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

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 ...

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:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120206.html
(avg psnr: -0.03%, glb psnr: -0.02%, ssim: -0.04%)
It should be noted here, as 8x8 transform coding itself is disabled
for cif size clips, the 0.03% loss is purely from the 1 bit/frame
flag overhead on if 8x8 transform is used or not for the frame.

---patch history for future reference---
Patch 1:
this commit tries to select transform size based on macroblock
prediction mode. If the size of a prediction mode is 16x16, then
the macroblock is forced to use 8x8 transform. If the prediction
mode is B_PRED, SPLITMV or I8X8_PRED, then the macroblock is forced
to use 4x4 transform. Tests on the following HD clips showed mixed
results: (all hd clips only used first 100 frames in the test)

http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8.html
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_log.html

while the results are mixed and overall negative, it is interesting to
see 8x8 helped a few of the clips.

Patch 2:
this patch tries to hard-wire selection of transform size based on
prediction modes without using segmentation to signal the transform size.
encoder and decoder both takes the same assumption that all macroblocks
use 8x8 transform except when prediciton mode is B_PRED, I8X8_PRED or
SPLITMV. Test results are as follows:

http://www.corp.google.com/~yaowu/no_crawl/t8x8/cifmodebase8x8_0125.html
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_0125log.html

Interestingly, by removing the overhead or coding the segmentation, the
results on this limited HD set have turn positive on average.

Patch 3:
this patch disabled the usage of 8x8 transform on key frames, and kept the
logic from patch 2 for inter frames only. test results on HD set turned
decidedly positive with 8x8 transform enabled on inter frame with 16x16
prediction modes: (avg psnr: .81% glb psnr: .82 ssim: .55%)

http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdintermode8x8_0125.html
results on cif set still negative overall

Patch 4:
continued from last patch, but now in mode decision process, the rate and
distortion estimates are computed based on 8x8 transform results for MBs
with modes associated with 8x8 transform. This patch also fixed a problem
related to segment based eob coding when 8x8 transform is used. The patch
significantly improved the results on HD clips:

http://www.corp.google.com/~yaowu/no_crawl/t8x8/hd8x8RDintermode.html
(avg psnr: 2.70% glb psnr: 2.76% ssim: 3.34%)
results on cif also improved, though they are still negative compared to
baseline that uses 4x4 transform only:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif8x8RDintermode.html
(avg psnr: -.78% glb psnr: -.86% ssim: -.19%)

Patch 5:
This patch does 3 things:
a. a bunch of decoder bug fixes, encodings and decodings were verified
to have matched recon buffer on a number of encodes on cif size mobile and
hd version of _pedestrian.
b. the patch further improved the rate distortion calculation of MBS that
use 8x8 transform. This provided some further gain on compression.
c. the patch also got the experimental work SEG_LVL_EOB to work with 8x8
transformed macroblock, test results indicates it improves the cif set
but hurt the HD set slightly.

Tests results on HD clips:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120201.html
(avg psnr: 3.19% glb psnr: 3.30% ssim: 3.93%)

Test results on cif clips:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120201.html
(avg psnr: -.47% glb psnr: -.51% ssim: +.28%)

Patch 6:
Added a frame level flag to indicate if 8x8 transform is allowed at all.
temporarily the decision is based on frame size, can be optimized later
one. This get the cif results to basically unchanged, with one bit per
frame overhead on both cif and hd clips.

Patch 8:
Rebase and Merge to head by PGW.
Fixed some suspect 4s that look like hey should be 64s in regard
to segmented EOB. Perhaps #defines would be bette.
Bulit and tested without T8x8 enabled and produces unchanged
output.

Patch 9:
Corrected misalligned code/decode of "txfm_mode" bit.
Limited testing for correct encode and decode with
T8x8 configured on derf clips.

Change-Id: I156e1405d25f81579d579dff8ab9af53944ec49c

Change-Id: Ieaaa07c50eae41118596197f6a4d848135946e41

This commit only involves the removal of placeholder comments
//#if CONFIG_SEGFEATURES.

Change-Id: I94b350daaf998ee0cfdde5aa25b1d3b0522ab816

Merged in most of the current common prediction changes
that were under the #if CONFIG_COMPRED option.

Change-Id: If4e6f61dbe7b86dd449f6effbe93b5eb7e893885

Further changes to make experiments with the context
used for coding the dual pred flag easier.

Current best performing method tested on derf is a two
element context based on reference frame. I also tried
various combinations of mode and reference frame as
shown in commented out case using up to 6 contexts.

Derf +0.26 overall psnr +0.15% ssim vs original method.

Change-Id: I64c21ddec0abbb27feaaeaa1da2e9f164ebaca03

Further use of common prediction functions and experiments
with alternate contexts based on mode and reference frame.

For the Derf set using reference frame as basis of context
gives +0.18% Overall Psnr and +0.08 SSIM

Change-Id: Ie7eb76f329f74c9c698614f01ece31de0b6bfc9e

We should only change the dual prediction mode if we actually entered
the recode branch. Else, it may potentially undo beneficial changes
to the dual prediction mode in the first encode iteration.

Change-Id: I79fc53e5fd0bb551092ed422c797619f1566f002

Change-Id: Icf7a6749ca2f8ad6a032f86c34540d1c5880cf68

Some conditions were conditional under a threshold, whereas they should
always execute. Also, some conditions were testing an array instead of
the values within it.

Change-Id: Ia6892945cfbbe07322e6af6be42cd864bf9479c1

The existing code updated the reference frame probabilities before
the test to evaluate the impact of using updated probabilities
in vp8_estimate_entropy_savings().

