The idea is to have the following names for each transform size:
vp9_idct4x4_add
vp9_idct4x4_1_add
vp9_idct4x4_10_add
vp9_idct4x4_16_add
vp9_idct8x8_add
vp9_idct8x8_1_add
vp9_idct8x8_10_add
vp9_idct8x8_64_add
etc for 16x16, 32x32
The actual list of renames in this patch:
vp9_idct_add_lossless -> vp9_iwht4x4_add
vp9_short_iwalsh4x4_add -> vp9_iwht4x4_16_add
vp9_short_iwalsh4x4_1_add -> vp9_iwht4x4_1_add
vp9_idct_add -> vp9_idct4x4_add
vp9_short_idct4x4_add -> vp9_idct4x4_16_add
vp9_short_idct4x4_1_add -> vp9_idct4x4_1_add
Change-Id: I6f43f7437c68dd30cdd05d72e213765578ed30b1
Speed 4 still does not give a big gain over speed 3.
This just cleans it up a little from the last patch and comments
out features that do not seem to be giving much benefit.
Change-Id: I5f366e6160e1dbe5dc45cf5eb90cc02712baa1b6
Allow selective masking of individual split modes rather than
just a single on / off flag.
For speed 2 recovers the large speed loss seen for some derf
clips in change Ie6bdfa0a370148dd60bd800961077f7e97e67dd4
and a small quality gain.
For speed 1 10 % speed increase observed locally on some derf clips
for minimal quality change.
Change-Id: If86191087b93cbc05351c26c60c7933e2149e485
This commit separates the rate-distortion optimization loop of
superblocks from that of sub8x8 blocks. This allows better design
rate-distortion optimization search loop for each setting. It also
removes the use of SPLITMV and I4X4_PRED therein.
No performance change in speed 0 settings. For bus@CIF at 2000kbps,
the speed 1 runtime goes from 48009ms to 43894ms (about 10% faster).
The overall compression performance on derf changed by -0.021%.
Speed 2 runtime goes from 27114ms to 28700ms (6% slower), while the
overall coding efficiency goes up by 1.629% for derf, 1.236% for yt.
Change-Id: Ie6bdfa0a370148dd60bd800961077f7e97e67dd4
Substantial reworking of the speed vs quality trade offs for
speed 1 and 2.
In this patch I am attempting to freeze the "quality" meaning of
speeds 1 and 2 relative to speed 0 so that in future we can
better evaluate progress.
I am targeting :
Speed 1 quality ~-5% vs speed 0.
Speed 2 quality ~-10% vs speed 0
It is inevitable that quality will still fluctuate a little as we adjust
settings and add new features, but we will attempt to keep as
close as possible to these values. Above speed 2 things will remain
a bit more fluid for now.
In this patch speed 1 is approximately 4-5x as fast as speed 0. This
is similar to before but the quality hit is a lot less. Likewise speed 2
is approximately 2x as fast as speed 1 but is similar in quality to the
previous speed 1 configuration.
Also slight change to behavior of FLAG_EARLY_TERMINATE to insure
all reference frames get at least one rd test. Important for very low
variance regions.
WIP :- Added a new speed level with old speed 4 becoming speed 5.
Speed 3 and 4 tradeoffs still WIP
Change-Id: Ic7a38dd7b5b63ab1501f9352411972f480ac6264
The code now takes into account temporal and spatial
information to determine the partition size range, but the
frequency counts have been removed.
The net effect is similar in quality but about 10% faster.
Change-Id: I39a513fb79cec9177b73b2a7218f0da70963ae95
This patch deletes the variance based speed three partitioning.
Speed 3 now uses the same partitioning method as speed 2
but with some stricter conditions.
The speed and quality are now somewhere between speeds 2 and 4
whereas before it was worse in both than speed 4.
Change-Id: Ia142e7007299d79db3ceee6ca8670540db6f7a41
Some small changes to the quantizer mapping functions.
Also includes some cleanups.
Change-Id: I9dea29b24015f6e6697012a0e4d8983049d8e5c7
Results:
derfraw300: +0.106%
stdhdraw250: +0.139%
Adds modeled functions to decide the qp for altref frames in constant q
mode similar to other functions in use in bitrate mode.
Also turns on the constrained quality mode (end-usage=2) option which
was turned off before. Basic testing shows the mode works in principle,
to cap bitrate to the target-bitrate specified, while allowing lower
bitrate depending on the cq-level specified. The mode will need to be
improved over time.
Results for constant quality vs bitrate control mode:
derfraw300/fullderfraw: +3.0% at constant quality over bitrate control.
fullstdhdraw: +4.341%
stdhdraw250: +5.361%
Change-Id: If5027c9ec66c8e88d33e47062c6cb84a07b1cda9
This commit enables adaptive constraint on motion search range for
smaller partitions, given the motion vectors of collocated larger
partition as a candidate initial search point.
It makes speed 0 runtime of bus at CIF and 2000 kbps goes from
167s down to 162s (3% speed-up), at 0.01dB performance gains. In
the settings of speed 1, this makes the runtime goes from 33687 ms
to 32142 ms (4.5% speed-up), at 0.03dB performance gains.
Compression performance wise, it gains at speed 1:
derf 0.118%
yt 0.237%
hd 0.203%
stdhd 0.438%
Change-Id: Ic8b34c67810d9504a9579bef2825d3fa54b69454
Removes this speed feature since it is very slow and unlikely
to be used in practice. This cleanup removes a bunch of unnecessary
complications in the outer encode loop.
Change-Id: I3c66ef1ca924fbfad7dadff297c9e7f652d308a1
Propose some changes to the speed 2 settings to improve quality.
In particular, turns off the adjust_thresholds_by_speed feature
which improves results by 6%. Also removes the code for
adjust_thresholds_by_speed since it conflicts with the adaptive
rd thresh feature.
Overall, with this change speed 2 is -15.2% from speed 0 settings,
on derf, which is significantly better than -21.6% down before.
Change-Id: I6e90a563470979eb0c258ec32d6183ed7ce9a505
mode_info_context was stored as a grid of MODE_INFO structs.
