Refactors mbskip coding to be compatible with coding of the rest of
the symbols. Adds forward/backward adaptation and removes a lot of
the legacy code.

Results:
fast50: +1.6%
derfraw300: +0.317%

Change-Id: I395a2976d15af044d3b8ded5acfa45f6f065f980

Change-Id: Ib44541fbbdcf71ec881814bd6715ea1c6bd82cf4

Change-Id: Ifbf790c14cee0c08a27f6728e3c637404e1f8477

Change-Id: I4331cfd99a717938f4f970cad81c468cbf287b00

Change-Id: I19d5cb60a00a001f6e5b3d90ce2db6e49d6209ad

It has a range of -255,255, so should be int16_t, not int8_t.

Change-Id: I5ef4b6aefb6212b0f35f4754f3c4d73fddbc52a0

This can only happen if partition is partly out-of-frame, in which
case the referenced mv is either out-of-frame also (and thus has the
same value as an already-read one), or it is actually uninitialized,
in which case we don't want to use it.

Change-Id: Icf39fa4d987c7abcbebb9bbdcdd6311e8fb9d3c9

Change-Id: Ia36f626b9b3c2fe7eb89bb9acddf4701db1baef2

Simplify feature to only support a single reference frame
instead of a mask.

Change-Id: I5dd3a98c7a224aafb35708850ab82e2f220e68fb

Just an intermediate change set to simplify merges. Reordering several
uncompressed header bits, code restructuring + minor cleanups.

Change-Id: I28272f520762f8c4e3ad230ae39fff5102ba5c0d

With the removal of i4X4 and SPLIT_MV modes, the two entries for the
modes are no longer used. This patch remove the coding of the deltas.

Change-Id: Iea4eb500404ebe9706159380a03b8eca542fb4c3

The new neighorbhood adapts to the shape and size of the block type
cif +.16%
stdhd +.13%

Change-Id: I978db58278e9ae3fbd6726ef831bdfc5f5f37d02

This reverts commit c2574414

Change-Id: Ie9013cb0bb43e639e01b4588f630b1da59295d38

Changes to the coding of transform sizes, along with forward
and backward probability updates.

Results:
derf300: +0.241%

Context based coding of transform sizes will be in a separate
patch.

Change-Id: I97241d60a926f014fee2de21fa4446ca56495756

Wrong max data size (skip has no data) and use of vp9_get_segdata()
when it should be vp9_segfeature_active().

Change-Id: I1eb97d33df6e2a42cc589049f704266fe3639902

In the longer term the encoder should allow compound as long
as one of the buffers has opposite sign bias and as per the decoder
this buffer is then set as the fixed reference. However at the moment
the encoder and RD loop only supports the case where the ALTREF_FRAME
buffer (or third of the 3 allowed in any given frame) is the odd one out.

This patch fixes a bug that would allow compound inter and set
fixed ref to ALTREF_FRAME when it is not the odd one out.

Change-Id: Ic83a69486e088a147ba83a4aedc2a0042f6b3721

Adds the ability to have the decoder show one of the existing reference
frames directly, without having to code it indirectly as a series of
skip blocks.

Change-Id: Ib6c26c5f6a8709863cf304ab890db8559687d25e

Adds 3 bits for colorspace (sent on keyframes), 2 bits for version.

Change-Id: Iaa0cf1dcdd085cebb46e2bc4a7c78cd33cf24325

Adds a marker bit to allow distinguishing the frame header from its residual
data.

Change-Id: Id75d47acc9e5a97007e4690c4f8748a4ce63e641

Change-Id: I8fd21e3a8435b873c5687d8b273922fc60988295

ref_frame in MB_Mode_Info was changed in the ref frame coding patch
to be an array to handle first and second reference frame, this patch
fix the loop filter code that use the pointer directly as reference
frame.

Change-Id: I71afa5a49deb50c1bc38029fd07470b984c6dfe9

As all intra predictions happen on squared transform block now.

Change-Id: I7ec91e3f0ad01383a03d2bd3099bbf32e87e3466

Change-Id: Ic22f416a33de558519d5c30a929f6a954546ade9

Change-Id: I47a9857d35da1bff6153f8090c6b98b689b31a61

Code intra/inter, then comp/single, then the ref frame selection.
Use contextualization for all steps. Don't code two past frames
in comp pred mode.

Change-Id: I4639a78cd5cccb283023265dbcc07898c3e7cf95

This fixes a valgrind error.

Change-Id: I0e1ef212ba09d65e3d71dd209f0786ae6530d2c8