Yaowu Xu [Mon, 19 Mar 2012 18:03:27 +0000 (11:03 -0700)]
enable 8x8 transform for MBs in intra frames
When ac_yquant>171, a key frame is enabled to use 8x8 transform. In
such case, MBs with DC_PRED or TM_PRED are selected to use T8x8. This
change helped the full STD-HD set by ~.1% or so, which is reasonable
considering how often key frame occurs in these encodings.
Paul Wilkins [Wed, 21 Mar 2012 18:22:33 +0000 (18:22 +0000)]
Only support improved quant
Deprecate fast quant and strict_quant code.
Small effect on quality as fast was used in first pass but the
effect is basically neutral across the derf set.
The rationale here is to reduce the number of code paths for
now to make experimentation easier. Optimized and fast code
options can be re-introduced later along with other encode
speed options.
Deb Mukherjee [Mon, 19 Mar 2012 14:53:05 +0000 (07:53 -0700)]
Making subpel filters switchable at frame level
Various refactoring to make the subpel motion compensation
filters switchable by a frame level field.
Two types of 8-tap filters are supported in addition to the existing
bilinar and sixtap filters. One is the default 8-tap and the
other has a sharper cut-off for use with frames with substantial
edge content.
Patch 2: Added a preliminary strategy for filter selection based on
edginess detecton. Also includes some filter changes.
Deb Mukherjee [Mon, 19 Mar 2012 18:02:04 +0000 (11:02 -0700)]
Adding contextual coding of mb_skip_coeff flag.
Using contextual coding of the mkb_skip_coeff flag using the
values of this flag from the left and above. There is a small
improvement of about 0.15% on Derf:
http://www.corp.google.com/~debargha/vp8_results/mbskipcontext.html
Refactored to use pred_common.c by adding a new context type.
Results on HD set (about 0.66% improvement):
http://www.corp.google.com/~debargha/vp8_results/mbskipcontext_hd.html
Incliding missing refactoring to use the pred_common utilities.
Yaowu Xu [Tue, 13 Mar 2012 17:26:53 +0000 (10:26 -0700)]
added clamp for 2nd motion vector
The commit added a clamp to the 2nd motion vector used in compound
prediction to insure mv within UMV borders. The clamp is similar to
that of the first motion vector except that No SPLITMV is ever used
for the 2nd motion vector.
Yaowu Xu [Wed, 7 Mar 2012 20:25:50 +0000 (12:25 -0800)]
Added encode/decode recon buffer match test to vpxenc
The commit added a new command line option --test-decode to vpxenc.
The option enables encoder to decode compressed frames and test recon
buffers from the decode against those from encode for mismatch.
There are a few limitations on this option currently, one of them
being the match test is not done on a number of lagged frames at
the end of an encoding.
Yaowu Xu [Thu, 15 Mar 2012 00:29:39 +0000 (17:29 -0700)]
fixed a bug of context overwritten by key frame recoding
The recoding loop save and restore frame coding context for recodes.
However in recoding of key frames, some of the coding context saved
was stale from last encoded inter frame. The save/restore sometimes
overwrites the re-inintialized coding context with saved context
from last frame, resulting in encoder/decoder mismatch
Yaowu Xu [Mon, 12 Mar 2012 21:51:54 +0000 (14:51 -0700)]
fixed .mk files to reflect add/remove of a header file
In a previous commit, the duplicate of headerfile defaultcoefcounts.h
was identified. This commit updates the .mk file to ensure configure
and make works properly for all platforms.
Yaowu Xu [Wed, 7 Mar 2012 17:05:26 +0000 (09:05 -0800)]
Changed MAX_PSNR to be consistent with internal stats
The maximum psnr has a marginal impact on the overall output in high
quality encodings, the change will make sure the psnr output to be
consistent with encoder internal stats.
Jim Bankoski [Tue, 6 Mar 2012 17:31:51 +0000 (09:31 -0800)]
Imported a change from stable branch
https://gerrit.chromium.org/gerrit/#change,17319 fixes cost estimating
to take skip_eob into account. No quality difference seen on derf set
tests, but about .4% gain on STD_HD set.
Yaowu Xu [Wed, 22 Feb 2012 02:10:18 +0000 (18:10 -0800)]
Changed how UV r/d estimates are done for Intra Modes
The commit changed to compute UV intra RD estimates for 4x4 and 8x8
separately to be used in mode decision for MB modes associated with
the appropriate transform size respectively. Now finally after many
other changes related 8x8 quantizer zbin boost and zbin_mode_boost,
this change overall helps the HD(with 8x8) by around ~.13%.