The grid now constists of pointers to MODE_INFO structs. The
MODE_INFO structs are now stored as a stream (decoder only),
eliminating unnecessary copies and is a little more cache
friendly.
Change-Id: I031d376284c6eb98a38ad5595b797f048a6cfc0d
Thank Paul for the suggestions. While turning on static-thresh
for static-image videos, a big jump on bitrate was seen. In this
patch, we detected static frames in the video using first-pass
stats. For different cases, disable encode breakout or reduce
encode breakout threshold to limit the skipping.
More modification need be done to break incorrect partition
picking pattern for static frames while skipping happens.
Change-Id: Ia25f47041af0f04e229c70a0185e12b0ffa6047f
A previous speed feature skipped modes not used in earlier
partitions but this not longer worked as intended following
changes to the partition coding order and in conjunction
with some other speed features (Especially speed 2 and above).
This modified mode skip feature sets a mask after the first X
modes have been tested in each partition depending on the
reference frame of the current best case.
This patch also makes some changes to the order modes are
tested to fit better with this skip functionality.
Initial testing suggests speed and rd hit count improvements
of up to 20% at speed 1. Quality results. (derf -1.9%, std hd +0.23%).
Change-Id: Idd8efa656cbc0c28f06d09690984c1f18b1115e1
Sample app: vp9_spatial_scalable_encoder
vpx_codec_control extensions:
VP9E_SET_SVC
VP9E_SET_WIDTH, VP9E_SET_HEIGHT, VP9E_SET_LAYER
VP9E_SET_MIN_Q, VP9E_SET_MAX_Q
expanded buffer size for vp9_convolve
modified setting of initial width in vp9_onyx_if.c so that layer size
can be set prior to initial encode
Default number of layers set to 3 (VPX_SS_DEFAULT_LAYERS)
Number of layers set explicitly in vpx_codec_enc_cfg.ss_number_layers
Change-Id: I2c7a6fe6d665113671337032f7ad032430ac4197
Adds a new end-usage option for constant quality encoding in vpx. This
first version implemented for VP9, encodes all regular inter frames
using the quality specified in the --cq-level= option, while encoding
all key frames and golden/altref frames at a quality better than that.
The current performance on derfraw300 is +0.910% up from bitrate control,
but achieved without multiple recode loops per frame.
The decision for qp for each altref/golden/key frame will be improved
in subsequent patches based on better use of stats from the first pass.
Further, the qp for regular inter frames may also be varied around the
provided cq-level.
Change-Id: I6c4a2a68563679d60e0616ebcb11698578615fb3
mode_info_context was stored as a grid of MODE_INFO structs.
The grid now constists of a pointer to a MODE_INFO struct and
a "in the image" flag. The MODE_INFO structs are now stored
as a stream, eliminating unnecessary copies and is a little
more cache friendly.
For the test clips used, the decoder performance improved
by ~4.3% (1080p) and ~9.7% (720p).
Patch Set 2: Re-encoded clips with latest. Now ~1.7% (1080p)
and 5.9% (720p).
Change-Id: I846f29e88610fce2523ca697a9a9ef2a182e9256
Added some code to output normalized rd hit count stats.
In effect this approximates to the average number of rd
operations/tests per pixel for the sequence.
The results are not quite accurate and I have not bothered
to account for partial SB64s at frame edges and for key frames
However they do give some idea of the number of modes /
prediction methods being tested for each pixel across the
different partition sizes. This indicates how much scope their
is for further gains either by reducing the number of partitions
examined or the modes per partition through heuristics.
Patch 3 moved place where count incremented so partial rd
tests that are aborted with INT_MAX return are also counted.
Example numbers for first 50 frames of Akiyo.
Speed 0 ~84.4 rd operations / pixel
Speed 1 ~28.8
Speed 2 ~11.9
Change-Id: Ib956e787e12f7fa8b12d3a1a2f6cda19a65a6cb8
Incorporates a speed feature for fast forward updates of
coefficients. This feature takes 3 values:
0 - use standard 2-loop version
1 - use a 1-loop version
2 - use a 1-loop version with reduced updates
Results: derfraw300 +0.007% (on speed 0) at feature value = 1
-0.160% (on speed 0) at feature value = 2
There is substantial speed up at speeds 2 and above for low
resolution sequences where the entropy updates are a big part
of the overall computations.
Change-Id: Ie96fc50777088a5bd441288bca6111e43d03bcae
To the source buffer to be encoded as an alt ref frame. This is to fix
the problem of using uninitialized memory in encoder.
See https://code.google.com/p/webm/issues/detail?id=605
Change-Id: I97618a2fc207e08abcf5301b734aa9e3ad695e2c
Values now carried over frame to frame.
Change to algorithm for decreasing threshold after
a hit and to max threshold (now based on speed)
Removed some old commented out code relating to
VP8 adaptive thresholds.
The impact of these changes tested on Akiyo (50 frames)
and measured in terms of unit rd hits is as follows:
Speed 0 84.36 -> 84.67
Speed 1 29.48 -> 22.22
Speed 2 11.76 -> 8.21
Speed 3 12.32 -> 7.21
Encode speed impact is broadly in line with these.
Change-Id: I5b886efee3077a11553fa950d796fd6d00c8cb19
Most of the focus so far has been on inter frames.
At high speed settings the key frame is now taking a high %
of the cycles.
This patch puts in some masking to reduce the number
of INTRA modes searched during key frame coding (as already
happens for inter frames) at higher speed settings
TODO: Develop this further with either adaptive rd thresholds
when choosing which intra modes to consider or some other
heuristic.
Impact.
At high speed settings on some clips the key frame was starting
to dominate. In a coding of the first 50 frames of AKIYO at speed
2 limiting the key frame intra modes to DC or TM_PRED resulted in
~30% overall speedup. For Bus the number was lower at ~4-5%.
