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

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

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

Change-Id: I0ca77329d882a2026f6c1941b8e447d86bc87bda

Split partition probabilities between keyframes and non-keyframes,
since they are fairly different. Also have per-blocksize interframe
y intramode probabilities, since these vary heavily between different
blocksizes.

Lastly, replace default probabilities for partitioning and intra modes
with new ones generated from current codec. Replace counts with actual
probabilities also.

Change-Id: I77ca996e25e4a28e03bdbc542f27a3e64ca1234f

This avoids encoding tokens for blocks that are entirely
in the UMV border. This changes the bitstream.

Change-Id: I32b4df46ac8a990d0c37cee92fd34f8ddd4fb6c9

Bits moved: refresh_frame_flags, active_ref_idx[], ref_frame_sign_bias[],
allow_high_precision_mv, mcomp_filter_type, ref_pred_probs[].

Derf results: +0.040%

Change-Id: I011f43c7eac0371d533b255fd99aee5ed75b85a5

Adds backward adaptation and differential forward updates of switchable
interpolation filter probabilities. Also adds some cosmetic cleanups
and minor fixes on mv_ref probabilities.

derfraw300: +0.353% (with most coming from switchable interp changes)

Change-Id: Ie2718be73528c945fd0d80cfd63ca2d9cb3032de

Overall PSNR drop on derf set is -0.024.

Change-Id: I1c05d2ace83488205ca16e3b06cd5f0ebceec8d6

Change-Id: I2dfc569106b29fbe4da20585a0e85e5e9ea6a4db

Change-Id: Ieb4669ae564bec9f3051485ecdf186cb4e00decb

It remains as a local define in rdopt.c so we can distinguish between
split and non-split modes in the RD loop, but disappears outside that
scope in the codec.

Change-Id: I98c18fe5ab7e4fbd1d6620ec5695e2ea20513ce9

Also merge all counters. This removes a few unused probability updates
from the bitstream.

Change-Id: I20f58853e9dac84d8c0d9703ae012c55917516eb

This patch removes the implicit segmentation
experiment from the code base as the benefits
were still unproven as of the bitstream deadline.

Change-Id: I273b99d8d621d1853eac4182f97982cb5957247e

Added two flags to the frame header:

intra_only:
Signals that the frame is encoded using only INTRA
coding modes.

reset_frame_context:
Indicates that the coding context specified
in the frame header should be reset to default values before the
frame is encoded/decoded.

Change-Id: I182d46f1f84fb67a13c46ad767f246a38d7861a2

This patch changes the coefficient tree to move the EOB to below
the ZERO node in order to save number of bool decodes.

The advantages of moving EOB one step down as opposed to two steps down
in the other parallel patch are: 1. The coef modeling based on
the One-node becomes independent of the tree structure above it, and
2. Fewer conext/counter increases are needed.

The drawback is that the potential savings in bool decodes will be
less, but assuming that 0s are much more predominant than 1's the
potential savings is still likely to be substantial.

Results on derf300: -0.237%

Change-Id: Ie784be13dc98291306b338e8228703a4c2ea2242

This patch checks at the frame level to see if the previous
mode info context can be used.  This patch eliminates the
flag check that was done for every mode and removes another
check that was done prior to every vp9_find_mv_refs().

Change-Id: I9da5e18b7e7e28f8b1f90d527cad087073df2d73

Adding API to read/write uncompressed frame header bits (it is not final
yet). Separate functions to read/write uncompressed header. Moving
clr_type, error_resilient_mode, refresh_frame_context,
frame_parallel_decoding_mode, frame_context_idx from compressed partition
to uncompressed frame header.

Change-Id: Id3ed8a387980c652ae147549412f4ec24a0a5bd0

This reverts commit df037b61

Change-Id: I1a529f2590df7bc912f5035d22311268933e3dd6

Also do per-partition motion vector referencing in <sb8x8 partitions,
and adjust mvref finding for sub8x8 partitions.

Change-Id: Id3ed1ed4d2a8910d11d327db6cc63b8eb79f941f

Change-Id: I1a979bf74c286b157c31bab6bdcba0494acb4918

As intra coded blocks are always decoded using decode_sb_intra(), this
commmit removed the code no longer in use.

Change-Id: I09f14fa9cdc875656e8fbe245f72c8fd83b9e31e

Move 4x4/4x8/8x4 partition coding out of experimental list.

This commit fixed the unit test failure issues. It also resolved
the merge conflicts between 4x4 block level partition and iterative
motion search for comp_inter_inter.

