The denoiser function was modified to reduce the computational
complexity.
1. The denoiser c function modification:
The original implementation calculated pixel's filter_coefficient
based on the pixel value difference between current raw frame and last
denoised raw frame, and stored them in lookup tables. For each pixel c,
find its coefficient using
filter_coefficient[c] = LUT[abs_diff[c]];
and then apply filtering operation for the pixel.
The denoising filter costed about 12% of encoding time when it was
turned on, and half of the time was spent on finding coefficients in
lookup tables. In order to simplify the process, a short cut was taken.
The pixel adjustments vs. pixel diff value were calculated ahead of time.
adjustment = filtered_value - current_raw
= (filter_coefficient * diff + 128) >> 8
The adjustment vs. diff curve becomes flat very quick when diff increases.
This allowed us to use only several levels to get a close approximation
of the curve. Following the denoiser algorithm, the adjustments are
further modified according to how big the motion magnitude is.
2. The sse2 function was rewritten.
This change made denoiser filter function 3x faster, and improved the
encoder performance by 7% ~ 10% with the denoiser on.
Change-Id: I93a4308963b8e80c7307f96ffa8b8c667425bf50
Enable ADST/DCT of dimension 16x16 for I16X16 modes. This change provides
benefits mostly for hd sequences.
Set up the framework for selectable transform dimension.
Also allowing quantization parameter threshold to control the use
of hybrid transform (This is currently disabled by setting threshold
always above the quantization parameter. Adaptive thresholding can
be built upon this, which will further improve the coding performance.)
The coding performance gains (with respect to the codec that has all
other configuration settings turned on) are
derf: 0.013
yt: 0.086
hd: 0.198
std-hd: 0.501
Change-Id: Ibb4263a61fc74e0b3c345f54d73e8c73552bf926
Alternative strategy for finding a list of candidate motion
vectors to use as reference values in mv coding and as
nearest and near.
Sort by sad in vp8_find_best_ref_mvs() rather than just
pick the best. Allow 0,0 as a best ref option but not a
nearest or near unless there are no alternatives.
Encode/Decode verified on at least some clips.
Some commented out experimental and stats code still in place.
Gain over existing code averages about 1% on derf (alll metrics)
with improvement on all clips. Other test results pending.
The entropy coding of the mode (nearest/near etc) still
depends upon and requires the old "findnear" code so
this needs looking at and may provide room for further gains.
Change-Id: I871d7cba1d1c379c4bad9bcccce1fb19c46b8247
For videos with big static background(such as video conferencing
clips), the mode decision was biased to ZEROMV in order to
obtain a stable background. The percentage of ZEROMV on last
frame was used to predict if there is static area in current frame,
and checking already-encoded neighboring macroblocks' motion
vectors to make sure the local area has low motion.
Change-Id: I05b3241d3a56a0bda88b6681e5646c1c8baf2e57
The current way of counting inter_zz_count doesn't work correctly
in multi-threaded encoding. Calculating it after the frame is
encoded fixed the problem.
Change-Id: Ifcb1972cde950b8cc194f75c6d7b6af09e8b0e65
This commit adds a pick_sb_mode() function which selects the best 32x32
superblock coding mode. Then it selects the best per-MB modes, compares
the two and encodes that in the bitstream.
The bitstream coding is rather simplistic right now. At the SB level,
we code a bit to indicate whether this block uses SB-coding (32x32
prediction) or MB-coding (anything else), and then we follow with the
actual modes. This could and should be modified in the future, but is
omitted from this commit because it will likely involve reorganizing
much more code rather than just adding SB coding, so it's better to let
that be judged on its own merits.
Gains on derf: about even, YT/HD: +0.75%, STD/HD: +1.5%.
Change-Id: Iae313a7cbd8f75b3c66d04a68b991cb096eaaba6
Loop filter producing wierd artifacts when
repeatedly applied in noisy video. This
mitigates the effect.
Change-Id: If4b1a8543912d186a486f84e11d8b01f7436fa5f
The reference motion vector selected by surrounding pixels that has
the best matching score is used as nearest motion vector.
The change has shown consistent gain on all test sets, compression
gains range from .2% to .6%. The variation is largely dependent on
various other experiments on or off.
Change-Id: I5552e1c2f6fc57c3e8818a5ee41ffda89af05e75
References to MACROBLOCKD that use "x" changed to "xd"
to comply with convention elsewhere that x = MACROBLOCK
and xd = MACROBLOCKD.
Simplify some repeat references using local variables.
Change-Id: I0ba2e79536add08140a6c8b19698fcf5077246bc
Add local variable in several places to reference the MB mode
info structure. Currently this is usually accessed in the code as
x->e_mbd.mode_info_context->mbmi.* or in some places
xd->mode_info_context->mbmi.*
Resolved some uses of x-> for the MACROBLOCKD structure.
Rebased without dependency on motion reference experiment.
Change-Id: If6718276ee4f2ef131825d1524dfdb02a3793aed
