The ABOVESPREFMV experiment uses four pixels to the left of the
current block, which don't exist for the left-most column.

Change-Id: I4cf0b42ae8f54c0b3e7b1ed8755704b74fafc39c

Update the code to call the new convolution functions to do subpixel
prediction rather than the existing functions. Remove the old C and
assembly code, since it is unused. This causes a 50% performance
reduction on the decoder, but that will be resolved when the asm for
the new functions is available.

There is no consensus for whether 6-tap or 2-tap predictors will be
supported in the final codec, so these filters are implemented in
terms of the 8-tap code, so that quality testing of these modes
can continue. Implementing the lower complexity algorithms is a
simple exercise, should it be necessary.

This code produces slightly better results in the EIGHTTAP_SMOOTH
case, since the filter is now applied in only one direction when
the subpel motion is only in one direction. Like the previous code,
the filtering is skipped entirely on full-pel MVs. This combination
seems to give the best quality gains, but this may be indicative of a
bug in the encoder's filter selection, since the encoder could
achieve the result of skipping the filtering on full-pel by selecting
one of the other filters. This should be revisited.

Quality gains on derf positive on almost all clips. The only clip
that seemed to be hurt at all datarates was football
(-0.115% PSNR average, -0.587% min). Overall averages 0.375% PSNR,
0.347% SSIM.

Change-Id: I7d469716091b1d89b4b08adde5863999319d69ff

This commit makes the NearestMV match the chosen
best reference MV. It can be a 0,0 or non zero vector
which means the the compound nearest mv mode can
combine a 0,0 and a non zero vector.

Change-Id: I2213d09996ae2916e53e6458d7d110350dcffd7a

Adds an error-resilient mode where frames can be continued
to be decoded even when there are errors (due to network losses)
on a prior frame. Specifically, backward updates are turned off
and probabilities of various symbols are reset to defaults at
the beginning of each frame. Further, the last frame's mvs are
not used for the mv reference list, and the sorting of the
initial list based on search on previous frames is turned off
as well.

Also adds a test where an arbitrary set of frames are skipped
from decoding to simulate errors. The test verifies (1) that if
the error frames are droppable - i.e. frame buffer updates have
been turned off - there are no mismatch errors for the remaining
frames after the error frames; and (2) if the error-frames are non
droppable, there are not only no decoding errors but the mismatch
PSNR between the decoder's version of the post-error frames and the
encoder's version is at least 20 dB.

Change-Id: Ie6e2bcd436b1e8643270356d3a930e8989ff52a5

Change-Id: Iac7f3d108863552b850c92c727e00c95571c9e96

Change-Id: Ibcc342efac0a9be7a21d9b2c09984d9e16bbb225

Change-Id: If6c88752dffdb566f8d4322f135145270716fb8e

Change-Id: I0df99742029834a85c4933652b0587cf5b6b2587

About 5% decoder speedup.

Change-Id: Ib6687d337af758a536a0e7e289f400990f1f9794

3.2% gains on std/hd, 1.0% gains on hd.

Change-Id: I481d5df23d8a4fc650a5bcba956554490b2bd200

For coefficients, use int16_t (instead of short); for pixel values in
16-bit intermediates, use uint16_t (instead of unsigned short); for all
others, use uint8_t (instead of unsigned char).

Change-Id: I3619cd9abf106c3742eccc2e2f5e89a62774f7da

Some further changes and refactoring of mv
reference code and selection of center point for
searches. Mainly relates to not passing so many
different local copies of things around.

Some place holder comments.

Change-Id: I309f10ffe9a9cde7663e7eae19eb594371c8d055

This patch reduces the cpu cost of the MV ref
search by only allowing insert for candidates
that would be in the current top 4.

This could alter the outcome and slightly favors
near candidates which are tested first but also
limits the worst case loop count to 4 and means in
many cases it will drop out and not happen.

Change-Id: Idd795a825f9fd681f30f4fcd550c34c38939e113

clears up some warnings

Change-Id: I9899637497c6ad7519f098e055ab98580ae6d688

Change-Id: Ia1cce221f8511561b9cbd8edb7726fbc286ff243

Support for gyp which doesn't support multiple objects in the same
static library having the same basename.

Change-Id: Ib947eefbaf68f8b177a796d23f875ccdfa6bc9dc

Vp9_sad3x16_sse2() is heavily called in decoder, in which the
unaligned reads consume lots of cpu cycles. When CONFIG_SUBPELREFMV
is off, the unaligned offset is 1. In this situation,
we can adjust the src_ptr to be 4-byte aligned, and then do the
aligned reads. This reduced the reading time significantly. Tests
on 1080p clip showed over 2% decoder performance gain with
CONFIG_SUBPELREFM off.

Change-Id: I953afe3ac5406107933ef49d0b695eafba9a6507

duplicate code clean-up and variable name corrections

Change-Id: Ibc4703228e652ec425125de5e7bc038fa46595c5

Change-Id: I7b6f27826052eb706fc6080d4e3a940dff7d3a58

Change-Id: I417e39867c020a17d85370972446a8ce2bbe9a6d

This change is a fix / extension of the newbestrefmv
experiment. As such it is presented without IFDEF.

The change creates a new context for coding inter modes
in vp9_find_mv_refs(). This replaces the context that
was previously calculated in vp9_find_near_mvs().
The new context is unoptimized and not necessarily
any better at this stage (results pending), but eliminates
the need for a legacy call to vp9_find_near_mvs().
Based on numbers from Scott, this could help decode
speed by several %.

In a later patch I will add support for forward update of
context (assuming this helps) and refine the context as
necessary.

