give guidance for huge defaultProps payloads

packages/bundler/src/renderEntry.tsx

@@ -12,6 +12,20 @@ import {Homepage} from './homepage/homepage';
 
 Internals.CSSUtils.injectCSS(Internals.CSSUtils.makeDefaultCSS(null, '#fff'));
 
+const getCanSerializeDefaultProps = (object: unknown) => {
+	try {
+		const str = JSON.stringify(object);
+		// 256MB is the theoretical limit, making it throw if over 90% of that is reached.
+		return str.length < 256 * 1024 * 1024 * 0.9;
+	} catch (err) {
+		if ((err as Error).message.includes('Invalid string length')) {
+			return false;
+		}
+
+		throw err;
+	}
+};
+
 const GetVideo: React.FC<{state: BundleState}> = ({state}) => {
 	const video = Internals.useVideo();
 	const compositions = useContext(Internals.CompositionManager);
@@ -215,18 +229,40 @@ if (typeof window !== 'undefined') {
 			throw new Error('Unexpectedly did not have a CompositionManager');
 		}
 
-		return Internals.compositionsRef.current
-			.getCompositions()
-			.map((c): TCompMetadata => {
-				return {
-					defaultProps: c.defaultProps,
-					durationInFrames: c.durationInFrames,
-					fps: c.fps,
-					height: c.height,
-					id: c.id,
-					width: c.width,
-				};
-			});
+		const compositions = Internals.compositionsRef.current.getCompositions();
+
+		const canSerializeDefaultProps = getCanSerializeDefaultProps(compositions);
+		if (!canSerializeDefaultProps) {
+			console.warn(
+				'defaultProps are too big to serialize - trying to find the problematic composition...'
+			);
+			for (const comp of compositions) {
+				if (!getCanSerializeDefaultProps(comp)) {
+					throw new Error(
+						`defaultProps too big - could not serialize - the defaultProps of composition with ID ${comp.id} - the object that was passed to defaultProps was too big. Learn how to mitigate this error by visiting https://remotion.dev/docs/troubleshooting/serialize-defaultprops`
+					);
+				}
+			}
+
+			console.warn(
+				'Could not single out a problematic composition -  The composition list as a whole is too big to serialize.'
+			);
+
+			throw new Error(
+				'defaultProps too big - Could not serialize - an object that was passed to defaultProps was too big. Learn how to mitigate this error by visiting https://remotion.dev/docs/troubleshooting/serialize-defaultprops'
+			);
+		}
+
+		return compositions.map((c): TCompMetadata => {
+			return {
+				defaultProps: c.defaultProps,
+				durationInFrames: c.durationInFrames,
+				fps: c.fps,
+				height: c.height,
+				id: c.id,
+				width: c.width,
+			};
+		});
 	};
 
 	window.siteVersion = '4';

packages/docs/docs/composition.md

@@ -7,34 +7,79 @@ This is the component to use to register a video to make it renderable and make
 
 A composition represents the video you want to create, as a collection of clips (for example, several `<Sequence>`) that will play back to back to form your video.
 
+```tsx twoslash title="src/Video.tsx"
+const Component: React.FC = () => null;
+// ---cut---
+
+import { Composition } from "remotion";
+
+export const RemotionRoot: React.FC = () => {
+  return (
+    <>
+      <Composition
+        component={Component}
+        durationInFrames={300}
+        width={1080}
+        height={1080}
+        fps={30}
+        id="test-render"
+        defaultProps={{}}
+      />
+      {/* Additional compositions can be rendered */}
+    </>
+  );
+};
+```
+
 ## API
 
 A `<Composition />` should be placed within a fragment of the root component (which is registered using [`registerRoot()`](/docs/register-root)).
 
 The component takes the following props:
 
-- `id`: ID of the composition, as shown in the sidebar and also a unique identifier of the composition that you need to specify if you want to render it. The ID can only contain letters, numbers and `-`.
+### `id`
+
+ID of the composition, as shown in the sidebar and also a unique identifier of the composition that you need to specify if you want to render it. The ID can only contain letters, numbers and `-`.
+
+### `fps`
+
+At how many frames the composition should be rendered.
+
+### `durationInFrames`
+
+How many frames the composition should be long.
 
-- `fps`: At how many frames the composition should be rendered.
+### `height`
 
-- `durationInFrames`: How many frames the composition should be long.
+Height of the composition in pixels.
 
-- `height`: Height of the composition in pixels.
+### `width`
 
-- `width`: Width of the composition in pixels.
+Width of the composition in pixels.
 
-- `component` **or** `lazyComponent`: Pass the component in directly **or** pass a function that returns a dynamic import. Passing neither or both of the props is an error.
+### `component` **or** `lazyComponent`
+
+Pass the component in directly **or** pass a function that returns a dynamic import. Passing neither or both of the props is an error.
 
 :::note
 If you use `lazyComponent`, Remotion will use React Suspense to load the component. Components will be compiled by Webpack as they are needed, which will reduce startup time of Remotion. If you use `lazyComponent`, you need to use a default export for your component. This is a restriction of React Suspense.
 :::
 
-- `defaultProps` _optional_: Give your component default props that will be shown in the preview. You can override these props during render using a CLI flag.
+### `defaultProps`
+
+_optional_
+
+Give your component default props that will be shown in the preview. You can override these props during render using a CLI flag.
 
