Overall, on all test sets, this gains about +0.2% on all metrics.
City is a clip where this really hurts (-1.0% on all metrics), I'm
not quite sure why yet. Maybe interesting to look into in the future.

Change-Id: I6f0eecb20e72f0194633270d30bf00d76d9eae78

Skips mode searches for intra and compound inter modes depending
on the best mode so far and the reference frames. The various
heuristics to be used are selected by bits from a flag. The
previous direction based intra mode search pruning is also absorbed
in this framework.

Specifically the flags and their impact are:

1) FLAG_SKIP_INTRA_BESTINTER (skip intra mode search for oblique
directional modes and TM_PRED if the best so far is
an inter mode)
derfraw300: -0.15%, 10% speedup

2) FLAG_SKIP_INTRA_DIRMISMATCH (skip D27, D63, D117 and D153
mode search if the best so far is not one of the closest
hor/vert/diagonal directions.
derfraw300: -0.05%, about 9% speedup

3) FLAG_SKIP_COMP_BESTINTRA (skip compound prediction mode
search if the best so far is an intra mode)
derfraw300: -0.06%, about 7-8% speedup

4) FLAG_SKIP_COMP_REFMISMATCH (skip compound prediction search
if the best single ref inter mode does not have the same ref
as one of the two references being tested in the compound mode)
derfraw300: -0.56%, about 10% speedup

Change-Id: I1a736cd29b36325489e7af9f32698d6394b2c495

Change-Id: I221126f22ab9067348eb0efb8a73b15a8f49c3fd

This commit allows encoder to detect the cumulative rate-distortion
cost per transformed block inside a partition. If the cumulative
rd cost is already above the best rd value, it terminates the rest
operations and continue to next prediction mode test.

It reduces the runtime of bus at target bit-rate 2000 from 308 second
to 266 second, i.e., about 13% speed-up at no performance penalty.

Change-Id: I5f15a3d8955d97031d5653006027866a00654e7a

Change-Id: I32276552b3ea6dc1dce8e298be114cfe1019b31c

Change-Id: Ib41f0643fdcc088500e7420708f4e72f1f64c710

These serve as building blocks for SSE2 8x8 and 16x16 ADST/DCT
hybrid transform coding.

Change-Id: I4089a754c66e0c986f67d9b8ec4dfb9627ad430d

When this is 0 (BLOCK_SIZE_AB4X4) we want to do
the inter joint search for all sizes.

Change-Id: Id40cd6fe7790e7e1165352b9cef5e12fa8c0bc88

sf->unused_mode_skip_lvl. Tests modes as normal for all
sizes at or below the given level. At larger sizes it skips
all modes that were not chosen at any smaller size.
Hence setting BLOCK_SIZE_SB64X64 is in effect off.
Setting BLOCK_SIZE_AB4X4 will only consider modes that
were chosen for one or more 4x4 blocks at larger sizes.

sf->reference_masking.
Do a test encode of the NONE partition at one size and create
a reference frame mask based on the best rd choice. In the
full search only allow this reference frame.
Currently it is testing 64x64 and repeats this in the full search.
This does not work well with Jim's Partition code just now and
is disabled by default.

Change-Id: I8f8c52d2ef4a0c08100150b0ea4155d1aaab93dd

Change-Id: I08fc6e474ff2c12cfa065bae4989c724276e2c83

Change-Id: I143b430b7c24a964ccd0ebb75944cf317a072214

This commit adds a speed feature where only squared partition are
evaluated in partition picking. Enable this feature in cpu-used 2
reduces encoding time by ~30%.

loss of compression:
-0.9% on cif set
-1.23% on stdhd

Change-Id: Ia6fad11210f0b78365abb889f9245604513be5b9

If none of the 16 coefficients that we quantize per loop iteration
are larger than the zbin, directly skip to the next round of coeffs,
rather than doing a full quantize loop that will eventually result
in 16 zeroes. This incurs a jump cost, but saves a lot of other work.
32x32 quant goes from 1349 -> 1184 cycles. The same approach yielded
no significantly positive results for smaller transforms, so is not
used there (8x8: 103 -> 101 cycles; 16x16: 302 -> 306 cycles).