Change-Id: I898671f0631f5ddc4f5cc68d4c62ead7de9c5a58

This commit changed the encoding and decoding of intra blocks to be
based on transform block. In each prediction block, the intra coding
iterates thorough each transform block based on raster scan order.

This commit also fixed a bug in D135 prediction code.

TODO next:
The RD mode/txfm_size selection should take this into account when
computing RD values.

Change-Id: I6d1be2faa4c4948a52e830b6a9a84a6b2b6850f6

The API is not final yet and can be changed. Actual layout of
uncompressed frame part will be finalized later. Right now moving
clr_type, error_resilient_mode, refresh_frame_context,
frame_parallel_decoding_mode from first compressed partition to
uncompressed frame part.

Change-Id: I3afc5d4ea92c5a114f4c3d88f96858cccc15b76e

Merges the experiment.

Change-Id: I4eb19af6de6df6aa3a96a2e82f231d47ed9b3ae9

Cleans up the experiment. Actually uses reduced counts for backward
updates, and reduced number of probabilities in the context.

No change in bitstream when the experiment is on.

Between expt on and off:
derfraw300 is down only -0.062% (which is better than when expts
were run previously).

Change-Id: I55285a049a0c22810bdb42914212ab5a4f8521b5

This patch eliminates the intermediate diff buffer usage by
combining the short idct and the add residual into one function.
The encoder can use the same code as well.

Change-Id: I296604bf73579c45105de0dd1adbcc91bcc53c22

The new code is 0x49, 0x83, 0x42

There is nothing particularly special about this code bitstream wise.
Its derivation is the word "sync" coded using 4x6bit alphabetic indices.

Change-Id: Ie2430a854af32ddc5a5c25a6c1c90cf6497ba647

The recursive partition type search is enabled down to 4x4, 4x8 and
8x4, followed by the corresponding rate-distortion optimization for
the per-partition encoding mode decisions.

The bit-stream writing/reading synchronized in supporting the
rectangular partition of 8x8 block.

This provides above 1% coding performance gains on derf.

To do next:
1. re-design the rate-distortion loop for inter prediction below 8x8.
2. re-design the rate-distortion loop for intra prediction below 4x4.
3. make the loop-filter aware of rectangular partition of 8x8 block.
4. clean the unused probability models.
5. update default probability values.

Change-Id: Idd41a315b16879db08f045a322241f46f1d53f20

Change-Id: Ica75bdd4905c4a04b7f92795d0b8ce6836a99ef4

Change-Id: If6aee510cbc4910f2f24fcd92dddc65fdf8edeea

Change-Id: I2408ad22717784a40e23701ccb9d978265440e4f

This commit allows the rate-distortion optimization recursion
at encoder to go down to 4x4 block size. It deprecates the use
of I4X4_PRED and SPLITMV syntax elements from bit-stream
writing/reading. Will remove the unused probability models in
the next patch.

The partition type search and bit-stream are now capable of
supporting the rectangular partition of 8x8 block, i.e., 8x4
and 4x8. Need to revise the rate-distortion parts to get these
two partition tested in the rd loop.

Change-Id: I0dfe3b90a1507ad6138db10cc58e6e237a06a9d6

Change band calculation back to simpler model based
on the order in which coefficients are coded in scan order
not the absolute coefficient positions.

With the scatter scan experiment enabled the results were
appear broadly neutral on derf (-0.028) but up a little on std-hd +0.134).

Without the scatterscan experiment on the results were up derf as well.

Change-Id: Ie9ef03ce42a6b24b849a4bebe950d4a5dffa6791

Move set_partition_seg_context_ to common file. Use consistent
context setup conditions for partition probability model update at
encoder and decoder.

Change-Id: I24b7ed3b1c48e3d2568191a46b70136b99b67b1a

Use common function to fetch/assign sb_index in rd loop, bit-stream
writing and reading.

Change-Id: I1d8a214a57ed9cbcd026040436ef33e5e39d65b7

This commit enables the search for the optimal superblock
partition types in the recursion form. The intention is to
make the optimization process more concise and ready to
support partition down to 4x4 block size next.

Change-Id: Iae279a67df3a7cc372553c84c775bc4d2f3e4336

Make framebuffer allocations according to the chroma subsamping
factors in use. A bit is placed in the raw part of the frame header for
each of the two subsampling factors. This will be moved in a future
commit to make them part of the TBD feature set bits, probably only set
on keyframes, etc.

Change-Id: I59ed38d3a3c0d4af3c7c277617de28d04a001853