Some correction for entropy impact of segment signaled (EOB and ref frame)

Other slight tweaks.

Derf VBR average gain now over 1% (best over 7%)
One YT test clip has gains of circa 30% (VBR)

There is still an issue with noisy clips where making the background static
and coded with 0,0 can have a negative effect, especially at low Q.
This is probably because of the loss of smoothing by fractional pixel filters.

Change-Id: I7a225613c98067b96f8fc7a7e36f95d465b2b834

Resolved experimental branch build problem when seg_features not configured.

Change-Id: Ia0f9b460a26dc3eac9844ee595a7b196e9faf6a5

Prior to the added rounding, tests on randomly generated data showed
that forward-inverse transform round trip errors are about 3.02/block
for input range [-10,10] and 2.68/block for input range [-256, 255].
The added rounding reduced the errors to 0.031/block for input range
[-10,10] and 0.037/block for input range [-256, 255].

Maximum round trip error on for any pixel position is 1.

The average errors are calculated based on 100,000 blocks of randomly
with the specified ranges.

Paul mentioned in discussion that the change was not clear on why we
need change the rounding, so Patch 2 intends to make the rationale
obvious in code, it merged the two separate shifts into one, and the
two separate rounding factors into one. Patch 1 and 2 have same
numerical test results.

Change-Id: Ic5e2f5463de17253084d8b2398c4a210194b20de

Only encode sign bit for feature data that can have a sign.

Tweaks to the test segmentation rules so that it now actually gives
a net benefit on the derf set of about 0.4% though much higher
on some clips at the low end.

Change-Id: I8e61f1aebf41c9037db7e67e2f8975aa18a0c986

This quite large check in includes the following:

Merge in some code from Ronald (mbgraph.c) that scans a Gf/arf group.
This is used as a basis for a simple segmentation for the normal frames
in a gf/arf group. This code also uses satd functions from Yaowu.

Adds functionality for coding the latest possible position of an EOB for
blocks in the segment. (Currently 0-15 only, hence just for 4x4 dct).
Where the EOB position is 0 this acts like "skip" and the normal coding
of skip at the per mb level is disabled.

Added functions (seg_common.c) for setting and reading segment feature
elements. These may want to be optimized away at some point but while the
mecahnism is in a state of flux they provide a single location for making
changes and keep things a bit cleaner.

This is still proof of concept code. Currently the tested feature set:-

Quantizer,
Loop Filter level,
Reference frame,
Prediction Mode,
EOB end stop.

TBD:-

Add functions for setting and reading the feature...

Given the current forward haar transform:
 f0 = I0 + I1 + I2 + I3
 f1 = I0 + I1 - I2 - I3
 f2 = I0 - I1 + I2 - I3
 f3 = I0 - I1 - I2 + I3
the output of the inverse haar prior rounding:
 i0 = f0 + f1 + f2 + f3 = I0 * 4;
 i1 = f0 + f1 - f2 - f3 = I1 * 4;
 i2 = f0 - f1 + f2 - f3 = I2 * 4;
 i3 = f0 - f1 - f2 + f3 = I3 * 4;
As all the numbers are 4 multiples, simply >>2 always produces prefect
results in term of forward-inverse transform round trip error.

Change-Id: Id6658b00ea819ee61cfeef8c5985d4cd3e77f44e

When 8x8 transform is enabled, the decoder does an extra reconstruct
on MBs that are coded using 8x8. This commit fixed the logic around
the decoding of mb encoded with 8x8 transform.

Change-Id: I6926557c9ef00eecb375f62946f7e140c660bf6f

Proof of concept test code that encodes mode and reference
frame data at the segment level.

Decode-able bit stream but some issues not yet resolved.
As it this helps a little on a couple of clips but hurts on most as
the basis for segmentation is unsound.

To build and test, configure with
--enable-experimental --enable-segfeatures

Change-Id: I22a60774f69273523fb152db8c31f4b10b07c7f4

New setting added to configure script

Change-Id: I4e515276d197e1dfb1f3e75edfa9823d08c9b366

Search for the word EQU so that extraneous
symbols are not matched.

Change-Id: Ice6c9ca886211e2ca8a2f5174bdd4103db5c4989

These files don't contain generic arm code, so should
only be compiled by neon.

