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
Extended prediction and coding of reference frame where
a subset of options are flagged as available at the segment level.
Updated copyright notices.
Switch to SAD in mbgraph code as SATD problematic for the
foreground and background separation as it can ignore large DC shifts.
Change-Id: I661dbbb2f94f3ec0f96bb928c1655e5e415a7de1
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
Picks a per segment loopfilter. Adapts the algorithm to search for
a loopfilter value for each separate segment. Further todo fix the
bias
Improvements .06 % ov psnr, .11% ssim
http://www.corp.google.com/~jimbankoski/no_crawl/segmentedpicklpf.html
Change-Id: Ic6a571c16fcd6ec0139f4de1f8061f87c6515a10
using an 8-tap filter.
The results with 3 different 8-tap filters on the derf set are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html
The one that gives the most gain achieves an overall gain of about
0.6%. The results for a set of 12 hd (720p) videos are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd.html
with max gain of 0.55% with the same filter. The best filter apparently
achieves the best trade-off between pass band ripple and stop band
attenuation.
Change-Id: I919e28ae245c0493147fa0864f8c9d048a9dd530
This introduces base functions for introducing implicit segmentation.
The code that actually stores the results to the segment map isn't
here yet. This just prints out the segmentation map results
if you call it.
Uses connected component labeling technique on mbmi info so that only
if 2 mbs are horizontally or vertically touching do they get the same
segment.
vp8next - plumbing for rotation
code to produce taps for rotation ( tapify. py ), code
for predicting using rotation ( predict_rotated.c ) , code
for finding the best rotation find_rotation.c.
didn't checkin code that uses this in the codec. still work
in progress.
Fixed copyright notice
Change-Id: I450c13cfa41ab2fcb699f3897760370b4935fdf8
This commit added a set of loop filter functions for macroblocks
using 8x8 transform. First we turned off the regular loop filtering
on 4x4 block boundaries that do not exist in macroblocks using 8x8
transform. Second, we change to use the same loop filter(mask and
7 tap filter) that used for macroblock edge filtering.
Change-Id: I3a00460b7674ced116917d86812ffc32578c1d3a
The commit adds a new set of loop filter for macroblock edge filtering.
The new loop filter has a mask to detect so-called "flat" regions. The
detection checks 5 pixels of each side of an edge. If the all pixels
have value with +/-1 from the edge pixel on the same side, the region
is treated as a "flat" region. For such case, a 7 tap filter is used
to change 3 pixel values on each side. The 7 taps are:
[1, 1, 1, 2, 1, 1, 1]/8
The furthest away pixels used as input are +/-5 away from edge. For
non-flat region, we fall back to old filtering. It should be noted
here that the thresholds and filter taps may require more optimization
for best possible results.
Tests on a set of hd clips showed consistent gains:
http://www.corp.google.com/~yaowu/no_crawl/mblpf_hd.html
(avg psnr: .83% glb psnr: .77% ssim: .82%)
Tests on derf set also showed consistent gains:
http://www.corp.google.com/~yaowu/no_crawl/mblpf_derf.html
(avg psnr: .24% glb psnr: .22% ssim: .48%)
Change-Id: I0855b1ff48e79e1175c20b81967137e18b2af352
Previously, the mode context is always udpated based on stats of current
frame, when there is no count, 50% is used for both left and right branch.
However, it is observed that with such strategy, a small count or no count
at all can skew the probability distribution significantly. This commmit
changed the mode_context update strategy to prevent small counts from
skewing the probability distributions.
Tests on derf set showed a small gain: .06% in psnr and .09% in ssim
Change-Id: Ic812e64ae5f70251c170b0717f7b7fa587055488
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
High Q end extended a little.
Some clean up.
Slightly better on SSIM, Slightly worse on PSNR over derf set.
Change-Id: I3dceea8a39e11c26e1a389a40e40b86efc76d28c
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
A previous commit 76feb965 made the vp8_mode_context adaptive on a frame
frame basis, this commit further made the coding context adaptive to two
frame types separately. Tests on derf set showed a further small gain on
all metrics: avg psnr 0.10%, glb psnr: 0.11%, ssim: 0.08%
http://www.corp.google.com/~yaowu/no_crawl/newNearMode_1209.html
Change-Id: I7b3e32ec8729de1903d14a3f1213f1624b78cdee
This commit removed the macro CONFIG_MULCONTEXT, which was used to
indicate the experiment code for using separate context for altref
and normal frames. This commit made the change fully merged in.
Change-Id: I525f927f68e2365d37b340ef23b836a136a4f70b
This commit removed the macro CONFIG_I8X8, which was used to indicate
the 8x8 intra prediction experiment, made the change fully merged in.
