorSpace = new VideoSampleColorSpace(colorSpaceInit);
-
 			this.visibleRect = {
 				left: init.visibleRect?.left ?? 0,
 				top: init.visibleRect?.top ?? 0,
@@ -473,6 +468,48 @@ export class VideoSample implements Disposable {
 				this.squarePixelWidth = this.visibleRect.width;
 				this.squarePixelHeight = this.visibleRect.height;
 			}
+
+			// If VideoFrame is available, route through it directly instead of holding onto the buffer. Going
+			// buffer -> VideoSample -> VideoFrame would copy the data twice (once here, once in toVideoFrame);
+			// building the VideoFrame now means it's only ever copied once.
+			if (typeof VideoFrame !== 'undefined' && !init._doNotCopy) {
+				let videoFrame: VideoFrame | null = null;
+
+				try {
+					videoFrame = new VideoFrame(toUint8Array(data), {
+						format: init.format as VideoPixelFormat,
+						codedWidth: init.codedWidth!,
+						codedHeight: init.codedHeight!,
+						layout,
+						colorSpace: colorSpaceInit,
+						visibleRect: {
+							x: this.visibleRect.left,
+							y: this.visibleRect.top,
+							width: this.visibleRect.width,
+							height: this.visibleRect.height,
+						},
+						displayWidth: this.squarePixelWidth,
+						displayHeight: this.squarePixelHeight,
+						timestamp: Math.trunc(init.timestamp! * SECOND_TO_MICROSECOND_FACTOR),
+						// Drag 0 to undefined
+						duration: Math.trunc((init.duration ?? 0) * SECOND_TO_MICROSECOND_FACTOR) || undefined,
+					});
+				} catch {
+					// Ignore the error and move on like it didn't happen. We don't want errors caused by the local
+					// VideoFrame implementation to prevent us from creating the VideoSample. Errors, for example, could
+					// be caused by an unsupported pixel format.
+				}
+
+				if (videoFrame) {
+					return new VideoSample(videoFrame, init);
+				}
+			}
+
+			this._data = init._doNotCopy
+				? toUint8Array(data)
+				: toUint8Array(data).slice(); // Copy it
+			this._layout = layout;
+			this.colorSpace = new VideoSampleColorSpace(colorSpaceInit);
 		} else if (typeof VideoFrame !== 'undefined' && data instanceof VideoFrame) {
 			if (init?.rotation !== undefined && ![0, 90, 180, 270].includes(init.rotation)) {
 				throw new TypeError('init.rotation, when provided, must be 0, 90, 180, or 270.');
@@ -1036,6 +1073,7 @@ export class VideoSample implements Disposable {
 				timestamp: this.microsecondTimestamp,
 				duration: this.microsecondDuration,
 				colorSpace: this.colorSpace,
+				visibleRect: this.visibleRect,
 				displayWidth: this.squarePixelWidth, // Not display* since we're not passing rotation
 				displayHeight: this.squarePixelHeight,
 			});
@@ -1045,13 +1083,17 @@ export class VideoSample implements Disposable {
 				duration: this.microsecondDuration || undefined, // Drag 0 duration to undefined, glitches some codecs
 			});
 		} else if (this._data instanceof Uint8Array) {
+			assert(this._layout);
+
 			return new VideoFrame(this._data, {
 				format: this.format! as VideoPixelFormat,
-				codedWidth: this.codedWidth,
-				codedHeight: this.codedHeight,
+				codedWidth: this.codedWidth, // This is technically wrong! codedWidth is a lie technically. But, since
+				codedHeight: this.codedHeight, // we pass the layout (which contains the true coded width), we're good.
+				layout: this._layout,
 				timestamp: this.microsecondTimestamp,
 				duration: this.microsecondDuration || undefined,
 				colorSpace: this.colorSpace,
+				visibleRect: this.visibleRect,
 				displayWidth: this.squarePixelWidth, // Not display* since we're not passing rotation
 				displayHeight: this.squarePixelHeight,
 			});
@@ -1,4 +1,5 @@
 import { expect, test } from 'vitest';
+import { registerProresDecoder } from '@mediabunny/prores';
 import { Input } from '../../src/input.js';
 import { BufferSource, UrlSource } from '../../src/source.js';
 import { ALL_FORMATS } from '../../src/input-format.js';
@@ -7,28 +8,29 @@ import { MkvOutputFormat, MovOutputFormat } from '../../src/output-format.js';
 import { BufferTarget } from '../../src/target.js';
 import { Conversion } from '../../src/conversion.js';
 import { VideoSampleSink } from '../../src/media-sink.js';
-import { CustomVideoDecoder, registerDecoder } from '../../src/custom-coder.js';
-import { ProResDecoder } from '../../packages/prores-decoder/src/index.js';
+import { assert } from '../../src/misc.js';
+
+const SAMPLE_URL = 'https://pub-1ee78aacb848486482b20a72b55b3121.r2.dev/turbores-sample.mov';

