The commit added an integer version of 8x8 forward DCT, based on the
orginal forward DCT from VP6. The constants, roundings, and shifts
were adjusted to improve the accuracy. The latest patch has a very
similar accuracy in term of round trip error against the floating
point version.

It should be noted here that the purpose of the patch is to help
encoding speed and facilitate all other experiments. There will be
futher review in combination with inverse DCT before finalization.

configure with "--enable--int_8x8fdct" to use the integer version

Change-Id: I5a4f80507429f0e07cf02a13768ec81cbfddc5bc

Remove testing of whether we estimate that it will be possible
to code an arf at a lower Q than the ambient Q.  This adds quite
a bit of extra code and complexity for marginal gain.

Factored out some code relating to ARNR selection to a separate
function as this is likely to be changed / simplified soon.

Change-Id: Ia1cf060405637ef5bbf7018355437be21d12375f

Removed odd *100 >> 4 factor from boost calculations. Not all the
calculations exactly match what was there before so there may be
some minor impact on results.

Some other minor tidying up in regard to coding conventions.

The specific values of factors and thresholds will likely change as
part of subsequent patches.

Change-Id: Id976321484ac02ba50294cf54fafbc17dda85686

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

This is the first patch in a series of changes to the first
pass code. (Broken down for ease of testing/merging/review).

This patch introduces a new stats element "sr_coded_error".
This is the coded error recorded vs the second reference
frame (which is updated such that it lags by at least one frame).
No use is made of the new structure in this change so this patch
should have no material effect.

Removed some ifdefs and deprecated code (#if NEW_BOOST).
Removed twopass.gf_decay_rate (not used any more)

Change-Id: I1be672a73017f7c13fd50fb4f99236aa2ed30916

Change-Id: I960c6eb81f8d76c958e8af989700447f581a8812

adds unit testing via google test

Change-Id: I144b50a976d79251fc5135186a4e0a5051ed0e8c

This commit changed the forward and the inverse 4x4 Walsh Hadamard
transform to a new pair, where the inverse transform can pefectly
reconstuct the input to forward transform. It also does so without
changing the input and output value range. Even more, it does not
change the complexity of the transforms.

While it was not expected to improve the results of our current test,
it does improve std-hd set by 0.2% on all metrics. No change on derf.

Change-Id: Ie4f23ddd3a0f3c5fbe97fb58399f860031f99337

Also includes some clean ups and refactoring.

Rebased.

Change-Id: I268c97fe325b4881103fe19f41ae818569e7ccf7

1. block types
There are only three types of blocks for 8x8 transformed MBs, i.e. Y
block with DC does not exist for 8x8 transformed MBs as all MB using
8x8 transform have 2nd order haar transform. This commit introduced
a new macro BLOCK_TYPES_8X8 to reflect such fact.

2. context counters
This commit also fixed the mixed of context_counters between 4x4 and
8x8 transformed MBs. The mixed use of the counters leads me to think
the existing the context probabilities were not properly generated
from 8x8 transformed MBs.

3. redundant collecting in recoding
The commit also corrected the code that accumulates entropy stats by
making sure stats only collected for final packing, not during the
recode loop

Change-Id: I029f09f8f60bd0c3240cc392ff5c6d05435e322c

This patch expands the set of prev contexts used for video coding
from 3 to 4.

There is a small improvement of the order of 0.08% for derf and
0.15% on the HD set. The tests were rerun after the various merges
last week. There are two columns in each test - the first are the
results with the mbskip change, and the second with expanded contexts
added on top of that.

Derf:
http://www.corp.google.com/~debargha/vp8_results/explibvpx_newentropy_expcontext.html

HD:
http://www.corp.google.com/~debargha/vp8_results/explibvpx_hd_newentropy_expcontext.html

Rebased.

Broke up 80 char lines.

Change-Id: I82d2e72d054e530cbf5ce9aa0e6d85c582965675

missed the decoder side in last commit

Change-Id: Ie97f35189e93f78783e3d8072a36eea768beed27

This commit adjusted slightly the 4x4 coefficents band definition to
better classify coefficients with similar distributions and usages.
It helps derf set about .1%, it is alos slightly positive for std-hd
set, where 4x4 blocks are used less frequently.