Change-Id: I1cd991b82c8df86cc02237a34185e6d67510698a

Preliminary patch on a new 4x4 intra mode B_CONTEXT_PRED where the
dominant direction from the context is used to encode. Various decoder
changes are needed to support decoding of B_CONTEXT_PRED in conjunction
with hybrid transforms since the scan order and tokenization depends on
the actual direction of prediction obtained from the context. Currently
the traditional directional modes are used in conjunction with the
B_CONTEXT_PRED, which also seems to provide the best results.

The gains are small - in the 0.1% range.

Change-Id: I5a7ea80b5218f42a9c0dfb42d3f79a68c7f0cdc2

Change-Id: Ib39ad47a7d188f3b45416937b7eeb28c3e79b74c

In the variance calculations the difference is summed and later squared.
When the sum exceeds sqrt(2^31) the value is treated as a negative when
it is shifted which gives incorrect results.

To fix this we force the multiplication to be unsigned.

The alternative fix is to shift sum down by 4 before multiplying.
However that will reduce precision.

For 16x16 blocks the maximum sum is 65280 and sqrt(2^31) is 46340 (and
change).

This change is based on:
16982342 Missed some variance casts
fea3556e Fix variance overflow

Change-Id: I2c61856cca9db54b9b81de83b4505ea81a050a0f

Change-Id: Iedaa108ddb65f54d768424f9c47ad4d069b656fd

Change-Id: Ic084c475844b24092a433ab88138cf58af3abbe4

For non-static functions, change the prefix to vp9_. For static functions,
remove the prefix. Also fix some comments, remove unused code or unused
function prototypes.

Change-Id: I1f8be05362f66060fe421c3d4c9a906fdf835de5

This change encompasses VP8_PTR, VP8_COMP, VP8D_COMP, VP8_COMMON,
VP8Decompressor and VP8Common.

Change-Id: I514ef4ad4e682370f36d656af1c09ee20da216ad

For local symbols, make them static instead.

Change-Id: I13d60947a46f711bc8991e16100cea2a13e3a22e

Change-Id: Ic5a5f60e1ff9d9ccae4174160d36529466eeb509

As suggested by Paul, this commit separate the subpel refmv selection
into a separate experiment. It also changed a couple variable names
to better reflect the nature of the variables.

Change-Id: Id951c3cadc61a982dd15afe641000f60213b8995

Previously, in evaluating reference motion vectors, MVs are always
rounded to integer pixel position and SADs are calculated.  This
commit takes into account the subpixel portion of the mvs, and uses
bilinear interpolation to produce reference pixel values in subpixel
postions. In addition, SSE is used in place of SAD. Pixels used are
16x2 above and 2x16 to the left.

This commmit intends to test the potential of this line of work in
term of compression improvement, obviously, the change would increase
decoder complexity significantly.

Test results
std-hd: 1.738%(avg) 1.779%(glb), 1.663%(ssim)
derf: 0.472%(avg) 0.477%(glb), 0.418%(ssim)

Change-Id: I3ae1b098f6289df78891134d9a5e4bb2fde87a0b

Coding and costing of mv reference signal.

Issues in updating MV ref with COMPANDED_MVREF_THRESH
to be resolved. Ideally the MV precision should be defined based
on absolute MV magnitude not as now the MV ref magnitude.

Update to mv counts moved into bitstream.c because otherwise
if the motion reference is changed at the last minute the encoder
and decoder get out of step in terms of the counts used to update
entropy probs.

Code working on a few test clips but no results yet re benefit vs
signaling cost and no tuning of red loop to test lower cost alternatives
based on the available reference values.

Patch 3. Added check to make sure we don't pick a reference
that would give rise to an uncodeable / out of range residual.

Patch 6-7: Attempt to rebase. OK to submit but best to leave flag off for now.

Patch 9. Remove print no longer needed.

Change-Id: I1938c2ffe41afe6d3cf6ccc0cb2c5d404809a712

Removes the old mv encoding code.

Change-Id: I1026d48cc5ac15ccb776f98463e929254c3dc7da

The previous double if and else code snippets were rather confusing.

Change-Id: Id1b6152fa0e471beb9b20407aa406e109c1471e3

Change-Id: I5bca7b7a4b230082d36ac6fb84db84137ad177d7

The commit changed to avoid using pixels from extended border in
in evaluating and select best reference motion vector.

Change-Id: I39b758889373e42ed2889d59744388e5b9c1a20a

The commit changed to use 3 rows above and 3 cols from left for SAD
scoring for selecting the best reference motion vector. The change
helped std-hd set by >.2% on psnr/ssim metrics.

Change-Id: Ifad3b528d0b4b6e3c22518af789d76eff23c1520

The high-precision (1/8) pel bit is turned off if the reference
MV is larger than a threshold. The motivation for this patch is
the intuition that if motion is likely large (as indicated by
the reference), there is likley to be more motion blur, and as
a result 1/8 pel precision would be wasteful both in rd sense
as well as computationally.

The feature is incorporated as part of the newmventropy experiment.
There is a modest RD improvement with the patch. Overall the
results with the newmventropy experiment with the threshold being
16 integer pels are:

derf: +0.279%
std-hd: +0.617%
hd: +1.299%
yt: +0.822%

With threshold 8 integer pels are:

derf: +0.295%
std-hd: +0.623%
hd: +1.365%
yt: +0.847%

Patch: rebased
Patch: rebase fixes

Change-Id: I4ed14600df3c457944e6541ed407cb6e91fe428b

This commit merges those parts of the CONFIG_NEW_MVREF
that specifically relate to choosing a better set of candidate
MV references into the NEWBESTREFMV experiment.

CONFIG_NEW_MVREF will then be used for changes relating
to the explicit coding of a cost optimized MV reference in the
bitstream as part of MV coding.

Change-Id: Ied982c0ad72093eab29e38b8cd74d5c3d7458b10