[Anime-on-demand.de] Add support to extract only a portion of the overall episodes

[s1e2b3i4]

Checklist

• I'm reporting a site feature request
• I've verified that I'm running youtube-dl version 2021.01.08
• I've searched the bugtracker for similar site feature requests including closed ones

Description

On Anime-on-Demand, some animes have a large number of episodes (100 or even over 200 episodes). This results in a very long extraction time for the page (sometimes up to 1-2 hours). This is particularly unfavorable if you only want to download some episodes or even just one.
Another problem is that the extracted links expire after a certain time and so only a small part of the episodes can be downloaded, after this long extraction time, until the links have expired.

One possibility to implement this feature would be to use the episode_number in the extractor and the existing parameters --playlist-start, --playlist-end and --playlist-items to decide which episodes have to be extracted.

@dstftw @remitamine

[ch4d1]

youtube-dl -v https://www.anime-on-demand.de/anime/78 --playlist-start 95 --playlist-end 100
[debug] System config: [u'-n', u'-o', u'~/ytdl/%(title)s.%(ext)s', u'-f', u'[format_id*=jap-OmU]/[format_id*=ger-OmU]/[format_id*=jap-Dub]/[format_id*=ger-Dub]/best']
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'https://www.anime-on-demand.de/anime/78', u'--playlist-start', u'95', u'--playlist-end', u'100']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2021.01.16
[debug] Python version 2.7.16 (CPython) - Linux-5.10.5-v8+-aarch64-with-debian-10.7
[debug] exe versions: ffmpeg 4.1.6-1, ffprobe 4.1.6-1
[debug] Proxy map: {}
[debug] Using fake IP 82.117.13.214 (LI) as X-Forwarded-For.
[AnimeOnDemand] Downloading login page
[AnimeOnDemand] Logging in
[AnimeOnDemand] 78: Downloading webpage
[download] Downloading playlist: InuYasha
[AnimeOnDemand] episode-1: Downloading ger-Dub videomaterial JSON
[AnimeOnDemand] episode-1: Downloading m3u8 information
[AnimeOnDemand] episode-1: Downloading ger-OmU videomaterial JSON
[AnimeOnDemand] episode-1: Downloading m3u8 information
^C
ERROR: Interrupted by user

am i doing it wrong?

[stnokott]

Unfortunately, this occured for me again...

youtube-dl -v "https://www.anime-on-demand.de/anime/226" -u "xxxxxxxx" -p "xxxxxxx" --playlist-start 95 --playlist-end 100
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www.anime-on-demand.de/anime/226', '-u', 'PRIVATE', '-p', 'PRIVATE', '--playlist-start', '95', '--playlist-end', '100']
[debug] Encodings: locale cp1252, fs utf-8, out utf-8, pref cp1252
[debug] youtube-dl version 2021.06.06
[debug] Python version 3.9.4 (CPython) - Windows-10-10.0.19041-SP0
[debug] exe versions: none
[debug] Proxy map: {}
[debug] Using fake IP 77.116.95.51 (AT) as X-Forwarded-For.
[AnimeOnDemand] Downloading login page
[AnimeOnDemand] Logging in
[AnimeOnDemand] 226: Downloading webpage
[download] Downloading playlist: Detektiv Conan - 1. Staffel
[AnimeOnDemand] episode-1: Downloading ger-Dub videomaterial JSON

ERROR: Interrupted by user

Am I missing something?