This object specifies Abr inverse of rate increase factor
(1/rif) to the power of two.
Note that the actual value in the system is the power of
two of this object. That is, for example, a value 5 of
this object means 2**5 = 32 in the system for AbrIORIF.
Range (0..15) to the power of two is the range (1..32768).