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

Commented out changes from earlier checking:

"Change Iab7f1eff: vpnext use segref segmentation filter"

Which in its current state breaks the decoder.

Change-Id: I9185098aeda8ce65310f338c4c9375f4a39005d3

The bug was introduced by the commit that added I8X8 intra prediction
mode for inter frames, the decoder was not update to accept the additional
probability update from encoder. This causes the decoder typicall to crash
when encoder sends intra mode probability update.

Change-Id: Ib7dc42dc77a51178aa9ece41e081829818a25016

Please see the following for details:
https://gerrit.chromium.org/gerrit/#change,10925

Change-Id: Ie692261c255c58d7762df22eeca566a7d13adcba

Please see the following public commit for details:
https://gerrit.chromium.org/gerrit/#change,7608

Change-Id: I589eed0b6078e2c5c9c74e942886e503bd02b273

This line of code incorrectly set maxq = maxq rather than
capping minqtarget.

Change-Id: Ifbc86df8b0ff2779e7b2a5f7349724d04a18bd62

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

This does not change any functionality just modifies the code to
use the common prediction module interface for coding
the segment data.

Change-Id: Ifd43e9153573365619774a4f5572215e44fb5aa3

This function adds the common prediction modules,  some data structures
and a config option but does not use them.

It also corrects a bug in clearing down  the MODE_INFO border and introduces
a new element that indicates if an entry corresponds to an "in image" macro block
or is part of the border.

Change-Id: Ib69eec0876173ebe9d1de9df9537d0b2447702e0

Encoder side changes

Change-Id: I8921800e4fccec5e5a9e4755b80cbd472623107b

In this commit only the decoder side was updated.

Change-Id: Ia9bd58da07d1a943f028e330f0489344e62b0d02

Moved some segmentation data structures into VP8_COMMON

Change-Id: I59c6e2edf7a0176e35319936eea450027aeb3b39

Fixes a rounding issue with the 8-tap filters, which allows us to
use sharper filters that before with a little better performance.
Results on derf (0verall gain 0.76):
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html
Results on a 720P set (Overall gain 0.61):
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd.html

Change-Id: I4cd7bdf3583db974dc5589fa64857bc31ac861fa

Goes through set of ref frames used by each macroblock and
sets seg_lvl_ref_frame flags accordingly..

http://www.corp.google.com/~jimbankoski/no_crawl/segref.html

Change-Id: Iab7f1effd75a839b34eb310d7168692c8f105411

Picks a per segment loopfilter.  Adapts the algorithm to search for
a loopfilter value for each separate segment.  Further todo fix the
bias

Improvements .06 % ov psnr, .11% ssim
http://www.corp.google.com/~jimbankoski/no_crawl/segmentedpicklpf.html

Change-Id: Ic6a571c16fcd6ec0139f4de1f8061f87c6515a10

changed the token cost for 8x8 transformed macroblock used in trellisquant
from those derived from 4x4 transform coefficient distribution to those
derived from 8x8 transform coefficient distribution. Test results show
this fix help 8x8 transform based compression consistently on cif and hd
sets:

http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_cost8x8only.html
(avg psnr:.14% glb psnr: .17% ssim: .20%)
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hd_cost8x8only.html
(avg psnr:.17% glb psnr: .18% ssim: .58%)

Note: To test the effect of this change, 8x8 transform was forced to be used
only on 16x16 predicted macroblocks on inter frames, the effect would be
bigger had all macroblocks been forcd to use 8x8 transform.

Change-Id: If9b7868b75357c66541f511e5ee78e4d2d4929a4

using an 8-tap filter.

The results with 3 different 8-tap filters on the derf set are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html
The one that gives the most gain achieves an overall gain of about
0.6%. The results for a set of 12 hd (720p) videos are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd.html
with max gain of 0.55% with the same filter. The best filter apparently
achieves the best trade-off between pass band ripple and stop band
attenuation.

Change-Id: I919e28ae245c0493147fa0864f8c9d048a9dd530

This introduces base functions for introducing implicit segmentation.
The code that actually stores the results to the segment map isn't
here yet.   This just prints out the segmentation map results
if you call it.

Uses connected component labeling technique on mbmi info so that only
if 2 mbs are horizontally or vertically touching do they get the same
segment.

vp8next - plumbing for rotation

code to produce taps for rotation ( tapify. py ),  code
for predicting using rotation ( predict_rotated.c ) ,  code
for finding the best rotation find_rotation.c.

didn't checkin code that uses this in the codec.   still work
in progress.

