virtual package "video-player"?

[Jonas Smedegaard]

Quoting IOhannes m zmölnig (Debian/GNU) (2017-11-13 21:50:32)
> thanks jonas for the reply,
> 
> On 11/13/2017 08:59 PM, Jonas Smedegaard wrote:
> > Quoting IOhannes m zmölnig (Debian/GNU) (2017-11-13 19:59:28)
> >>
> >> a good name might be "video-player" or "desktop-video-player" (i'd
> >> favour the first).
> >>
> >>
> >> what do you think?
> >> if we can come to a consensus, i'd propose this on debian-devel.
> > 
> > To address bug#881326, fallback dependencies should be limited to tools 
> > not exploding in your face in a non-GUI environment, and tools using 
> > same syntax to play media.
> 
> hmm, well:
> in the specific case of bug#881326, it turned out that the
> "Recommends:mpv" was indeed intended to mean "mpv" specifically, rather
> than "a generic video player" (as i originally assumed).
> so for bug#881326, the "video-player" virtual package is irrelevant anyhow.
> 
> however, i still think being able to install "*a* video player capable
> of playing my video collection" is a desirable goal.
> 
> > Simplest approach to address issues like bug#881326 generally would 
> > probably be to extend package sensible-utils with a "sensible-player", 
> > knowledgeable about the possible players in Debian fitting the critera.>
> > /etc/alternatives could be used (in addition to or instead of 
> > sensible-utils helper) to provide local sysadmin freedom to prioritize 
> > among multiple installed players.
> 
> i personally favour a decentralized effort, where any sensible video
> player can declare their usability themselves (rather than depending on
> a gatekeeper (sensible-utils) to decide which one is part of that group).
> (just telling; sensible-utils allows for such a decentralized workflow
> anyhow)
> i consider "sensible-player" a bad naming (for the thing i was
> proposing), as it is too generic.

Ok.  Then how about doing this, for each video player package:

 * Package "Provides:" gui-video-player
 * postinst script register with update-alternatives as providing 
   "/usr/bin/gui-video-player".

Done.

> in any case, i don't really buy the "not exploding in your face in a
> non-GUI environment" argument, in this case.
> i'm talking explicitly about an application that displays videos as
> pixel data. i see little (useful) ways to not have a GUI (that is: an
> X-server or the like) to display a video.

Fine - that simply means that you only care about the gui case, not the 
non-gui-supportive case - which is fine by me - I just recommend to then 
include "gui" in the virtual name to make that constraint explicit.

(alternative keyword is "x11" but I guess in these modern times with 
Wayland it might be more sensible with the more abstract "gui")


> the proposal was modeled after the already existing "pdf-viewer", with
> similar uses.
> afaict, each "pdf-viewer" will pull in GUI (so you can actually *view*
> something).
> as a consequence, it is hardly ever "depended" on (mostly recommended or
> suggested) - it's perfectly valid to store PDFs on your fileserver that
> doesn't have a desktop; otoh, many people who install PDFs via packages
> might actually want to look at them.
> similarily, i suspect that most people installing software to download
> movies will actually want some way to view them (and then there's a few
> who don't).

If you propose something as vague as "pdf-viewer" then I disagree there 
is a need for it.  Can you elaborate on use cases?  It is common in 
Debian to include a bunch of PDF documents in a package and then declare 
sloppily "needs a viewer for this stuff" without a need for triggering 
said viewer - but I am unaware that it is common in Debian to ship a 
bunch of video files needing similar package hinting.

If you want to hint to _users_ that they can pick whatever, then a 
better approach than virtual package name is to use debtags:

  axi-cache search video::player interface::graphical


(...and then update debtags for e.g. mpv to improve such lookups)


 - Jonas

-- 
 * Jonas Smedegaard - idealist & Internet-arkitekt
 * Tlf.: +45 40843136  Website: http://dr.jones.dk/

 [x] quote me freely  [ ] ask before reusing  [ ] keep private