There is a macro DEFAULT_INTERP_FILTER defined in encoder/onyx_if.c that
is set as EIGHTTAP for now - so SWITCHABLE is not really used. Ideally,
this should be SWITCHABLE but that would make the encoder quite a bit slower.
We will change the default filter to SWITCHABLE once we find a faster way to
search for switchable filters.
Change-Id: Iee91832cdc07e6e14108d9b543130fdd12fc9874
Results: derf (vanilla or +hybridtx) +0.2% and (+hybrid16x16
or +tx16x16) +0.7%-0.8%; HD (vanilla or +hybridtx) +0.1-0.2%
and (+hybrid16x16 or +tx16x16) +1.4%, STD/HD (vanilla or +hybridtx)
about even, and (+hybrid16x16 or +tx16x16) +0.8-1.0%.
Change-Id: I03899e2f7a64e725a863f32e55366035ba77aa62
Separates the entropy coding context models for 4x4, 8x8 and 16x16
ADST variants.
There is a small improvement for HD (hd/std-hd) by about 0.1-0.2%.
Results on derf/yt are about the same, probably because there is not
enough statistics.
Results may improve somewhat once the initial probability tables are
updated for the hybrid transforms which is coming soon.
Change-Id: Ic7c0c62dacc68ef551054fdb575be8b8507d32a8
Adds a new experiment with redesigned/refactored motion vector entropy
coding. The patch also takes a first step towards separating the
integer and fractional pel components of a MV. However the fractional
pel encoding still depends on the integer pel part and so they are
not fully independent. Further experiments are in progress to see
how much they can be decoupled without affecting performance.
All components including entropy coding/decoding, costing for MV
search, forward updates and backward updates to probability tables,
have been implemented.
Results so far:
derf: +0.19%
std-hd: +0.28%
yt: +0.80%
hd: +1.15%
Patch: Simplifies the fractional pel models:
derf: +0.284%
std-hd: +0.289%
yt: +0.849%
hd: +1.254%
Patch: Some changes in the models, rebased.
derf: +0.330%
std-hd: +0.306%
yt: +0.816%
hd: +1.225%
Change-Id: I646b3c48f3587f4cc909639b78c3798da6402678
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
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
Merged in the high_precision_mv experiment to make it easier
to work on new mv encoding strategies. Also removed
coef_update_probs3().
Change-Id: I82d3b0bb642419fe05dba82528bc9ba010e90924
Set on all 16x16 intra/inter modes
Features:
- Butterfly fDCT/iDCT
- Loop filter does not filter internal edges with 16x16
- Optimize coefficient function
- Update coefficient probability function
- RD
- Entropy stats
- 16x16 is a config option
Have not tested with experiments.
hd: 2.60%
std-hd: 2.43%
yt: 1.32%
derf: 0.60%
Change-Id: I96fb090517c30c5da84bad4fae602c3ec0c58b1c
Allows for swtiching/setting interpolation filters at the MB
level. A frame level flag indicates whether to use a specifc
filter for the entire frame or to signal the interpolation
filter for each MB. When switchable filters are used, the
encoder chooses between 8-tap and 8-tap sharp filters. The
code currently has options to explore other variations as well,
which will be cleaned up subsequently.
One issue with the framework is that encoding is slow. I
tried to do some tricks to speed things up but it is still slow.
Decoding speed should not be affected since the number of
filter taps remain unchanged.
With the current version, we are up 0.5% on derf on average but
some videos city/mobile improve by close to 4 and 2% respectively.
If we did a full-search by turning the SEARCH_BEST_FILTER flag
on, the results are somewhat better.
The framework can be combined with filtered prediction, and I
seek feedback regarding that.
Rebased.
Change-Id: I8f632cb2c111e76284140a2bd480945d6d42b77a
The following five experiments are merged:
newentropy
newupdate
adaptive_entropy (also includes a couple of parameter changes
that improves results a little
in common/entropymode.c and encoder/modecosts.c
that were not merged from the internal branch)
newintramodes
expanded_coef_context
Change-Id: I8a142a831786ee9dc936f22be1d42a8bced7d270
Added the ability to optionally filter the prediction data
when inter modes are selected (excludes SPLITMV, for now).
The mode selection loop considers both the filtered and
non-filtered prediction data when choosing mode. The filter
can be turned on/off at the frame-level, or signaled for
each MB.
Change-Id: I1b783c71d95a361ab36c761b07e8a6b06bc36822
Incorporates mv_ref, mbsplit and second_mv into the adaptive
entropy framework. The mv_ref framework has been modified from
before.
Adds some clean-ups and fixes.
Results with the adaptive entropy experiment are currently up by
+1.93% on derf; +2.33% std-hd and +1.87% yt-hd.
Fixed a nasty intermittent bug.
Change-Id: I4b1ac9f9483b48432597595195bfec05f31d1e39
This patch incorporates adaptive entropy coding of coefficient tokens,
and mode/mv information based on distributions encountered in a frame.
Specifically, there is an initial forward update to the probabilities
in the bitstream as before for coding the symbols in the frame, however
at the end of decoding each frame, the forward update to the
probabilities is reverted and instead the probabilities are updated
towards the actual distributions encountered within the frame.
