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
Implements some of the helper functions more efficiently with
lookups rathers than branches. Modeling function is consolidated
to reduce some computations.
Also merged the two enums BLOCK_SIZE_TYPES and BlockSize into
one because there is no need to keep them separate (even though
the semantics are a little different).
No bitstream or output change.
About 0.5% speedup
Change-Id: I7d71a66e8031ddb340744dc493f22976052b8f9f
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
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>
Total encoding time for first 50 frames of bus (speed 0) @ 1500kbps
goes 2min34.8 to 2min14.4, i.e. a 10.4% overall speedup. The code is
x86-64 only, it needs some minor modifications to be 32bit compatible,
because it uses 15 xmm registers, whereas 32bit only has 8.
Change-Id: I2df53770c2e850813ffa713e1a91b45b0082b904
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 replaces zrun_zbin_boost, a method of biasing non-zero
coefficients following runs of zero-coefficients to be rounded towards
zero, with an explicit skip-block choice in the RD loop.
The logic is basically that if individual coefficients should be rounded
towards zero (from a RD point of view), the trellis/optimize loop should
take care of it. If whole blocks should be zero (from a RD point of
view), a single RD check is much more efficient than a complete
serialization of the quantization loop.
Quality change: derf +0.5% psnr, +1.6% ssim; yt +0.6% psnr, +1.1% ssim.
SIMD for quantize will follow in a separate patch. Results for other
test sets pending.
Change-Id: Ife5fa641163ac5150ac428011e87188f1937c1f4
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
This commit enables configurable reference buffer pointer for intra
predictor. This allows later removal of spatial dependency between
blocks inside a 64x64 superblock in the rate-distortion optimization
loop.
Change-Id: I02418c2077efe19adc86e046a6b49364a980f5b1
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
This uses variance to split partition. Variance is calculated using
nearest mv, always from last ref frame.
Change-Id: Idd015b4a9aa3bc82591759eac239680c07496896
Reduces TX_SIZE contexts to 2 for each kind. The code is
cleaner and there is hardly any performance difference with
more than two contexts.
Results: almost neutral
Change-Id: I17656bd6db76224ae2856adf882504560e7dbaa4
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
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
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
Split partition probabilities between keyframes and non-keyframes,
since they are fairly different. Also have per-blocksize interframe
y intramode probabilities, since these vary heavily between different
blocksizes.
Lastly, replace default probabilities for partitioning and intra modes
with new ones generated from current codec. Replace counts with actual
probabilities also.
Change-Id: I77ca996e25e4a28e03bdbc542f27a3e64ca1234f
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
Fixes an issue with reducing branch cts in the encoder causing
a drop in performance. The bug was introduced in a previous
clean up patch.
Test: Went back to the offending patch, applied this same fix
to it, and checked that results are identical to the parent
of that patch.
Change-Id: I0bad8e2d930235d0284300fcebf836ceb56f2498
This commit enables iterative motion search for 4x4/4x8/8x4 block
size compound inter-inter prediction.
WIP: borg run testing
Change-Id: I2b318db4a03cdca5a8002b3fa6c0fa89b129288b
1. remove prediction mode conversion
2. unified bmode, same for key and non-key frame
3. set I4X4_PRED count for pdf to 0, as I4X4_PRED is no longer
coded ever. It is determined by ref_frame and block partition
Change-Id: If5b282957c24339b241acdb9f2afef85658fe47d
Also do per-partition motion vector referencing in <sb8x8 partitions,
and adjust mvref finding for sub8x8 partitions.
Change-Id: Id3ed1ed4d2a8910d11d327db6cc63b8eb79f941f
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 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
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
There is only one instance of these structures, no need for them
to be allocated separately on the heap.
Change-Id: I1333cc92d06bbe21be643c2b2f0e3936f0264cac
Work-in-progress, not yet ready for review. TODO items:
- bitstream writing (encoder) and reading (decoder)
- decoder reconstruction
Change-Id: I5afb7284e7e0480847b47cd0097cb469433c9081
This commit enables selecting probability models for recursive block
partition information syntax, depending on its above/left partition
information, as well as the current block size. These conditional
probability models are reasonably stationary and consistent across
frames, hence the backward adaptive approach is used to maintain and
update the contextual models.
It achieves coding performance gains (on top of enabling rectangular
block sizes):
derf: 0.242%
yt: 0.391%
hd: 0.376%
stdhd: 0.645%
Change-Id: Ie513d9673337f0d27abd65fb566b711d0844ec2e
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
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 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
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
