This commit enables selecting probability models for recursive block
partition information syntax, depending on its above/left partition
information, as well as the current block size. These conditional
probability models are reasonably stationary and consistent across
frames, hence the backward adaptive approach is used to maintain and
update the contextual models.

It achieves coding performance gains (on top of enabling rectangular
block sizes):
derf:   0.242%
yt:     0.391%
hd:     0.376%
stdhd:  0.645%

Change-Id: Ie513d9673337f0d27abd65fb566b711d0844ec2e

Change-Id: I6ea9e110b5c5b07ab7d092886dbd51a6eccc0217

Also some further simplification following removal
of top node code.

There is an issue in regards to the shared file vp8cx.h
in regard to the roi_map as this interface assumes that
there are only 4 segments. I have left the value here as
4 for now meaning that the roi_map interface is broken
for VP9.

Note that this change would have been easier if I hadn't
had to search for hard wire instances of the number 4
and <= 3.

Change-Id: Ia8b6deea4be4dbd20deb1656e689dd43a5f190e8

Remove top node optimization.
The improvement this gives is not sufficient to justify
the extra complexity.

Change-Id: I2bb4a12a50ffd52cacfa4a3e8acbb2e522066905

Change-Id: Iaef16122732c2a81e0927f9862b51b68dc788712

This data is fixed at the MB level, so move it to the common part
of MACROBLOCK.

Change-Id: Idd8c87118e501cdf0a202bd84c28b502a8234edf

Quantizers can vary per plane, but not per block. Move these values to
the per-plane part of MACROBLOCK.

Change-Id: I320a55e38b7b28b29aec751a4aca5ccd0c9b9326

Lookup the data per-plane from the MACROBLOCK struct.

Change-Id: I9253c4d3cf886aa9ab4aeab23a2156bfcf994ede

This commit moves the coeff storage from the MACROBLOCK struct to its
per-plane part. The next commit will remove the coeff member from the
BLOCK structure so that it is consistently accessed per-plane.

Also refactors vp9_sb_block_error_c and vp9_sb_uv_block_error_c to be
variable subsampling aware.

Change-Id: I18c30f87f27c3a012119b6c1970d5fa499804455

Change-Id: Id06b7a299a26ed944a401faae51907537f722a7e

Change-Id: Ia7266b8d3aa3d5cff2db0c3b2f014def045759af

Change-Id: I62dde981f5201c5fbc22001609ee4b5fd0a9bdf5

This commit enables rectangular block prediction of compound
inter-intra mode. It combines the mb/sb32/sb64 prediction functions
into a unified version with configurable block width and height.
This fixes the enc/dec mismatch of the codebase when
comp-interintra-pred is enabled.

Change-Id: I1d0db2f1f184007802df04fcd12b9dadb3189ff0

* changes:
  Make some sb_type comparisons independent of literal enum values.
  Make loopfilter aware of rectangular blocks.

The variable gf_active_ptr is not used anywhere, hence is removed.

Change-Id: I6badc20fade48ae12fd19e7e4cd8fe5e051c20ac

Change-Id: I0cdc951558e4d7748f63df8c03b1c9dce086acb0

Change-Id: I274a1d2e461e6ffdb106bac4ad6951692ace314e

Change-Id: I54acef342b8e787e05af0febd7cf0d7d10288383

Also use explicitely named enum values in sb_type comparisons, rather
than relying on absolute integer values, because enum values may
change in the future.

Change-Id: I72d42971a98157af93413a25ac2c7e6f9b369cec

First in a series of commits making certain MACROBLOCK members
addressable per-plane. This commit also refactors the block subtraction
functions vp9_subtract_b, vp9_subtract_sby_c, etc to be
loops-over-planes and variable subsampling aware.

Change-Id: I371d092b914ae0a495dfd852ea1a3d2467be6ec3

Change-Id: Ic659544ca12b1bc191b93ddfa378964bd133bfc9

Change-Id: I2bc8d775f8d698bf8582f4eecabc2329452e8d9b