Change-Id: I7bde68aee04995f9d9beb13a1902143112e341e2
remove duplicate allocation from vp9_create_compressor, it was added to
vp9_alloc_frame_buffers in:
d5bec52 Added resizing & initialization of last frame segment map
Change-Id: I996723226a16a62aff8f9a52ac74e0b73cc98fdf
This commit changes the partition search order of superblocks from
{SPLIT, NONE, HORZ, VERT} to {NONE, SPLIT, HORZ, VERT} for
consistency with that of sub8x8 partition search. It enable the use
of early termination in partition search for all block sizes.
For ped_area_1080p 50 frames coded at 4000 kbps, it makes the runtime
goes down from 844305ms -> 818003ms (3% speed-up) at speed 0.
This will further move towards making the in-search partition types
configurable, hence unifying various speed-up approaches.
Some speed 1 and 2 features are turned off during the refactoring
process, including:
disable_split_var_thresh
using_small_partition_info
Stricter constraints are applied to use_square_partition_only for
right/bottom boundary blocks. Will bring back/refine these features
subsequently. At this point, it makes derf set at speed 1 about
0.45% higher in compression performance, and 9% down in run-time.
Change-Id: I3db9f9d1d1a0d6cbe2e50e49bd9eda1cf705f37c
Adds a couple of minor fixes, which may be absorbed in Jingning's
patch. Thanks to Guillaume for pointing these out.
Also adjusts the thresholds for speed 1 and 2 to 16 and 32
respectively, to keep quality drops small.
Results:
--------
derfraw300: threshold = 16, psnr -0.082%, speedup 2-3%
threshold = 32, psnr -0.218%, speedup 5-6%
stdhdraw250: threshold = 16, psnr -0.031%, speedup 2-3%
threshold = 32, psnr -0.273%, speedup 5-6%
Change-Id: I4b11ae8296cca6c2a9f644be7e40de7c423b8330
Cleans up the switchable filter search logic. Also adds a
speed feature - a variance threshold - to disable filter search
if source variance is lower than this value.
Results: derfraw300
threshold = 16, psnr -0.238%, 4-5% speedup (tested on football)
threshold = 32, psnr -0.381%, 8-9% speedup (tested on football)
threshold = 64, psnr -0.611%, 12-13% speedup (tested on football)
threshold = 96, psnr -0.804%, 16-17% speedup (tested on football)
Based on these results, the threshold is chosen as 16 for speed 1,
32 for speed 2, 64 for speed 3 and 96 for speed 4.
Change-Id: Ib630d39192773b1983d3d349b97973768e170c04
Changes to code to auto select a partition size range
based on data from spatial neighbors.
Now looks at the sb_type in each 8x8 block of above
and left SB64.
The effect on speed 1 is now weaker giving better
quality but less speed gain. Now also used in speed 2.
Change-Id: Iace33a97d5c3498dd2a9a8a4067351941abcbabc
VP9_COMMON is the right place to segmentatation struct because it has
global segmentation parameters, not something specific to macroblock
processing.
Change-Id: Ib9ada0c06c253996eb3b5f6cccf6a323fbbba708
Adds a speed feature to disable split partition search based on a
given threshold on the source variance. A tighter threshold derived
from the threshold provided is used to also disable horizontal and
vertical partitions.
Results on derfraw300:
threshold = 16, psnr = -0.057%, speedup ~1% (football)
threshold = 32, psnr = -0.150%, speedup ~4-5% (football)
threshold = 64, psnr = -0.570%, speedup ~10-12% (football)
Results on stdhdraw250:
threshold = 32, psnr = -0.18%, speedup is somewhat more than derf
because of a larger number of smoother blocks at higher resolution.
Based on these results, a threshold of 32 is chosen for speed 1,
and a threshold of 64 is chosen for speeds 2 and above.
Change-Id: If08912fb6c67fd4242d12a0d094783a99f52f6c6
Loop filter configuration doesn't belong to macroblock, so moving it from
MACROBLOCKD to VP9_COMMON. Also moving the declaration of loopfilter struct
from vp9_blockd.h to vp9_loopfilter.h.
Change-Id: I4b3e34be9623b47cda35f9b1f9951f8c5b1d5d28
Adds a new subpel motion estimation function that uses a 2-level
tree-structured decision tree to eliminate redundant computations.
It searches fewer points than iterative search (which can search
the same point multiple times) but has the same quality roughly.
This is made the default setting at speeds 0 and 1, while at
speed 2 and above only a 1-level search is used.
Also includes various cleanups for consistency and redundancy removal.
Results:
derf: +0.012% psnr
stdhd: +0.09% psnr
Speedup of about 2-3%
Change-Id: Iedde4866f5475586dea0f0ba4cb7428fba24eee9
The low precision 32x32 fdct has all the intermediate steps within
16-bit depth, hence allowing faster SSE2 implementation, at the
expense of larger round-trip error. It was used in the rate-distortion
optimization search loop only.
Using the low precision version, in replace of the high precision one,
affects the compression performance by about 0.7% (derf, stdhd) at
speed 0. For speed 1, it makes derf set down by only 0.017%.
Change-Id: I4e7d18fac5bea5317b91c8e7dabae143bc6b5c8b
Removes some unused code and speed features, and organizes the
interfaces for fractional mv step functions for use in new speed
features to come.
In the process a new speed feature - number of iterations per
step during the subpel search - is exposed.
No change when this parameter is set as the original value of 3.
Results:
subpel_iters_per_step = 3: baseline
subpel_iters_per_step = 2: psnr -0.067%, 1% speedup
subpel_iters_per_step = 1: psnr -0.331%, 3-4% speedup
Change-Id: I2eba8a21f6461be8caf56af04a5337257a5693a8
Adds a few pattern searches to achieve various tradeoffs
between motion estimation complexity and performance.
The search framework is unified across these searches so that a
common pattern search function is used for all. Besides it will
be easier to experiment with various patterns or combinations
thereof at different scales in the future.
The new pattern search is multi-scale and is capable of using
different patterns at different scales.
The new hex search uses 8 points at the smallest scale
and 6 points at other scales.
Two other pattern searches - big-diamond and square are
also added. Big diamond uses 4 points at the smallest scale and
8 points in diamond shape at the larger scales.