The amount of update is weighted by the number of hits within each
context.
Results on derf/hd/std-hd are all up by 1.6%.
On derf, the most of the gains come from coefficients, however for the
hd and std-hd sets, the most of the gains come from the mode/mv
information updates.
Change-Id: I708c0e11fdacafee04940fe7ae159ba6844005fd
1. block types
There are only three types of blocks for 8x8 transformed MBs, i.e. Y
block with DC does not exist for 8x8 transformed MBs as all MB using
8x8 transform have 2nd order haar transform. This commit introduced
a new macro BLOCK_TYPES_8X8 to reflect such fact.
2. context counters
This commit also fixed the mixed of context_counters between 4x4 and
8x8 transformed MBs. The mixed use of the counters leads me to think
the existing the context probabilities were not properly generated
from 8x8 transformed MBs.
3. redundant collecting in recoding
The commit also corrected the code that accumulates entropy stats by
making sure stats only collected for final packing, not during the
recode loop
Change-Id: I029f09f8f60bd0c3240cc392ff5c6d05435e322c
This commit merge the QI mode experiment. As the experiment affects
the encoding of intra coding modes on key frame only, the overall
effect of the experiment on encoding tests is insignificant.
Change-Id: I9e4e3933adface88867ad429cee3986e529c511d
The commit merges the UVINTRA experiment and removed the related
macros. The overall effect of the experiment is a small gain (.1%
on derf)
Change-Id: Ia34b3312fb9b5b34c9ba111bf0fa78c6f78ac80b
Some code re-factored / moved to allow the main
pack operation inside the recode loop so that the
size estimate is accurate.
Deletion of some redundant code relating to one pass.
Aproximate improvement over March 27 code base:
Derf 0.0%, YT 0.5%, YThd 0.3% Std_hd 0.25%
Change-Id: Id2d071794ab44f0b52935f6fcdb5733d09a6bb86
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.
Change-Id: I866085bda5ae143cfdf2ec88157feaabdf7bd63a
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.
Patch 3: Fixes lines exceeding 80 char
Patch 4:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html
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.
Change-Id: I3ef392ad338329f4d68a85257a49f2b14f3af472
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.
Change-Id: I657c0246aef4d1fa8c8ffc6a1adfeee45bce8e24
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)
http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8.htmlhttp://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_log.html
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:
http://www.corp.google.com/~yaowu/no_crawl/t8x8/cifmodebase8x8_0125.htmlhttp://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_0125log.html
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.
Change-Id: I156e1405d25f81579d579dff8ab9af53944ec49c
Merged in most of the current common prediction changes
that were under the #if CONFIG_COMPRED option.
Change-Id: If4e6f61dbe7b86dd449f6effbe93b5eb7e893885
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.
Change-Id: I64c21ddec0abbb27feaaeaa1da2e9f164ebaca03
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.
Change-Id: I8b34950a1333231ced9928aa11cd6d6459984b65
Trial of a modified prediction function that ranks each possible
reference frame based on a combination of local usage and
frame level probability. The code is a bit cleaner and simpler.
In direct comparison with old unpredicted method with segment level
coding turned off for mode,ref & EOB the prediction gives a gain on derf
of around 0.4%. There is some further gain from bug fixes over earlier code.
With segment coding on the prediction method is slightly -ve on some very
easy clips (at low rates) due to slightly higher overheads, but better on harder
clips. Overall neutral on derf in direct comparison on latest code base, but
compared to earlier code without bug fixes about +0.7% overall psnr
+0.3% SSIM.
Change-Id: I5b8474658b208134d352d24f6517f25795490789
This function adds the common prediction modules, some data structures
and a config option but does not use them.
It also corrects a bug in clearing down the MODE_INFO border and introduces
a new element that indicates if an entry corresponds to an "in image" macro block
or is part of the border.
Change-Id: Ib69eec0876173ebe9d1de9df9537d0b2447702e0
This commit extends the number of Q steps to 256 from 128.
The q_trans[] array has been altered to distribute available Q index values
(using the current 64 steps available as input parameters) evenly across the
available range. This is coupled with the fact that each Q step where possible
now equates to a fixed % change in the quantizer. This may want refinement
later especially in terms of the granularity at the high quality end but is a
reasonable starting point.
Change-Id: I2aaa6874fa10ce05c958dd182947ce39f6f1eecb
Added code to support 256 index steps instead of 128 but disabled for now.
Replace hard wired table vp8cx_base_skip_false_prob[128]
Observed Qindex problem with setting minimum loop filter value.
(Experiment code using real Q in place but for now just returning 0. This has a big
beneficial effect on some clips, particularly waterfall which shows 5% ssim gain)
Change-Id: I2f7117de8adc1797164c106aa13effc900a1467e
Previously, Y-adaptive UV intra coding only enabled on key frames in
UVINTRA experiment. This commit enabled the same coding for inter
frames, so the encoding of UV intra modes are consistent cross all
frame types. Tests on derf set showed a very small overall gain around
.04%:
http://www.corp.google.com/~yaowu/no_crawl/interUVintra.html
The gain looks to be reasonable given inta coded MBs is only a
small portion of MBs in inter frames.
Change-Id: Ic6fc261923f2c253f4a0c9f8bccf4797557b9e16
