bug#33282: ImageMagick delegates

bug#33282: ImageMagick delegates

[Juri Linkov]

WebP is an image format that is gaining popularity,
but currently can't be displayed by image-mode.

It's supported by ImageMagick after installing

  sudo apt-get install webp

The command `identify -list delegate` confirms that:

  webp => "dwebp' -pam '%i' -o '%o"

It's possible to work around its missing support by adding to ~/.emacs:

  (add-to-list 'imagemagick-enabled-types 'WEBP)

  (advice-add 'imagemagick-types :around
              (lambda (orig-fun &rest args)
                (append (apply orig-fun args) '(WEBP))))

  (imagemagick-register-types)

So the question is: should `imagemagick-types' return
the delegate list in addition to the current list
of non-delegate image types?

bug#33282: ImageMagick delegates

[Juri Linkov]

> WebP is an image format that is gaining popularity,
> but currently can't be displayed by image-mode.
>
> It's supported by ImageMagick after installing
>
>   sudo apt-get install webp
>
> The command `identify -list delegate` confirms that:
>
>   webp => "dwebp' -pam '%i' -o '%o"
>
> It's possible to work around its missing support by adding to ~/.emacs:
>
>   (add-to-list 'imagemagick-enabled-types 'WEBP)
>
>   (advice-add 'imagemagick-types :around
>               (lambda (orig-fun &rest args)
>                 (append (apply orig-fun args) '(WEBP))))
>
>   (imagemagick-register-types)
>
> So the question is: should `imagemagick-types' return
> the delegate list in addition to the current list
> of non-delegate image types?

I tried GetDelegateList, but it returned some delegates on whose
calling MagickRelinquishMemory caused a crash during bootstrapping.
There is no crash when calling MagickRelinquishMemory not during
bootstrapping, and I have no idea what is wrong.

bug#33282: ImageMagick delegates

[Lars Ingebrigtsen]

Juri Linkov <juri@linkov.net> writes:

> WebP is an image format that is gaining popularity,
> but currently can't be displayed by image-mode.

I wonder -- do you think its popularity merits Emacs getting native
support for it?  I don't think I've seen too many sites that serve out
WebP only, but perhaps that'll change now what Chrome is the only web
browser people care about.

Juri Linkov <juri@linkov.net> writes:

> I tried GetDelegateList, but it returned some delegates on whose
> calling MagickRelinquishMemory caused a crash during bootstrapping.
> There is no crash when calling MagickRelinquishMemory not during
> bootstrapping, and I have no idea what is wrong.

Perhaps if you post the gdb backtrace, somebody here has an idea.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#33282: ImageMagick delegates

[Juri Linkov]

>> WebP is an image format that is gaining popularity,
>> but currently can't be displayed by image-mode.
>
> I wonder -- do you think its popularity merits Emacs getting native
> support for it?  I don't think I've seen too many sites that serve out
> WebP only, but perhaps that'll change now what Chrome is the only web
> browser people care about.

I tried to open https://developers.google.com/speed/webp/gallery
in EWW and it displays images.  Then I clicked the right mouse button
to use the image context menu to open it in a new tab, but there is
no such menu in EWW yet (I could implement "Open image in new tab"
in EWW after merging the tabs branch).  But it seems the web server
returns PNG images when the web client doesn't support WebP format.

>> I tried GetDelegateList, but it returned some delegates on whose
>> calling MagickRelinquishMemory caused a crash during bootstrapping.
>> There is no crash when calling MagickRelinquishMemory not during
>> bootstrapping, and I have no idea what is wrong.
>
> Perhaps if you post the gdb backtrace, somebody here has an idea.

Since Emacs no longer defaults to using ImageMagick, there is no point
in trying to implement ImageMagick support for WebP anymore.  Regarding
native support, if web servers return more widespread formats as fallback
when WebP is not supported on client, then there is not much need in WebP.

bug#33282: ImageMagick delegates

[Lars Ingebrigtsen]

Juri Linkov <juri@linkov.net> writes:

> I tried to open https://developers.google.com/speed/webp/gallery
> in EWW and it displays images.  Then I clicked the right mouse button
> to use the image context menu to open it in a new tab, but there is
> no such menu in EWW yet (I could implement "Open image in new tab"
> in EWW after merging the tabs branch).  But it seems the web server
> returns PNG images when the web client doesn't support WebP format.

It probably uses User-Agent sniffing, I guess...

> Since Emacs no longer defaults to using ImageMagick, there is no point
> in trying to implement ImageMagick support for WebP anymore.  Regarding
> native support, if web servers return more widespread formats as fallback
> when WebP is not supported on client, then there is not much need in WebP.

So I'm closing this bug report.  If ever WebP becomes important, then
we'll need to support it, and that should be done natively.  

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no