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
Resolved or factored out some further issues with Q index.
Put in a 3rd order polynomial instead of less accurate power function
as the best fit on gf and kf boost adjustment.
Added avg_q value to use instead of ni_av_qi.
Compute segment delta Q values based on avg_q.
Fixed bug in adjust_maxq_qrange().
The extended range Q on the derf set, using standard data rates
(which do not extend high enough to get big benefits) still show
a shortfall of between 0.5 and 1% though so there would appear to
be further issues that need to be tracked down.
Change-Id: Icfd49b9f401906ba487ef1bef7d397048295d959
Added two experimental options to the configure script:
1. newnear:
new scheme of doing mv encoding that include a motion vector from
last frame in nearest and near mv search
2. mulcontext:
tracks entropy context separately for regular frames and alt ref
frames.
Change-Id: If6e0d5d593351707b497a26eb6a763e080f77e6f
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
Slight tweaks to the new minq equations to bring results more into line with
original lookup tables.
Change-Id: I969fc87d95912df549b6775e83ee2345e84d4da0
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
This comitt brings accross changes from the public branch
commit number Icf74d13af77437c08602571dc7a97e747cce5066.
The main puurpose of this comit relates to CQ mode but it
also includes some refactoring of the two pass code which
I hope will make tuning the experimental branch for the new
quantizer range a little less painfull.
Change-Id: I278e989436a928fc1fe7761068960048f9d7a376
This commit resolves further QIndex look up tables to facilitate
experimentation with the quantizer range.
In some cases rather than remove the look up tables completely
I have created functions that are called once to populate them
using a formulaic approach base on the actual quantizer.
The use of these functions based on best fit of data from the original
tables does affect the results on some clips but across the derf test
set the effect was broadly neutral.
Change-Id: I8baa61c97ce87dc09a6340d56fdeb681b9345793
One of the problems arising when tweaking or adjusting the quantizer
tables is that there are a lot of look up tables that depend on the QINDEX.
Any adjustment to the link between QINDEX and real quantizer therefore tends
to break aspects of for example the rate control.
In this check in I have replaced several of the look up tables with functions that
approximate the same results as the old Q luts but use a formulaic approach
based on real Q values rather than QIndex. This should hopefully make it easier
to experiment with changes to the Q tables without always having to go through
and hand optimize a set of look up tables. Once things stabilize we may choose
to re-instate luts for the sake of performance.
Patch 2:
Addressed Ronald's comments.
vp8_init_me_luts() Added so luts only initialized once.
Change-Id: Ic80db2212d2fd01e08e8cb5c7dca1fda1102be57
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
Fix decoder segmentation bug for temporal coding where the segment map
was first initialized on a key frame.
in vp8_kfread_modes() after reading the segment id it must be written to
the pbi->segmentation_map[] for use in temporal coding on subsequent frames.
Change-Id: I1489305efc376564e734a216f69c2844646ee3d3
The buffer level was able to increase indefinitely rather than
being clipped to the maximum buffer size specified by the user.
This change checks the buffrer level and prevents it from
going beyond the upper limit of the buffer.
Change-Id: Ifff55f79d3c018e4d3d77e554b11ada543cc1654
This commit has a few minor fixes to the 8x8 trellis quant, so to
make it work regardless if extend_qrange is enabled or not. It also
borrowed adaptive RDMULT constants from 4x4 trellis that was missed
in the 8x8 trellis quant.
Change-Id: I60d7769071f102c699b5084597e62bca87a1f759
Explicit inclusion of limits.h to satisfy unix build for definition of INT_MAX.
Some commented out code removed.
Change-Id: I5b5980dfaa9b4d2d12bfd729cfd35bd982106908
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
Added last_segmentation_map[] structure
to keep track of what we had before when
doing temporal prediction. With this change
the existing code does once again appear to
be giving a decodable bitstream for both
temporal and standard prediction modes.
However, it is still somewhat messy and
confused and there is no option to take
advantage of spatial prediction so it could
do with further work.
Some housekeeping / clean out.
Change-Id: I368258243f82127b81d8dffa7ada615208513b47
Some initial cleanup to aid testing and debug.
Pull code to choose temporal or spatial encoding
out of encodeframe.c into a dedicated function
in segmentation.c.
For now disable broken temporal mode.
Move the coding of "temporal_update" flag and
only transmit if segment map update is indicated.
Rename the functions read_mb_features() and
write_mb_features() to read_mb_segid() and
read_mb_segid() as they only read and write
the macroblock segment id not any of the
features.
Change-Id: Ib75118520b1144c24d35fdfc6ce46106803cabcf
The dequantizer functions for 2nd order haar block had confusing 8x8
in their names. this commit fixed their name to avoid confusion.
Change-Id: I6ae4e7888330865f831436313637d4395b1fc273
This commit added scaling factors to 8x8 transform, quant, dequant and
inverse transform pipeline to make 8x8 transform to work when configed
with enable-extend_qrange. This commit also disabled the trellis-quant
when extend_qrange is configured.
Change-Id: Icfb3192e4746f70a4bb35ad18b7b47705b657e52
updated the decode_macroblock logic to reflect that 8x8 transform is
not used for "SPLITMV". Also fixed an issue where 2nd order haar block
has wrong dequant/idct process.
Change-Id: I1e373f6535c009dfec503b6362c8a5cfc196e1da
extend_qrange introduces a different scaling factor, this commit takes
the scaling difference into account for reset 2nd order coefficients.
Change-Id: Ie58bca9f52698fa759e3f88da2aa4d82630fa91a
the bug caused the encoder to produce invalid bitstream when configured
with enable_extend_qrange.
Change-Id: I1e81c48b13359d0043cbbd480e679380a2da117c
For ease of testing and merging experiments I have
removed in line code in encode_frame() that assigns
MBs to be t8x8 or t4x4 coded segments and have
moved the decision point and segment setup to
the init_seg_features0 test function.
Keeping everything in one place helps make sure
for now that experiments using segmentation are
not fighting each other.
Also made sure mode selection code can't choose 4x4
modes if t8x8 is selected.
Patch2: In init_seg_features() add checks
for SEG_LVL_TRANSFORM active.
Change-Id: Ia1767edd99b78510011d4251539f9bc325842e3a
Removed code in #if CONFIG_SEGMENTATION that
enables segmentation and creates a test segmentation
map, to avoid conflicts with the other segmentation test
code,
Change-Id: I7a21a44ed188b814cd80b30dd628c62474eba730
Bug fix to logic in vp8_pick_inter_mode() and
vp8_rd_pick_inter_mode().
The block on the use of segment features
for the cm->refresh_alt_ref_frame case
was just for testing and is not correct.
The special case code for alt ref can
be re-enabled as an else clause.
Change-Id: Ic9b57cdb5f04ea7737032b8fb953d84d7717b3ce
The 8x8 forward transform makes use of floating operations, therefore
requires emms call to reset mmx registers to correct state. Without
the resets, the 8x8 forward transform results are indefinite on win32
platform.
Change-Id: Ib5b71c3213e10b8a04fe776adf885f3714e7deb1
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
