Making Amiga IFF Thumbnails Work in Linux | Hacker News Reader

Making Amiga IFF Thumbnails Work in Linux

linuxjedi.co.uk

59 pointsdoener12 comments

Given this is about an Amiga format: How I miss Datatypes.

The datatypes library provided a simple object model that allows you to drop a system-wide library in place to handle a new format.

If you wanted to scale images for thumbnails, for example, you would simply obtain a data type object and get back decoded image data and scale it, and automatically be able to handle everything the user have picture datatypes for.

So you add basic support for a format once.

There are non mainstream systems out there that support datatypes, like BeOS and its successor Haiku.

Windows offers something similar via WIC since Vista.

However it requires some COM wrestling, the Amiga way was definitely more developer friendly.

It seems that's specific to image codecs? If so, it's incredible to see them add a feature like that so much later and fail to make it generic.

One of the nice things about datatypes is that the app asks for an instance of the overall type of data it cares about that matches the given file, and gets back a subclass, but anyone can implement new base types for people to subclass, or you can augment an existing class with additional functionality.

As a result there are datatypes for syntax highlighting, viewing binary files, images, sound, animations, video, viewing directory listings etc, and ,ore.

Yes mostly images, there are other COM interfaces for those purposes, although not all.

That's one thing I never understood how it didn't pick up in mainstream OS's. And Datatypes did not only cover images - audio, video, hypertext (Who can forget AmigaGuide) - you name it, there was a datatype for it. An idea so ahead of its time.

I was really surprised when I drank the koolaid and switched to windows that every app had its own set of favorite formats.

It's fantastic looking at Aminet today and finding datatypes for the original 68k AmigaOS adding support for modern formats to every datatype supporting program.

Full agreement, and with the addition of xpk¹/xfd² as natural extensions to that extensibility too. I see things like xfd supporting xz¹, and I'm simultaneously amazed that it exists and happy that I don't need to do xz {,de}compression on 68k ;)

I guess we have the essence of something similar-ish with libarchive⁴, but nobody(including me) has pushed the extra mile to get file dialogs to support random compression and decompression formats.

Beyond OT: I didn't realise how much stuff was still going on at aminet, but I love love LOVE that people are still dropping new car sets for Geoff Crammond's F1GP.

¹ http://aminet.net/package/util/pack/xpk_User

² http://aminet.net/package/util/pack/xfdmaster

³ http://aminet.net/package/util/pack/xfd_lzma.lha

⁴ https://www.libarchive.org/

Yeah many things like that were so backward when you had to move to other operating systems from AmigaOS

    Exec=convert %i -thumbnail %s %o

Seeing things like that always makes me wonder how it behaves if you happen to have a file named something like '; rm -rf *' or similar; a quick online search unfortunately reveals very little documentation on how exactly that command is parsed, substituted, and executed.

This is called 'shell command injection' and is a very common attack on software.

Part of the standard https://specifications.freedesktop.org/thumbnail-spec/thumbn...

I believe that this would be part of GnomeDesktopThumbnailFactory , probably https://gitlab.gnome.org/GNOME/gnome-desktop/-/blob/master/l...

Looks like its working by design.

there's netpbm too. I like imagemagik but somehow I found netpbm closer to how I think about problems.

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