(avg .13% glb .13% ssim .17%)
The commit also has a few changes for eliminating compiler warnings.
Yaowu Xu [Tue, 28 Feb 2012 22:19:38 +0000 (14:19 -0800)]
Correct zbinboost lookup for 8x8 quantizer
The commit fixed a problem where 8x8 regular quantizer was using the
4x4 zbinboost lookup table that only has 16 entries at each Q. The
commit assigned a uniform zbin boost value for all cases that there
are more than 16 consective zeros. The change only affects MBs using
8x8 transform. The fix has a slightly positive impact on quality.
Deb Mukherjee [Mon, 27 Feb 2012 18:22:38 +0000 (10:22 -0800)]
Initial refactoring of high_precision mv code.
This is the first patch for refactoring of the code related to
high-precision mv, so that 1/4 and 1/8 pel motion vectors can
co-exist in the same bit-stream by use of a frame level flag.
The current patch works fine for only use of 1/4th and
only use of 1/8th pel mv, but there are some issues with the
mode switching in between. Subsequent patches on this change Id
will fix the remaining issues.
Patch 2: Adds fixes to make sure that multiple mv precisions can
co-exist in the bit-stream. Frame level switching has been tested
to work correctly.
Results on derf after ssse3 bugfix, compared to everything
enabled but the 8-tap, 1/8-subpel and 1/16-subpel uv. Overall the
gains are about 3% now. Hopefully there are no more bugs lingering.
Apparently the sse3 bug affected the quartel subpel results more than
the eighth pel ones (which is understandabale because one bad predictor
due to the bug, matters less if there are a lot more subpel options
available as in the 1/8 subpel case).
The results in the 4th column correspond to the current settings.
The first two columns correspond to two settings of adaptive switching
of the 1/4 or 1/8 subpel mode based on initial Q estimate. These
do not work as good as just using 1/8 all the time yet.
Yaowu Xu [Tue, 28 Feb 2012 02:23:15 +0000 (18:23 -0800)]
fixed a wrong intialization value
The "update" variable was used as a flag in coef_prob update dry run
that tests if a frame should encodes update at all. The wrong init
value forced the update happening always. fixing this has a minor
improvement in low bit rate situation when 8x8 transform is allowed.
Paul Wilkins [Sat, 25 Feb 2012 18:13:57 +0000 (18:13 +0000)]
Removal of temporal re sampling code.
For now the interface elements have been left in place
to make sure existing parameter files work but parameters
relating to drop frame wont do anything.
Deb Mukherjee [Fri, 24 Feb 2012 17:08:00 +0000 (09:08 -0800)]
Changing default 8-tap filter to Langrangian interpolator.
The Lagrangian interpolation filter is maximally flat in the
passband. There is non-trivial improvement with the hd set, while
for derf the results are virtually unchanged.
See:
http://www.corp.google.com/~debargha/vp8_results/enhinterpn.html (derf)
http://www.corp.google.com/~debargha/vp8_results/enhinterpn_hd.html (HD)
Patch 2: Updated the results for derf in the html above to use the
new baseline. There is still about 4% improvement. Will update the
hd baseline later (since it takes 9 hours to run on my machine)
Patch 3: By mistake the default filter was left at 60 - should be 0
to use the new interpolation filter.
Deb Mukherjee [Thu, 23 Feb 2012 19:47:18 +0000 (11:47 -0800)]
Clean ups and minor changes in high precision mv with 8-tap interpolation
* Removes EDGE_PIXEL_FILTER for external sanpshot
* changes the default 8-tap filter based on high precision results
in http://www.corp.google.com/~debargha/vp8_results/enhinterpn.html
* changes the default prob tables for high-precision mv encoding to
favor zeros in the last bit (i.e. quarter pel). This is only important
for short clips.
Deb Mukherjee [Thu, 16 Feb 2012 17:29:54 +0000 (09:29 -0800)]
Supporting high precision 1/8-pel motion vectors
This is the initial patch for supporting 1/8th pel
motion. Currently if we configure with enable-high-precision-mv,
all motion vectors would default to 1/8 pel. Encode and
decode syncs fine with the current code. In the next phase
the code will be refactored so that we can choose the 1/8
pel mode adaptively at a frame/segment/mb level.
Derf results:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hpmv.html
(about 0.83% better than 8-tap interpoaltion)
Patch 3: Rebased. Also adding 1/16th pel interpolation for U and V
Patch 4: HD results.
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd_hpmv.html
Seems impressive (unless I am doing something wrong).
