bug#57990: Add package: python-mat2 (remove metadata from images to improve privacy)

[Chris Marusich]

Apologies for the top post.  I noticed this email and wanted to point you to prior work, in case it proves useful:

https://issues.guix.gnu.org/31307#14

On Thu, Sep 22, 2022 at 12:24 PM Maxime Devos <maximedevos@telenet.be> wrote:

On 22-09-2022 13:38, Dr. Arne Babenhauserheide wrote:
>
> Tobias Geerinckx-Rice <me@tobias.gr> writes:
>
>>> can I express "any version of ffmpeg"?
>>
>> No, this would go against the goals of Guix: packages can't depend on properties of the environment they'll end up in (if any).
>
> What’s the right way to deal with this, then? I need ffmpeg at as
> propagated-input, but I do not want to create a conflict with a manifest
> that just defines "ffmpeg".

In one my replies, I have proposed a method that avoids propagating ffmpeg:

> To avoid profile collisions when the user installed a different version of ffmpeg (e.g. ffmpeg@5) in their profile, could you modify the code to look at a /gnu/store/.../bin/ffmpeg instead?  Likewise for bubblewrap, gdk-pixbuf, poppler and librsvg, if feasible.
>
> For ffmpeg, the following function needs to be modified:
>
> https://0xacab.org/jvoisin/mat2/-/blob/master/libmat2/video.py#L139
>
> (substitute* + search-input-file can be useful).

Greetings,
Maxime.