The spec allows at least thirty-two zero bits followed by a one to mean
2^32-1, with no constraint on the number of zeroes. The libaom
reference decoder does not match this, instead reading thirty-two zeroes
but not the following one to mean 2^32-1. These two interpretations are
incompatible and other implementations may follow one or the other.
Therefore reject thirty-two zeroes because the intended behaviour is not
clear.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>