Change-Id: I8fca17dc2543fc8eed1dbcd5100145e3c3a9b647

Change-Id: Ibfd2def2c088f4bc541a1de25990d73480b53d4b

Tests q0 ( lossless),  very high bitrate and low bitrates at cpu speed
0, 1 and 2.

Change-Id: I0c5cdca00acd8d01e7b13f124b3b08d4b1ae9f6d

This speed feature will skip searching the directional intra prediction
modes D63, D117, D27, D153 if the best intra mode so far is not one of
the diagonal, horizontal or vertical directions closest to the respective
directions being tested. In other words, this implements a sort of
binary search in the angular domain.

Speedup: about 9-10%
Results: -0.05% only on derfraw300.

Change-Id: I413584c41f2a3e8dabfbdeb40718c8fc4b1d63a2

(1) Refines the modeling function and uses that to add some speed
features. Specifically, intead of using a flag use_largest_txfm as
a speed feature, an enum tx_size_search_method is used, of which
two of the types are USE_FULL_RD and USE_LARGESTALL. Two other
new types are added:
USE_LARGESTINTRA (use largest only for intra)
USE_LARGESTINTRA_MODELINTER (use largest for intra, and model for
inter)

(2) Another change is that the framework for deciding transform type
is simplified to use a heuristic count based method rather than
an rd based method using txfm_cache. In practice the new method
is found to work just as well - with derf only -0.01 down.
The new method is more compatible with the new framework where
certain rd costs are based on full rd and certain others are
based on modeled rd or are not computed. In this patch the existing
rd based method is still kept for use in the USE_FULL_RD mode.
In the other modes, the count based method is used.
However the recommendation is to remove it eventually since the
benefit is limited, and will remove a lot of complications in
the code

(3) Finally a bug is fixed with the existing use_largest_txfm speed feature
that causes mismatches when the lossless mode and 4x4 WH transform is
forced.

Results on derf:
USE_FULL_RD: +0.03% (due to change in the tables), 0% encode time reduction
USE_LARGESTINTRA: -0.21%, 15% encode time reduction (this one is a
pretty good compromise)
USE_LARGESTINTRA_MODELINTER: -0.98%, 22% encode time reduction
(currently the benefit of modeling is limited for txfm size selection,
but keeping this enum as a placeholder) .
USE_LARGESTALL: -1.05%, 27% encode-time reduction (same as existing
use_largest_txfm speed feature).

Change-Id: I4d60a5f9ce78fbc90cddf2f97ed91d8bc0d4f936

Uses mapping tables instead of complicated modulo/division
operations for prob mapping for forward updates.

No bit-stream or output change.

Change-Id: Ifd9ce8ac1437835c305c94f64c18273c7a68f546

Change-Id: I8a2983fb14274a6ac53681fa4cd5d4209cbd2905

Added a speed feature in speed 1 to disable splitmv for HD (>=720)
clips. Test result on stdhd set: 0.3% psnr loss and 0.07% ssim
loss. Encoding speedup is 36%.

(For reference: The test result on derf set showed 2% psnr loss
and 1.6% ssim loss. Encoding speedup is 34%. SPLITMV should be
enabled for small resolution videos.)

Change-Id: I54f72b94f506c6d404b47c42e71acaa5374d6ee6

Compute the rate-distortion cost per transformed block, and cumulate
the cost through all blocks inside a partition. This allows encoder
to detect if the cumulative rd cost is already above the best rd cost,
thereby enabling early termination in the rate-distortion optimization
search.

Change-Id: I0a856367a9a7b6dd0b466e7b767f54d5018d09ac