YouTube --write-info-json only writes info on available automatic subtitles if they have been downloaded

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Output:

kermit@frog:/yt$ youtube-dl --skip-download -o "%(id)s.mp4" --write-info-json --all-subs -v https://www.youtube.com/watch?v=bdkXTKZNlSo
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--skip-download', '-o', '%(id)s.mp4', '--write-info-json', '--all-subs', '-v', 'https://www.youtube.com/watch?v=bdkXTKZNlSo']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.03.18
[debug] Python version 3.5.2 (CPython) - Linux-4.4.0-138-generic-x86_64-with-Ubuntu-16.04-xenial
[debug] exe versions: ffmpeg 2.8.15, ffprobe 2.8.15
[debug] Proxy map: {}
[youtube] bdkXTKZNlSo: Downloading webpage
[youtube] bdkXTKZNlSo: Downloading video info webpage
WARNING: video doesn't have subtitles
[debug] Default format spec: bestvideo+bestaudio/best
[info] Writing video description metadata as JSON to: bdkXTKZNlSo.info.json
...
<end of log>

Section `automatic_captions` is empty in info.json

With the command given above, the section automatic_captions remains empty in the info.json file (see attachment). It will be filled if I run the following command:

kermit@frog:/yt$ youtube-dl --skip-download -o "%(id)s.mp4" --write-info-json --all-subs --write-auto-sub -v https://www.youtube.com/watch?v=bdkXTKZNlSo

However, this will download 104 subtitle files I do not want. My plan is to download the JSON file first and then decide on the basis of available subtitles and video resolutions whether I want to download the video and which video format to request. But it appears I cannot do this at the moment. In short: If --all-subs is switched on, I would expect the automatic_captions section to be populated in the info.json.

Thanks and best wishes, Peter

EDIT: Adding --list-subs does not do the trick either. Then it does not write the info.json.

ytdl-org / youtube-dl