This version of the loop filter supports non-4:2:0 subsampling and
a fourth plane, as well as changing the filtering order to be more
friendly to hardware implementations.

The filters are applied first to all vertical edges within the
64x64 SB, followed by the top horizontal edge and any internal
horizontal edges. Since filtering is applied on each 4x4 edge
serially, a dependency is created from filtering one block edge
to the next. It would be possible to remove this depencnecy by
building all filtering decisions from the unfiltered
reconstruction data.

Change-Id: I08f3e9683eb7bded8a76651cbc50fc0dfdd05fa7

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

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

Change-Id: I1a979bf74c286b157c31bab6bdcba0494acb4918

Removal from under configure flag.
A bit  renaming

Change-Id: I2213229dfe852001dfec16b149f47c52ce88f3aa

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

Merge this experiment so that it is under a speed feature
flag not a configuration flag.

Change-Id: I536f7f125a4ff5149bb3a64f791e835c324535fd

Merges the experiment.

Change-Id: I4eb19af6de6df6aa3a96a2e82f231d47ed9b3ae9

This is a mostly-working implementation of an extra channel in the
bitstream. Configure with --enable-alpha to test. Notable TODOs:

 - Add extra channel to all mismatch tests, PSNR, SSIM, etc
 - Configurable subsampling
 - Variable number of planes (currently always uses all 4)
 - Loop filtering
 - Per-plane lossless quantizer
 - ARNR support

This implementation just uses the same contents as the Y channel
for the A channel, due to lack of content and general pain in
playing back 4 channel content. A later patch will use the actual
alpha channel passed in from outside the codec.

Change-Id: Ibf81f023b1c570bd84b3064e9b4b8ae52e087592

In current code, motion vectors got from single prediction mode are used
in compound prediction mode directly. These motion vectors may not give
accurate prediction since they are searched independently. In this patch,
we took Pascal's suggestion, and did joint motion search in compound
prediction mode to find better motion vectors in this situation.
Test results:
Overall PSNR: 0.570%(derf), 0.918%(stdhd);
SSIM: 0.572%(derf), 1.009%(stdhd);

The encoder is a little slower. This can be improved since some c
code is used in motion search.

Change-Id: Ib30c9240f6c56c9b070867b4ca89412a76d9f3c6

Delete code under the CONFIG_CODE_ZEROGROUP flag.

Change-Id: I5fe6c7b42a5da9b73118e33594301da4129f320a

Delete code under the CONFIG_COMP_INTERINTRA_PRED
flag.

Change-Id: I3d1079cf46305c08f7e11d738596ea112e7b547f

Clean out code under CONFIG_ENABLE_6TAP flag.

Change-Id: Ic45b624081181027d6ba24d55dd644c3197f9830

Clean out code relating to newbintramode.

Change-Id: Ie91f4f156cdf60ce0da8ca407c1c9cb00c7d0705

Macro ab4x4 contains experiments for recursive partition down to
4x4 block size.

Change-Id: Ic727842fa98a4df9fd51e0025a545dc76a5c76c1

Pull sb8x8 out of experimental list. verified via borg run tests.
Fixed unit test failures.

Change-Id: I12a4bbd17395930580c048ab68becad1ffe46e76

Adds a new experiment CONFIG_NON420 that allows other chroma subsamplings
to be passed to the codec. This commit allows the data to be passed from
a y4m input file through vpxenc to the codec, where they're currently
rejected. Later commits will finish support for this inside the codec.

Change-Id: Ib3aac604d8cad9e24cef395fa1067f16ba7e8e43

(while still abusing the gcc targets)

Change-Id: I40f33f619ed1ee760caf23f5598587b30cf8a9ed

Move rectangular superblock coding out of experimental list.

Change-Id: I96c37547d122330d666a67b4bf577ae54547857f

Change-Id: I274a1d2e461e6ffdb106bac4ad6951692ace314e

Change-Id: Ibe0628905925fc81bbb192651276f417c2aa7552

This patch does not seem to give any benefits.

Change-Id: I9d2b4091d6af3dfc0875f24db86c01e2de57f8db

Adds an experiment that codes an end-of-orientation symbol
for every eligible zero encountered in scan order.

This cleans out various other sub-experiments that were part
of the origiinal patch, which will be later included if found
useful.

Results are slightly positive on all sets (0.1 - 0.2% range).

Change-Id: I57765c605fefc7fb9d1b57f1b356843602abefaf

This experiment has failed to give much benefit but
does add complexity so deprecated.

Change-Id: Ic7b929ba706390b9907ef0b4f965bd401ca799a4

that are related to using reconstructed pixel for selecting reference
motion vectors.

Change-Id: I048dfae39ca7385e344b57d46347ecc6e753e1bb

This is work-in-progress, it implements multiple ARF
encoding behind an experimental flag.

It adds the ability to insert multiple ARF frames into a
single ARF group. This patch implements the reordering
of the coded frames, and implements a fixed-length coding
pattern. It applies a fixed quantizer strategy based on
where the frame is in the coding sequence.

Further work to modify the rate control strategy is
ongoing and will be submitted via a set of future patches.

In this first step, each ARF group is recursively
bisected and an ARF frame added at that position in the
sequence. The recursion continues until ARF frames are
within MIN_GF_INTERVAL frames.