 :::note
 Type your components using the `React.FC<{}>` type and the `defaultProps` prop will be typesafe.
 :::
 
+:::note
+Passing huge objects to `defaultProps` can be slow. [Learn how to avoid it.](/docs/troubleshooting/defaultprops-too-big)
+
+:::
+
 ## Example using `component`
 
 ```tsx twoslash
@@ -127,3 +172,4 @@ export const Video = () => {
 - [`<Sequence />`](/docs/sequence)
 - [`<Still />`](/docs/still)
 - [`<Folder />`](/docs/folder)
+- [Avoid huge payloads for `defaultProps`](/docs/troubleshooting/defaultprops-too-big)

packages/docs/docs/parametrized-rendering.md

@@ -154,3 +154,7 @@ you can still use it as normal in your videos and pass it's props directly. Defa
 // ---cut---
 <MyComponent propOne="hi" propTwo={10} />
 ```
+
+## See also
+
+- [Avoid huge payloads for `defaultProps`](/docs/troubleshooting/defaultprops-too-big)

packages/docs/docs/troubleshooting/defaultprops-too-big.md

@@ -0,0 +1,127 @@
+---
+id: defaultprops-too-big
+sidebar_label: defaultProps too big
+title: defaultProps too big - could not serialize
+---
+
+If you experience an error during rendering:
+
+```
+defaultProps too big - could not serialize - the defaultProps of composition with ID "[composition-id]" - the object that was passed to defaultProps was too big. Learn how to mitigate this error by visiting https://remotion.dev/docs/troubleshooting/serialize-defaultprops
+```
+
+It means the object that was passed to [`defaultProps`](/docs/composition#defaultprops) for the specified composition is too big that Chrome cannot serialize it into a string.
+
+If you see this variant of the error:
+
+```
+defaultProps too big - Could not serialize - an object that was passed to defaultProps was too big. Learn how to mitigate this error by visiting https://remotion.dev/docs/troubleshooting/serialize-defaultprops
+```
+
+The [`defaultProps`](/docs/composition#defaultprops) is not too big, but the list of compositions as a whole is too big to serialize.
+
+## Why this error occurs
+
+Remotion is trying to gather a list of compositions using [`getCompositions()`](/docs/renderer/get-compositions), and is copying them from the headless browser into Node.JS. During this operation, the JavaScript object needs to be converted into a string. The upper limit for this is 256MB, however dependending on the machine Remotion runs on, the error may also occur on smaller payloads.
+
+## How to fix the error
+
+Avoid passing huge data payloads to `defaultProps`. Instead, derive the big data payload inside the component based on slim `defaultProps`. For example:
+
+- Instead of passing a data URL or Buffer that represents an asset, pass a URL to the asset and fetch the asset from inside the composition
+- Don't fetch an audio visualization using [`getAudioData()`](/docs/get-audio-data) and pass it as default props - instead, pass the URL of the audio asset and fetch the audio visualization inside the component.
+
+Example:
+
+```tsx twoslash title="❌ Avoid - big data chunk as defaultProps"
+import { AudioData, getAudioData } from "@remotion/media-utils";
+import { useEffect, useState } from "react";
+import { Composition, continueRender, delayRender, staticFile } from "remotion";
+
+// MyComp.tsx
+const MyComp: React.FC<{
+  audioData: AudioData | null;
+}> = ({ audioData }) => {
+  return null;
+};
+
+// src/Video.tsx
+const RemotionRoot = () => {
+  const [audioData, setAudioData] = useState<AudioData | null>(null);
+  const [handle] = useState(() => delayRender());
+
+  useEffect(() => {
+    getAudioData(staticFile("audio.mp3"))
+      .then((data) => {
+        setAudioData(data);
+        continueRender(handle);
+      })
+      .catch((e) => {
+        console.log(e);
+      });
+  }, [handle]);
+
+  return (
+    <Composition
+      id="my-comp"
+      durationInFrames={90}
+      width={1080}
+      height={1080}
+      fps={1080}
+      component={MyComp}
+      defaultProps={{
+        audioData,
+      }}
+    />
+  );
+};
+```
+
+This can lead to problems because the `audioData` variable can become very big since it contains raw data about the waveform, and Remotion needs to serialize this data into a string, which is slow and can lead to this error. Instead, pass the audio URL and do the audio data fetching inside the component:
+
+```tsx twoslash title="✅ Do - Fetch data inside composition"
+import { getAudioData } from "@remotion/media-utils";
+import { useEffect, useState } from "react";
+import { Composition, continueRender, delayRender, staticFile } from "remotion";
+
+// MyComp.tsx
+const MyComp: React.FC<{ src: string }> = ({ src }) => {
+  const [audioData, setAudioData] = useState<any>(undefined);
+  const [handle] = useState(() => delayRender());
+
+  useEffect(() => {
+    getAudioData(src)
+      .then((data) => {
+        setAudioData(data);
+        continueRender(handle);
+      })
+      .catch((e) => {
+        console.log(e);
+      });
+  }, [handle]);
+
+  return null;
+};
+
+// src/Video.tsx
+const RemotionRoot = () => {
+  return (
+    <Composition
+      id="my-comp"
+      durationInFrames={90}
+      width={1080}
+      height={1080}
+      fps={1080}
+      component={MyComp}
+      defaultProps={{
+        src: staticFile("audio.mp3"),
+      }}
+    />
+  );
+};
+```
+
+## See also
+
+- [Parametrized rendering](/docs/parametrized-rendering)
+- [`<Composition>`](/docs/composition)

packages/docs/docs/troubleshooting/rosetta.md

@@ -1,6 +1,6 @@
 ---
 id: rosetta
-sidebar_label: Rosetta
+sidebar_label: Apple Silicon detected
 title: Apple Silicon under Rosetta
 ---
 

packages/docs/sidebars.js

@@ -347,7 +347,8 @@ module.exports = {
         "wrong-composition-mount",
         "staticfile-relative-paths",
         "staticfile-remote-urls",
-        "troubleshooting/rosetta"
+        "troubleshooting/rosetta",
+        "troubleshooting/defaultprops-too-big",
       ],
     },