Fixed copyright notice

Change-Id: I450c13cfa41ab2fcb699f3897760370b4935fdf8

This commit added a set of loop filter functions for macroblocks
using 8x8 transform. First we turned off the regular loop filtering
on 4x4 block boundaries that do not exist in macroblocks using 8x8
transform. Second, we change to use the same loop filter(mask and
7 tap filter) that used for macroblock edge filtering.

Change-Id: I3a00460b7674ced116917d86812ffc32578c1d3a

This fixed a conflict introduced by the change of adding 8x8 intra
prediction modes. The 8x8 intra prediction mode code assumed the
use of 4x4 transform, and causes encoder crashes when the codec is
configured with --enable-t8x8.

Change-Id: I00cc94df63e9725377ffba9eb51be6b77fe3fcf9

commit cf561bad accidentally deleted a line of code that sets the
base_qindex for each frame, which leads to every frame is encoded
at Q of 0.

Change-Id: Ib5f8022e856bf3b3bd0d4147405e46241e3dcf2d

The commit adds a new set of loop filter for macroblock edge filtering.
The new loop filter has a mask to detect so-called "flat" regions. The
detection checks 5 pixels of each side of an edge. If the all pixels
have value with +/-1 from the edge pixel on the same side, the region
is treated as a "flat" region. For such case, a 7 tap filter is used
to change 3 pixel values on each side. The 7 taps are:
               [1, 1, 1, 2, 1, 1, 1]/8
The furthest away pixels used as input are +/-5 away from edge. For
non-flat region, we fall back to old filtering. It should be noted
here that the thresholds and filter taps may require more optimization
for best possible results.

Tests on a set of hd clips showed consistent gains:
http://www.corp.google.com/~yaowu/no_crawl/mblpf_hd.html
(avg psnr: .83% glb psnr: .77% ssim: .82%)

Tests on derf set also showed consistent gains:
http://www.corp.google.com/~yaowu/no_crawl/mblpf_derf.html
(avg psnr: .24% glb psnr: .22% ssim: .48%)

Change-Id: I0855b1ff48e79e1175c20b81967137e18b2af352

Put traps to prevent two possible divide by 0 errors.

Change-Id: Ia415b945244253dcdd12f54f1f157f9ca8c94d6b

A problem can arise on static clips with force key frames where
attempts to avoid popping lead to a progressive reduction in key
frame Q that ultimately may lead to unexpected overspend against
the  rate target.

The changes in this patch help to insure that in such clips the
quality of the key frames across the clip is more uniform (rather
than starting bad and getting better - especially at low target rates).

This patch also includes a fix that removes a delta on the Y2DC
when the baseline q index < 4 as this is no longer needed.

There is also a fix to try and prevent repeat single step Q adjustment in
the recode loop leading to lots of recodes, especially where the use
of forced skips as part of segmentation has made the impact of Q on
the number of bits generated much smaller.

Patch 2: Amend "last_boosted_qindex" calculation for arf overlay frames.

Change-Id: Ia1feeb79ed8ed014e4239994fcf5e58e68fd9459

In certain hardware configuration, where mmx code is enabled and
other simd (sse2/sse3) disabled, lacking of this emms caused invalid
internal stats outputs.

Change-Id: I77c61cf6e0448d3f3b8c11781aa9e42f31d231c9

Change-Id: Ifadf65026a11bdb5d39840748613880bcfb364bb

Change-Id: I6bbed8bcb2dfa3458ffc59179dfba66c92e18125

Previously, the mode context is always udpated based on stats of current
frame, when there is no count, 50% is used for both left and right branch.
However, it is observed that with such strategy, a small count or no count
at all can skew the probability distribution significantly. This commmit
changed the mode_context update strategy to prevent small counts from
skewing the probability distributions.

Tests on derf set showed a small gain:  .06% in psnr and .09% in ssim

Change-Id: Ic812e64ae5f70251c170b0717f7b7fa587055488

Cleanup and switch to Q extended at low end too.

Change-Id: Ie22676bb9e961097d75dbd1d81745208b63e5f4b

This commit extends the number of Q steps to 256 from 128.
The q_trans[] array has been altered to distribute available Q index values
(using the current 64 steps available as input parameters) evenly across the
available range. This is coupled with the fact that each Q step where possible
now equates to a fixed % change in the quantizer. This may want refinement
later especially in terms of the granularity at the high quality end but is a
reasonable starting point.

Change-Id: I2aaa6874fa10ce05c958dd182947ce39f6f1eecb