Patch 5: Added mmx/sse for bilateral filtering, as well as enforced
use of c-versions of subpel filters with 8-taps and 1/16th pel;
Also redesigned the 8-tap filters to reduce the cut-off in order to
introduce a denoising effect. There is a new configure option
sixteenth-subpel-uv which will use 1/16 th pel interpolation for
uv, if the motion vectors have 1/8 pel accuracy.
With the fixes the results are promising on the derf set. The enhanced
interpolation option with 8-taps alone gives 3% improvement over thei
derf set:
http://www.corp.google.com/~debargha/vp8_results/enhinterpn.html
Results on high precision mv and on the hd set are to follow.
Patch 6: Adding a missing condition for CONFIG_SIXTEENTH_SUBPEL_UV in
vp8/common/x86/x86_systemdependent.c
Yaowu Xu [Fri, 17 Feb 2012 23:52:30 +0000 (15:52 -0800)]
Fixed skippable evaluation in mode decision
Yunqing fixed an oddity in UVIntra skippable evaluation for stable
branch, which brought up the fact that the evaluation is broken.
The issue was that for MBs with 2nd order block, the eob for 1st
order blocks is set at 1. The previous evaluation did not take that
into account. This commit intend to fix the problem. The commit also
absorbed Yunqing's fix for UVIntra skippable evalution.
Test on hd showed some good gains in combination with LPF bias fix:
http://www.corp.google.com/~yaowu/no_crawl/LPFBias_FixSkip.html
(avg psnr: .34%, glb psnr: .32%, ssim: .22%)
Yaowu Xu [Fri, 17 Feb 2012 20:03:34 +0000 (12:03 -0800)]
Reduced bias in picking loop filter level
The bias in picklpf intended to bias toward less greedy in getting
best frame level psnr while maximize overall quality for a clip.
This commit reduced the bias for frames using 8x8 transform to
achieve better compression overall.
The change improve compression by ~.15% consistently on most of the
HD clips tested.
Yaowu Xu [Fri, 20 Jan 2012 23:30:31 +0000 (15:30 -0800)]
Reworked context conversion between 8x8 and 4x4
The commit rationized and simplified the entropy context conversion
betwen MB using 8x8 transform and MB using 4x4 transform. The old version
had a number of weirdness in how 4x4 transform MB's context is used for
8x8 blocks other than the first 8x8 within a MB.
Test showed the change has a gain ~.1% for avg psnr, glb psnr and ssim on
the limited HD set.
Yaowu Xu [Thu, 16 Feb 2012 01:35:48 +0000 (17:35 -0800)]
optmized rounding for transforms
the changes are still temporary, the final transforms, especially
inverse ones should take in account both accuracy, complexity, and
sign-bias, which should be decided at a later time.
Yaowu Xu [Wed, 15 Feb 2012 23:01:35 +0000 (15:01 -0800)]
re-scaled 2nd order haar transform
During the work of extend_qrange, we have rolled a factor of 2 from
quantization/dequatnization into 2nd order walsh-hadamard transform.
This commit does the same for the 2nd order haar transform. so they
can share the same quantizaiton process as the 2nd order WHT.
Yaowu Xu [Tue, 14 Feb 2012 15:40:26 +0000 (07:40 -0800)]
moved scaling from dequantization to inverse transform for T8x8
Previously, the scaling related to extended quantize range happens in
dequantization stage, which implies the coefficients form forward
transform are in different scale(4x) from dequantization coefficients
This worked fine when there was not distortion computation done based
on 8x8 transform, but it completely wracked the distortion estimation
based on transform coefficients and dequantized transform coefficients
introduced in commit f64725a00 for macroblocks using 8x8 transform.
This commit fixed the issue by moving the scaling into the stage of
inverse 8x8 transform.
TODO: Test&Verify the transform/quantization pipeline accuracy.
Results with the new filter coefficients compared with the previous
versions are here:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html (derf)
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd.html (HD)
Overall, the derf set improves by 0.94% with 8-tap filters while
the HD set improves by 0.58%.
Ronald S. Bultje [Thu, 16 Feb 2012 00:38:04 +0000 (16:38 -0800)]
Remove dual prediction frame re-encoding loop.
I'm basically not convinced that the concept works at all, let alone
that this is the right place to do it. I think if we want something
like this at all, I should integrate it with the main encoding loop
and re-encode checks in onyx_if.c, and show that it has a significant
benefit (which right now, it doesn't; removing this re-encode check
actually increases all metrics by ~0.15%).
