Youtube-dl doesn't provide all subtitles for a video(translation only subtitles)

[133794m3r]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.05.20
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

[debug] System config: []
[debug] User config: [u'-f', u'18[height<=360]/best[ext=mp4]', u'-o', u'/tmpdownload/%(title)s.%(ext)s']
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'--list-subs', u'https://www.youtube.com/watch?v=jc5DlOkOcU4']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.05.20
[debug] Python version 2.7.16 (CPython) - Linux-4.19.0-parrot4-28t-amd64-x86_64-with-Parrot-4.6-stable
[debug] exe versions: ffmpeg 4.1.1-1, ffprobe 4.1.1-1, phantomjs 5, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] jc5DlOkOcU4: Downloading webpage
[youtube] jc5DlOkOcU4: Downloading video info webpage
[youtube] jc5DlOkOcU4: Looking for automatic captions
Available automatic captions for jc5DlOkOcU4:
Language formats
gu       vtt, ttml, srv3, srv2, srv1
zh-Hans  vtt, ttml, srv3, srv2, srv1
zh-Hant  vtt, ttml, srv3, srv2, srv1
gd       vtt, ttml, srv3, srv2, srv1
ga       vtt, ttml, srv3, srv2, srv1
gl       vtt, ttml, srv3, srv2, srv1
lb       vtt, ttml, srv3, srv2, srv1
la       vtt, ttml, srv3, srv2, srv1
lo       vtt, ttml, srv3, srv2, srv1
tr       vtt, ttml, srv3, srv2, srv1
lv       vtt, ttml, srv3, srv2, srv1
lt       vtt, ttml, srv3, srv2, srv1
th       vtt, ttml, srv3, srv2, srv1
tg       vtt, ttml, srv3, srv2, srv1
te       vtt, ttml, srv3, srv2, srv1
fil      vtt, ttml, srv3, srv2, srv1
haw      vtt, ttml, srv3, srv2, srv1
yi       vtt, ttml, srv3, srv2, srv1
ceb      vtt, ttml, srv3, srv2, srv1
yo       vtt, ttml, srv3, srv2, srv1
de       vtt, ttml, srv3, srv2, srv1
da       vtt, ttml, srv3, srv2, srv1
el       vtt, ttml, srv3, srv2, srv1
eo       vtt, ttml, srv3, srv2, srv1
en       vtt, ttml, srv3, srv2, srv1
eu       vtt, ttml, srv3, srv2, srv1
et       vtt, ttml, srv3, srv2, srv1
es       vtt, ttml, srv3, srv2, srv1
ru       vtt, ttml, srv3, srv2, srv1
ro       vtt, ttml, srv3, srv2, srv1
bn       vtt, ttml, srv3, srv2, srv1
be       vtt, ttml, srv3, srv2, srv1
bg       vtt, ttml, srv3, srv2, srv1
uk       vtt, ttml, srv3, srv2, srv1
jv       vtt, ttml, srv3, srv2, srv1
bs       vtt, ttml, srv3, srv2, srv1
ja       vtt, ttml, srv3, srv2, srv1
xh       vtt, ttml, srv3, srv2, srv1
co       vtt, ttml, srv3, srv2, srv1
ca       vtt, ttml, srv3, srv2, srv1
cy       vtt, ttml, srv3, srv2, srv1
cs       vtt, ttml, srv3, srv2, srv1
ps       vtt, ttml, srv3, srv2, srv1
pt       vtt, ttml, srv3, srv2, srv1
pa       vtt, ttml, srv3, srv2, srv1
vi       vtt, ttml, srv3, srv2, srv1
pl       vtt, ttml, srv3, srv2, srv1
hy       vtt, ttml, srv3, srv2, srv1
hr       vtt, ttml, srv3, srv2, srv1
ht       vtt, ttml, srv3, srv2, srv1
hu       vtt, ttml, srv3, srv2, srv1
hmn      vtt, ttml, srv3, srv2, srv1
hi       vtt, ttml, srv3, srv2, srv1
ha       vtt, ttml, srv3, srv2, srv1
mg       vtt, ttml, srv3, srv2, srv1
uz       vtt, ttml, srv3, srv2, srv1
ml       vtt, ttml, srv3, srv2, srv1
mn       vtt, ttml, srv3, srv2, srv1
mi       vtt, ttml, srv3, srv2, srv1
mk       vtt, ttml, srv3, srv2, srv1
ur       vtt, ttml, srv3, srv2, srv1
mt       vtt, ttml, srv3, srv2, srv1
ms       vtt, ttml, srv3, srv2, srv1
mr       vtt, ttml, srv3, srv2, srv1
ta       vtt, ttml, srv3, srv2, srv1
my       vtt, ttml, srv3, srv2, srv1
af       vtt, ttml, srv3, srv2, srv1
sw       vtt, ttml, srv3, srv2, srv1
is       vtt, ttml, srv3, srv2, srv1
am       vtt, ttml, srv3, srv2, srv1
it       vtt, ttml, srv3, srv2, srv1
iw       vtt, ttml, srv3, srv2, srv1
sv       vtt, ttml, srv3, srv2, srv1
ar       vtt, ttml, srv3, srv2, srv1
su       vtt, ttml, srv3, srv2, srv1
zu       vtt, ttml, srv3, srv2, srv1
az       vtt, ttml, srv3, srv2, srv1
id       vtt, ttml, srv3, srv2, srv1
ig       vtt, ttml, srv3, srv2, srv1
nl       vtt, ttml, srv3, srv2, srv1
no       vtt, ttml, srv3, srv2, srv1
ne       vtt, ttml, srv3, srv2, srv1
ny       vtt, ttml, srv3, srv2, srv1
fr       vtt, ttml, srv3, srv2, srv1
ku       vtt, ttml, srv3, srv2, srv1
fy       vtt, ttml, srv3, srv2, srv1
fa       vtt, ttml, srv3, srv2, srv1
fi       vtt, ttml, srv3, srv2, srv1
ka       vtt, ttml, srv3, srv2, srv1
kk       vtt, ttml, srv3, srv2, srv1
sr       vtt, ttml, srv3, srv2, srv1
sq       vtt, ttml, srv3, srv2, srv1
ko       vtt, ttml, srv3, srv2, srv1
kn       vtt, ttml, srv3, srv2, srv1
km       vtt, ttml, srv3, srv2, srv1
st       vtt, ttml, srv3, srv2, srv1
sk       vtt, ttml, srv3, srv2, srv1
si       vtt, ttml, srv3, srv2, srv1
so       vtt, ttml, srv3, srv2, srv1
sn       vtt, ttml, srv3, srv2, srv1
sm       vtt, ttml, srv3, srv2, srv1
sl       vtt, ttml, srv3, srv2, srv1
ky       vtt, ttml, srv3, srv2, srv1
sd       vtt, ttml, srv3, srv2, srv1
Available subtitles for jc5DlOkOcU4:
Language formats
en       vtt, ttml, srv3, srv2, srv1
ja       vtt, ttml, srv3, srv2, srv1
es       vtt, ttml, srv3, srv2, srv1

