I'm using Rockbox on my iPod Classic. It supports showing embedded album art from MP3 files, but only if those images have the JPG extension.
Some of my embedded images have the PNG extension. The accompanying songs show up without the corresponding album art.
I'm looking for a script that will change these embedded images to the JPG format, so they will be showed correctly.
This doesn't have to be a bash script - any programming language will do.