Found this bug while tracking down some anomalies in my experiments.
Since vp8_cost_one and vp8_cost_zero return unsigned int, the
bit shift by 8 will be incorrect if the value is negative.
I am cautiously optimistic that this fix will make the prob
updates more correct and somewhat improve results across the board.
But the update probabilities will need to be retuned I think.

Patch 2: Adding more of the same fixes using a macro.

Change-Id: I1a168f040e74e8c67e7225103b1c2af9a611da49

Change-Id: Ia52ac825400eb83ff663e3a05a3fe0b3526bac9a

When ac_yquant>171, a key frame is enabled to use 8x8 transform. In
such case, MBs with DC_PRED or TM_PRED are selected to use T8x8. This
change helped the full STD-HD set by ~.1% or so, which is reasonable
considering how often key frame occurs in these encodings.

Change-Id: Id17009ef6327252177b19e6bf0d6628827febaf1

Deprecate fast quant and strict_quant code.
Small effect on quality as fast was used in first pass but the
effect is basically neutral across the derf set.

The rationale here is to reduce the number of code paths for
now to make experimentation easier. Optimized and fast code
options can be re-introduced later along with other  encode
speed options.

Change-Id: Ia30c5daf3dbc52e72c83b277a1d281e3c934cdad

Change-Id: Id2412a7f24a7c1016ec9fc3b9b0fbd16871f374a

Various refactoring to make the subpel motion compensation
filters switchable by a frame level field.
Two types of 8-tap filters are supported in addition to the existing
bilinar and sixtap filters. One is the default 8-tap and the
other has a sharper cut-off for use with frames with substantial
edge content.

Patch 2: Added a preliminary strategy for filter selection based on
edginess detecton. Also includes some filter changes.

Change-Id: I866085bda5ae143cfdf2ec88157feaabdf7bd63a

Using contextual coding of the mkb_skip_coeff flag using the
values of this flag from the left and above. There is a small
improvement of about 0.15% on Derf:
http://www.corp.google.com/~debargha/vp8_results/mbskipcontext.html

Refactored to use pred_common.c by adding a new context type.

Results on HD set (about 0.66% improvement):
http://www.corp.google.com/~debargha/vp8_results/mbskipcontext_hd.html

Incliding missing refactoring to use the pred_common utilities.

Change-Id: I95373382d429b5a59610d77f69a0fea2be628278

The recoding loop save and restore frame coding context for recodes.
However in recoding of key frames, some of the coding context saved
was stale from last encoded inter frame. The save/restore sometimes
overwrites the re-inintialized coding context with saved context
from last frame, resulting in encoder/decoder mismatch

Change-Id: I354ae2f71074d142602d51d06544c05a2462caaf

Removed the copy in encoder and changed to use the one in common

Change-Id: Ief0985a50ffd6053a269638fd4816b055ca273ec

Pulled out super block code for the snapshot as this
is not quite ready and will need an extensive re-merge.

Change-Id: I436369b511257447a7b0ea064016cb63f5011849

https://gerrit.chromium.org/gerrit/#change,17319 fixes cost estimating
to take skip_eob into account. No quality difference seen on derf set
tests, but about .4% gain on STD_HD set.

Change-Id: Ic5fe6d35ee021e664a6fcd28037b8432a0e470ca

Change-Id: I4159ff365953598d9c9bc3ecacfb5c5f4a315b45

This gives a modest gain on derf overall, although at low bitrates the
cost is still too high, so this can be improved further.

Patch 2. Re-base and fix 80 column issues

Change-Id: Ida2f9fa3fe75370669f6a27b37108dc602231c63

The commit changed to compute UV intra RD estimates for 4x4 and 8x8
separately to be used in mode decision for MB modes associated with
the appropriate transform size respectively. Now finally after many
other changes related 8x8 quantizer zbin boost and zbin_mode_boost,
this change overall helps the HD(with 8x8) by around ~.13%.
(avg .13%  glb .13% ssim .17%)

The commit also has a few changes for eliminating compiler warnings.

Change-Id: Ibab35dad44820c87e6b44799c66f8d519cc37344

The commit added the correct Zbin_mode_boost initialization based on
Intra Mode before using rate distortion to pick UV intra mode.

Change-Id: I8e57878ff356a06672f6fa2431be860bf9b9a5c7

Change-Id: I4ea6d819bbbde312792c4f813ab63ea50cf0cd1d

Change-Id: I6ade229ff400fe492709010ac5bada37f8afa73e

Change-Id: I8e9b6b154e1a0d0cb42d596366380d69c00ac15f

need further investigation on some odd behavior on one  youtube clip

Change-Id: Iec477986a86b54ef26df2ef69d2f9484e2d1a043

Change-Id: Ie5a7c87d71bd4a541463b68704620d89cec142cf

Incorrect scaling of savings for t8x8.

Change-Id: If01e08f8c73faa73afc3c70e501e6acc54d7e26f

Change-Id: I3b8a230d5b119910e6a6767331a4d97768089355

Change-Id: Ibcd2b9b247ff9f83331dac47f91ec285e8955ff1

Also remove duplicate build_intra_predictors_mby/uv().

Change-Id: I78607e7304952a9b962a5b25af9bb9c48692187b

The commit fixed a problem where 8x8 regular quantizer was using the
4x4 zbinboost lookup table that only has 16 entries at each Q. The
commit assigned a uniform zbin boost value for all cases that there
are more than 16 consective zeros. The change only affects MBs using
8x8 transform. The fix has a slightly positive impact on quality.

