Fetch playlist information even if --no-playlist is used

[mdirik]

Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2018.02.04. If it's not, read this FAQ entry and update. Issues with outdated version will be rejected.

• I've verified and I assure that I'm running youtube-dl 2018.02.04

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• At least skimmed through the README, most notably the FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones
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• Site support request (request for adding support for a new site)
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Description of your issue, suggested solution and other information

I want to download a single video out of a playlist, but I want to use playlist output templates such as "playlist_title" and "playlist_index" at the same time.

"--no-playlist" option seems to be the preferred way for downloading a single video, but playlist metadata is not available if it is used (note that playlist is in the URL, so playlist information can be inferred):

$ /opt/youtube-dl/youtube-dl -v --get-filename --no-playlist -o '%(playlist_title)s/%(playlist_index)s. %(title)s-%(id)s.%(ext)s' 'https://www.youtube.com/watch?v=gOVD-DrUpwQ&list=PL0lo9MOBetEGRAJzoTCdco_fOKDfhqaOY&index=7'
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'--get-filename', u'--no-playlist', u'-o', u'%(playlist_title)s/%(playlist_index)s. %(title)s-%(id)s.%(ext)s', u'https://www.youtube.com/watch?v=gOVD-DrUpwQ&list=PL0lo9MOBetEGRAJzoTCdco_fOKDfhqaOY&index=7']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2018.02.04
[debug] Python version 2.7.9 (CPython) - Linux-2.6.32-042stab125.5-i686-with-debian-8.10
[debug] exe versions: ffmpeg 3.4.1-static, ffprobe 3.4.1-static
[debug] Proxy map: {}
[debug] Default format spec: bestvideo+bestaudio/best
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Omitting "--no-playlist", playlist info is present but it wants to download all videos:

$ /opt/youtube-dl/youtube-dl -v --get-filename -o '%(playlist_title)s/%(playlist_index)s. %(title)s-%(id)s.%(ext)s' 'https://www.youtube.com/watch?v=gOVD-DrUpwQ&list=PL0lo9MOBetEGRAJzoTCdco_fOKDfhqaOY&index=7'
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'--get-filename', u'-o', u'%(playlist_title)s/%(playlist_index)s. %(title)s-%(id)s.%(ext)s', u'https://www.youtube.com/watch?v=gOVD-DrUpwQ&list=PL0lo9MOBetEGRAJzoTCdco_fOKDfhqaOY&index=7']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2018.02.04
[debug] Python version 2.7.9 (CPython) - Linux-2.6.32-042stab125.5-i686-with-debian-8.10
[debug] exe versions: ffmpeg 3.4.1-static, ffprobe 3.4.1-static
[debug] Proxy map: {}
[debug] Default format spec: bestvideo+bestaudio/best
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I didn't try using "--playlist-start/end/items" to work around as I wanted to report this issue first.

[dstftw]

This is expected behavior.

[mdirik]

If this is the expected behaviour, please consider this as a feature request.

Note how both playlist id and index are inside URL ("...&list=PL0lo9MOBetEGRAJzoTCdco_fOKDfhqaOY&index=7...") so it should be possible to figure them out.