Square is very similar conceptually to the default n-step search
but is somewhat faster since it keeps only one survivor across
all scales.
Psnr/speed-up results on derf300:
hex: -1.6% psnr%, 6-8% speed-up
big-diamond: -0.96% psnr, 4-5% speedup
square: -0.93% psnr, 4-5% speedup
Change-Id: I02a7ef5193f762601e0994e2c99399a3535a43d2
Adds a speed feature to skip all intra modes other than
DC_PRED if the source variance is small. This feature is
made part of speed 1 and up.
Results on derf300: psnr -0.07%, speedup about 1-2%
Also uses the source variance to fine-tune the early
termination criteria when FLAG_EARLY_TERMINATE is on.
This feature is made part of speed 2 and up.
Results on derf300: psnr -0.52%, speedup about 5-7%
Change-Id: I59e38aa836557cfa5405ae706fc64815cbfe4232
use_min_partition_size and use_max_partition_size are not used
currently, and could be added back if needed later.
Change-Id: Ib22a9c06b064567a7c1d6d5445567ed77e0d3acc
Speed feature experiment to set an upper and lower
partition size limit based on what has been seen
in spatial neighbors.
This seems to gives quite reasonable speed gains in local
(10-15%) and when used with speed 0 the losses are small
(0.25% derf, 0.35% stdhd). However, for now I am only
enabling it on speed 1 as there may be clashes with the existing
temporal partition selection in speed 2.
Using a tighter min / max around the range derived from the
neighbors increases speed further but at the cost of a
bigger quality loss. However, I think this spatial method could
be combined with data from either the last frame or a variance
method (or both) to refine the range of minimum and maximum
partition size. I.e. consider the min and max from spatial and
temporal neighbors and the variance recommendation.
Change-Id: I1b96bf8b84368d6aad0c7aa600fe141b4f07435f
Removing unused constants, macros, and function declarations. Using
ROUND_POWER_OF_TWO macro, vp9_zero, vp9_copy where possible. Moving
#include from *.h to *.c. Merging for loops for motion vectors.
Change-Id: Ic3bf841764a2bb177128bb3a6d7aa8f68229cd13
Counts are separate from frame context. We have several frame contexts but
need only one copy of all counts.
Change-Id: I5279b0321cb450bbea7049adaa9275306a7cef7d
Renamed:
MAX_MB_SEGMENTS to MAX_SEGMENTS
MB_SEG_TREE_PROBS to SEG_TREE_PROBS
The minimum unit for segmentation in the segment map
is now 8x8 so it is misleading to use MB_ as macro-block
traditionally refers to a 16x16 region.
Change-Id: I0b55a6f0426bb46dd13435fcfa5bae0a30a7fa22
Mode search order in rd loop changed to better reflect
observed hit counts.
Also some adjustment of the baseline mode rd thresholds
to reflect the order change and observed frequencies.
Change-Id: I47a131cc83e11551df8add6d6d8d413d78d3a63c
When CONFIG_POSTPROC is set there was a now
invalid reference to cm->filter_level.
Changed to cpi->mb.e_mbd.lf.filter_level in line with
change Iaf5fb71c33719cdfa1b991f671caf071be9ea035
Change-Id: If746e60044903f7ba8d0d346225b3d015226c7d0
Adding loopfilter struct with fields from MACROBLOCKD and VP9Common.
Eventually it will be moved to vp9_loopfilter.h for better code structure.
Change-Id: Iaf5fb71c33719cdfa1b991f671caf071be9ea035
This patch modifies the auto_mv_step_size speed feature to
use a combination of the maximum magnitude mv from the last
inter frame, and the maximum magnitude mv for the two reference
mvs with the same reference. For arf frames, the max mav step
for the resolution is used.
The bounds therefore are slightly tighter. The feature is made
a speed 1 feature.
Rebased.
Results (when this feature is turned on over speed 0):
derfraw300: -0.046% psnr, about 5+% speedup
(tested on football: goes from 4m30.760s to 4m17.410s).
Change-Id: If492797a61b0b4b3e58c0b8f86afb880165fc9f6
these are only used in the encoder.
frames_since_golden / frames_till_alt_ref_frame -> VP[89]_COMP
Change-Id: Ie14a6f46987bced685ddb449b85dc261caba6dfe
vp9_init_quantizer() is called in vp9_create_compressor(), and
should not be called in vp9_set_speed_features().
Change-Id: Ic2f1f4b0531b9d46bb841d7e1d8da9812207dad6
Current partition checking starts from small sizes, and then goes up
to large sizes. This experiment uses the small partitions' motion
estimation result, which is already available, to speed up the
large partition's motion estimation. We can decide to skip some
patition checkings if they are unlikely choices. We could use the
motion vector(MV) result as current partition's prediction MV, limit
the search range and reference frame.
Current result at speed 1:
psnr loss: 1.19% for stdhd, 0.287% for derf.
speed gain: 14% for sunflower(hd), 11% for akiyo.
Further improvement will be done later.
Change-Id: I5abfd070e9cace2e91e2a0247d1325df313887ab
Use an estimate based on DC_PRED for intra uv cost
within the rd loop then only do a full uv mode analysis
if an intra mode is chosen.
Significant speed gains in some cases. Currently only
enabled for speed 2 pending speed/quality tests.
Change-Id: Ie851a12400d5483bce47ec0e3ccb8516041e91c0
Removing tile_rows and tile_columns from VP9Common, removing redundant
constants MIN_TILE_WIDTH and MAX_TILE_WIDTH, changing signature of
vp9_get_tile_n_bits.
Change-Id: I8ff3104a38179b2c6900df965c144c1d6f602267
This is a short term optimization till we work out a decoder
implementation requiring no frame border extension.
Change-Id: I02d15bfde4d926b50a4e58b393d8c4062d1be70f
This speed feature allows the encoder to largely remove the spatial
dependency between blocks inside a 64x64 superblock, thereby removing
the need to repeatedly encode superblocks per partition type in the
rate-distortion optimization loop.
