Today I started hacking Rhythmbox. Things aren't going so well. I expected to be able to quickly hack the new functionality into it but I ran into problems. You see, although Gentoo (my Linux distribution of choice) has GStreamer 0.10.8 marked as stable, which is the GStreamer version that includes the new GST_TAG_IMAGE that I need to show the pictures embedded within the MP3 files, it has the base plug-ins of GStreamer that still don't provide this tag when the ID3 tag on the MP3 file has an image.
I still have to think weather I attempt an upgrade, with all the risks it involves, or weather I simply give up on trying to make a patch for this. It seems to be rather simple after having GStreamer obtaining the image data: I'll use the GDK-Pixbuf library to turn it into something that can be used by the Album Cover plug-in of Rhythmbox to convince it to show the embedded picture. Guess it will take more hacking to get it done, but I don't want to give up just yet.