Allows for swtiching/setting interpolation filters at the MB
level. A frame level flag indicates whether to use a specifc
filter for the entire frame or to signal the interpolation
filter for each MB. When switchable filters are used, the
encoder chooses between 8-tap and 8-tap sharp filters. The
code currently has options to explore other variations as well,
which will be cleaned up subsequently.

One issue with the framework is that encoding is slow. I
tried to do some tricks to speed things up but it is still slow.
Decoding speed should not be affected since the number of
filter taps remain unchanged.

With the current version, we are up 0.5% on derf on average but
some videos city/mobile improve by close to 4 and 2% respectively.
If we did a full-search by turning the SEARCH_BEST_FILTER flag
on, the results are somewhat better.

The framework can be combined with filtered prediction, and I
seek feedback regarding that.

Rebased.

Change-Id: I8f632cb2c111e76284140a2bd480945d6d42b77a

The following five experiments are merged:

newentropy
newupdate
adaptive_entropy (also includes a couple of parameter changes
                  that improves results a little
                  in common/entropymode.c and encoder/modecosts.c
                  that were not merged from the internal branch)
newintramodes
expanded_coef_context

Change-Id: I8a142a831786ee9dc936f22be1d42a8bced7d270

Although it can be useful, in some cases it causes artifacts in motion-
based content.

Change-Id: I27bb80901020c40636e2018a8217759175a23f5b

this commit removes a number of experiment options from configure
script. the associated experiments are already fully merged, the
options in configure script have no effect at all.

Change-Id: I8054ccaee0a04610162ed76ac9e59c4538217113

Approximate the Google style guide[1] so that that there's a written
document to follow and tools to check compliance[2].

[1]: http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml
[2]: http://google-styleguide.googlecode.com/svn/trunk/cpplint/cpplint.py

Change-Id: Idf40e3d8dddcc72150f6af127b13e5dab838685f

vp8_encode_inter_macroblock() is called in both pick_mb_modes() as
well as encode_sb(), thus the number of macroblocks in the counter
were twice as big as actual numbers. This doesn't affect output.

Change-Id: I6de8a996ee44d2f7f2080d8d2177dd7bc6207c93

Also use the 8x8 transform in the RD loop.

Change-Id: If1a25aa15d3f64e05c9a31875e309d8cd5bc812d

Change-Id: Ibfecf1fb0fcf51fb349746fec015b1a3e44a4530

Added the ability to optionally filter the prediction data
when inter modes are selected (excludes SPLITMV, for now).

The mode selection loop considers both the filtered and
non-filtered prediction data when choosing mode. The filter
can be turned on/off at the frame-level, or signaled for
each MB.

Change-Id: I1b783c71d95a361ab36c761b07e8a6b06bc36822

Incorporates mv_ref, mbsplit and second_mv into the adaptive
entropy framework. The mv_ref framework has been modified from
before.

Adds some clean-ups and fixes.

Results with the adaptive entropy experiment are currently up by
+1.93% on derf; +2.33% std-hd and +1.87% yt-hd.

Fixed a nasty intermittent bug.

Change-Id: I4b1ac9f9483b48432597595195bfec05f31d1e39

Change-Id: I883b4f63559c1cf66a25016e946b1b1ae98a20da

This patch incorporates adaptive entropy coding of coefficient tokens,
and mode/mv information based on distributions encountered in a frame.
Specifically, there is an initial forward update to the probabilities
in the bitstream as before for coding the symbols in the frame, however
at the end of decoding each frame, the forward update to the
probabilities is reverted and instead the probabilities are updated
towards the actual distributions encountered within the frame.
The amount of update is weighted by the number of hits within each
context.

Results on derf/hd/std-hd are all up by 1.6%.

On derf, the most of the gains come from coefficients, however for the
hd and std-hd sets, the most of the gains come from the mode/mv
information updates.

Change-Id: I708c0e11fdacafee04940fe7ae159ba6844005fd

I now see I didn't write a very long description, so let's do it
here then. We took a pretty big quality hit (0.1-0.2%) from my
recent fix of the inversion of arguments to vp8_cost_bit() in the
RD reference frame costing. I looked into it and basically the
costing prevented us from switching reference frames. This is of
course silly, since each frame codes its own prob_intra_coded, so
using last frame cost indications as a limiting factor can never
be right.

Here, I've rewritten that code to estimate costings based partially
on statistics from progress on current frame encoding. Overall,
this gives us a ~0.2%-0.3% improvement over what we had previously
before my argument-inversion-fix, and thus about ~0.4% over current
git (on derf-set), and a little more (0.5-1.0%) on HD/STD-HD/YT.

Change-Id: I79ebd4ccec4d6edbf0e152d9590d103ba2747775

Adds 6 directional intra predictiom modes for 16x16 and 8x8 blocks.

Change-Id: I25eccc0836f28d8d74922e4e9231568a648b47d1

These frames can force reference frame (arf), mode (zeromv) and skip,
which means that if we use compound prediction (i.e. arf+last), we
might use a blend of a perfect (arf) and an imperfect (last) predictor,
leading to semi-garbage display and thus a huge drop in SSIM/PSNR (up
to 10dB for some frames I analyzed).

Gives a +0.2% gain on YT.