A major challenge lies in the intra modes tested in the rate-distortion
optimization loop. The subsequent blocks do not have access to the
reconstructed boundary pixels without the intermediate coding steps.
This was resolved by using the original pixels for intra prediction
in the rd loop, followed by an appropriately designed distortion
modeling on the quantization parameters. Experiments also suggested
that the performance impact is more discernible at lower bit-rate/psnr
settings. Hence a quantizer dependent threshold is applied to deactivate
skip of block coding.
For bus_cif at 2000 kbps,
speed 0: runtime 269854ms -> 237774ms (12% speed-up) at 0.05dB
performance loss.
speed 1: runtime 65312ms -> 61536ms, (7% speed-up) at 0.04dB
performance loss.
This operation is currently turned on in settings of speed 1.
Change-Id: Ib689741dfff8dd38365d8c1b92860a3e176f56ec
this was never fleshed out in the context of VP8, for which it was
added. for VP9 it has no meaning.
Change-Id: Iba2ecc026d9e947067b96690245d337e51e26eff
Adding segmentation struct to vp9_seg_common.h. Struct members are from
macroblockd and VP9Common structs. Moving segmentation related constants
and enums to vp9_seg_common.h.
Change-Id: I23fabc33f11a359249f5f80d161daf569d02ec03
This patch is in experimental but was not merged into master.
This patch swaps ptrs instead of copying and uses the
last show_frame flag instead of setting the entire buffer
to zero.
Change-Id: Ia0950466c8ba301a2a5bf917ff3d07bc1a2c2311
With sf->auto_mv_step_size on it is questionable
whether sf->reduce_first_step_size is worthwhile.
At speed 2 it was not having a big impact.
Even at speed 2 sf->optimize_coefficients = 0 is not
having a big speed imapct so for now I have moved it
down into a higher speed setting.
Change-Id: I8a54de76d486ad37aabce76474889da2768b14c1
Adds a speed feature to eliminate full-rd computation if the modeled
rd or rd based on a different parameter in the same mode is already
a lot larger than the best rd yet.
Specifically, only search the sharp and smooth filters if the modeled
rd cost based on the regular filter is within a certain factor of the
best rd cost so far. Also, skip full-rd computation of non splitmv
inter modes if the modeled rd cost based on pred error is within the
same factor of the best rd cost so far.
Also adds some enhancements in the rd search for splitmv mode to
speed things up by early breakouts. Negligible impact on performance.
Resuts on derfraw300:
psnr: -0.013% with the splitmv enhancements, -0.24% with the rd
breakout feature on.
speedup: 6% with splitmv enhancements, 20% with also residual breakout
(tested on football sequence at 600 Kbps)
Change-Id: I37abc308ea9f110c1679ce649b6a7e73ab1ad5fc
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
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
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
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
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
Remove the use of sf->comp_inter_joint_search_thresh
from the baseline speed 0. Approx +0.4% on derf.
Change-Id: Icc14db98909830f40e5ac66130d40e78d2e55c71
This cl converts use partition from last frame to do the following:
if part is none,horz, vert -> try split
if part != none and one of the children is not split - try none
Change-Id: I5b6c659e35f3ac9f11c051b92ba98af6d7e8aa87
Signed-off-by: Jim Bankoski <jimbankoski@google.com>
Added a speed feature that focuses only on thresholds
for new motion modes.
Moved sf->comp_inter_joint_search_thresh into speed
1. This has ~+0.4% impact on quality at speed 0 as
our quality reference baseline.
Slight adjustment to baseline thresholds.
Change-Id: I7ebf104f1fe29af77ed4837b2e84be065621bbe5
Adding CHECK_MEM_ERROR macro to vp9_common.h and removing two duplicated
ones from vp9_onyx_int.h and vp9_onyxd_int.h.
Change-Id: I916afec61b3019f18193135dac7c35ed0f89b8b6
This commit change the partition search order to allow checking of
rectangular partition to be done after square partitions. It also
added a speed feature to skip rectangular partition check when
NONE is better than SPLIT in RD sense.
This feature roughly speed up encoder by 1.5X with loss on compression
-0.91% on cif set
-0.56% on stdhd set
Change-Id: I0d2d06993041aa9ea9073fcc39c54f73a127dfa4
Also tweaks to other features and experiments with
what is on and off at different speed settings.
Change-Id: I3e1d0be0d195216bf17c2ac5df67f34ce0b306b2
Renamed cpi->sf.first_step to cpi->sf.reduce_first_step_size
and changed its meaning such that it is a delta applied to
reduce the default first step size (>> x) in the motion search
rather than an absolute value.
The default first step size is already changed according to the image
dimensions (smaller for smaller images). cpi->sf.reduce_first_step_size
now applies a further correction from the default.
Change-Id: Ia94e08bc24c67b604831f980909af7e982fcd16d
The part where we align it by 8 or 16 is an implementation detail that
shouldn't matter to the outside world.
Change-Id: I9edd6f08b51b31c839c0ea91f767640bccb08d53
Makes first 50 frames of bus @ 1500kbps encode from 3min22.7 to 3min18.2,
i.e. 2.3% faster. In addition, use the sub_pixel_avg functions to calc
the variance of the averaging predictor. This is slightly suboptimal
because the function is subpixel-position-aware, but it will (at least
for the SSE2 version) not actually use a bilinear filter for a full-pixel
position, thus leading to approximately the same performance compared to
if we implemented an actual average-aware full-pixel variance function.
That gains another 0.3 seconds (i.e. encode time goes to 3min17.4), thus
leading to a total gain of 2.7%.
Change-Id: I3f059d2b04243921868cfed2568d4fa65d7b5acd
This uses variance to split partition. Variance is calculated using
nearest mv, always from last ref frame.
Change-Id: Idd015b4a9aa3bc82591759eac239680c07496896
The encode-side scaling was not indexing through the image correctly
for the chroma planes, causing a green checkerboard-like output in
the unit test.
Change-Id: I9abbd73615404cd6699588be3e64dcf59005bc14
* New probs for subpel filters/tx_count
* Makes a change to not reset to defaults for the tx_size
probs if an intermediate frame reverts to using a fixed tx_size.