Change-Id: Ie712823aa04d4235e7cfe7a3b725e73ee4c3e564

- Removed fast_fdct4x4_neon and fast_fdct8x4_neon
- Uses now short_fdct4x4 and short_fdct8x4
- Gives ~1-2% speed-up on Cortex-A8/A9

Change-Id: Ib62f2cb2080ae719f8fa1d518a3a5e71278a41ec

Rd and Rm registers should be different in 'mul'. This register
combination results in unpredictable behaviour. GCC will give
a warning and RVCT an error in this case.

Restriction applies only to armv5 targets and not for armv6 and above.

Change-Id: I378d17c51e1f16a6820814fbed43e115aaabb03e

Change-Id: I717768a6b248bd4ae3a96f711287758ba78a384a

These changes fixes a glitch between the RTP profile and the input
partitions interface. Since there's no way for the user to know the
actual number of partitions, the decoder have to read the
multi_token_paritition bits also when input partitions mode is
enabled.

Included are also a couple of fixes for issues with independent
partitions and uninitialized memory reads.

Change-Id: I6f93b15287d291169ed681898ed3fbcc5dc81837

- Updated walsh transform to match C
  (based on Change Id24f3392)
- Changed fast_fdct4x4 and 8x4 to short_fdct4x4 and 8x4
  correspondingly

Change-Id: I704e862f40e315b0a79997633c7bd9c347166a8e

Modified original patch If2f07220885c4c3a0cae0dace34ea0e36124f001
according to comments. Scheduled code a little bit to prevent some
interlocks.

Change-Id: I338f02b881098782f82af63d97f042b85e63e902

Change-Id: I83fd03ca0970314c81e834857cbd911dffa9a9de

This commit added a 3 bit index to the bitstream, the index is used to
look into the intra mode coding entropy context table. The commit uses
the mode stats to calculate the cost of transmitting modes using 8
possible entropy distributions, and selects the distribution that
provides the lowest cost to do the actual mode coding.

Initial test show this provides additional .2%~.3% gain over quantizer
adaptive intra mode coding. So the adaptive intra mode coding provides
a total of .5%(psnr) to .6% gain(ssim) combined for all-key-encoding

To build and test, configure with
--enable-experimental --enable-qimode

Change-Id: I7c41cd8bfb352bc1fe7c5da1848a58faea5ed74a

make intra mode coding entropy distribution adaptive to baseQindex, an
encoding test on hd clips with all key frame shows universal gain on
all clips in both .2%(psnr) and (ssim).3%.

To build and test, configure with
--enable-experimental --enable-qimode

Change-Id: Iaa69241b984d4fdd8baa6d77ee78c0140f5ac00a

Patch 1 to Patch 3 is an initial implementation of 8x8 intra prediction
modes, here are with the following assumptions:
a. 8x8 has 4 prediction modes DC, H, V and TM
b. UV 4x4 block use the same mode as corresponding 8x8 area
c. i8x8 modes are enabled for key frame only for now
Patch 4:
d. removed debug code from previous patches
Patch 5:
e. added stats code to collect entropy stats and further cleaned up
Patch 6:
f. changed mode stats code to collect finer stats of modes
Patch 7:
g. normalized i8x8 modes distribution to total at 256 (8bits).
Patch 8:
h. fixed a bug in decoder and removed debug printf output.
Patch 9:
i. more cleanups to address paul's comment
Patch 10:
j. messy rebase/merges to bring the commit up to date.

Tests on HD clips encoded with all key frame showing consistent gain
on all clips and all metrics:~0.5%(psnr) and 0.6%(ssim):
http://www.corp.google.com/~yaowu/no_crawl/i8x8hd_allkey_fixedq.html

To build and test, configure with:
--enable-experimental --enable-i8x8

Change-Id: I9813fe07ae48cab5fdb5d904bca022514ad01e7f

Conflicts:
	vp8/decoder/decodframe.c
	vp8/encoder/encodeframe.c
	vp8/encoder/encodemb.c

Change-Id: I6e0d1669e4409a2dfd73ba2c7038d730842d3953

Change-Id: I20df6781013786cbf56ded31e1c726de6c34bc42

Change-Id: I5b47d39d1604f2650d2f2d1ca2a3f40843c8e1ea

Plumbing for tuning new segment features on and off.

Change-Id: If86cd6f103296b73030e8af7cf85c5b9bbffdbaf