Values now carried over frame to frame.
Change to algorithm for decreasing threshold after
a hit and to max threshold (now based on speed)

Removed some old commented out code relating to
VP8 adaptive thresholds.

The impact of these changes tested on Akiyo (50 frames)
and measured in terms of unit rd hits is as follows:

Speed 0 84.36 -> 84.67
Speed 1 29.48 -> 22.22
Speed 2 11.76 -> 8.21
Speed 3 12.32 -> 7.21

Encode speed impact is broadly in line with these.

Change-Id: I5b886efee3077a11553fa950d796fd6d00c8cb19

Most of the focus so far has been on inter frames.

At high speed settings the key frame is now taking a high %
of the cycles.

This patch puts in some masking to reduce the number
of INTRA modes searched during key frame coding (as already
happens for inter frames) at higher speed settings

TODO: Develop this further with either adaptive rd thresholds
when choosing which intra modes to consider or some other
heuristic.

Impact.
At high speed settings on some clips the key frame was starting
to dominate. In a coding of the first 50 frames of AKIYO at speed
2 limiting the key frame intra modes to DC or TM_PRED resulted in
~30% overall speedup. For Bus the number was lower at ~4-5%.

Change-Id: I7bde68aee04995f9d9beb13a1902143112e341e2

Put rectangular partition check flag change according to the rd
costs of NONE and SPLIT partition types under the speed feature.

Change-Id: If681e1e078a8d43d86961ea4b748da5cd1b6c331

vp9_short_idct10_16x16_add is used to handle the block that only have valid data
at top left 4x4 block. All the other datas are 0. So we could cut many
unnecessary calculations in order to save instructions.

Change-Id: I6e30a3fee1ece5af7f258532416d0bfddd1143f0

Removing unused get_sbuv_perpixel_variance function, using has_second_ref/
is_inter_block functions, organizing includes.

Change-Id: I016de4af12fbbb8b4ece26a70759b2392651b095

Change-Id: Ib7803857b35c00e317c9deb8630e777e25eb278f

gets rid of a mix of styles

Change-Id: I3591d312157bc6f53a25438bf047765c671fd8a8

remove duplicate allocation from vp9_create_compressor, it was added to
vp9_alloc_frame_buffers in:

d5bec522 Added resizing & initialization of last frame segment map

Change-Id: I996723226a16a62aff8f9a52ac74e0b73cc98fdf

Change-Id: Ieb7077ca3586b9491912027eed450a4f6fd38d30

This commit changes the partition search order of superblocks from
{SPLIT, NONE, HORZ, VERT} to {NONE, SPLIT, HORZ, VERT} for
consistency with that of sub8x8 partition search. It enable the use
of early termination in partition search for all block sizes.

For ped_area_1080p 50 frames coded at 4000 kbps, it makes the runtime
goes down from 844305ms -> 818003ms (3% speed-up) at speed 0.

This will further move towards making the in-search partition types
configurable, hence unifying various speed-up approaches.

Some speed 1 and 2 features are turned off during the refactoring
process, including:
disable_split_var_thresh
using_small_partition_info

Stricter constraints are applied to use_square_partition_only for
right/bottom boundary blocks. Will bring back/refine these features
subsequently. At this point, it makes derf set at speed 1 about
0.45% higher in compression performance, and 9% down in run-time.

Change-Id: I3db9f9d1d1a0d6cbe2e50e49bd9eda1cf705f37c

Adds a couple of minor fixes, which may be absorbed in Jingning's
patch. Thanks to Guillaume for pointing these out.
Also adjusts the thresholds for speed 1 and 2 to 16 and 32
respectively, to keep quality drops small.

Results:
--------
derfraw300:  threshold = 16, psnr -0.082%, speedup 2-3%
             threshold = 32, psnr -0.218%, speedup 5-6%
stdhdraw250: threshold = 16, psnr -0.031%, speedup 2-3%
             threshold = 32, psnr -0.273%, speedup 5-6%

Change-Id: I4b11ae8296cca6c2a9f644be7e40de7c423b8330

It appears that the above/left mb_skip_coeff used during
the pick modes, is left over from the previously
encode frame.  This patch initializes the flag to the default
value of zero.


Change-Id: Ida4684cc99611d6e3e82628db35ed717e28ce550

enable|disable -> (enable|disable)_feature

Change-Id: I7494913c78ebe8bb532fa6545e0ae53a79ccd388

+ disable() -> disable_feature() for balance

this avoids shadowing the bash builtin 'enable' allowing the scripts to
be linted with checkbashisms

Change-Id: Ia11cf86c92ec25bd14e69427b0ac0a9a61a5f7a5

Change-Id: I9f45af3894c57f35cb266c255e2b904295d39c34

currently protected by CONFIG_NON420 as v1 is still not entirely stable

Change-Id: Id1c5081b04a2c47a842822048b8804be67d23a6d

Change-Id: Ib2c975e1d96deefb7ac4d6b600c8c5388035d111

Change-Id: Ib3e72671eb8da6f2e9767a6de292ec7c7cde6bc7

Using size_group_lookup table and better variable names.

Change-Id: I6e67f2ce091845db43ace7d21b7ae31c6f165aec