Speed feature experiment to set an upper and lower
partition size limit based on what has been seen
in spatial neighbors.

This seems to gives quite reasonable speed gains in local
(10-15%) and when used with speed 0 the losses are small
(0.25% derf, 0.35% stdhd). However, for now I am only
enabling it on speed 1 as there may be clashes with the existing
temporal partition selection in speed 2.

Using a tighter min / max around the range derived from the
neighbors increases speed further but at the cost of a
bigger quality loss. However,  I think this spatial method could
be combined with data from either the last frame or a variance
method (or both) to refine the range of minimum and maximum
partition size. I.e. consider the min and max from spatial and
temporal neighbors and the variance recommendation.

Change-Id: I1b96bf8b84368d6aad0c7aa600fe141b4f07435f

This option exists in VP8, and it was rewritten in VP9 to support
skipping on different partition levels. After prediction is done,
we can check if the residuals in the partition block will be all
quantized to 0. If this is true, the skip flag is set, and only
prediction data are needed in reconstruction. Based on DCT's energy
conservation property, the skipping check can be estimated in
spatial domain.

The prediction error is calculated and compared to a threshold.
The threshold is determined by the dequant values, and also
adjusted by partition sizes. To be precise, the DC and AC parts
for Y, U, and V planes are checked to decide skipping or not.

Test showed that
1. derf set:
when static-thresh = 1, psnr loss is 0.666%;
when static-thresh = 500, psnr loss is 1.162%;
2. stdhd set:
when static-thresh = 1, psnr loss is 1.249%;
when static-thresh = 500, psnr loss is 1.668%;

For different clips, encoding speedup range is between several
percentage and 20+% when static-thresh <= 500. For example,
clip            bitrate  static-thresh psnr    time
akiyo(cif)       500        0          48.923  5.635s(50f)
akiyo            500        500        48.863  4.402s(50f)

parkjoy(1080p)   4000       0          30.380  77.54s(30f)
parkjoy          4000       500        30.384  69.59s(30f)

sunflower(1080p) 4000       0          44.461  85.2s(30f)
sunflower        4000       500        44.418  78.1s(30f)

Higher static-thresh values give larger speedup with larger
quality loss.

Change-Id: I857031ceb466ff314ab580ac5ec5d18542203c53

Change-Id: I0625d8ffddf590dfecd1bb8b8d6f57ef64b8bf18

Change-Id: Ia6144d77ebed66e0739b62e4d673e26a95aa9550

Simplified the code that extracts and uses the motion
vectors for the 4 sub-partitions in rd_pick_partition.

Change-Id: Iaf698ef7ee3aef9edd59015e1ae065dd359b17d9

This commit makes the initialization of trellis coeff optimization
a per-plane operation, thereby eliminating the redundant steps in
encode_sby and encode_sbuv. It makes the encoder at speed 0 slightly
faster.

Change-Id: Iffe9faca6a109dafc0dd69dc7273cbdec19b17cd

Already defined in vp9_seg_common.h.

Change-Id: I5a0e3fa15966b1ebeb77ccd506b55fc231c22342

Moving code from vp9_adapt_mode_context to vp9_adapt_mode_probs.

Change-Id: I60829c30b28968cd813551ef3a206dfb98d323c9

The feature that uses small partition results as a measure to skip
mode evaluation at larger partition requires the flags to be reset.
The reset was missing in the code path that calls rd_use_partition().

Change-Id: Ia0a3a0aee1a862b6e2333d596808db7c48033d50

Add SSE2 implementation to handle the special case of inverse 2D-DCT
where only DC coefficient is non-zero.

Change-Id: I2c6a59e21e5e77b8cf39a4af5eecf4d5ade32e2f

Adding common merge_probs and merge_probs2 functions. Changing ints to
usigned ints in some places.

Change-Id: Icf088ffdea7cf5b95284a128916409bdd53506b0

Change-Id: I21ee76bcae101cc9f6ef1d867622e50b7ae565fc

They share the same functionality, so merging together.

Change-Id: I98a0386fcee052cb854f9ff90c283c1b844bcb79

Change-Id: I61a8b0101eac3ee2e0621d56151b90c269fd4db4

Change-Id: Ic99d07a56b1752ec49fc5074b1dd6804b17609a0

Prior to 73c4e284, the generated .sln files didn't contain any
information about the different configurations when using .vcxproj
project files. The MSVS IDE was able to fill this in just fine when
loaded though.

When building for ARM, the obj_int_extract project still is built
for x86, in order for the build process to be able to use
obj_int_extract.exe.

Now that configuration info is generated, it breaks current ARM
setups, since the configurations generated by gen_msvs_sln.sh only
included configurations from the last parsed project file (as
mentioned in the comment).

In these setups, the MSVS IDE generated a third meta-platform, called
"Mixed Platforms". This meta-platform points to either ARM or
Win32 as platform in each of the individual projects.

When the MSVS IDE generated this automatically, it also included
the original ARM and Win32 platforms as separate choices, but these
can be omitted since they don't make sense.

Change-Id: Ie2522...

Adding plane type check condition because it was always used outside of
get_tx_type_{4x4, 8x8, 16x16}.

Change-Id: I02f0bbfee8063474865bd903eb25b54d26e07230

variable was write only

Change-Id: I04b002178f66961836ee08fb60a05b91b54e91d8

Although local copies of the mode member variables
(mode, ref_frame) were made, they were not used in
all places. Also, made a local copy of the
second_ref_frame member.

Change-Id: I84d8c822e5cb3d8a02fc3de8a4037ca3fea8bfad

Change-Id: Id4138293efeac4503b2e01ce7a6c150a5abeef77