Downloading a video using fluent-ffmpeg in nodejs and express

Question

I am working on a side project to download videos from Reddit, but they separate video and audio in different files. so i have to merge them first before downloading them in the client. i was able to do all of this as in the following snippet of code.

const ffmpeg = require("fluent-ffmpeg");
const proc = new ffmpeg();

app.post('/download', async (req, res) => {
   
   const audio = "some aduio link";
   const video = "some video link";

   proc.addInput(video)
     .output('${some path}./video.mp4')
     .format('mp4')
     .on("error", err => console.log(err))
     .on('end', () => console.log('Done'));

  if(audio) {
  proc.addInput(audio);
  }

  proc.run()
 
});

using the above code, the video is being download locally in the the server in the specified path.

but i want to download the video in the client browser who sent the request. i tried:

proc.pipe(res); 

but it didn't work, it's my first time working with ffmpeg, so it would be nice if someone give me a hint

Answer 1

add writeToStream(res, { end: true }); atn the end to stream

        const ffmpeg = require("fluent-ffmpeg");
        const proc = new ffmpeg();

        app.post('/download', async (req, res) => {
           
           const audio = "some aduio link";
           const video = "some video link";

           ffmpeg(video).format('mp4')
             .on("error", err => console.log(err))
             .on('end', () => console.log('Done')).writeToStream(res, { end: true });
         
        });

` i hope it works