MPEG-I audio layer 1 analysis window

Hello list,

I am currently trying to understand the MPEG-I Audio Layer 1 encoding.
In the official specification, the coefficients for the MPEG-I audio
layer 1 analysis window are hardcoded. Is there a possibility to
calculate (or approximate) them?

And by the way, what do this coefficients exactly do? Are they a
(modified) Hanning window?

Best Regards,
Patric