From b41624edea14840f80a3e926e7cacb29c00837db Mon Sep 17 00:00:00 2001
From: Samuel Newman <mozzius@protonmail.com>
Date: Wed, 8 Jul 2026 16:21:16 +0300
Subject: [PATCH] Lazy-load mediabunny on web (#11094)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
---
 src/lib/media/video/compress.web.ts          | 28 ++++++++++++--------
 src/lib/media/video/mediabunny.ts            | 20 ++++++++++++++
 src/view/com/composer/videos/metadata.web.ts |  3 ++-
 3 files changed, 39 insertions(+), 12 deletions(-)
 create mode 100644 src/lib/media/video/mediabunny.ts

diff --git a/src/lib/media/video/compress.web.ts b/src/lib/media/video/compress.web.ts
index 7f96141b74..46fff5b058 100644
--- a/src/lib/media/video/compress.web.ts
+++ b/src/lib/media/video/compress.web.ts
@@ -1,17 +1,8 @@
 import {type ImagePickerAsset} from 'expo-image-picker'
 import {
-  ALL_FORMATS,
   type AudioCodec,
-  BlobSource,
-  BufferTarget,
-  canEncodeAudio,
-  canEncodeVideo,
-  Conversion,
-  Input,
-  Mp4OutputFormat,
-  Output,
+  type Input as MediaBunnyInput,
   type VideoCodec,
-  WebMOutputFormat,
 } from 'mediabunny'
 
 import {VIDEO_MAX_SIZE} from '#/lib/constants'
@@ -23,6 +14,7 @@ import {
   COMPRESSION_MIN_SIZE_BYTES,
   COMPRESSION_TARGET_BITRATE,
 } from './constants'
+import {loadMediaBunny} from './mediabunny'
 import {type CompressedVideo, type ProbedMetadata} from './types'
 
 // Codecs to try in order of preference
@@ -112,6 +104,7 @@ export async function compressVideo(
 }
 
 async function probeWithMediaBunny(blob: Blob): Promise<ProbedMetadata> {
+  const {ALL_FORMATS, BlobSource, Input} = await loadMediaBunny()
   const input = new Input({source: new BlobSource(blob), formats: ALL_FORMATS})
   try {
     const videoTrack = await input.getPrimaryVideoTrack()
@@ -153,6 +146,7 @@ async function findEncodableVideoCodec(
   width: number,
   height: number,
 ): Promise<{codec: VideoCodec; useWebM: boolean} | null> {
+  const {canEncodeVideo} = await loadMediaBunny()
   for (const codec of VIDEO_CODECS) {
     const canEncode = await canEncodeVideo(codec, {
       width,
@@ -179,9 +173,10 @@ const AUDIO_CODECS_MP4: AudioCodec[] = ['aac']
 const AUDIO_CODECS_WEBM: AudioCodec[] = ['opus', 'vorbis']
 
 async function findEncodableAudioCodec(
-  audioTrack: Awaited<ReturnType<Input['getPrimaryAudioTrack']>>,
+  audioTrack: Awaited<ReturnType<MediaBunnyInput['getPrimaryAudioTrack']>>,
   useWebM: boolean,
 ): Promise<{codec: AudioCodec} | null> {
+  const {canEncodeAudio} = await loadMediaBunny()
   if (!audioTrack) {
     return null
   }
@@ -228,6 +223,17 @@ async function doCompression(
 ): Promise<CompressedVideo> {
   const {onProgress, signal} = opts
 
+  const {
+    ALL_FORMATS,
+    BlobSource,
+    BufferTarget,
+    Conversion,
+    Input,
+    Mp4OutputFormat,
+    Output,
+    WebMOutputFormat,
+  } = await loadMediaBunny()
+
   const input = new Input({
     source: new BlobSource(blob),
     formats: ALL_FORMATS,
diff --git a/src/lib/media/video/mediabunny.ts b/src/lib/media/video/mediabunny.ts
new file mode 100644
index 0000000000..edcbc805c1
--- /dev/null
+++ b/src/lib/media/video/mediabunny.ts
@@ -0,0 +1,20 @@
+type MediaBunnyModule = typeof import('mediabunny')
+
+let promise: Promise<MediaBunnyModule> | undefined
+
+/**
+ * Lazily loads mediabunny into its own webpack chunk and caches the resulting
+ * promise so the module is fetched at most once. If the import fails (e.g. a
+ * transient chunk-load error), the cached promise is reset so a later call can
+ * retry the load.
+ */
+export function loadMediaBunny(): Promise<MediaBunnyModule> {
+  promise ??= import(/* webpackChunkName: "mediabunny" */ 'mediabunny').catch(
+    e => {
+      // reset so a later attempt can retry after a transient chunk-load failure
+      promise = undefined
+      throw e
+    },
+  )
+  return promise
+}
diff --git a/src/view/com/composer/videos/metadata.web.ts b/src/view/com/composer/videos/metadata.web.ts
index 62383bce7b..920dcdb6af 100644
--- a/src/view/com/composer/videos/metadata.web.ts
+++ b/src/view/com/composer/videos/metadata.web.ts
@@ -1,6 +1,6 @@
 import {type ImagePickerAsset} from 'expo-image-picker'
-import {ALL_FORMATS, BlobSource, Input} from 'mediabunny'
 
+import {loadMediaBunny} from '#/lib/media/video/mediabunny'
 import {logger} from '#/logger'
 
 export function hasWebCodecs(): boolean {
@@ -55,6 +55,7 @@ async function getMetadataWithWebCodecs(
   file: File,
   blobUrl: string,
 ): Promise<ImagePickerAsset> {
+  const {ALL_FORMATS, BlobSource, Input} = await loadMediaBunny()
   const input = new Input({
     source: new BlobSource(file),
     formats: ALL_FORMATS,