The 32x32 forward transform can potentially reach peak coefficient
value close to 32700, while the rounding factor can go upto 610.
This could cause overflow issue in the SSSE3 implementation of 32x32
quantization process.
This commit resolves this issue by replacing the addition operations
with saturated addition operations in 32x32 block quantization.
Change-Id: Id6b98996458e16c5b6241338ca113c332bef6e70
The 32x32 quantization process can potentially have the intermediate
stacks over 16-bit range, thereby causing enc/dec mismatch. This commit
fixes this overflow issue in the SSSE3 implementation, as well as the
prototype, of 32x32 quantization.
This fixes issue 607 from webm@googlecode.
Change-Id: I85635e6ca236b90c3dcfc40d449215c7b9caa806
VP9_COMMON is the right place to segmentatation struct because it has
global segmentation parameters, not something specific to macroblock
processing.
Change-Id: Ib9ada0c06c253996eb3b5f6cccf6a323fbbba708
Cycle times:
4x4: 151 to 131 cycles (15% faster)
8x8: 334 to 306 cycles (9% faster)
16x16: 1401 to 1368 cycles (2.5% faster)
32x32: 7403 to 7367 cycles (0.5% faster)
Total encode time of first 50 frames of bus @ 1500kbps (speed 0)
goes from 1min39.2 to 1min38.6, i.e. a 0.67% overall speedup.
Change-Id: I799a49460e5e3fcab01725564dd49c629bfe935f
Adding segmentation struct to vp9_seg_common.h. Struct members are from
macroblockd and VP9Common structs. Moving segmentation related constants
and enums to vp9_seg_common.h.
Change-Id: I23fabc33f11a359249f5f80d161daf569d02ec03
Encode time of bus (speed 0) 50 frames @ 1500kbps goes from 2min14.4 to
2min10.1, i.e. a 2.3% overall speed increase.
Change-Id: I3699580e74ec26c7d24e03681bc47ba25ee1ee87
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
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
Encoding time of first 50 frames of bus @ 1500kbps (speed 0) goes from
3min15.0 to 3min10.9, i.e. 2.1% faster overall.
Change-Id: If592ee99be09bcd34a7c8498347f44e7305e982c
Optimized the quantization function by making it a two-pass
process. The first pass does a quick checking of the transform
coefficients against the base ZBIN, and only keep the good
enough set of coefficients for quantization. A skipping
check is added. If all coefficients are within the base ZBIN, no
quantization is needed. The second pass is the actual quantization
pass, which only processes the coefficient subset determined
in first pass. This reduces the computation. Furthermore, an
alternitive method is used for large transform size, which often
has sparse nonzero quantized coefficients.
Overall, the encoder speedup is about 4%. The quantization function
itself gets 20% faster.
Change-Id: I3a9dd0da6db030260b6d9c314a9fa48ecae89f22
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
Skip Q values between the q.0 mode and a real q of
2.0 as these are not valuable from an RD perspective.
Change-Id: I110c4858c57f97315953f4d88a2596d4764360df
This allows removing a large number of transform size specific functions,
as well as supporting 444/alpha by routing all code through the
subsampling-aware path.
Change-Id: Ieb085cebe9f37f24fc24de179898b22abfda08a4
Creates a common encode (subtract, transform, quantize, optimize,
inverse transform, reconstruct) function for all sb sizes, including
the old 16x16 path.
Change-Id: I964dff1ea7a0a5c378046a069ad83495f54df007
Work-in-progress, not yet ready for review. TODO items:
- bitstream writing (encoder) and reading (decoder)
- decoder reconstruction
Change-Id: I5afb7284e7e0480847b47cd0097cb469433c9081
Moving common code from encoder and decoder to vp9_get_qindex function.
Also moving quant-related constants from vp9_onyxc_int.h to
vp9_quant_common.h.
Change-Id: I70c5bfbaa1c8bf00fde0bfc459d077f88b6d46c8
Basic assumption: when talking about transform units, use b_; when
talking about macroblock indices, use mb_.
Change-Id: Ifd163f595d4924ff892de4eb0401ccd56dc81884
Quantizers can vary per plane, but not per block. Move these values to
the per-plane part of MACROBLOCK.
Change-Id: I320a55e38b7b28b29aec751a4aca5ccd0c9b9326
This commit moves the coeff storage from the MACROBLOCK struct to its
per-plane part. The next commit will remove the coeff member from the
BLOCK structure so that it is consistently accessed per-plane.
Also refactors vp9_sb_block_error_c and vp9_sb_uv_block_error_c to be
variable subsampling aware.
Change-Id: I18c30f87f27c3a012119b6c1970d5fa499804455
More specifically, remove vp9_quantize_mb*, vp9_optimize_mb*,
vp9_inverse_transform_mb* and vp9_transform_mb*. Instead, use the
generic _sb* functions that take a size argument, and call them with
BLOCK_SIZE_MB16X16.
Change-Id: I33024afea95d3a23ffbc1df7da426e4645110f29
Merge sb32x32 and sb64x64 functions; allow for rectangular sizes. Code
gives identical encoder results before and after. There are a few
macros for rectangular block sizes under the sbsegment experiment; this
experiment is not yet functional and should not yet be used.
Change-Id: I71f93b5d2a1596e99a6f01f29c3f0a456694d728
Start grouping data per-plane, as part of refactoring to support
additional planes, and chroma planes with other-than 4:2:0
subsampling.
Change-Id: Idb76a0e23ab239180c818025bae1f36f1608bb23
These are mostly just for experimental purposes. I saw small gains (in
the 0.1% range) when playing with this on derf.
Change-Id: Ib21eed477bbb46bddcd73b21c5c708a5b46abedc
Replaces the default tables for single coefficient magnitudes with
those obtained from an appropriate distribution. The EOB node
is left unchanged. The model is represeted as a 256-size codebook
where the index corresponds to the probability of the Zero or the
One node. Two variations are implemented corresponding to whether
the Zero node or the One-node is used as the peg. The main advantage
is that the default prob tables will become considerably smaller and
manageable. Besides there is substantially less risk of over-fitting
for a training set.
Various distributions are tried and the one that gives the best
results is the family of Generalized Gaussian distributions with
shape parameter 0.75. The results are within about 0.2% of fully
trained tables for the Zero peg variant, and within 0.1% of the
One peg variant.
The forward updates are optionally (controlled by a macro)
model-based, i.e. restricted to only convey probabilities from the
codebook. Backward updates can also be optionally (controlled by
another macro) model-based, but is turned off by default. Currently
model-based forward updates work about the same as unconstrained
updates, but there is a drop in performance with backward-updates
being model based.
The model based approach also allows the probabilities for the key
frames to be adjusted from the defaults based on the base_qindex of
the frame. Currently the adjustment function is a placeholder that
adjusts the prob of EOB and Zero node from the nominal one at higher
quality (lower qindex) or lower quality (higher qindex) ends of the
range. The rest of the probabilities are then derived based on the
model from the adjusted prob of zero.
Change-Id: Iae050f3cbcc6d8b3f204e8dc395ae47b3b2192c9