* A few updates to the parameters for backward adaptation for mode/mv
* some cosmetic cleanups
derf300: +0.06%
Change-Id: I22994d659bc31ca7a4fc8820fde24001e64a2920
Remove the bilinear filter mode, and the no-loopfilter mode, and the
related vp9_setup_version() function.
Change-Id: I32311367812faf37863131df3af37d63d03973d7
Adds coding of transform size within a frame by use of context
of transform sizes selected in left and above blocks.
Also incorporates code for generating stats.
TODO: generate and incorporate new default stats
Change-Id: I6a7af099f6ad61d448521d9a51167aedaf638ed6
Refactors mbskip coding to be compatible with coding of the rest of
the symbols. Adds forward/backward adaptation and removes a lot of
the legacy code.
Results:
fast50: +1.6%
derfraw300: +0.317%
Change-Id: I395a2976d15af044d3b8ded5acfa45f6f065f980
The partition types of blocks sitting on the frame boundary are
constrained by the block size and the position of each sub-block
relative to the frame. Hence we use truncated probability models
to handle the coding of such information.
100 frames run:
yt 0.138%
Change-Id: I85d9b45665c15280069c0234ea6f778af586d87d
With the removal of i4X4 and SPLIT_MV modes, the two entries for the
modes are no longer used. This patch remove the coding of the deltas.
Change-Id: Iea4eb500404ebe9706159380a03b8eca542fb4c3
Changes to the coding of transform sizes, along with forward
and backward probability updates.
Results:
derf300: +0.241%
Context based coding of transform sizes will be in a separate
patch.
Change-Id: I97241d60a926f014fee2de21fa4446ca56495756
Wrong max data size (skip has no data) and use of vp9_get_segdata()
when it should be vp9_segfeature_active().
Change-Id: I1eb97d33df6e2a42cc589049f704266fe3639902
Code intra/inter, then comp/single, then the ref frame selection.
Use contextualization for all steps. Don't code two past frames
in comp pred mode.
Change-Id: I4639a78cd5cccb283023265dbcc07898c3e7cf95
Added structures to support independent rd thresholds
for different block sizes (and set experimental block
size correction factors).
Added structure to to allow dynamic adaptation of thresholds
per mode and per block size basis depending on how often
the mode/block size combination is seen (currently fixed factor).
Removed some unused variables.
TODO
- Adaptation of thresholds based on how often each mode chosen.
- The baseline mode values could also be adjusted based on
the block size (e.g. for a particular intra mode use a low threshold
for 4x4 prediction blocks but a relatively high value for 64x64.
Change-Id: Iddee65ff3324ee309815ae7c1c5a8584720e7568
Adds backward adaptation and differential forward updates of switchable
interpolation filter probabilities. Also adds some cosmetic cleanups
and minor fixes on mv_ref probabilities.
derfraw300: +0.353% (with most coming from switchable interp changes)
Change-Id: Ie2718be73528c945fd0d80cfd63ca2d9cb3032de
This speed 1 - uses variance threshold stolen from static-thresh
to determine split. Any superblock with greater than the variance
set by static thresh * quantizer index squared is split. In addition
transform size is set to largest size less than or equal to partition
size, sub pixel filter is set to normal, and only 12 modes are used
at all.
Change-Id: If7a2858ee70f96d1eb989c04fd87a332b147abef
This patch removes the implicit segmentation
experiment from the code base as the benefits
were still unproven as of the bitstream deadline.
Change-Id: I273b99d8d621d1853eac4182f97982cb5957247e
This commit enables iterative motion search for 4x4/4x8/8x4 block
size compound inter-inter prediction.
WIP: borg run testing
Change-Id: I2b318db4a03cdca5a8002b3fa6c0fa89b129288b
Added two flags to the frame header:
intra_only:
Signals that the frame is encoded using only INTRA
coding modes.
reset_frame_context:
Indicates that the coding context specified
in the frame header should be reset to default values before the
frame is encoded/decoded.
Change-Id: I182d46f1f84fb67a13c46ad767f246a38d7861a2
This patch changes the coefficient tree to move the EOB to below
the ZERO node in order to save number of bool decodes.
The advantages of moving EOB one step down as opposed to two steps down
in the other parallel patch are: 1. The coef modeling based on
the One-node becomes independent of the tree structure above it, and
2. Fewer conext/counter increases are needed.
The drawback is that the potential savings in bool decodes will be
less, but assuming that 0s are much more predominant than 1's the
potential savings is still likely to be substantial.
Results on derf300: -0.237%
Change-Id: Ie784be13dc98291306b338e8228703a4c2ea2242
This patch checks at the frame level to see if the previous
mode info context can be used. This patch eliminates the
flag check that was done for every mode and removes another
check that was done prior to every vp9_find_mv_refs().
Change-Id: I9da5e18b7e7e28f8b1f90d527cad087073df2d73
Adding API to read/write uncompressed frame header bits (it is not final
yet). Separate functions to read/write uncompressed header. Moving
clr_type, error_resilient_mode, refresh_frame_context,
frame_parallel_decoding_mode, frame_context_idx from compressed partition
to uncompressed frame header.
Change-Id: Id3ed8a387980c652ae147549412f4ec24a0a5bd0
Also do per-partition motion vector referencing in <sb8x8 partitions,
and adjust mvref finding for sub8x8 partitions.
Change-Id: Id3ed1ed4d2a8910d11d327db6cc63b8eb79f941f
Move 4x4/4x8/8x4 partition coding out of experimental list.
This commit fixed the unit test failure issues. It also resolved
the merge conflicts between 4x4 block level partition and iterative
motion search for comp_inter_inter.
Change-Id: I898671f0631f5ddc4f5cc68d4c62ead7de9c5a58
This commit changed the encoding and decoding of intra blocks to be
based on transform block. In each prediction block, the intra coding
iterates thorough each transform block based on raster scan order.
This commit also fixed a bug in D135 prediction code.
TODO next:
The RD mode/txfm_size selection should take this into account when
computing RD values.
