Set Nautilus file icon per extension

Is it possible to change the icon (not the emblem) of a file in Nautilus' icon view mode by means of its extension interface?

It would be cool, I think, to see the album covers of MP3 files of embedded ID3v2 APIC frames while browsing folders with music. Until now, I am able to extract the picture and I copypastehacked some example code to add emblems and menu items to Nautilus. But neither the column provider nor the file info provider offer an obvious way to change the icon.

Another answer suggests using gvfs-set-attribute, but I would rather extract the icon dynamically instead of creating 开发者_如何学运维a lot of unnecessary files somewhere.

Thanks in advance for any helpful suggestions!

---

No, not with the extension interface. The canonical way to create individual icons is to register a so called "thumbnailer" in the gconf database under /desktop/gnome/thumbnailers. For ID3v2 APIC frames, solutions are already available.