cb4x4 itself should not require these sizes.

This simplifies compatibility with other experiments, since we can
first make them work with cb4x4 (which is now on by default), and
then worry about chroma_sub8x8 and chroma_2x2 (which is not) in
separate steps.

Encoder and decoder output should remain unchanged.

Change-Id: Iff2a5494cab3b7d96f881e8bd9cd4bf18c817cfa

Make the level-map and var-tx work together.

Change-Id: I5ff80a3cbc43af64b504934209720f387b89dbd8

This commit makes the level map coding system support the transform
coefficients from rectangular transform block sizes.

Change-Id: I5cd6c71d12e41938f942adc98cc1e1f286336f12

Explicilty use the transform block size to determine the coeff
band array. Remove the assumption on square transform block size.

Change-Id: I18e285130465a5eced49304a27a6cb617e297760

Map the rectangular transform block size into the bigger square
transform block size as the context for level map probability
model.

Change-Id: I20cf2b16daec16172855a78a201b670ff0547bf5

This function pre-generate counts/magnitudes of each level map
such that we don't have to re-calculate the counts/magnitudes
while doing the optimization.

Change-Id: Ifdfc89522cf2f2b9f3734d451324081f42b47cb0

BUG=aomedia:443

Change-Id: Iebdb609564c2c3040f3902052afeeec7ae83412d

This will separate the transform kernel selection from lv_map
experiment such that we can evaluate each feature's performance
separately

Note that txk_sel is build on top of lv_map

Change-Id: I5bd1ea99be30000efcdc2bcd42de002b78b1c3c8

This is for lv_map experiment

Change-Id: Ie000f7850efac32ffb46b9a4679cff2814c6246a

Change-Id: I3e9d9b3b59ee179b0fd24da2f0366ec841d2cfcf

The while loop may become infinite loop due to bitstream error.
Therefore, we add a breaking rule to avoid that.

Change-Id: I5bcda7dea846e280b59abc97c42baf334bca2603

Change-Id: I215c4bed9ba5c7f4fc93533249610217de14ce54

The feature is implemented in the following two functions.
av1_write_txb_probs
av1_read_txb_probs

Change-Id: I0b646e17ec54d7a10a77a6853439217091455af1

Change-Id: Id70fbfbca6c53a0aa15ff5606bb972e7412b3ed0

Change-Id: I45c8e26214cedb822ee5c38556ad03e3f2ad66a5

Change-Id: I3f059dc16124bbce2210296de5b884b5906ec182

Change-Id: Ifcdd3ce2953c1ecb1d0962da412a4b5ba2cda912

Change-Id: I222b5ce9ee1a1c1aac5620b94835967dd9a014c1