Change-Id: If1f2b7899ad165684af3808fd379295e82558cbb

Change-Id: I9d6083d54e3d478ec20dc6dc48d3f45eb5c7e16b

Change-Id: I0af3395500b1cb0ed629249eb6636a0c9322cb18

Added code to save the coding context in vp8_rd_pick_inter_mode
when the coding mode is forced to ARF(0,0).

Also, modified the MV bounds computation to comply with the
change in MV border from 32 to 64 pixels.

Change-Id: I96963a6f5f4d04ce84c807ae11e0635177c3ad6c

Some code re-factored / moved to allow the main
pack operation inside the recode loop so  that the
size estimate is accurate.

Deletion of some redundant code relating to one pass.

Aproximate improvement over March 27 code base:
Derf 0.0%, YT 0.5%, YThd 0.3% Std_hd 0.25%

Change-Id: Id2d071794ab44f0b52935f6fcdb5733d09a6bb86

This is the first patch to add superblock (32x32) coding
order capabilities. It does not yet do any mode selection
at the SB level, that will follow in a further patch.

This patch encodes rows of SBs rather than
MBs, each SB contains 2x2 MBs.

Two intra prediction modes have been disabled since they
require reconstructed data for the above-right MB which
may not have been encoded yet (e.g. for the bottom right
MB in each SB).

Results on the one test clip I have tried (720p GIPS clip)
suggest that it is somewhere around 0.2dB worse than the
baseline version, so there may be bugs.

It has been tested with no experiments enabled and with
the following 3 experiments enabled:
  --enable-enhanced_interp
  --enable-high_precision_mv
  --enable-sixteenth_subpel_uv
in each case the decode buffer matches the recon buffer
(using "cmp" to compare the dumped/decoded frames).
Note: Testing these experiments individually created
errors.

Some problems were found with other experiments but it
is unclear what state these experiments are in:
  --enable-comp_intra_pred
  --enable-newentropy
  --enable-uvintra

This code has not been extensively tested yet, so there
is every likelihood that further bugs remain. I also
intend to do some code cleanup & refactoring in tandem
with the next patch that adds the 32x32 modes.

Change-Id: I1eba7f740a70b3510df58db53464535ef881b4d9

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

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

This is a code snapshot of experimental work currently ongoing for a
next-generation codec.

The codebase has been cut down considerably from the libvpx baseline.
For example, we are currently only supporting VBR 2-pass rate control
and have removed most of the code relating to coding speed, threading,
error resilience, partitions and various other features.  This is in
part to make the codebase easier to work on and experiment with, but
also because we want to have an open discussion about how the bitstream
will be structured and partitioned and not have that conversation
constrained by past work.

Our basic working pattern has been to initially encapsulate experiments
using configure options linked to #IF CONFIG_XXX statements in the
code. Once experiments have matured and we are reasonably happy that
they give benefit and can be merged without breaking other experiments,
we remove the conditional compile statements and merge them in.

Current changes include:
* T...

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

Change-Id: I436369b511257447a7b0ea064016cb63f5011849

Change-Id: I8e9b6b154e1a0d0cb42d596366380d69c00ac15f

Change-Id: Ie5a7c87d71bd4a541463b68704620d89cec142cf

Change-Id: Ibcd2b9b247ff9f83331dac47f91ec285e8955ff1

Also remove duplicate build_intra_predictors_mby/uv().

Change-Id: I78607e7304952a9b962a5b25af9bb9c48692187b

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

Removed redundant code for ref frame cost.

Removal of most code to do with 1 pass.
Removal of cyclic refresh code.

Change-Id: I74971082bc19dd76e795d4d2e781a0424cec5c8c

Removal of the pickinter.c and .h files and calls to this
code.

Removal of some code relating to real time and one pass
settings  though there is more to be done in this regard.

However,  vp8_set_speed_features() now
only supports modes 0 and 1 and speeds up to 3
so rd should always be set.

Change-Id: I62c0c1b6154ab499785baef310536080e87bc4d8

I'm basically not convinced that the concept works at all, let alone
that this is the right place to do it. I think if we want something
like this at all, I should integrate it with the main encoding loop
and re-encode checks in onyx_if.c, and show that it has a significant
benefit (which right now, it doesn't; removing this re-encode check
actually increases all metrics by ~0.15%).

Change-Id: I1b597385dc17f468384a994484fb24813389411f

Change-Id: I265ad46e01a307bca21e6223725e4055f5e08648

For the experimental branch we are trying to slim the codebase
down removing features such as threading for now which complicate
the process of development and testing.

Change-Id: I657c0246aef4d1fa8c8ffc6a1adfeee45bce8e24

In summary, this commit encompasses a series of changes in attempt to
improve the 8x8 transform based coding to help overall compression
quality, please refer to the detailed commit history below for what
are the rationale underly the series of changes:

a. A frame level flag to indicate if 8x8 transform is used at all.
b. 8x8 transform is not used for key frames and small image size.
c. On inter coded frame, macroblocks using modes B_PRED, SPLIT_MV
and I8X8_PRED are forced to using 4x4 transform based coding, the
rest uses 8x8 transform based coding.
d. Encoder and decoder has the same assumption on the relationship
between prediction modes and transform size, therefore no signaling
is encoded in bitstream.
e. Mode decision process now calculate the rate and distortion scores
using their respective transforms.

Overall test results:
1. HD set
http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120206.html
(avg psnr: 3.09% glb psnr: 3.22%, ssim: 3.90%)
2. Cif set:...

Change-Id: Ieaaa07c50eae41118596197f6a4d848135946e41