Can you call out to FFMPEG in a Firebase Cloud Function

Question

Per the Firebase Cloud Functions documentation, you can leverage ImageMagick from within a cloud function: https://firebase.google.com/docs/functions/use-cases

Is it possible do something similar but call out to FFMPEG instead of ImageMagick? While thumbnailing images is great, I'd also like the capability to append incoming images to a video file stored out on Firebase Storage.

Answer 1

Update: ffmpeg is now preinstalled in the Cloud Functions environment. For a complete list of preinstalled packages, check out https://cloud.google.com/functions/docs/reference/system-packages.

Note As of April 2023, google does not offer ffmpeg as a pre-installed package for cloud functions with the latest version of Ubuntu (v22.04). So make sure you pick a runtime environment that uses Ubuntu (v18.04) in order to have ffmpeg pre-installed on your cloud function. You can find a complete list of runtime environments that use Ubuntu (v18.04) available here.

Note: you only have disk write access at /tmp/.

Option 1: use ffmpeg-fluent npm module

This module abstracts the ffmpeg command line options with an easy to use Node.js module.

const ffmpeg = require('fluent-ffmpeg');

let cmd = ffmpeg('example.mp4')
    .clone()
    .size('300x300')
    .save('/tmp/smaller-file.mp4')
    .on('end', () => {
      // Finished processing the video.
      console.log('Done');

      // E.g. return the resized video:
      res.sendFile('/tmp/smaller-file.mp4');
    });

Full code on GitHub

Option 2: invoke the ffmpeg binary directly

Because ffmpeg is already installed, you can invoke the binary and its command line options via a shell process.

const { exec } = require("child_process");

exec("ffmpeg -i example.mp4", (error, stdout, stderr) => {
  //ffmpeg logs to stderr, but typically output is in stdout.
  console.log(stderr);
});

Full code on GitHub

Option 3: upload your own binary

If you need a specific version of ffmpeg, you can include an ffmpeg binary as part of the upload and then run a shell command using something like child_process.exec. You'll need an ffmpeg binary that's compiled for the target platform (Ubuntu).

File listing with pre-compiled ffmpeg binary

./
../
index.js
ffmpeg

index.js

const { exec } = require("child_process");

exec("ffmpeg -i example.mp4", (error, stdout, stderr) => {
  //ffmpeg logs to stderr, but typically output is in stdout.
  console.log(stderr);
});

I've included two full working examples on GitHub. The examples are for Google Cloud Functions (not specifically Cloud Functions for Firebase).