tree dd1446bb06ab04f69d71c40d568f52cb4f0aa90e
parent 42015d1ddd1d2be67583d2f896fba9ff61ccfd90
author Linfeng Zhang <linfengz@google.com> 1508284170 -0700
committer Linfeng Zhang <linfengz@google.com> 1508348640 +0000

Update txb context calculation code

Split coefficients into signs (0 or 1) and levels (0 to 255),
so that they both can be fit in 1-byte.

Change-Id: I0f486368b7b819a77aaddda4710e83189e53fc55