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Handling user video uploads

In an app where users can upload videos and edit them, we can create a better user experience by loading the video into a player even before the upload is finished. Good news: This can be done pretty easily!

Allowing user uploads​

We have a component which returns a <Video> tag that includes an URL as source.

MyComposition.tsx
tsx
import { AbsoluteFill, Video } from "remotion";
 
type VideoProps = {
  videoURL: string;
};
 
export const MyComponent: React.FC<VideoProps> = ({ videoURL }) => {
  return (
    <AbsoluteFill>
      <Video src={videoURL} />
    </AbsoluteFill>
  );
};
MyComposition.tsx
tsx
import { AbsoluteFill, Video } from "remotion";
 
type VideoProps = {
  videoURL: string;
};
 
export const MyComponent: React.FC<VideoProps> = ({ videoURL }) => {
  return (
    <AbsoluteFill>
      <Video src={videoURL} />
    </AbsoluteFill>
  );
};

The video URL will be passed from the Remotion Player to our component.
Using a <input type="file"> element, we allow a user upload.
As soon as a file is fully uploaded to the cloud, the URL will be set and can be used by the component to display the video.

App.tsx
tsx
import { Player } from "@remotion/player";
import { useState } from "react";
 
export const RemotionPlayer: React.FC = () => {
  const [videoUrl, setVideoUrl] = useState<string | null>(null);
 
  const handleChange = useCallback(
    async (event: React.ChangeEvent<HTMLInputElement>) => {
      if (event.target.files === null) {
        return;
      }
 
      const file = event.target.files[0];
      //upload is an example function  & returns a URL when a file is uploaded on the cloud.
      const cloudURL = await upload(file);
      // E.g., cloudURL = https://exampleBucketName.s3.ExampleAwsRegion.amazonaws.com
      setVideoUrl(cloudURL);
    },
    []
  );
 
  return (
    <div>
      {videoUrl === null ? null : (
        <Player
          component={MyComposition}
          durationInFrames={120}
          compositionWidth={1920}
          compositionHeight={1080}
          fps={30}
          inputProps={{ videoUrl }}
        />
      )}
 
      <input type="file" onChange={handleChange} />
    </div>
  );
};
App.tsx
tsx
import { Player } from "@remotion/player";
import { useState } from "react";
 
export const RemotionPlayer: React.FC = () => {
  const [videoUrl, setVideoUrl] = useState<string | null>(null);
 
  const handleChange = useCallback(
    async (event: React.ChangeEvent<HTMLInputElement>) => {
      if (event.target.files === null) {
        return;
      }
 
      const file = event.target.files[0];
      //upload is an example function  & returns a URL when a file is uploaded on the cloud.
      const cloudURL = await upload(file);
      // E.g., cloudURL = https://exampleBucketName.s3.ExampleAwsRegion.amazonaws.com
      setVideoUrl(cloudURL);
    },
    []
  );
 
  return (
    <div>
      {videoUrl === null ? null : (
        <Player
          component={MyComposition}
          durationInFrames={120}
          compositionWidth={1920}
          compositionHeight={1080}
          fps={30}
          inputProps={{ videoUrl }}
        />
      )}
 
      <input type="file" onChange={handleChange} />
    </div>
  );
};

The implementation of the upload() function is provider-specific and we do not show an implementation in this article. We assume it is a function that takes a file, uploads it and returns an URL.

Optimistic updates​

When we start the upload of the file, we can create a blob URL using URL.createObjectURL() which can be used to display the local file in a <Video> tag. When the file is done uploading and we get the remote URL, the component shall use remote URL as source.

App.tsx
tsx
import { Player } from "@remotion/player";
import { useCallback, useState } from "react";
 
type VideoState =
  | {
      type: "empty";
    }
  | {
      type: "blob" | "cloud";
      url: string;
    };
 
export const RemotionPlayer: React.FC = () => {
  const [videoState, setVideoState] = useState<VideoState>({
    type: "empty",
  });
 
  const handleChange = useCallback(
    async (event: React.ChangeEvent<HTMLInputElement>) => {
      if (event.target.files === null) {
        return;
      }
 
      const file = event.target.files[0];
      const blobUrl = URL.createObjectURL(file);
      setVideoState({ type: "blob", url: blobUrl });
      const cloudUrl = await upload(file);
      setVideoState({ type: "cloud", url: cloudUrl });
      URL.revokeObjectURL(blobUrl);
    },
    []
  );
 
  return (
    <div>
      {videoState.type !== "empty" ? (
        <Player
          component={MyComposition}
          durationInFrames={120}
          compositionWidth={1920}
          compositionHeight={1080}
          fps={30}
          inputProps={{ videoUrl: videoState.url }}
        />
      ) : null}
      <input type="file" onChange={handleChange} />
    </div>
  );
};
App.tsx
tsx
import { Player } from "@remotion/player";
import { useCallback, useState } from "react";
 
type VideoState =
  | {
      type: "empty";
    }
  | {
      type: "blob" | "cloud";
      url: string;
    };
 
export const RemotionPlayer: React.FC = () => {
  const [videoState, setVideoState] = useState<VideoState>({
    type: "empty",
  });
 
  const handleChange = useCallback(
    async (event: React.ChangeEvent<HTMLInputElement>) => {
      if (event.target.files === null) {
        return;
      }
 
      const file = event.target.files[0];
      const blobUrl = URL.createObjectURL(file);
      setVideoState({ type: "blob", url: blobUrl });
      const cloudUrl = await upload(file);
      setVideoState({ type: "cloud", url: cloudUrl });
      URL.revokeObjectURL(blobUrl);
    },
    []
  );
 
  return (
    <div>
      {videoState.type !== "empty" ? (
        <Player
          component={MyComposition}
          durationInFrames={120}
          compositionWidth={1920}
          compositionHeight={1080}
          fps={30}
          inputProps={{ videoUrl: videoState.url }}
        />
      ) : null}
      <input type="file" onChange={handleChange} />
    </div>
  );
};

This will result in the user immediately seeing the video as they drag it into the input field. It is a good practice to call URL.revokeObjectURL() after the local video is not used anymore to free up the used memory.

See also​