In the partition search, the encoder checks all possible
partitionings in the superblock's partition search tree.
This patch proposed a set of criteria for partition search
early termination, which effectively decided whether or
not to terminate the search in current branch based on the
"skippable" result of the quantized transform coefficients.
The "skippable" information was gathered during the
partition mode search, and no overhead calculations were
introduced.

This patch gives significant encoding speed gains without
sacrificing the quality.

Borg test results:
1. At speed 1,
   stdhd set: psnr: +0.074%, ssim: +0.093%;
   derf set:  psnr: -0.024%, ssim: +0.011%;
2. At speed 2,
   stdhd set: psnr: +0.033%, ssim: +0.100%;
   derf set:  psnr: -0.062%, ssim: +0.003%;
3. At speed 3,
   stdhd set: psnr: +0.060%, ssim: +0.190%;
   derf set:  psnr: -0.064%, ssim: -0.002%;
4. At speed 4,
   stdhd set: psnr: +0.070%, ssim: +0.143%;
   derf set:  psnr: -0.104%, ssim: +0.039%;

The speedup ranges from several percent to 60+%.
                 speed1    speed2    speed3    speed4
(1080p, 100f):
old_town_cross:  48.2%     23.9%     20.8%     16.5%
park_joy:        11.4%     17.8%     29.4%     18.2%
pedestrian_area: 10.7%      4.0%      4.2%      2.4%
(720p, 200f):
mobcal:          68.1%     36.3%     34.4%     17.7%
parkrun:         15.8%     24.2%     37.1%     16.8%
shields:         45.1%     32.8%     30.1%      9.6%
(cif, 300f)
bus:              3.7%     10.4%     14.0%      7.9%
deadline:        13.6%     14.8%     12.6%     10.9%
mobile:           5.3%     11.5%     14.7%     10.7%

Change-Id: I246c38fb952ad762ce5e365711235b605f470a66

Updates the vp9_pattern_search function to return integer one-away
neighbors' sad values, for subsequent use in speeding up the
sub-pel search. Also, removes code for the do_refine option
which is not being used currently.
Updates the integer and subpel functions to pass in a 5-element
sad list for output or input.

A new pruned sub-pel search algorithm is implemented that uses
the sad returned from the integer pel search. But it is not
deployed yet.

Change-Id: Ifa9f5ad024b5b660570366d2bd900343e1891520

Change-Id: I94667a23046e3cf17c421ac97ca66ea57f846b5c

This commit re-work the operation flow related to prediction
residual generation and the rate-distortion modeling. It saves one
call for model_rd_for_sb.

Change-Id: Icaf96c0ff09c903637ed5283448afe01d798195f

The value of switchable rate has been stored in a local variable.
This change skips the second call to vp9_get_switchable_rate() by
reusing the local variable.

Change-Id: Ib7d3fef7621cc4bde94c6d6e6b3a71f1fd4559f2

Check the mode and motion vector cost. If it is already above
the existing best rate-distortion cost, skip the rest check process
on this mode.

Change-Id: Ie065cebdfda2a3be3be18b8e8b43dc29aaa8c179

This commit makes the rate distortion modeling run in the unit of
maximum transform block size. No compression/speed change observed.
It is for the use of later fast forward transform purpose.

Change-Id: Ibaaedb69c765e8d0c5d5012f0ec07f36fd9f68fd

Change-Id: Ibc91a46d11ad9c58e340b4346ed813a1be9b404a

Keep one test, BasicBufferModel, with denoiser set off.

Change-Id: I762c2004b3adca24f677535cfa5b991108f31f01

Change-Id: I483a2fefc5f9ea4533dfd64448f3b6b426dd9eed

Change-Id: I7f3bc292b1b411e10586f0975143ae996ea78d1d

This commit addes a new strategy to reduce the search for optimal
interpolation filter type. The encoder counts and store how many each
filter type is selected and used for each of the reference frames.
A filter type that is rarely used for all three reference frames is
masked out to avoid computation.

The impact on compression is neglectible:
-0.02% on derf
+0.02% on stdhd

Encoding time is seen to reduce by 2~3%.

Change-Id: Ibafa92291b51185de40da513716222db4b230383

Change-Id: Ib04a545b43f3a36c6df7eaf3ed2d802cf41119bb

We don't output invisible frames with VP9.

Change-Id: I7b874d3ac454c1b2966d5d7d72e12a864b49afae

Echo args back from new util functions to decrease the repetition
in this file.

Change-Id: Id4d7c02bf81cf2c5261f58b560e033869a346677

The variable is never read.

Change-Id: I94141c1667fa5d10604cd6f83c5f64df107dee94

- Make $1 input file at all call sites.
- Actually use vpxenc_pipe().

Change-Id: I22f25719aeb3dce60863207b2e2a49e42e27ed06

Change-Id: I3e319f581215ccb814afca247c1d911be231a4ac