Add support for NHK for School

[devesh]

Checklist

• [x] I'm reporting a new site support request
• [x] I've verified that I'm running youtube-dl version 2021.05.16
• [x] I've checked that all provided URLs are alive and playable in a browser
• [x] I've checked that none of provided URLs violate any copyrights
• [x] I've searched the bugtracker for similar site support requests including closed ones

Example URLs

• Single video: https://www2.nhk.or.jp/school/movie/bangumi.cgi?das_id=D0005150191_00000
• Playlist: https://www.nhk.or.jp/school/kokugo/drill/
• Playlist: https://www.nhk.or.jp/school/ouchi/playlist_g1_march.html

Description

[SuperSonicHub1]

@devesh Doing some starting research at the moment:

• This site has a search function we should support:

  https://www.nhk.or.jp/school/keyword/?kw=メダカ&cat=all&from=1&sort=ranking
  https://www.nhk.or.jp/school/keyword/?kw=<query>&cat=<category>&from=<page>&sort=<sorting>

  • Supported values for category:
  • all
  • b (program)
  • c (clip)
  • Supported values for sort
  • ranking (most popular)
  • update (most recent)
• Alongside bangumi, we also have clip:

  https://www2.nhk.or.jp/school/movie/bangumi.cgi?das_id=D0005150191_00000 (program)
  https://www2.nhk.or.jp/school/movie/clip.cgi?das_id=D0005311329_00000&p=box (clip)
  https://www2.nhk.or.jp/school/movie/<type>.cgi?das_id=<id>

• The site has its own playlist feature, separate from the concept of playlists in youtube-dl, that allows you to create and share custom playlists. Should we support this, and if so, do you have any playlist IDs?
• kokugo pages have a JSON version of the page (https://www.nhk.or.jp/school/kokugo/drill/meta/program.json), which will make them super easy to scrape.
• ouchi pages, unlike kokugo pages, aren't very standardized on the frontend and backend, so I'm probably going to have to skip parsing them; sorry.

[devesh]

I created playlist ID 9178 if you want to try to implement support for it. I do not plan to use it myself, but somebody else might.

Similarly, I do not plan to download from ouchi pages and instead plan to use only the kokugo pages, so what you're proposing to implement support for is fantastic.

[Lesmiscore]

Apart from the issue, they do use Akamai!? so rich they are!

Anyway, I'll try to write extractor for that later.