Yaowu Xu [Wed, 15 Feb 2012 01:52:18 +0000 (17:52 -0800)]
moved segment based LPF level selection under CONFIG_FEATUREUPDATES
This commit moved segment based loop filter level selection into
the experiment of CONFIG_FEATUREUPDATES. As previous commit noted,
the segment based loop filter selection helps the compression by
~0.1% on cif set, the ongoing experiment CONFIG_FEATUREUPDATES
made encoding updates of the segment based LPF level more efficient,
hence, another .04% gain on cif set. The commit also fixed an issue
previously where encoder/decoder may use different loop filter level
for one of the segments.
Yaowu Xu [Mon, 13 Feb 2012 22:34:19 +0000 (14:34 -0800)]
added 8x8 based Rate estimation for dualpred case
This commmit added logic for MB using dual-pred to compute rate
estimation based on correct transform size. The section of code
was previously located under #if CONFIG_DUALPRED, that was made
to be working with T8x8 experiment at the same time.
Jim Bankoski [Mon, 13 Feb 2012 16:21:24 +0000 (08:21 -0800)]
vp8 - config_featureupdates
Added a bit to signify that the feature changed since
the last time we sent it, or not so that we don't need
to send all the databits for every feature change.
Yaowu Xu [Mon, 6 Feb 2012 23:10:13 +0000 (15:10 -0800)]
Changed how coefficient probability table is updated
Added a frame level flag to indicate if coef probabilities are updated
at all for the frame.
During the experimental work with 8x8 transform, it is discovered that
even in the case of no probability is ever update, cost of transmitting
"no update" for each of probabilities can run up to become a significant
overhead cost. A single bit to indicate no-update for all coef probs
is therefore helpful, which is also demonstrated by the test results:
2. On HD set:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_updprob.html
(avg psnr: .02% glb psnr: .01% SSIM: .02%)
It should be noted that the gain on HD is smaller because the average bit
rate is much higher in contrast to the overhead bit cost.
Yaowu Xu [Fri, 10 Feb 2012 19:49:22 +0000 (11:49 -0800)]
fixed an issue related to 2nd order size due to merge artifacts.
For 8x8 transformed macroblock, the 2nd order transform is a 2x2 haar
transform, here there is only 4 coefficients total. A previous merge
changed these to 64, causing crashes when encoding with 8x8 transform
enabled. (i.e. when input video image size > 640x360 ) This commit
reverts them back to 4 and fixes the crashes.
Paul Wilkins [Fri, 10 Feb 2012 16:02:10 +0000 (16:02 +0000)]
Removal of threading code.
For the experimental branch we are trying to slim the codebase
down removing features such as threading for now which complicate
the process of development and testing.
Ronald S. Bultje [Fri, 10 Feb 2012 00:12:23 +0000 (16:12 -0800)]
Improved coding using 8x8 transform
In summary, this commit encompasses a series of changes in attempt to
improve the 8x8 transform based coding to help overall compression
quality, please refer to the detailed commit history below for what
are the rationale underly the series of changes:
a. A frame level flag to indicate if 8x8 transform is used at all.
b. 8x8 transform is not used for key frames and small image size.
c. On inter coded frame, macroblocks using modes B_PRED, SPLIT_MV
and I8X8_PRED are forced to using 4x4 transform based coding, the
rest uses 8x8 transform based coding.
d. Encoder and decoder has the same assumption on the relationship
between prediction modes and transform size, therefore no signaling
is encoded in bitstream.
e. Mode decision process now calculate the rate and distortion scores
using their respective transforms.
Overall test results:
1. HD set
http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120206.html
(avg psnr: 3.09% glb psnr: 3.22%, ssim: 3.90%)
2. Cif set:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120206.html
(avg psnr: -0.03%, glb psnr: -0.02%, ssim: -0.04%)
It should be noted here, as 8x8 transform coding itself is disabled
for cif size clips, the 0.03% loss is purely from the 1 bit/frame
flag overhead on if 8x8 transform is used or not for the frame.
---patch history for future reference---
Patch 1:
this commit tries to select transform size based on macroblock
prediction mode. If the size of a prediction mode is 16x16, then
the macroblock is forced to use 8x8 transform. If the prediction
mode is B_PRED, SPLITMV or I8X8_PRED, then the macroblock is forced
to use 4x4 transform. Tests on the following HD clips showed mixed
results: (all hd clips only used first 100 frames in the test)
while the results are mixed and overall negative, it is interesting to
see 8x8 helped a few of the clips.
