Skip to main content

How do I make the composition the same duration as my video?

If you have a component rendering a video:

MyComp.tsx
tsx
import React from 'react';
import {OffthreadVideo, staticFile} from 'remotion';
 
export const MyComp: React.FC = () => {
  return <OffthreadVideo src={staticFile('video.mp4')} />;
};
MyComp.tsx
tsx
import React from 'react';
import {OffthreadVideo, staticFile} from 'remotion';
 
export const MyComp: React.FC = () => {
  return <OffthreadVideo src={staticFile('video.mp4')} />;
};

and you want to make the composition the same duration as the video, first make the video source a React prop:

MyComp.tsx
tsx
import React from 'react';
import {OffthreadVideo, staticFile} from 'remotion';
 
type MyCompProps = {
  src: string;
};
 
export const MyComp: React.FC<MyCompProps> = ({src}) => {
  return <OffthreadVideo src={src} />;
};
MyComp.tsx
tsx
import React from 'react';
import {OffthreadVideo, staticFile} from 'remotion';
 
type MyCompProps = {
  src: string;
};
 
export const MyComp: React.FC<MyCompProps> = ({src}) => {
  return <OffthreadVideo src={src} />;
};

Then, define a calculateMetadata() function that calculates the duration of the composition based on the video.
Install @remotion/media-utils if necessary.

MyComp.tsx
tsx
import {CalculateMetadataFunction} from 'remotion';
import {getVideoMetadata} from '@remotion/media-utils';
 
export const calculateMetadata: CalculateMetadataFunction<
  MyCompProps
> = async ({props}) => {
  const data = await getVideoMetadata(props.src);
  const fps = 30;
 
  return {
    durationInFrames: Math.floor(data.durationInSeconds * fps),
    fps,
  };
};
MyComp.tsx
tsx
import {CalculateMetadataFunction} from 'remotion';
import {getVideoMetadata} from '@remotion/media-utils';
 
export const calculateMetadata: CalculateMetadataFunction<
  MyCompProps
> = async ({props}) => {
  const data = await getVideoMetadata(props.src);
  const fps = 30;
 
  return {
    durationInFrames: Math.floor(data.durationInSeconds * fps),
    fps,
  };
};

Finally, pass the calculateMetadata function to the Composition component and define the previously hardcoded src as a default prop:

Root.tsx
tsx
import React from 'react';
import {Composition} from 'remotion';
import {MyComp, calculateMetadata} from './MyComp';
 
export const Root: React.FC = () => {
  return (
    <Composition
      id="MyComp"
      component={MyComp}
      durationInFrames={300}
      fps={30}
      width={1920}
      height={1080}
      defaultProps={{
        src: 'https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4',
      }}
      calculateMetadata={calculateMetadata}
    />
  );
};
Root.tsx
tsx
import React from 'react';
import {Composition} from 'remotion';
import {MyComp, calculateMetadata} from './MyComp';
 
export const Root: React.FC = () => {
  return (
    <Composition
      id="MyComp"
      component={MyComp}
      durationInFrames={300}
      fps={30}
      width={1920}
      height={1080}
      defaultProps={{
        src: 'https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4',
      }}
      calculateMetadata={calculateMetadata}
    />
  );
};

How do I make the composition the same duration as my audio?​

Follow the same steps, but instead if getVideoMetadata(), use getAudioDurationInSeconds() from @remotion/media-utils to calculate the duration of the composition based on the audio file.

See Also​