This comitt brings accross changes from the public branch
commit number Icf74d13af77437c08602571dc7a97e747cce5066.

The main puurpose of this comit relates to CQ mode but it
also includes some refactoring of the two pass code which
I hope will make tuning the experimental branch for the new
quantizer range a little less painfull.

Change-Id: I278e989436a928fc1fe7761068960048f9d7a376

This commit resolves further QIndex look up tables to facilitate
experimentation with the quantizer range.

In some cases  rather than remove the look up tables completely
I have created functions that are called once  to populate them
using a formulaic approach base on the actual quantizer.

The use of these functions based on best fit of data from the original
tables does affect the results on some clips but across the derf test
set the effect was broadly neutral.

Change-Id: I8baa61c97ce87dc09a6340d56fdeb681b9345793

Removed unused variables lf_or_gf and frame_lf_or_gf.

Change-Id: I88692cd7d53e532d303c4525ee4667c1ecea3026

One of the problems arising when tweaking or adjusting the quantizer
tables is that there are a lot of look up tables that depend on the QINDEX.
Any adjustment to the link between QINDEX and real quantizer therefore tends
to break aspects of for example the rate control.

In this check in I have replaced several of the look up tables with functions that
approximate the same results as the old Q luts but use a formulaic approach
based on real Q values rather than QIndex. This should hopefully make it easier
to experiment with changes to the Q tables without always having to go through
and hand optimize a set of look up tables. Once things stabilize we may choose
to re-instate luts for the sake of performance.

Patch 2:
    Addressed Ronald's comments.
    vp8_init_me_luts() Added so luts only initialized once.

Change-Id: Ic80db2212d2fd01e08e8cb5c7dca1fda1102be57

Corrected dc lookup table to maintain ac/dc balance
close to what it was previously.

Firstpass not being passed the adjusted Q index for
the extended range.

Change-Id: Ic0200dabda445fea03bf81067999cb2670e99b77

Clean up of vp8_kfread_modes().
Remove unnecessary indentation and enforce line length.

Change-Id: I0864d1aff55368126db01bb23efa815786b5245d

Fix decoder segmentation bug for temporal coding where the segment map
was first initialized on a key frame.

in vp8_kfread_modes() after reading the segment id it must be written to
the  pbi->segmentation_map[] for use in temporal coding on subsequent frames.

Change-Id: I1489305efc376564e734a216f69c2844646ee3d3

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

Change-Id: Ie5729ec22a999d9a1996f020bd4b941e29514992

The buffer level was able to increase indefinitely rather than
being clipped to the maximum buffer size specified by the user.

This change checks the buffrer level and prevents it from
going beyond the upper limit of the buffer.

Change-Id: Ifff55f79d3c018e4d3d77e554b11ada543cc1654

This commit has a few minor fixes to the 8x8 trellis quant, so to
make it work regardless if extend_qrange is enabled or not. It also
borrowed adaptive RDMULT constants from 4x4 trellis that was missed
in the 8x8 trellis quant.

Change-Id: I60d7769071f102c699b5084597e62bca87a1f759

Explicit inclusion of limits.h to satisfy unix build for definition of INT_MAX.
Some commented out code removed.

Change-Id: I5b5980dfaa9b4d2d12bfd729cfd35bd982106908

Removal of CONFIGURE_SEGMENTATION ifdefs.

Removal of legacy support code fo the old coding mechanism.

Use local reference "xd" for MACROBLOCKD structure in
encode_frame_to_data_rate()

Moved call to choose_segmap_coding_method() out of encode
loop as the cost of segmentation is not properly accounted
in the loop anyway. If this is desirable in the future it
can be moved back. The use of this function to do all the
analysis and set the probabilities also removes the need
to track segment useage in threading code.

Change-Id: I85bc8fd63440e7176c73d26cb742698f9b70cade

Changed name and sense of segment_flag to "seg_id_predicted"
Added some additional comments and retested.

I also did some experimentation with a spatial prediction option
using a similar strategy to the temporal mode implemented.
This helps in some cases where temporal prediction is bad but
I suspect there is more overlap here with work on a larger scale
block structure and spatial correlation will likely be better
handled through that mechanism.

Next check in will remove #ifdefs and legacy mode code.

Change-Id: I3b382b65ed2a57bd7775ac0f3a01a9508a209cbc

This check in includes quite a lot of clean up and refactoring.

Most of the analysis and set up for the different coding options for the
segment map (currently simple distribution based coding or temporaly
predicted coding), has been moved to one location (the function
choose_segmap_coding_method() in segmenation.c). This code was previously
scattered around in various locations making integration with other
experiments and modification / debug more difficult.

Currently the functionality is as it was with the exception that the
prediction probabilities are now only transmitted when the temporal
prediction mode is selected.

There is still quite a bit more clean up work that will be possible
when the #ifdef is removed. Also at that time I may rename and alter
the sense of macroblock based variable "segment_flag" which indicates
(1 that the segmnet id is not predicted vs 0 that it is predicted).

I also intend to experiment with a spatial prediction mode that can be
used when coding a key frame segment map or in cases where temporal
prediction does not work well but there is spatial correlation.

In a later check in when the ifdefs have gone I may also move the call
to choose_segmap_coding_method() to just before where the bitsream is
packed (currently it is in vp8_encode_frame()) to further reduce the
possibility of clashes with other experiments and prevent it being called
on each itteration of the recode loop.

Change-Id: I3d4aba2a2826ec21f367678d5b07c1d1c36db168

Added last_segmentation_map[] structure
to keep track of what we had before when
doing temporal prediction. With this change
the existing code does once again appear to
be giving a decodable bitstream for both
temporal and standard prediction modes.
However, it is still somewhat messy and
confused and there is no option to take
advantage of spatial prediction so it could
do with further work.

