Re: New library wallpaper.el pushed to master

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: Stefan Kangas <stefankangas@gmail.com>,  Ken Brown <kbrown@cornell.edu>,
>   emacs-devel@gnu.org
> Date: Thu, 15 Sep 2022 21:39:47 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I added support for this on MS-Windows.  Strangely, it works with some
> > images, but not with others.  On XP, only BMP images seem to work (and
> > I think I saw someone on the Internet saying this is all XP supports).
> > On Windows 10, I can set the wallpaper to JPEG images as well, but
> > some don't work.  I guess someone more knowledgeable than myself will
> > have to fix whatever needs fixing here.
> 
> Perhaps Emacs could convert the wallpapers to the appropriate format
> using any installed external conversion programs?

Which ones?  The ones I know about are unlikely to be installed on
Windows.

And I don't know what are the requirements for "appropriate format",
so I wouldn't know how to invoke those programs, even if they are
available.  If you or someone else knows, feel free to make the
necessary changes.

(Btw, my trials with installing wallpapers all used only the images
that Windows itself succeeds to install, somehow, if one goes via the
Display->Personalize dialogs.  I never tried even a single image file
that is not under C:\Windows\Web\Wallpaper.)