Change-Id: I6d1be2faa4c4948a52e830b6a9a84a6b2b6850f6
The API is not final yet and can be changed. Actual layout of
uncompressed frame part will be finalized later. Right now moving
clr_type, error_resilient_mode, refresh_frame_context,
frame_parallel_decoding_mode from first compressed partition to
uncompressed frame part.
Change-Id: I3afc5d4ea92c5a114f4c3d88f96858cccc15b76e
Cleans up the experiment. Actually uses reduced counts for backward
updates, and reduced number of probabilities in the context.
No change in bitstream when the experiment is on.
Between expt on and off:
derfraw300 is down only -0.062% (which is better than when expts
were run previously).
Change-Id: I55285a049a0c22810bdb42914212ab5a4f8521b5
This patch eliminates the intermediate diff buffer usage by
combining the short idct and the add residual into one function.
The encoder can use the same code as well.
Change-Id: I296604bf73579c45105de0dd1adbcc91bcc53c22
This is a mostly-working implementation of an extra channel in the
bitstream. Configure with --enable-alpha to test. Notable TODOs:
- Add extra channel to all mismatch tests, PSNR, SSIM, etc
- Configurable subsampling
- Variable number of planes (currently always uses all 4)
- Loop filtering
- Per-plane lossless quantizer
- ARNR support
This implementation just uses the same contents as the Y channel
for the A channel, due to lack of content and general pain in
playing back 4 channel content. A later patch will use the actual
alpha channel passed in from outside the codec.
Change-Id: Ibf81f023b1c570bd84b3064e9b4b8ae52e087592
These building blocks enable rate-distortion optimization search
over block sizes of 8x4 and 4x8. Need to convert them into mmx/sse
forms.
Change-Id: I570ea2d22d14ceec3fe3575128d7dfa172a577de
This patch creates a new inter mode contest that avoids
a dependence on the reconstructed motion vectors from
neighboring blocks. This was a change requested by
a hardware vendor to improve decode performance.
As part of this change I have also made some modifications
to stats output code (under a flag) to allow accumulation of
inter mode context flags over multiple clips
Some further changes will be required to accommodate the
deprecation of the split mv mode over the next few days.
Performance as stands is around -0.25% on derf and
std-hd but up on the YT and YT-HD sets. With further tuning
or some adjustment to the context criteria it should be
possible to make this change broadly neutral.
Change-Id: Ia15cb4470969b9e87332a59c546ae0bd40676f6c
Adds a subsampling aware border extension function. This may be reworked
soon to support more than 3 planes.
Change-Id: I76b81901ad10bb1e678dd4f0d22740ca6c76c43b
Trial use of a combination of reference frame,
prediction block size and mv to define segmentation.
Change-Id: Ie8946a0446dbad777fdcf7626f89e5af0994db50
In current code, motion vectors got from single prediction mode are used
in compound prediction mode directly. These motion vectors may not give
accurate prediction since they are searched independently. In this patch,
we took Pascal's suggestion, and did joint motion search in compound
prediction mode to find better motion vectors in this situation.
Test results:
Overall PSNR: 0.570%(derf), 0.918%(stdhd);
SSIM: 0.572%(derf), 1.009%(stdhd);
The encoder is a little slower. This can be improved since some c
code is used in motion search.
Change-Id: Ib30c9240f6c56c9b070867b4ca89412a76d9f3c6
Make framebuffer allocations according to the chroma subsamping
factors in use. A bit is placed in the raw part of the frame header for
each of the two subsampling factors. This will be moved in a future
commit to make them part of the TBD feature set bits, probably only set
on keyframes, etc.
Change-Id: I59ed38d3a3c0d4af3c7c277617de28d04a001853
Skip Q values between the q.0 mode and a real q of
2.0 as these are not valuable from an RD perspective.
Change-Id: I110c4858c57f97315953f4d88a2596d4764360df
There is only one instance of these structures, no need for them
to be allocated separately on the heap.
Change-Id: I1333cc92d06bbe21be643c2b2f0e3936f0264cac
This allows removing a large number of transform size specific functions,
as well as supporting 444/alpha by routing all code through the
subsampling-aware path.
Change-Id: Ieb085cebe9f37f24fc24de179898b22abfda08a4
Work-in-progress, not yet ready for review. TODO items:
- bitstream writing (encoder) and reading (decoder)
- decoder reconstruction
Change-Id: I5afb7284e7e0480847b47cd0097cb469433c9081
This minor tweak makes segment 0 neutral and used by
key frames and also extends beyond 4 segments.
Change-Id: Ife4744602aba66ac9432746db3113cc5cd88a482
Also some further simplification following removal
of top node code.
There is an issue in regards to the shared file vp8cx.h
in regard to the roi_map as this interface assumes that
there are only 4 segments. I have left the value here as
4 for now meaning that the roi_map interface is broken
for VP9.
Note that this change would have been easier if I hadn't
had to search for hard wire instances of the number 4
and <= 3.
Change-Id: Ia8b6deea4be4dbd20deb1656e689dd43a5f190e8
Adds an experiment that codes an end-of-orientation symbol
for every eligible zero encountered in scan order.
This cleans out various other sub-experiments that were part
of the origiinal patch, which will be later included if found
useful.
Results are slightly positive on all sets (0.1 - 0.2% range).
Change-Id: I57765c605fefc7fb9d1b57f1b356843602abefaf
Adjustments take heavier account of the frame near a kf
in deciding boost and limit the total number that can contribute.
Also adjusted the minq calculations such that in most cases we
generate a smaller key frame.
Modified the code that accounts for how static the sequence is and
added some adjustment based on image size. This is still very
crude but smaller images tend to behave better with a larger
delta between KF Q and other frames than larger image formats.
Changes give sizable gains in overall PSNR on all the test sets but the
biggest gains (~3%) were on the std-hd set.
The gains were smaller for SSIM but still significant.
Average PSNR results are mixed because this metric can very easily
be altered by having a very good / lossless coding of one or two frames.