The commit also removed a const array not in use.

Change-Id: I78d16905d4036641ec905b0c32c190c1def5b249

This commit added usage information that was missed in usage output.

Change-Id: If1a85bcc20131314f5d047c6db4e76a40d945e66

Change-Id: I9f1686249ac812f7b9b872eabe3970d1dfb25e56

Change-Id: I87291fb40c745f34c36b067f47abdf69774a812f

Removes a set of spurious declarations that were inadvertently checked
in.

Change-Id: I2f80b6b66d2ec9ea667c810eaf1a6e7d52478c67

The ARNR filter uses a motion compensated temporal filter,
but the motion estimation implementation accounts for the
cost of the mv in its decision making process. The ARNR
filter uses a dummy cost table initialized to 0 as a way
to ignore the mv costs (which are irrelevant to the filter).

This CL modifies the ARNR filter implementation to so that
the mv costing is ignored without the requirement for
dummy tables.

Change-Id: I0dd9620c3b70682f938b2a70912c11d4d7c9284c

Adds a speed feature to conduct a brute force search among a set of
available interpolation filters for the best one in an RD sense.

There is a gain of 0.4% on derf, 1.0% on Std-HD.

Patch 2: A macro added to determine if the encoder state is reset
for each new filter tried.

Patch 3: rebase, also fixes a bug (decodframe.c) introduced by a
couple of missing function pointer assignements.

Patch 4: rebase.

Change-Id: Ic9ccca9d8c35c6af557449ae867391a2f996cc29

This commit merge the QI mode experiment. As the experiment affects
the encoding of intra coding modes on key frame only, the overall
effect of the experiment on encoding tests is insignificant.

Change-Id: I9e4e3933adface88867ad429cee3986e529c511d

The commit merges the UVINTRA experiment and removed the related
macros. The overall effect of the experiment is a small gain (.1%
on derf)

Change-Id: Ia34b3312fb9b5b34c9ba111bf0fa78c6f78ac80b

Change-Id: I8708358bb37edabcbe5dfc755ed18791d9e143c4

Adds differential encoding of prob updates using a subexponential
code centered around the previous probability value.
Also searches for the most cost-effective update, and breaks
up the coefficient updates into smaller groups.

Small gain on Derf: 0.2%

Change-Id: Ie0071e3dc113e3d0d7ab95b6442bb07a89970030

Change-Id: I7c0597dede20cc71145c053f76bd99aaf759d144

This commit changed to enable the usage 8x8 transform for all frame
type, all resolution and all quantizer range. This has an overall
benefit .2% to .3% in term of compression, but more importantly,
the difficult clips benefits much more, up to 2% to 3% on clips
like football, harbour and so on.

We observed some weird humps on very high end on a couple of youtube
clips, but have determined the underly cause was the aggressive zbin
having an effect of lowering rate with lower quality, which have
an impact on slide show clips around 60DB.

The commit does not change the association between prediction mode
and transform size.

Change-Id: I33043bdce6207528ae00b4a4b26d8ff63cfea1f4

This is to prevent the evaluation of a mode from using values left
over from a mode evaluated prior in the loop.

Change-Id: Ife2c6ceb76d2f7365fd262515d3ae48229033c2d

Change-Id: I9d6083d54e3d478ec20dc6dc48d3f45eb5c7e16b

Change-Id: I0af3395500b1cb0ed629249eb6636a0c9322cb18

With the NEWENTROPY experiment enabled encoding certain clips
produced invlid bitstreams, or files that had a high degree
of artefacts.

This was the results of pointers in MACROBLOCKD not being
setup correctly (mode_info_context and prev_mode_info_context).

Change-Id: Ice13e1efa8bd122997d2f8f3f1e761c6c16e0403

These contexts need to be saved and restored for recode, otherwise
encoder/decoder mismatch happens for some clips (eg._mobcal 720p)

Change-Id: Ic65cfa0bf56ed0472ecab962ce31394d59d344bf