Patch 2:
this patch tries to hard-wire selection of transform size based on
prediction modes without using segmentation to signal the transform size.
encoder and decoder both takes the same assumption that all macroblocks
use 8x8 transform except when prediciton mode is B_PRED, I8X8_PRED or
SPLITMV. Test results are as follows:
Interestingly, by removing the overhead or coding the segmentation, the
results on this limited HD set have turn positive on average.
Patch 3:
this patch disabled the usage of 8x8 transform on key frames, and kept the
logic from patch 2 for inter frames only. test results on HD set turned
decidedly positive with 8x8 transform enabled on inter frame with 16x16
prediction modes: (avg psnr: .81% glb psnr: .82 ssim: .55%)
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdintermode8x8_0125.html
results on cif set still negative overall
Patch 4:
continued from last patch, but now in mode decision process, the rate and
distortion estimates are computed based on 8x8 transform results for MBs
with modes associated with 8x8 transform. This patch also fixed a problem
related to segment based eob coding when 8x8 transform is used. The patch
significantly improved the results on HD clips:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hd8x8RDintermode.html
(avg psnr: 2.70% glb psnr: 2.76% ssim: 3.34%)
results on cif also improved, though they are still negative compared to
baseline that uses 4x4 transform only:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif8x8RDintermode.html
(avg psnr: -.78% glb psnr: -.86% ssim: -.19%)
Patch 5:
This patch does 3 things:
a. a bunch of decoder bug fixes, encodings and decodings were verified
to have matched recon buffer on a number of encodes on cif size mobile and
hd version of _pedestrian.
b. the patch further improved the rate distortion calculation of MBS that
use 8x8 transform. This provided some further gain on compression.
c. the patch also got the experimental work SEG_LVL_EOB to work with 8x8
transformed macroblock, test results indicates it improves the cif set
but hurt the HD set slightly.
Tests results on HD clips:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120201.html
(avg psnr: 3.19% glb psnr: 3.30% ssim: 3.93%)
Test results on cif clips:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120201.html
(avg psnr: -.47% glb psnr: -.51% ssim: +.28%)
Patch 6:
Added a frame level flag to indicate if 8x8 transform is allowed at all.
temporarily the decision is based on frame size, can be optimized later
one. This get the cif results to basically unchanged, with one bit per
frame overhead on both cif and hd clips.
Patch 8:
Rebase and Merge to head by PGW.
Fixed some suspect 4s that look like hey should be 64s in regard
to segmented EOB. Perhaps #defines would be bette.
Bulit and tested without T8x8 enabled and produces unchanged
output.
Patch 9:
Corrected misalligned code/decode of "txfm_mode" bit.
Limited testing for correct encode and decode with
T8x8 configured on derf clips.
Paul Wilkins [Thu, 9 Feb 2012 15:44:18 +0000 (15:44 +0000)]
Dual pred flag
Further changes to make experiments with the context
used for coding the dual pred flag easier.
Current best performing method tested on derf is a two
element context based on reference frame. I also tried
various combinations of mode and reference frame as
shown in commented out case using up to 6 contexts.
Derf +0.26 overall psnr +0.15% ssim vs original method.
We should only change the dual prediction mode if we actually entered
the recode branch. Else, it may potentially undo beneficial changes
to the dual prediction mode in the first encode iteration.
Some conditions were conditional under a threshold, whereas they should
always execute. Also, some conditions were testing an array instead of
the values within it.
Paul Wilkins [Fri, 3 Feb 2012 17:08:37 +0000 (17:08 +0000)]
Move update of ref frame probabilities in encode loop.
The existing code updated the reference frame probabilities before
the test to evaluate the impact of using updated probabilities
in vp8_estimate_entropy_savings().
The estimate of cost and savings is still basic and does not reflect
the new prediction code but this would require per MB costings
and the benefit is probably marginal, as this is really just used for
rate estimation in the loop.
Paul Wilkins [Fri, 3 Feb 2012 15:10:44 +0000 (15:10 +0000)]
Merged NEWNEAR experiment
This commit merges the NEWNEAR experiment such that it
is effectively always on.
The fact that there were changes in the threading code again
highlights the need to strip out such features during the
bitstream development phase as trying to maintain this code
(especially as it is not being tested) slows the development cycle.
Paul Wilkins [Thu, 2 Feb 2012 17:30:27 +0000 (17:30 +0000)]
Coding the hybrid dual prediction signal.
Initial modifications to make limited use of common prediction
functions.
The only functional change thus far is that updates to the probabilities are
no longer "damped". This was a testing convenience but in fact seems to
help by a little over 0.1% over the derf set.
projects / libvpx / log