The estimate of cost and savings is still basic and does not reflect
the new prediction code but this would require per MB costings
and the benefit is probably marginal, as this is really just used for
rate estimation in the loop.

Change-Id: Id6ba88ae6e11c273b3159deff70980363ccd8ea1

This commit merges the NEWNEAR experiment such that it
is effectively always on.

The fact that there were changes in the threading code again
highlights the need to strip out such features during the
bitstream development phase as trying to maintain this code
(especially as it is not being tested) slows the development cycle.

Change-Id: I8b34950a1333231ced9928aa11cd6d6459984b65

Trial of a modified prediction function that ranks each possible
reference frame based on a combination of local usage and
frame level probability. The code is a bit cleaner and simpler.

In direct comparison with old unpredicted method with segment level
coding turned off for mode,ref & EOB the prediction gives a gain on derf
of around 0.4%. There is some further gain from bug fixes over earlier code.

With segment coding on the prediction method is slightly -ve on some very
easy clips (at low rates) due to slightly higher overheads, but better on harder
clips. Overall neutral on derf in direct comparison on latest code base, but
compared to earlier code without bug fixes about +0.7% overall psnr
+0.3% SSIM.

Change-Id: I5b8474658b208134d352d24f6517f25795490789

Extended prediction and coding of reference frame where
a subset of options are flagged as available at the segment level.

Updated copyright notices.

Switch to SAD in mbgraph code as SATD problematic for the
foreground and background separation as it can ignore large DC shifts.

Change-Id: I661dbbb2f94f3ec0f96bb928c1655e5e415a7de1

As a precursor to encoding 32x32 blocks this cl adds the
ability to encode the frame superblock (=32x32 block) at
a time. Within a SB the 4 indiviual MBs are encoded in
raster-order (NW,NE,SW,SE).

This functionality is added as an experiment which can be
enabled by ispecifying --enable-superblocks in the
command line specified to configure (CONFIG_SUPERBLOCKS
macro in the code).

To make this work I had to disable the two intra
prediction modes that use data from the top-right of the
MB.

On the tests that I have run the results produce
almost exactly the same PSNRs & SSIMs with a very
slightly higher average data rate (and slightly higher
data rate than just disabling the two intra modes in
the original code).

NOTE: This will also break the multi-threaded code.

This replaces the abandoned change:
Iebebe0d1a50ce8c15c79862c537b765a2f67e162

Change-Id: I1bc1a00f236abc1a373c7210d756e25f970fcad8

This check in uses the common prediction interface functions
to code reference frame.

Some updates made regarding the impact of the new code in rd loop
but there remain TODOs in this regard.

Change-Id: I9da3ed5dfdaa489e0903ab33258b0767a585567f

Encoder side changes

Change-Id: I8921800e4fccec5e5a9e4755b80cbd472623107b

Change-Id: Ifadf65026a11bdb5d39840748613880bcfb364bb

This commit removed the macro CONFIG_I8X8, which was used to indicate
the 8x8 intra prediction experiment, made the change fully merged in.

Change-Id: Iafa4443781ce6e83f5591c12ba615a0e92ce0ea0

The MODE_STATS macro was used to #ifdef around code for mode entropy
stats collection, this commit fixed a crash when MODE_STATS is on.
The commit also changed a number of array definitions to use defined
macros instead of hard-coded numbers.

Change-Id: I114592f53a1e44e31e455f5725f036ae6168735a

This patch introduces the concept of dual inter16x16 prediction. A
16x16 inter-predicted macroblock can use 2 references instead of 1,
where both references use the same mvmode (new, near/est, zero). In the
case of newmv, this means that two MVs are coded instead of one. The
frame can be encoded in 3 ways: all MBs single-prediction, all MBs dual
prediction, or per-MB single/dual prediction selection ("hybrid"), in
which case a single bit is coded per-MB to indicate whether the MB uses
single or dual inter prediction.

In the future, we can (maybe?) get further gains by mixing this with
Adrian's 32x32 work, per-segment dual prediction settings, or adding
support for dual splitmv/8x8mv inter prediction.

Gain (on derf-set, CQ mode) is ~2.8% (SSIM) or ~3.6% (glb PSNR). Most
gain is at medium/high bitrates, but there's minor gains at low bitrates
also. Output was confirmed to match between encoder and decoder.

Note for optimization people: this patch introduces a 2nd version of
1...

This commit enabled the usage of 8x8 intra prediction modes on inter
frames. There are a few TODO items related to this: 1)baseline entropy
need be calibrated; 2)cost of UV need to be done more properly rather
than using decision only relying on Y; 3)Threshold for allowing picking
8x8 intra prediction should be lowered to lower than the B_PRED.

Even with all the TODOs, tests showed consistent gain on derf set ~0.1%
(PSNR:0.08% and SSIM:0.14%). It is assumed that 8x8 intra prediction
will help more on large resolution clips, especially with above TODOs
addressed.

Change-Id: I398ada49dfc32575cfab962a569c2885111ae3ba

This is an experiment to include a mv contribution from last frame to
nearest and near mv definition. Initial test showed some small though
consistent gain.

latest patch slightly better result ~.13%-~.18%.

TODO: the entropy used to encode the mode choice, i.e. the mv counts
based conditional distribution of modes should be re-collected to
reflect this change, it is expected that there is some further gain
from that.

Change-Id: Ief1e284a36d8aa56b49ae5b360c91419ec494fa4

Block the selection of 4x4 modes in key frames if 8x8 is selected.

Change-Id: Ie5729ec22a999d9a1996f020bd4b941e29514992