 test.concurrent('ProRes MOV file reading', async () => {
 	using input = new Input({
-		source: new UrlSource('https://pub-cf9fcfcb5c0a44e9b1bb5ff890e041ae.r2.dev/IMG_0158-prores-log.MOV'),
+		source: new UrlSource(SAMPLE_URL),
 		formats: ALL_FORMATS,
 	});

 	const videoTrack = (await input.getPrimaryVideoTrack())!;
-	expect(videoTrack.codec).toBe('prores');
-	expect(videoTrack.codedWidth).toBe(1920);
-	expect(videoTrack.codedHeight).toBe(1080);
+	expect(await videoTrack.getCodec()).toBe('prores');
+	expect(await videoTrack.getCodedWidth()).toBe(1920);
+	expect(await videoTrack.getCodedHeight()).toBe(1080);

 	const decoderConfig = (await videoTrack.getDecoderConfig())!;
 	expect(decoderConfig.codec).toBe('apch');
 	expect(decoderConfig.description).toBeUndefined();
 });

-test.concurrent('ProRes transmuxing into MOV', { timeout: 60_000 }, async () => {
+test.concurrent('ProRes transmuxing into MOV', { timeout: 10_000 }, async () => {
 	using input = new Input({
-		source: new UrlSource('https://pub-cf9fcfcb5c0a44e9b1bb5ff890e041ae.r2.dev/IMG_0158-prores-log.MOV'),
+		source: new UrlSource(SAMPLE_URL),
 		formats: ALL_FORMATS,
 	});

@@ -55,7 +57,7 @@ test.concurrent('ProRes transmuxing into MOV', { timeout: 60_000 }, async () =>
 	});

 	const videoTrack = (await newInput.getPrimaryVideoTrack())!;
-	expect(videoTrack.codec).toBe('prores');
+	expect(await videoTrack.getCodec()).toBe('prores');
 	expect((await videoTrack.computePacketStats()).packetCount).toBe(15);

 	const decoderConfig = (await videoTrack.getDecoderConfig())!;
@@ -63,9 +65,9 @@ test.concurrent('ProRes transmuxing into MOV', { timeout: 60_000 }, async () =>
 	expect(decoderConfig.description).toBeUndefined();
 });

-test.concurrent('ProRes transmuxing into MKV', { timeout: 60_000 }, async () => {
+test.concurrent('ProRes transmuxing into MKV', { timeout: 10_000 }, async () => {
 	using input = new Input({
-		source: new UrlSource('https://pub-cf9fcfcb5c0a44e9b1bb5ff890e041ae.r2.dev/IMG_0158-prores-log.MOV'),
+		source: new UrlSource(SAMPLE_URL),
 		formats: ALL_FORMATS,
 	});

@@ -77,9 +79,6 @@ test.concurrent('ProRes transmuxing into MKV', { timeout: 60_000 }, async () =>
 	const conversion = await Conversion.init({
 		input,
 		output,
-		video: {
-			rotate: 270, // To undo the source rotation metadata so the copy path is taken
-		},
 		audio: {
 			discard: true,
 		},
@@ -95,7 +94,7 @@ test.concurrent('ProRes transmuxing into MKV', { timeout: 60_000 }, async () =>
 	});

 	const videoTrack = (await newInput.getPrimaryVideoTrack())!;
-	expect(videoTrack.codec).toBe('prores');
+	expect(await videoTrack.getCodec()).toBe('prores');
 	expect((await videoTrack.computePacketStats()).packetCount).toBe(15);

 	const decoderConfig = (await videoTrack.getDecoderConfig())!;
@@ -103,17 +102,51 @@ test.concurrent('ProRes transmuxing into MKV', { timeout: 60_000 }, async () =>
 	expect(decoderConfig.description).toBeUndefined();
 });

-test.concurrent.only('ProRes sample ahh', async () => {
-	registerDecoder(ProResDecoder);
-
+test('Custom coder registration', { timeout: 10_000 }, async () => {
 	using input = new Input({
-		source: new UrlSource('https://pub-cf9fcfcb5c0a44e9b1bb5ff890e041ae.r2.dev/IMG_0158-prores-log.MOV'),
+		source: new UrlSource(SAMPLE_URL),
 		formats: ALL_FORMATS,
 	});

 	const videoTrack = (await input.getPrimaryVideoTrack())!;
-	const sink = new VideoSampleSink(videoTrack);
-	const sample = await sink.getSample(0);
+	expect(await videoTrack.getCodec()).toBe('prores');