The code sits behind the "multiple-arf" experimental
flag ("CONFIG_MULTIPLE_ARF"). The experimental flag
"oneshotq" ("CONFIG_ONESHOTQ") also needs to be enabled
for this patch to work correctly.

Change-Id: Ie473b05ebb43ac473c0cfb659b2b8042823085e2

Merge sb32x32 and sb64x64 functions; allow for rectangular sizes. Code
gives identical encoder results before and after. There are a few
macros for rectangular block sizes under the sbsegment experiment; this
experiment is not yet functional and should not yet be used.

Change-Id: I71f93b5d2a1596e99a6f01f29c3f0a456694d728

so it is configurable to faciliate testings

Change-Id: I247b62736c3a08ec2934793959d1ae605a05efa3

This gains about 0.2% on derf, 0.1% on hd and 0.4% on stdhd. I can put
this under an experimental flag if wanted, just trying to get my patch
queue in shape.

Change-Id: Ibe1a30fe0e0b07bec4802e0f3ff0ba22e505f576

Adds an experiment to use a weighted prediction of two INTER
predictors, where the weight is one of (1/4, 3/4), (3/8, 5/8),
(1/2, 1/2), (5/8, 3/8) or (3/4, 1/4), and is chosen implicitly
based on consistency of the predictors to the already
reconstructed pixels to the top and left of the current macroblock
or superblock.

Currently the weighting is not applied to SPLITMV modes, which
default to the usual (1/2, 1/2) weighting. However the code is in
place controlled by a macro. The same weighting is used for Y and
UV components, where the weight is derived from analyzing the Y
component only.

Results (over compound inter-intra experiment)
derf: +0.18%
yt: +0.34%
hd: +0.49%
stdhd: +0.23%

The experiment suggests bigger benefit for explicitly signaled weights.

Change-Id: I5438539ff4485c5752874cd1eb078ff14bf5235a

Adds a per-frame, strength adjustable, in loop deringing filter. Uses
the existing vp9_post_proc_down_and_across 5 tap thresholded blur
code, with a brute force search for the threshold.

Results almost strictly positive on the YT HD set, either having no
effect or helping PSNR in the range of 1-3% (overall average 0.8%).
Results more mixed for the CIF set, (-0.5 min, 1.4 max, 0.1 avg).
This has an almost strictly negative impact to SSIM, so examining a
different filter or a more balanced search heuristic is in order.

Other test set results pending.

Change-Id: I5ca6ee8fe292dfa3f2eab7f65332423fa1710b58

Replaces the default tables for single coefficient magnitudes with
those obtained from an appropriate distribution. The EOB node
is left unchanged. The model is represeted as a 256-size codebook
where the index corresponds to the probability of the Zero or the
One node. Two variations are implemented corresponding to whether
the Zero node or the One-node is used as the peg. The main advantage
is that the default prob tables will become considerably smaller and
manageable. Besides there is substantially less risk of over-fitting
for a training set.

Various distributions are tried and the one that gives the best
results is the family of Generalized Gaussian distributions with
shape parameter 0.75. The results are within about 0.2% of fully
trained tables for the Zero peg variant, and within 0.1% of the
One peg variant.

The forward updates are optionally (controlled by a macro)
model-based, i.e. restricted to only convey probabilities from the
codebook. Backwar...

New decoder control paramter VP8_SET_DECRYPT_KEY to set the decryption key.

Change-Id: I6fc1f44d41f74f3b3f702778af1a6f8f5cc9439f

and turn the experiment off by default.

Change-Id: If9e684aa6cc49eacd39f36645a110a447e38d2de

This patch revamps the entropy coding of coefficients to code first
a non-zero count per coded block and correspondingly remove the EOB
token from the token set.

STATUS:
Main encode/decode code achieving encode/decode sync - done.
Forward and backward probability updates to the nzcs - done.
Rd costing updates for nzcs - done.
Note: The dynamic progrmaming apporach used in trellis quantization
is not exactly compatible with nzcs. A suboptimal approach has been
used instead where branch costs are updated to account for changes
in the nzcs.

TODO:
Training the default probs/counts for nzcs

Change-Id: I951bc1e22f47885077a7453a09b0493daa77883d

Change-Id: I35e64998b25694a3bb4a62164bba3c03c1db4bc7

Rebased.

Remove the old matrix multiplication transform computation. The 16x16
ADST/DCT can be switched on/off and evaluated by setting ACTIVE_HT16
300/0 in vp9/common/vp9_blockd.h.

Change-Id: Icab2dbd18538987e1dc4e88c45abfc4cfc6e133f

Change-Id: I7b7b8d4fda3a23699e0c920d727f8c15d37d43aa

rebased.

This patch includes 16x16 butterfly inverse ADST/DCT hybrid
transform. It uses the variant ADST of kernel
    sin((2k+1)*(2n+1)/4N),
which allows a butterfly implementation.

The coding gains as compared to DCT 16x16 are about 0.1% for
both derf and std-hd. It is noteworthy that for std-hd sets
many sequences gains about 0.5%, some 0.2%. There are also few
points that provides -1% to -3% performance. Hence the average
goes to about 0.1%.

Change-Id: Ie80ac84cf403390f6e5d282caa58723739e5ec17

Removal of the  NEWCOEFCONTEXT experiment to
reduce code clutter and make it easier to experiment with
some other changes to the coefficient coding context.

Change-Id: Icd17b421384c354df6117cc714747647c5eb7e98