ARM actually publishes reference code under the library name "OpenMAX" for their mobile processors.

I've read ARM's source code and found they they too use the AAN algorithm for the DCT. (They provide a tonne of code for other multimedia related stuff too.)

I learned a lot from their code, even though my implementation is completely different and original.

I would also dare to say that my asm source is maintainable. I had a very hard time understanding their code as it wasn't very well documented or laid out... but nevertheless a valuable learning tool.