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

Modify reference frame segmentation so that ONE or MORE
reference frames may be marked as a available for a given
segment.

Fixed bugs relating to segment coding of INTRA and some
INTER modes at the segment level.

Modified Q boost for static areas based on ambient average Q.

Strong results now on clips with significant static areas.
(some data points in derf set as high as 9% and some static &
slide show type content in YT set > 20%)

Change-Id: Ia79f912efa84b977f35a23683ae3643251e24f0c

The block of code skipped testing the current mode if the
reference frame is AltRef, the mv is not (0,0) and
ARNR filtering is disabled.

This block of code has already been tested above if the
macro CONFIG_SEGFEATURES is set to 0.

Change-Id: I3f5710bb8270caad06c9a0eee59fa0daf1f70776

The variable this_mode was being used before it had been
initialized.

Moved the line that sets-up this_mode toward the top of the
enclosing loop, prior to its first use. The bug would result in
tests in the loop lagging the mode that was expected to be
tested.

Change-Id: If4e51600449ce6b4285f112da17a44c24b4a19fb

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

similar logic to http://gerrit.chromium.org/gerrit/#change,10359

Change-Id: Ia12acd2f2b3b92ef2a601da43c2497034ef62174

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 data with range
and validity checking.

Handling of signed and unsigned feature data. At the moment all is assumed
to be signed and a sign bit is coded but many cannot be negative.

Correct handling of EOB feature with intra coded blocks.

Testing/trapping of legal/illegal ref frame and mode combinations.

Transform size switch plus merge and test with 8c8 DCT work

Merge and test with Sumans Segmenation coding optimizations

Change-Id: Iee12e83661c7abbd1e0ce6810915eb4ec35e2d8e

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