Using audioonly filter slows down download tremendously

When downloading a video and converting to mp3 with ffmpeg, using filter: 'audioonly' in the options slows down speeds by magnitudes; ~72 seconds with filter, ~8 with no options, also ~8 with quality: 'highestaudio' (seems weird considering highestaudio requests just audio, like the filter).

This is tested using a 4:13 video on my gigabit ethernet.

code used:

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

let id = 'sDLsSQf3Hc0';
let start = Date.now();
let stream = ytdl(id, { quality: 'highestaudio'/*, filter: 'audioonly' */}); // mess around with quality, filter, and nothing at all being used

ffmpeg(stream)
	.on('end', () => {console.log('done, thanks - ' + (Date.now() - start) / 1000 + 's')})
	.audioBitrate(128)
	.save(`${__dirname}/${id}-${(Math.random() * 100000).toFixed(0)}.mp3`); // very efficient naming system here

This doesn’t really affect me because I can just use quality: 'highestaudio', but it does seem like a weird effect.

[corwin-of-amber]

I looked into it a little bit more, and it seems that adding a Range header, e.g.

fetch(u, {headers: {Range: 'bytes=0-10380331'}})

(here, using node-fetch) improves download speed dramatically.

[weltonrodrigo]

Hi, I suppose you investigated this, but youtube-dl doesn’t seem to suffer from rate limiting. I think you can copy its behaviour in ytdl-core.