tree 1a06c26e1523f56dd647f9b798c9d2f03b8eec52
parent 199a2f40522f8912d980fd70f41ccf4d6330fd24
author Urvang Joshi <urvang@google.com> 1485464809 -0800
committer Urvang Joshi <urvang@google.com> 1485798526 +0000

Palette Optimization: O(1) context lookup.

Now that we have small number of contexts (5), use hash multipliers
(instead of base 11), so that color context hash is within a small
range. This allows us to use a lookup table to get color context
instead of a for loop.

Output bitstreams are bit-exact, so no change in compression.

Change-Id: I8cd8c893048c2fc6b22ccbd56f652d11486e2ee9