Description

Youtube-dl doesn't show all subtitles for videos that do partial translations. E.g. videos that have partial translations in them that are no hardcoded. Primarily these are ones where the primary video is in one language but there are speakers that are interviewed in another language. The subtitles listed do not include the -<extra info saying it's translations only>.

I expect to see 4 subtitles listed under the language option. 2 EN ones and then the rest. The second EN could be something like "EN-?" or something similar so that the user doesn't know what the full language is.

Here is the URL with the translation-only subtitles.
https://www.youtube.com/api/timedtext?xorp=True&hl=en&expire=1558428502&sparams=asr_langs%2Ccaps%2Cv%2Cxoaf%2Cxorp%2Cexpire&key=yttt1&asr_langs=en%2Cja%2Cpt%2Cde%2Cko%2Cru%2Cfr%2Cit%2Cnl%2Ces&v=jc5DlOkOcU4&signature=0C77E44B4DDB483F66369EE6CFA9D99B35810C15.38C7B0AC330EE14A3E6F5A50EE2E5C13524933B9&caps=asr&xoaf=1&lang=en&name=Japanese%20Translation&fmt=srv3

It seems the issue is that it doesn't look for multiple subtitles for the same language. I don't know if this is a bug or a feature request, but the "all subs" option should download all of the subtitles and would(ideally) utilize the name that the uploader has chosen for the subtitles themselves.