Remotion Rule: Compositions

Rule Content

A <Composition> defines the component, width, height, fps and duration of a renderable video.

It normally is placed in the src/Root.tsx file.

import { Composition } from "remotion";
import { MyComposition } from "./MyComposition";

export const RemotionRoot = () => {
  return (
    <Composition
      id="MyComposition"
      component={MyComposition}
      durationInFrames={100}
      fps={30}
      width={1080}
      height={1080}
    />
  );
};

Default Props

Pass defaultProps to provide initial values for your component.
Values must be JSON-serializable (Date, Map, Set, and staticFile() are supported).

import { Composition } from "remotion";
import { MyComposition, MyCompositionProps } from "./MyComposition";

export const RemotionRoot = () => {
  return (
    <Composition
      id="MyComposition"
      component={MyComposition}
      durationInFrames={100}
      fps={30}
      width={1080}
      height={1080}
      defaultProps={
        {
          title: "Hello World",
          color: "#ff0000",
        } satisfies MyCompositionProps
      }
    />
  );
};

Use type declarations for props rather than interface to ensure defaultProps type safety.

Folders

Use <Folder> to organize compositions in the sidebar.
Folder names can only contain letters, numbers, and hyphens.

import { Composition, Folder } from "remotion";

export const RemotionRoot = () => {
  return (
    <>
      <Folder name="Marketing">
        <Composition id="Promo" /* ... */ />
        <Composition id="Ad" /* ... */ />
      </Folder>
      <Folder name="Social">
        <Folder name="Instagram">
          <Composition id="Story" /* ... */ />
          <Composition id="Reel" /* ... */ />
        </Folder>
      </Folder>
    </>
  );
};

Stills

Use <Still> for single-frame images. It does not require durationInFrames or fps.

import { Still } from "remotion";
import { Thumbnail } from "./Thumbnail";

export const RemotionRoot = () => {
  return (
    <Still id="Thumbnail" component={Thumbnail} width={1280} height={720} />
  );
};

Calculate Metadata

Use calculateMetadata to make dimensions, duration, or props dynamic based on data.

import { Composition, CalculateMetadataFunction } from "remotion";
import { MyComposition, MyCompositionProps } from "./MyComposition";

const calculateMetadata: CalculateMetadataFunction<
  MyCompositionProps
> = async ({ props, abortSignal }) => {
  const data = await fetch(`https://api.example.com/video/${props.videoId}`, {
    signal: abortSignal,
  }).then((res) => res.json());

  return {
    durationInFrames: Math.ceil(data.duration * 30),
    props: {
      ...props,
      videoUrl: data.url,
    },
  };
};

export const RemotionRoot = () => {
  return (
    <Composition
      id="MyComposition"
      component={MyComposition}
      durationInFrames={100} // Placeholder, will be overridden
      fps={30}
      width={1080}
      height={1080}
      defaultProps={{ videoId: "abc123" }}
      calculateMetadata={calculateMetadata}
    />
  );
};

The function can return props, durationInFrames, width, height, fps, and codec-related defaults. It runs once before rendering begins.

Nesting compositions within another

To add a composition within another composition, you can use the <Sequence> component with a width and height prop to specify the size of the composition.

<AbsoluteFill>
  <Sequence width={COMPOSITION_WIDTH} height={COMPOSITION_HEIGHT}>
    <CompositionComponent />
  </Sequence>
</AbsoluteFill>