Some of the YT and YT-HD clips in particular have blank lead ins and
allowing lossless coding of these appears to make a big difference to
average PSNR but it reality does not help much at all.
Change-Id: I6bfe485a1d330b47c783832f1717c95c535464ec
Enable recursive partition information coding from SB64X64 down to
MB16X16. The bit-stream syntax is now supporting rectangular block
sizes. It starts from SB64X64 and recursively describes the partition
type of the current block. If the partition type is PARTITION_NONE,
the block is coded as a single unit; if it is PARTITION_HORZ or
PARTITION_VERT, the block is segmented into two independently coded
rectangular units, with no further partition needed; otherwise, the
block is segmented into 4 square blocks. i.e., PARTITION_SPLIT case,
each can be potentially further partitioned.
Forward adaptive probability modeling is used for the partition
information coding, conditioned on the current block size.
Change-Id: I499365fb547839d555498e3bcc0387d8a3587d87
This function is now called from configures the ARNR
filter so it belongs with the other temporal filter
functions.
Change-Id: I64211875918364b5b8edfb97743e573c6def1663
This flag was added to VP8 to allow a mode where MB-level skipping
was not allowed, saving a bit per mb. It was never used in practice,
and hasn't been tested in VP9, so remove it.
Change-Id: Id450ec6904c6d06c1919508e7efc52d05cde5631
This is work-in-progress, it implements multiple ARF
encoding behind an experimental flag.
It adds the ability to insert multiple ARF frames into a
single ARF group. This patch implements the reordering
of the coded frames, and implements a fixed-length coding
pattern. It applies a fixed quantizer strategy based on
where the frame is in the coding sequence.
Further work to modify the rate control strategy is
ongoing and will be submitted via a set of future patches.
In this first step, each ARF group is recursively
bisected and an ARF frame added at that position in the
sequence. The recursion continues until ARF frames are
within MIN_GF_INTERVAL frames.
The code sits behind the "multiple-arf" experimental
flag ("CONFIG_MULTIPLE_ARF"). The experimental flag
"oneshotq" ("CONFIG_ONESHOTQ") also needs to be enabled
for this patch to work correctly.
Change-Id: Ie473b05ebb43ac473c0cfb659b2b8042823085e2
This patch changes the default with the modecoefprob expt
to use mode-based forward updates with one-node pegged
modeling.
The maximum difference with fully trained tables is now
less that 0.1%.
Change-Id: I06b44322e10c6703f93f3c1d48d973b1136a0618
The strategy to run fast loop filter picking for encoder speed-up
should be revisited at a later stage.
Change-Id: I3b75e06d767cff41be952a42e63b3292f4eab996
This function expects real Q values as inputs
not index values.
The use-age her impacts the Q chosen for force key
frames. Though this is a bug fix I have not yet verified
whether following the bug fix the q multiplier value used is
correct.
Change-Id: I49f6da894d90baeb1e86c820c335f02dc80d3b66
Took vp9_setup_scale_factors_for_frame() out from
vp9_setup_interp_filters(), so that it is only called once per
frame instead of per macroblock. Decoder tests showed a 1.5%
performance gain.
Change-Id: I770cb09eb2140ab85132f82aed388ac0bdd3a0aa
Using clamp and MIN/MAX functions instead of plain C code. Lower case
variable names. Removing redundant parenthesis.
Change-Id: Ibf7cc5fbe4fbdb5029049a599af71534176e6f42
We used to calculate SSIM only over the postproc buffer, whereas we
calculate PSNR for both. Compared to postproc-SSIM, this is about 0.3%
higher for derf, 1.4% lower for hd and 0.5% lower for stdhd, although
it is highly variable on a per-clip basis.
Change-Id: I8dd491f0f5b4201dedfb15d288c854d5d4caa10f
Adds a per-frame, strength adjustable, in loop deringing filter. Uses
the existing vp9_post_proc_down_and_across 5 tap thresholded blur
code, with a brute force search for the threshold.
Results almost strictly positive on the YT HD set, either having no
effect or helping PSNR in the range of 1-3% (overall average 0.8%).
Results more mixed for the CIF set, (-0.5 min, 1.4 max, 0.1 avg).
This has an almost strictly negative impact to SSIM, so examining a
different filter or a more balanced search heuristic is in order.
Other test set results pending.
Change-Id: I5ca6ee8fe292dfa3f2eab7f65332423fa1710b58
Replaces the default tables for single coefficient magnitudes with
those obtained from an appropriate distribution. The EOB node
is left unchanged. The model is represeted as a 256-size codebook
where the index corresponds to the probability of the Zero or the
One node. Two variations are implemented corresponding to whether
the Zero node or the One-node is used as the peg. The main advantage
is that the default prob tables will become considerably smaller and
manageable. Besides there is substantially less risk of over-fitting
for a training set.
Various distributions are tried and the one that gives the best
results is the family of Generalized Gaussian distributions with
shape parameter 0.75. The results are within about 0.2% of fully
trained tables for the Zero peg variant, and within 0.1% of the
One peg variant.
The forward updates are optionally (controlled by a macro)
model-based, i.e. restricted to only convey probabilities from the
codebook. Backward updates can also be optionally (controlled by
another macro) model-based, but is turned off by default. Currently
model-based forward updates work about the same as unconstrained
updates, but there is a drop in performance with backward-updates
being model based.
The model based approach also allows the probabilities for the key
frames to be adjusted from the defaults based on the base_qindex of
the frame. Currently the adjustment function is a placeholder that
adjusts the prob of EOB and Zero node from the nominal one at higher
quality (lower qindex) or lower quality (higher qindex) ends of the
range. The rest of the probabilities are then derived based on the
model from the adjusted prob of zero.
Change-Id: Iae050f3cbcc6d8b3f204e8dc395ae47b3b2192c9
As things stand the zero bin mode boost is hurting somewhat.
In part this seems to be because the boost applied as is
interferes with the rd mode selection loop.
Average gains (derf 0.072, yt 0.243, ythd 0.179 std-hd 0.212%)
Change-Id: Icaecea3908d9a7352370e49b8fa822f2c2c49dc1