Some housekeeping / clean out.

Change-Id: I368258243f82127b81d8dffa7ada615208513b47

Some initial cleanup to aid testing and debug.

Pull code to choose temporal or spatial encoding
out of encodeframe.c into a dedicated function
in segmentation.c.

For now disable broken temporal mode.

Move the coding of "temporal_update" flag and
only transmit if segment map update is indicated.

Rename the functions read_mb_features() and
write_mb_features() to read_mb_segid() and
read_mb_segid() as they only read and write
the macroblock segment id not any of the
features.

Change-Id: Ib75118520b1144c24d35fdfc6ce46106803cabcf

The dequantizer functions for 2nd order haar block had confusing 8x8
in their names. this commit fixed their name to avoid confusion.

Change-Id: I6ae4e7888330865f831436313637d4395b1fc273

This commit added scaling factors to 8x8 transform, quant, dequant and
inverse transform pipeline to make 8x8 transform to work when configed
with enable-extend_qrange. This commit also disabled the trellis-quant
when extend_qrange is configured.

Change-Id: Icfb3192e4746f70a4bb35ad18b7b47705b657e52

updated the decode_macroblock logic to reflect that 8x8 transform is
not used for "SPLITMV". Also fixed an issue where 2nd order haar block
has wrong dequant/idct process.

Change-Id: I1e373f6535c009dfec503b6362c8a5cfc196e1da

extend_qrange introduces a different scaling factor, this commit takes
the scaling difference into account for reset 2nd order coefficients.

Change-Id: Ie58bca9f52698fa759e3f88da2aa4d82630fa91a

the bug caused the encoder to produce invalid bitstream when configured
with enable_extend_qrange.

Change-Id: I1e81c48b13359d0043cbbd480e679380a2da117c

For ease of testing and merging experiments I have
removed in line code in encode_frame() that assigns
MBs to be t8x8 or t4x4 coded segments and have
moved the decision point and segment setup to
the init_seg_features0 test function.

Keeping everything in one place helps make sure
for now that experiments using segmentation are
not fighting each other.

Also made sure mode selection code can't choose 4x4
modes if t8x8 is selected.

Patch2: In init_seg_features() add checks
for SEG_LVL_TRANSFORM active.

Change-Id: Ia1767edd99b78510011d4251539f9bc325842e3a

Removed code in #if CONFIG_SEGMENTATION that
enables segmentation and creates a test segmentation
map, to avoid conflicts with the other segmentation test
code,

Change-Id: I7a21a44ed188b814cd80b30dd628c62474eba730

Bug fix to logic in vp8_pick_inter_mode() and
vp8_rd_pick_inter_mode().

The block on the use of segment features
for the cm->refresh_alt_ref_frame case
was just for testing and is not correct.

The special case code for alt ref can
be re-enabled as an else clause.

Change-Id: Ic9b57cdb5f04ea7737032b8fb953d84d7717b3ce

The 8x8 forward transform makes use of floating operations, therefore
requires emms call to reset mmx registers to correct state. Without
the resets, the 8x8 forward transform results are indefinite on win32
platform.

Change-Id: Ib5b71c3213e10b8a04fe776adf885f3714e7deb1

logically this commit should NOT change anything, but seems to help
revert the 3DB loss on bowing in the following commit:

https://on2-git.corp.google.com/g/#change,6193

This is still debugging in progress. Need further investigation to
understand the root cause of the issue.

Change-Id: I0b49d1ef3a311dfff58c6acd3eaebdb3bda6257c

Initial attempt at using new segment feature signaling
to indicate 4x4 or 8x8 transform.

needs --enable-experimental --enable-t8x8

Note this is work in progress.

Change-Id: Ib160d46a5d810307bfcbc79853ce1a65b5b870b7

Temporary check in to turn off other segment features
tests when #if CONFIG_T8X8 is set as the assignment of
MBs to differnt segments in each case  will conflict.

The 8x8 code will be modified to use the new segment
feature method properly in a later check in.

Increase bits allowed for EOB end stop marker to 6 ready
for 8x8.

Change-Id: I4835bc8d3bf98e1775c3d247d778639c90b01f7f

No change to functionality or output.

Updates to the segment feature data structure now all done
through functions such as set_segdata() and get_segdata()
in seg_common.c.

The reason for this is to make changing the structures (if needed)
and debug easier.

In addition it provides a single location for subsequent addition
of range and validity checks. For  example valid combination of
mode and reference frame.

Change-Id: I2e866505562db4e4cb6f17a472b25b4465f01add

This commit tries to do UV intra mode coding adaptive to Y intra mode.
Entropy context is defined as conditional PDF of uv intra mode given
the Y mode. All constants are normalized with 256 to be fit in 8 bits.

This provides further coding efficiency beyond the quantizer adaptive
y intra mode coding. Consistent gains were observed on all clips and
all bit rates for HD all key encoding tests.

To test, configure with
--enable-experimental --enable-uvintra

Change-Id: I2d78d73f143127f063e19bd0bac3b68c418d756a

As discovered in path 10 of Change Ia12acd2f, reset 2nd order coeffs
without reset of above and left coding context may have introduced
problem that causes encoder/decoder mismatching. This commit added
update to coding context when the 2nd coefficients are cleared.

In addition, this commit also introduced early breakout in the checks
to speed up when coefficients are too significant to be cleared.

Change-Id: I85322a432b11e8af85001525d1e9dc218f9a0bd6

Removal of configure #ifdefs so that segment features
always available. Removal of code supporting old
segment feature method.

Still a good deal of tidying up to do.

Change-Id: I397855f086f8c09ab1fae0a5f65d9e06d2e3e39f