Test results:
http://www.corp.google.com/~yaowu/no_crawl/hd_fixzbinb.html
(avg psnr: .26% glb psnr: .21% ssim: .28%)

Results on cif size clip are also positive even though gain is smaller
http://www.corp.google.com/~yaowu/no_crawl/derf_fixzbinb.html

Change-Id: Ibe8f6da181d1fb377fbd0d3b5feb15be0cfa2017

This is the first patch for refactoring of the code related to
high-precision mv, so that 1/4 and 1/8 pel motion vectors can
co-exist in the same bit-stream by use of a frame level flag.
The current patch works fine for only use of 1/4th and
only use of 1/8th pel mv, but there are some issues with the
mode switching in between. Subsequent patches on this change Id
will fix the remaining issues.

Patch 2: Adds fixes to make sure that multiple mv precisions can
co-exist in the bit-stream. Frame level switching has been tested
to work correctly.

Patch 3: Fixes lines exceeding 80 char

Patch 4:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html

Results on derf after ssse3 bugfix, compared to everything
enabled but the 8-tap, 1/8-subpel and 1/16-subpel uv. Overall the
gains are about 3% now. Hopefully there are no more bugs lingering.
Apparently the sse3 bug affected the quartel subpel results more than
the eighth pel ones (which is understandabale because one bad predictor
due to the bug, matters less if there are a lot more subpel options
available as in the 1/8 subpel case).
The results in the 4th column correspond to the current settings.
The first two columns correspond to two settings of adaptive switching
of the 1/4 or 1/8 subpel mode based on initial Q estimate. These
do not work as good as just using 1/8 all the time yet.

Change-Id: I3ef392ad338329f4d68a85257a49f2b14f3af472

The commit overall on derf test is break even to very slightly positive
comparing to all 4x4 transform.

Change-Id: I2a7c19599aa54c2d3a5b35db0dc891ba8a6a2b26

Removal of some further code relating to partitions
and error resilience.

Spelling correction.

Change-Id: I36067aae67a4a23bec359541dda3400b0bbf26d0

Removal of code relating to token partitioning

Change-Id: Iaf3c88d6758639a55bd92c3be5c51e6bed407a3c

The "update" variable was used as a flag in coef_prob update dry run
that tests if a frame should encodes update at all. The wrong init
value forced the update happening always. fixing this has a minor
improvement in low bit rate situation when 8x8 transform is allowed.

Change-Id: Icb498e8d6a62fd074dcbc2065b797cba9237cb51

Apparently the correct spelling of segement is segment !

Change-Id: I88593ee0523f251b3a96794c6166ef8c7898a029

Removal of error_resilient_mode features.
The interface has been left in place but does nothing.

Change-Id: I2407863bd0d3c98407354507423ca48d29f63b17

For now the interface elements have been left in place
to make sure existing parameter files work but parameters
relating to drop frame wont do anything.

Change-Id: I579ee614726387381c546845dac4bc03c74c6a07

Fixes a bug that was introduced in the high precision mv patch.

Change-Id: Ieadb433ebe4c3ef3e0e63944dab11528bf8bd73a

Removal of code relating to spatial re sampling

Change-Id: Iff1bc651c62cd528f960c4b27f9673b172e68835

Change-Id: Ifdb17b56090a317b2aa82cf125d57934902c5298

Removed redundant code for ref frame cost.

This is the initial patch for supporting 1/8th pel
motion. Currently if we configure with enable-high-precision-mv,
all motion vectors would default to 1/8 pel. Encode and
decode syncs fine with the current code. In the next phase
the code will be refactored so that we can choose the 1/8
pel mode adaptively at a frame/segment/mb level.

Derf results:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hpmv.html
(about 0.83% better than 8-tap interpoaltion)

Patch 3: Rebased. Also adding 1/16th pel interpolation for U and V

Patch 4: HD results.
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd_hpmv.html
Seems impressive (unless I am doing something wrong).

Patch 5: Added mmx/sse for bilateral filtering, as well as enforced
use of c-versions of subpel filters with 8-taps and 1/16th pel;
Also redesigned the 8-tap filters to reduce the cut-off in order to
introduce a denoising effect. There is a new configure option
sixteenth-subpel-uv whic...

Yunqing fixed an oddity in UVIntra skippable evaluation for stable
branch, which brought up the fact that the evaluation is broken.
The issue was that for MBs with 2nd order block, the eob for 1st
order blocks is set at 1. The previous evaluation did not take that
into account. This commit intend to fix the problem. The commit also
absorbed Yunqing's fix for UVIntra skippable evalution.

Test on hd showed some good gains in combination with LPF bias fix:
http://www.corp.google.com/~yaowu/no_crawl/LPFBias_FixSkip.html
(avg psnr: .34%, glb psnr: .32%, ssim: .22%)

Change-Id: I36af11c8ef7f643e8ff46da7bf3a167b437039d4

The bias in picklpf intended to bias toward less greedy in getting
best frame level psnr while maximize overall quality for a clip.
This commit reduced the bias for frames using 8x8 transform to
achieve better compression overall.

The change improve compression by ~.15% consistently on most of the
HD clips tested.

http://www.corp.google.com/~yaowu/no_crawl/LPFBias_FixSkip.html

Change-Id: Ic30932d2b8eaebd52339b0195f569edc48eed7bc