Download all locales

[davelab6]

I noticed when checking out https://www.youtube.com/watch?v=IEfx30qHU50 that was recommended in the GE Patreon chat, that it is in Italian, but the autogenerated subtitles are also available in dozens of other languages:

It appears https://github.com/yt-dlp/yt-dlp can list these per video like this

yt-dlp --list-subs "https://www.youtube.com/watch?v=Ja9dTjY3uWU"

and this command will download everything:

yt-dlp --update ;
yt-dlp \
 --yes-playlist \
 --write-subs \
 --write-auto-subs \
 --all-subs \
 --sub-format "best" \
 --convert-subs vtt \
 --skip-download \
 --no-overwrites --continue --ignore-errors \
 --download-archive downloaded.txt \
 --sleep-interval 30 --max-sleep-interval 300 \
 --retries infinite --fragment-retries infinite \
 --rate-limit 0.1M --throttled-rate 0.05M \
 --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0 Safari/537.36" \
 -4 \
 -o "%(id)s.%(ext)s" \
 "https://www.youtube.com/@garyseconomics" ;

Option	Purpose
--yes-playlist	Ensures yt-dlp processes the whole playlist or channel
--write-subs	Download manually uploaded subtitles
--write-auto-subs	Also download auto-generated captions
--all-subs	Downloads all available subtitle languages
--sub-format "best"	Picks the best available subtitle format (e.g., .vtt or .srt).
--convert-subs vtt	Converts all subtitles to .srt
--skip-download	Downloads only subtitles, no video files
--sleep-interval 30 --max-sleep-interval 300	Waits 30 seconds to 5 mins, randomly between downloads, to avoid rate limiting
--retries infinite	Keeps retrying failed downloads forever
--fragment-retries infinite	Retries broken subtitle or video fragments
--rate-limit 0.1M	Limits download rate to 0.1 MB/s for stable performance
--throttled-rate 0.05M	Treats anything slower than 50 KB/s as throttled, helping yt-dlp retry correctly
--download-archive downloaded.txt	Logs downloaded videos so they won’t be re-downloaded on subsequent runs
--ignore-errors	Continues if a video is missing, age-restricted, or private
--user-agent "<UA">	Pretend to be a browser
-4	use IPv4 instead of IPv6
yt-dlp --cookies-from-browser firefox	Assuming you just used Firefox to use YouTube with cookies, reuse those here
-o "%(id)s.%(ext)s"	Uses the video ID as the filename stem

This produces files like this:

Ja9dTjY3uWU.ay.vtt
Ja9dTjY3uWU.ba.vtt
Ja9dTjY3uWU.be.vtt
Ja9dTjY3uWU.bg.vtt
Ja9dTjY3uWU.bho.vtt
Ja9dTjY3uWU.bn.vtt
Ja9dTjY3uWU.br.vtt
Ja9dTjY3uWU.bs.vtt
Ja9dTjY3uWU.ca.vtt
Ja9dTjY3uWU.ceb.vtt
Ja9dTjY3uWU.co.vtt
Ja9dTjY3uWU.cs.vtt
Ja9dTjY3uWU.da.vtt
Ja9dTjY3uWU.de.vtt
Ja9dTjY3uWU.dv.vtt
Ja9dTjY3uWU.dz.vtt
Ja9dTjY3uWU.ee.vtt
Ja9dTjY3uWU.el.vtt
Ja9dTjY3uWU.en-GB.srt
Ja9dTjY3uWU.en-GB.vtt
Ja9dTjY3uWU.en-orig.vtt
Ja9dTjY3uWU.en.vtt
Ja9dTjY3uWU.eo.vtt
Ja9dTjY3uWU.et.vtt
Ja9dTjY3uWU.eu.vtt
Ja9dTjY3uWU.fi.vtt
Ja9dTjY3uWU.fil.vtt
Ja9dTjY3uWU.fj.vtt
Ja9dTjY3uWU.fo.vtt
Ja9dTjY3uWU.fr.vtt
Ja9dTjY3uWU.ga.vtt
Ja9dTjY3uWU.gaa.vtt
Ja9dTjY3uWU.gl.vtt
Ja9dTjY3uWU.gn.vtt
Ja9dTjY3uWU.gu.vtt
Ja9dTjY3uWU.gv.vtt
Ja9dTjY3uWU.ha.vtt
Ja9dTjY3uWU.haw.vtt
Ja9dTjY3uWU.hi.vtt
Ja9dTjY3uWU.hmn.vtt
Ja9dTjY3uWU.hr.vtt
Ja9dTjY3uWU.ht.vtt
Ja9dTjY3uWU.hu.vtt
Ja9dTjY3uWU.id.vtt
Ja9dTjY3uWU.ig.vtt
Ja9dTjY3uWU.is.vtt
Ja9dTjY3uWU.it.vtt
Ja9dTjY3uWU.iu.vtt
Ja9dTjY3uWU.iw.vtt
Ja9dTjY3uWU.ja.vtt
Ja9dTjY3uWU.jv.vtt
Ja9dTjY3uWU.ka.vtt
Ja9dTjY3uWU.kha.vtt
Ja9dTjY3uWU.kk.vtt
Ja9dTjY3uWU.kl.vtt
Ja9dTjY3uWU.km.vtt
Ja9dTjY3uWU.kn.vtt
Ja9dTjY3uWU.lg.vtt
Ja9dTjY3uWU.mfe.vtt
Ja9dTjY3uWU.my.vtt
Ja9dTjY3uWU.nl.vtt
Ja9dTjY3uWU.rw.vtt
Ja9dTjY3uWU.sq.vtt
Ja9dTjY3uWU.zh-Hans.vtt
Ja9dTjY3uWU.zh-Hant.vtt

I'm running it now without such a high throttle rate, which is getting some but many are skipped with HTTP Error 429: Too Many Requests.

I'll make a PR to remove the duplicates, add the ones I could get so far, and change the code @mikemonteith wrote to process the en-GB ones by default, and then see how to add a locale selector