commit fa9c9d1cc0a0e63b01ef78c93ae34e47d4713514
author Alex Converse <aconverse@google.com> Fri Nov 04 14:06:06 2016 -0700
committer Alex Converse <aconverse@google.com> Mon Nov 28 23:25:46 2016 +0000
tree e29a27d4ab6f6c18552380c3627fb004212206ff
parent feffd11fe6295741ef36369976ff4a7fe9055937

Adjust how the final ANS state is written.

The new prefixes are
0: 15 bits of state are added to the base state.
10: 22 bits of state are added to the base state.
110: Reserved for super frame marker
111: 29 bits of state are added to the base state.

The likelihood of any final state is proportional to 1 / state. Given a
state range of [2**15, 2 **23) this should save on average 0.4 bits
per serialized final state.

BDRATE
subset1: -.000%
lowres: -.010%

Change-Id: I8e66e4a6667f5692c541083e6d6edc35ff411181