-	console.log(sample);
+	// Without a registered decoder, there's no way to decode ProRes in this environment
+	expect(await videoTrack.canDecode()).toBe(false);
+
+	registerProresDecoder();
+
+	expect(await videoTrack.canDecode()).toBe(true);
+});
+
+test('ProRes decoding', { timeout: 10_000 }, async () => {
+	registerProresDecoder();
+
+	using input = new Input({
+		source: new UrlSource(SAMPLE_URL),
+		formats: ALL_FORMATS,
+	});
+
+	const videoTrack = (await input.getPrimaryVideoTrack())!;
+	const firstTimestamp = await videoTrack.getFirstTimestamp();
+
+	const sink = new VideoSampleSink(videoTrack);
+	using sample = await sink.getSample(firstTimestamp);
+	assert(sample);
+
+	expect(sample.timestamp).toBe(firstTimestamp);
+	expect(sample.duration).toBeGreaterThan(0);
+
+	expect(sample.displayWidth).toBe(await videoTrack.getDisplayWidth());
+	expect(sample.displayHeight).toBe(await videoTrack.getDisplayHeight());
+	expect(sample.codedWidth).toBe(1920);
+	expect(sample.codedHeight).toBe(1080); // Technically a lie but the field is ill-defined
+	expect(sample.format).toBe('I422P10');
+
+	const allocationSize = sample.allocationSize();
+	expect(allocationSize).toBeGreaterThan(0);
+
+	const pixels = new Uint8Array(allocationSize);
+	await sample.copyTo(pixels);
+	expect(pixels.some(byte => byte !== 0)).toBe(true);
 });
@@ -1,2 +0,0 @@
- different codec strings
- separate out prores and prores raw (?) ffmpeg does this, so probably good reasons. Matroska does not.
@@ -10,6 +10,7 @@
 			"@mediabunny/ac3": ["./packages/ac3/src/index.ts"],
 			"@mediabunny/aac-encoder": ["./packages/aac-encoder/src/index.ts"],
 			"@mediabunny/flac-encoder": ["./packages/flac-encoder/src/index.ts"],
+			"@mediabunny/prores": ["./packages/prores/src/index.ts"],
 		},
 		"types": ["vite/client"]
 	},
@@ -11,6 +11,7 @@
 			"@mediabunny/aac-encoder": ["./packages/aac-encoder/src/index.ts"],
 			"@mediabunny/flac-encoder": ["./packages/flac-encoder/src/index.ts"],
 			"@mediabunny/mp3-encoder": ["./packages/mp3-encoder/src/index.ts"],
+			"@mediabunny/prores": ["./packages/prores/src/index.ts"],
 			"@mediabunny/server": ["./packages/server/src/index.ts"],
 		},
 	},
@@ -22,6 +23,7 @@
 		{ "path": "./packages/aac-encoder" },
 		{ "path": "./packages/flac-encoder" },
 		{ "path": "./packages/mp3-encoder" },
+		{ "path": "./packages/prores" },
 		{ "path": "./packages/server" },
 	]
 }
@@ -25,6 +25,8 @@ export default defineConfig({
 				path.resolve(__dirname, './packages/aac-encoder/dist/bundles/mediabunny-aac-encoder.mjs'),
 			'@mediabunny/flac-encoder':
 				path.resolve(__dirname, './packages/flac-encoder/dist/bundles/mediabunny-flac-encoder.mjs'),
+			'@mediabunny/prores':
+				path.resolve(__dirname, './packages/prores/dist/bundles/mediabunny-prores.mjs'),
 		},
 	},
 	plugins: [
@@ -33,6 +35,10 @@ export default defineConfig({
 	server: {
 		hmr: false,
 		allowedHosts: true,
+		headers: {
+			'Cross-Origin-Opener-Policy': 'same-origin',
+			'Cross-Origin-Embedder-Policy': 'require-corp',
+		},
 	},
 	build: {
 		outDir: 'dist-docs', // Build them directly into the docs build folder
@@ -14,6 +14,8 @@ export default defineConfig({
 				path.resolve(__dirname, './packages/flac-encoder/dist/bundles/mediabunny-flac-encoder.mjs'),
 			'@mediabunny/mp3-encoder':
 				path.resolve(__dirname, './packages/mp3-encoder/dist/bundles/mediabunny-mp3-encoder.mjs'),
+			'@mediabunny/prores':
+				path.resolve(__dirname, './packages/prores/dist/bundles/mediabunny-prores.mjs'),
 			'@mediabunny/server':
 				path.resolve(__dirname, './packages/server/src/index.ts'),
 		},