Apply 2D-DCT transform of dimension 8x8 to encode prediction
residuals of I8X8 mode.
Brought back block type 3 probability context model for 8x8 tokens,
which is used for the coefficients of Y blocks in I8x8 modes. The
coefficient costs estimate of I8X8 mode in rate-distortion is also
changed appropriately.
Performance results:
derf:   0.246
yt:     0.114
std-hd: 0.730
hd:     0.670

Change-Id: If1d970eeb4e1827c9f0d2c5b27d33089b347ea27

Removed two macros corresponding to experiments that were
merged into the main code.

Change-Id: I894e8b509a2bb88557f9aba6f226ed7807745065

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

Change-Id: Ibf357eb492e7d5883fbdf1ddf455e28767c1d65d

Use $^ vs $? to capture all prerequisites, rather than only newer ones.

Change-Id: I464ffb2913cf60f5ca5e07518ad4bf7da10baf87

The "codecs" array is defined as const so too
should the local variable that points too it.

Change-Id: I536a9ced52257dc44a04fc1a3cad94c1e86f69aa

Replaced local definitions of the extension required
by the filters with the globally defined value.

Change-Id: If9e590a1f2e5b0bdc2d3e3c3f04aacbd3b09bfee

This commit fixes up shared lib builds on linux.

Change-Id: Ib109dc5a226dc5d7874d2e5b333466cbfd4f4661

Change-Id: Id2bac0597b6dd1ce41bd78cbd9e9d876b71cd8a2

Change-Id: I74e50b4dfbe73eb98e1dce1695a9973f637220c0

Change-Id: I9ccbea76eaeb81ce7b833dd92216734725796e84

Adds ADST/DCT hybrid transform coding for Intra4x4 mode.
The ADST is applied to directions in which the boundary
pixels are used for prediction, while DCT applied to
directions without corresponding boundary prediction.

Adds enum TX_TYPE in b_mode_infor to indicate the transform
type used.

Make coding style consistent with google style.
Fixed the commented issues.

Experimental results in terms of bit-rate reduction:
derf:   0.731%
yt:     0.982%
std-hd: 0.459%
hd:     0.725%

Will be looking at 8x8 transforms next.

Change-Id: I46dbd7b80dbb3e8856e9c34fbc58cb3764a12fcf

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

Change-Id: I27bb80901020c40636e2018a8217759175a23f5b

the integer version has very good precision, the float version is no
longer useful. this commit also removes the experiment option from
configure script.

Change-Id: Ibb92e63c9f5083357cdf89c559d584a7deb3353f

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

Change-Id: Icac5b18e5c832681cea866679796a1dd4278cfb8

Change-Id: Ib6866e491994f6c7eeb6c2e5ecd1ff54cc187610

This allows CONFIG_SUPERBLOCKS experiment to almost compile succesfully,
except for the missing pick_sb_modes() function.

Change-Id: Ib2322f2aacdc371e8066f2eb4a8d761c40490b4d

Also use the 8x8 transform in the RD loop.

Change-Id: If1a25aa15d3f64e05c9a31875e309d8cd5bc812d

Change-Id: Ibfecf1fb0fcf51fb349746fec015b1a3e44a4530

Create a merge between the experimental development history and the
previously published snapshot.

Change-Id: If320df72a6bbefec53833626d08dbc9678be2d2d

Merge in the git history leading up to the first experimental
snapshot.

Change-Id: Ifbdbd5bdb585864b3f996c562ef38b6306731251

This is to avoid a rare encoder/decoder mismatch for MB using SPLITMV
mode. In decoder, the UV mv can be determined to need clamp, but the
flag is never set in encoder motion vector selection process, and the
clamp is not done in encoding in encoder.

Change-Id: I60520d3f790354c7855dadf03f0978ea9b77e2c0

Change-Id: Iff5ccf2400bcb7b78c7b70f289ea65c982efddd5

Change-Id: I6dd27a0ea661e6f10a55d7841021b66ae4fc72ae

Also factorize ACMRandom to acm_random.h.

Change-Id: I3b6eeb36fcbf7ae6dd3d2892bc40348f5c17982b

This commit adds lossless compression capability to the experimental
branch. The lossless experiment can be enabled using --enable-lossless
in configure. When the experiment is enabled, the encoder will use
lossless compression mode by command line option --lossless, and the
decoder automatically recognizes a losslessly encoded clip and decodes
accordingly.

To achieve the lossless coding, this commit has changed the following:
    1. To encode at lossless mode, encoder forces the use of unit
quantizer, i.e, Q 0, where effective quantization is 1. Encoder also
disables the usage of 8x8 transform and allows only 4x4 transform;
    2. At Q 0, the first order 4x4  DCT/IDCT have been switched over
to a pair of forward and inverse Walsh-Hadamard Transform
(http://goo.gl/EIsfy),  with proper scaling applied to match the range
of the original 4x4 DCT/IDCT pair;
    3. At Q 0, the second order remains to use the previous
walsh-hadamard transform pair. However, to maintain the reversibility
in second order transform at Q 0, scaling down is applied to first
order DC coefficients prior to forward transform, and scaling up is
applied to the second order output prior to quantization. Symmetric
upscaling and downscaling are added around inverse second order
transform;
    4. At lossless mode, encoder also disables a number of minor
features to ensure no loss is introduced, these features includes:
        a. Trellis quantization optimization
        b. Loop filtering
        c. Aggressive zero-binning, rounding and zero-bin boosting
        d. Mode based zero-bin boosting

Lossless coding test was performed on all clips within the derf set,
to verify that the commit has achieved lossless compression for all
clips. The average compression ratio is around 2.57 to 1.
(http://goo.gl/dEShs)

Change-Id: Ia3aba7dd09df40dd590f93b9aba134defbc64e34