Change-Id: Iafa4443781ce6e83f5591c12ba615a0e92ce0ea0
vp8_mode_contexts[] is an entropy table used to code inter mode
choices. It was a fixed constant table. This commit made the entropy
context adaptive. Tests on derf set showed very good consistent gains
on all metrics: avg psnr .47%, overall psnr .46% and ssim .40%.
http://www.corp.google.com/~yaowu/no_crawl/newModeContext.html
Change-Id: Ia62b14485c948e2b74586118619c5eb2068b43b2
This patch introduces the concept of dual inter16x16 prediction. A
16x16 inter-predicted macroblock can use 2 references instead of 1,
where both references use the same mvmode (new, near/est, zero). In the
case of newmv, this means that two MVs are coded instead of one. The
frame can be encoded in 3 ways: all MBs single-prediction, all MBs dual
prediction, or per-MB single/dual prediction selection ("hybrid"), in
which case a single bit is coded per-MB to indicate whether the MB uses
single or dual inter prediction.
In the future, we can (maybe?) get further gains by mixing this with
Adrian's 32x32 work, per-segment dual prediction settings, or adding
support for dual splitmv/8x8mv inter prediction.
Gain (on derf-set, CQ mode) is ~2.8% (SSIM) or ~3.6% (glb PSNR). Most
gain is at medium/high bitrates, but there's minor gains at low bitrates
also. Output was confirmed to match between encoder and decoder.
Note for optimization people: this patch introduces a 2nd version of
16x16/8x8 sixtap/bilin functions, which does an avg instead of a
store. They may want to look and make sure this is implemented to
their satisfaction so we can optimize it best in the future.
Change-ID: I59dc84b07cbb3ccf073ac0f756d03d294cb19281
This commit added code to keep track of separate entropy contexts for
normal frames and alt ref frames. The underly assumption was that the
two type of frames have different entropy characteristics given they
typically have quite different quantization levels. By keeping entropy
contexts separate, it helps the entropy context distribution to be more
closely adapted to each frame type.
Tests on derf set showed a good and very consistent gain on all clips
on all metrics, avg psnr: 0.89%, overall psnr: 0.84% and ssim 0.93%.
http://www.corp.google.com/~yaowu/no_crawl/mulcontext.html
Change-Id: I15bc9697f6ff7829042911fe0c62930585d7e65d
This commit enabled the usage of 8x8 intra prediction modes on inter
frames. There are a few TODO items related to this: 1)baseline entropy
need be calibrated; 2)cost of UV need to be done more properly rather
than using decision only relying on Y; 3)Threshold for allowing picking
8x8 intra prediction should be lowered to lower than the B_PRED.
Even with all the TODOs, tests showed consistent gain on derf set ~0.1%
(PSNR:0.08% and SSIM:0.14%). It is assumed that 8x8 intra prediction
will help more on large resolution clips, especially with above TODOs
addressed.
Change-Id: I398ada49dfc32575cfab962a569c2885111ae3ba
Fixed some further QIndex related issues and replaced some tables
(eg zbin and rounding)
Also Added function (currently disabled by default) to populate the
main AC and DC quantizer tables. Using the original AC range the
resulting computed DC values give behavior broadly comparable
on the DERF set. That is not to say that the equations will hold good
over a more extended range. The purpose of this code is to make it
easier to experiment with further alterations to the Q range and distribution
of Q values plus the relative weights given to AC and DC.
The function find_fp_qindex() ensures that changes to the Q tables
are reflected in the value passed in to the first pass code.
Slight experimental adjustment to static segment Q offset.
Change-Id: I36186267d55dfc2a3d565d0cff7218ef300d1cd5
this commit is to add an variable in the macroblock level mode
info structure to track the transform size used in each MB, so
the information can be used later in the loop filter to change
how loop filter works on MBs with different transform sizes.
Change-Id: Id0eeaba6cc854c6d1be00ed8d237b3d9e250e447
Fixed bug in firspass.c call to vp8_initialize_rd_consts()
This was passing in vp8_dc_quant(cm->base_qindex, cm->y1dc_delta_q)
instead of (cm->base_qindex + cm->y1dc_delta_q).
It just so happens that for the value 26 used for cm->base_qindex in the
unextended Q case, the two give similar results. However, when using
the extended Q range the two are very different.
Also added more stats output and partly disabled another broken feature.
Change-Id: Iddf6cf5ea8467c44b7c133f38e629f6ba6f2581e
This is an experiment to include a mv contribution from last frame to
nearest and near mv definition. Initial test showed some small though
consistent gain.
latest patch slightly better result ~.13%-~.18%.
TODO: the entropy used to encode the mode choice, i.e. the mv counts
based conditional distribution of modes should be re-collected to
reflect this change, it is expected that there is some further gain
from that.
Change-Id: Ief1e284a36d8aa56b49ae5b360c91419ec494fa4
Corrected dc lookup table to maintain ac/dc balance
close to what it was previously.
Firstpass not being passed the adjusted Q index for
the extended range.
Change-Id: Ic0200dabda445fea03bf81067999cb2670e99b77
Removal of CONFIGURE_SEGMENTATION ifdefs.
