Currently, the best quality mode in VP9 is not very well developed,
and unnecessarily makes the encode too slow. Hence the command line
default is changed to "good" quality. Also, the number of passes
default is changed to 2 passes as well, since 1-pass encoding is
not very efficient in VP9.

Besides, a number of VP9 defaults are set to the currently
recommended settings. With these changes, vpxenc
run with --codec=vp9 --kf-max-dist=9999 --cpu-used=0 should
work about the same as our borg results.
Note when the --cpu-used=0 option is dropped there will be a slight
difference in the output, because of a difference in the cpu-used
value for the first pass. Specifically, the default when unspecified
is to use cpu_used=1 for the first pass and cpu_used=0 for the
second pass. But when specified, both passes will use the cpu-used
value specified.

Note that this also changes the default for VP8 as being "good"
but other options stay unchanged.

Change-Id: Ib23c1a05ae2f36ee076c0e34403efbda518c5066

Adding set_contexts contexts function and call it instead of
set_contexts_on_border. Calling txfrm_block_to_raster_xy to get aoff and
loff.

Change-Id: I41897e344afd2cae1f923f4fdbe63daccf6fe80e

Change-Id: I32e43474e8651ef2eb181d24860a8f118cfea7bf

vp9_sad32x3, vp9_sad3x32

+ remove unnecessary sad include from vp9_findnearmv.c

Change-Id: Idef2a89cadc3fec64eff82ba9be60ffff50b3468

Change-Id: Ib394ea23f464591dad50b5c65c316701378d06d7

vp9_short_idct10_8x8_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 several
unnecessary calculations in order to save instructions.

Change-Id: I34fda95e29082b789aded97c2df193991c2d9195

Cleans up the switchable filter search logic. Also adds a
speed feature - a variance threshold - to disable filter search
if source variance is lower than this value.

Results: derfraw300
threshold = 16, psnr -0.238%, 4-5% speedup (tested on football)
threshold = 32, psnr -0.381%, 8-9% speedup (tested on football)
threshold = 64, psnr -0.611%, 12-13% speedup (tested on football)
threshold = 96, psnr -0.804%, 16-17% speedup (tested on football)

Based on these results, the threshold is chosen as 16 for speed 1,
32 for speed 2, 64 for speed 3 and 96 for speed 4.

Change-Id: Ib630d39192773b1983d3d349b97973768e170c04

The following issue was reported :
https://code.google.com/p/webm/issues/detail?id=601&q=jimbankoski&sort=-id&colspec=ID%20Pri%20mstone%20ReleaseBlock%20Type%20Component%20Status%20Owner%20Summary

This code makes the choice and code cleaner and removes any question
about whether the border needs to be checked.

Change-Id: Ia7aecfb3168e340618805bd318499176c2989597

Changes to code to auto select a partition size range
based on data from spatial neighbors.

Now looks at the sb_type in each 8x8 block of above
and left SB64.

The effect on speed 1 is now weaker giving better
quality but less speed gain. Now also used in speed 2.

Change-Id: Iace33a97d5c3498dd2a9a8a4067351941abcbabc

Removing VP9_FILTER_WEIGHT, VP9_FILTER_SHIFT, BLOCK_WIDTH_HEIGHT
constants. Using ROUND_POWER_OF_TWO for rounding.

Change-Id: I2e8d6858dcd600a87096138209731137d7decc24

Updating implementation of vp9_get_pred_context_single_ref_p1 using
has_second_ref function to make code easier to read.

Change-Id: Ie8f60403a7195117ceb2c6c43176ca9a9e70b909

As the pixel values beyond image border are duplicates of pixels
on edge, the change limits the mv search range, any mv beyond
the limits no longer produce new/different prediction values
as entire block with pixels used for subpel interpolation are
outside image border.

Change-Id: I4c6fdf06e33c1cef1489f5470ce0fb4e5e01fb79

For certain partition size, the function poniter may not be intialized
at all. The patch prevent the call if the pointer is not set.

Change-Id: I78b8c3992b639e8799a16b3c74f0973d07b8b9ac

Change-Id: Ib8af21f2e7f603c2fb407e5d15a3bba64b545b49

This commit enables early termination in the rate-distortion
optimization search loop for chroma components. When the cumulative
rd cost is above the current best value, skip the rest per-block
transform/quantization/coeff_cost and continue to the next
prediction mode.

For bus_cif at 2000 kbps, the average run-time goes down from
168546ms -> 164678ms, (2% speed-up) at speed 0
 36197ms ->  34465ms, (4% speed-up) at speed 1

Change-Id: I9d3043864126e62bd0166250d66b3170d520b3c0

Updating all foreach_transformed_block_visitor functions to work with
plane block size instead of general block. Removing a lot of duplicated
code.

Change-Id: I6a9069e27528c611f5a648e1da0c5a5fd17f1bb4

This change set is intermediate. The next one will remove all repetitive
plane_bsize calculations, because it will be passed as argument to
foreach_transformed_block_visitor.

Change-Id: Ifc12e0b330e017c6851a28746b3a5460b9bf7f0b

The intent was to initialize the deltas for the
segment to the computed value, irrespective of mode
and reference frame if (mode_ref_delta_enabled == 0).

(In response to bug posted by Manjit Hota to codec-devel
and webm-discuss lists)

Change-Id: I10435cb63d0f88359bb4c14f22181878a1988e72

Initialize the best mode and tx_size values in the rate-distortion
optimization search loop.

Change-Id: Ibfb5c0895691f172abcd4265c23aef4cb99fa8af

Return the distortion value in vp9_rd_pick_intra_mode_sb as sum of
dist_y and dist_uv. Remove the right shift operation on dist_uv,
and make it consistent with that of vp9_rd_pick_inter_mode_sb.

Change-Id: I9d564e242d9add38e32595d33b0e0dddb1d55e5b

Redundant dst, pre[2] from build_inter_predictors_args, unused cm from
encode_b_args.

Change-Id: I2c476cd328c5c0cca4c78ba451ca6ba2a2c37e2d