Thanks for your support everyone, it is appreciated. I have edit first post and added new archive with icons for AC3, DTS, OptimFROG (ofr right?) and TAK.
They look great. However, I think all the aliencats should be white.Did you use "Crisp" for the fonts? Maybe "Sharp" or some other antialiasing would be better. They seem a little too smooth.
Great work, OFR is for OptimFROG is correct. Just a note, the middle-sized icon for OptimFROG in the preview is labelled with OGG instead OFR. The icons in the archive are ok.