The existing test was triggering a lot of false positives on some types
of animated material with very plain backgrounds. These were triggering
code designed to catch key frames in letter box format clips.

This patch tightens up the criteria and imposes a minimum requirement
on the % blocks coded intra in the first pass and the ratio between the
% coded intra and the modified inter % after discounting neutral (flat)
blocks that are coded equally well either way.

On a particular problem animation clip this change eliminated a large
number of false positives including some cases where the old code
selected kf several times in a row. Marginal false negatives are less
damaging typically to compression and in the problem clip there are now
a couple of cases where "visual" scene cuts are ignored because of well
correlated content across the scene cut.

Replaced some magic numbers related to this with #defines and added
explanatory comments.

Change-Id: Ia3d304ac60eb7e4323e3817eaf83b4752cd63ecf

This patch limits  the maximum arf interval length to
approximately half a second. In some low fps animations in
particular the existing code was selecting an overly long interval
which was hurting visual quality. For a sample problem test clip
(360P animation , 15fps, ~200Kbit/s) this change also improved
metrics by >0.5 db.

There may be some clips where this hurts metrics a little, but the
worst case impact visually is likely to be less than having an
interval that is much too long. On more normal material at 24
fps or higher, the impact is likely to be nil/minimal.

Change-Id: Id8b57413931a670c861213ea91d7cc596375a297

This function has been replaced by other approaches and is not
in use now.

Change-Id: I387f45b5607d202539e482468ccc70e6c0f9341f

Change-Id: Ia31ada59172eb1818e1eb91009f83cbb1f581223

Change-Id: Ia2956f06f409b9b0ca8320ca4c1ea5680e938402

Refactor the loops in dec_build_inter_predictors to try and decrease
the number of instructions. Limited testing saw about 1% perf
increase on x86 and about 0.67 % perf increase on Arm.

Change-Id: I69cfe6335bb562fbaaebf43fb3f5c5a2a28882a2

add a check for the status line to awk and better report failure given
the program output will be lost in this case

Change-Id: I1348a80108c81099d609f2e2227dd2c31bd8cd54

Modifies a special handling that improves rate control accuracy in
the constrained quality mode, when the undershoot and overshoot
limits are set tighter.

Change-Id: If62103f0ef3ed1cac92807400678c93da50cf046

the sse4 code expects 16-byte aligned arrays; vp8 already had a similar
change applied:
b2aa4017 Align SAD output array to be 16-byte aligned

Change-Id: I5e902035e5a87e23309e151113f3c0d4a8372226

Skip redundant prediction filter type cost in filter search loop,
if the rate value will be reset in Hadamard transform based rate
distortion estimate.

Change-Id: Ie5221f4bc8da9461c449df367251aeeac52c6e5d

Reset the reached_eos flag in webm_guess_framerate in case it ends
up consuming the entire file. Also adding a vpxdec shell test to
verify this behavior.

Change-Id: I371eebd2105231dc0f60e65da1f71b233ad14be5

If U is not skippable, then do not perform the check on V.

Change-Id: Iba5e8362bd42390197f373c44388a426a4404549

* changes:
  vp8_regular_quantize_b_sse2: remove dead init
  vp8cx_pick_filter_level*: remove dead inits
  vp8_decode_frame: remove dead increment
  rdopt: remove dead stores
  find_next_key_frame: remove dead init & store
  multiframe_quality_enhance_block: remove dead stores
  vp8_print_modes_and_motion_vectors: remove dead stores

It uses about 10% less CPU cycles than the SSE2 intrinsic
implementation.

Change-Id: I91017c0c068679a214b98cdd4cff3a6facfb7499

This commit turns on the Hadamard transform based rate distortion
estimate for all block sizes in RTC coding mode. It conditionally
skips the rate distortion estimation if all zero block flag is set
on. No significant encoding speed change is observed. The
compression performance of speed -6 is improved by 1.7% over using
it only for block sizes of 32x32 and below.

Change-Id: I768145e6f05c737b05b5b5f1ee674e929532cafb

Change-Id: Ide5eefadbb3cab38743a69f744a003abb37a6506

Change-Id: I28026b86d03264b9f4e2fc8ac1d3c74aa3954208

Change-Id: Ie9a6fac02796d24e6f4a15416d0b4c19010547df

Change-Id: Ia8a20c6751cc6d63c60bb00b99c78faca1e61051

Change-Id: I8c7f5b9718ef14e4397a263aa9f52a9edcf7d1cd

Change-Id: I33ca9cddfdd54c3d8a23c1cb978986a537a20bf2

Change-Id: I438cbf4970fa2220fb73b0b41a29e654836d4e3b

The threshold scaling factor was calculated wrong using partition
size "bsize". Thank Yaowu for pointing it out. It was fixed and no
speed change was seen.

Change-Id: If7a5564456f0f68d6957df3bd2d1876bbb8dfd27

The following functions use the count parameter to either loop or select
dedicated paths:
vp9_lpf_horizontal_16_c
vp9_lpf_horizontal_16_sse2
vp9_lpf_horizontal_16_avx2
vp9_lpf_horizontal_16_neon
vp9_highbd_lpf_horizontal_16_c
vp9_highbd_lpf_horizontal_16_sse2

Change-Id: I7abfd2cb30baa292b4ebe11c847968481103c037