Removal of legacy support code fo the old coding mechanism.
Use local reference "xd" for MACROBLOCKD structure in
encode_frame_to_data_rate()
Moved call to choose_segmap_coding_method() out of encode
loop as the cost of segmentation is not properly accounted
in the loop anyway. If this is desirable in the future it
can be moved back. The use of this function to do all the
analysis and set the probabilities also removes the need
to track segment useage in threading code.
Change-Id: I85bc8fd63440e7176c73d26cb742698f9b70cade
Changed name and sense of segment_flag to "seg_id_predicted"
Added some additional comments and retested.
I also did some experimentation with a spatial prediction option
using a similar strategy to the temporal mode implemented.
This helps in some cases where temporal prediction is bad but
I suspect there is more overlap here with work on a larger scale
block structure and spatial correlation will likely be better
handled through that mechanism.
Next check in will remove #ifdefs and legacy mode code.
Change-Id: I3b382b65ed2a57bd7775ac0f3a01a9508a209cbc
This check in includes quite a lot of clean up and refactoring.
Most of the analysis and set up for the different coding options for the
segment map (currently simple distribution based coding or temporaly
predicted coding), has been moved to one location (the function
choose_segmap_coding_method() in segmenation.c). This code was previously
scattered around in various locations making integration with other
experiments and modification / debug more difficult.
Currently the functionality is as it was with the exception that the
prediction probabilities are now only transmitted when the temporal
prediction mode is selected.
There is still quite a bit more clean up work that will be possible
when the #ifdef is removed. Also at that time I may rename and alter
the sense of macroblock based variable "segment_flag" which indicates
(1 that the segmnet id is not predicted vs 0 that it is predicted).
I also intend to experiment with a spatial prediction mode that can be
used when coding a key frame segment map or in cases where temporal
prediction does not work well but there is spatial correlation.
In a later check in when the ifdefs have gone I may also move the call
to choose_segmap_coding_method() to just before where the bitsream is
packed (currently it is in vp8_encode_frame()) to further reduce the
possibility of clashes with other experiments and prevent it being called
on each itteration of the recode loop.
Change-Id: I3d4aba2a2826ec21f367678d5b07c1d1c36db168
the bug caused the encoder to produce invalid bitstream when configured
with enable_extend_qrange.
Change-Id: I1e81c48b13359d0043cbbd480e679380a2da117c
logically this commit should NOT change anything, but seems to help
revert the 3DB loss on bowing in the following commit:
https://on2-git.corp.google.com/g/#change,6193
This is still debugging in progress. Need further investigation to
understand the root cause of the issue.
Change-Id: I0b49d1ef3a311dfff58c6acd3eaebdb3bda6257c
Initial attempt at using new segment feature signaling
to indicate 4x4 or 8x8 transform.
needs --enable-experimental --enable-t8x8
Note this is work in progress.
Change-Id: Ib160d46a5d810307bfcbc79853ce1a65b5b870b7
Temporary check in to turn off other segment features
tests when #if CONFIG_T8X8 is set as the assignment of
MBs to differnt segments in each case will conflict.
The 8x8 code will be modified to use the new segment
feature method properly in a later check in.
Increase bits allowed for EOB end stop marker to 6 ready
for 8x8.
Change-Id: I4835bc8d3bf98e1775c3d247d778639c90b01f7f
No change to functionality or output.
Updates to the segment feature data structure now all done
through functions such as set_segdata() and get_segdata()
in seg_common.c.
The reason for this is to make changing the structures (if needed)
and debug easier.
In addition it provides a single location for subsequent addition
of range and validity checks. For example valid combination of
mode and reference frame.
Change-Id: I2e866505562db4e4cb6f17a472b25b4465f01add
This commit tries to do UV intra mode coding adaptive to Y intra mode.
Entropy context is defined as conditional PDF of uv intra mode given
the Y mode. All constants are normalized with 256 to be fit in 8 bits.
This provides further coding efficiency beyond the quantizer adaptive
y intra mode coding. Consistent gains were observed on all clips and
all bit rates for HD all key encoding tests.
To test, configure with
--enable-experimental --enable-uvintra
Change-Id: I2d78d73f143127f063e19bd0bac3b68c418d756a
Removal of configure #ifdefs so that segment features
always available. Removal of code supporting old
segment feature method.
Still a good deal of tidying up to do.
Change-Id: I397855f086f8c09ab1fae0a5f65d9e06d2e3e39f
Modify reference frame segmentation so that ONE or MORE
reference frames may be marked as a available for a given
segment.
Fixed bugs relating to segment coding of INTRA and some
INTER modes at the segment level.
Modified Q boost for static areas based on ambient average Q.
Strong results now on clips with significant static areas.
(some data points in derf set as high as 9% and some static &
slide show type content in YT set > 20%)
Change-Id: Ia79f912efa84b977f35a23683ae3643251e24f0c
