Youtube Annotations no longer download, and give 405 error

[Benjins]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2019.08.02
• 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 issues including closed ones

Verbose log

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--write-annotations', '--skip-download', '--verbose', 'https://www.youtube.com/watch?v=CwZdur1Pi3M']
[debug] Encodings: locale cp1252, fs mbcs, out cp437, pref cp1252
[debug] youtube-dl version 2019.08.02
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.17763
[debug] exe versions: none
[debug] Proxy map: {}
[youtube] CwZdur1Pi3M: Downloading webpage
[youtube] CwZdur1Pi3M: Downloading video info webpage
[youtube] CwZdur1Pi3M: Downloading annotations
WARNING: Unable to download video annotations: HTTP Error 405: Method Not Allowed
[debug] Default format spec: best/bestvideo+bestaudio
[info] Writing video annotations to: Fiber vs. Copper; What do we really need-CwZdur1Pi3M.annotations.xml
WARNING: There are no annotations to write.

Description

The YouTube annotations endpoint no longer is a simple GET, but instead is a POST with some additional parameters and data. As a result, the annotations download fails. Here is an example:

youtube-dl --write-annotations --skip-download --verbose https://www.youtube.com/watch?v=CwZdur1Pi3M

The video does have annotations, and looking in the Chrome inspector they are downloaded during normal viewing in a browser, just with a different URL scheme than youtube-dl expects.

[ivan]

Testing it with curl a bit, the POST request to the endpoint e.g. https://www.youtube.com/annotations_invideo?cap_hist=1&video_id=uaK1TSAXRvA&client=1 seems to require:

• a cookie with a valid VISITOR_INFO1_LIVE= and YSC=
• POST data with a valid session_token=

But I may have missed an even more-minimized approach to get annotations.