This commit exploits the sparsity of quantized coefficient matrix.
It detects each 32x8 array and skip the corresponding inverse
transformation if all entries are zero.
For ped1080p at 8000 kbps, this on average reduces the runtime of
32x32 inverse 2D-DCT SSE2 function from 6256 cycles -> 5200
cycles. It makes the overall encoding process about 2% faster at
speed 0. The speed-up is more pronounceable for the decoding process.
Change-Id: If20056c3566bd117642a76f8884c83e8bc8efbcf
This commit removes redundant arguments passing in the function of
rd_pick_reference_frame. This resolves the clang warnings about
potential use of uninitialized values.
Change-Id: Ic68f949a9f8fcd0a583786b0c75321104ea44739
Refactor the frame buffer referencing in choose_partition and make
it consistent with other places. This means to prevent potential
issues when we extend reference frame buffer.
Change-Id: I5ff33ed5f671e1f4cc7049622212769a9b4578d9
The tokenize_b function is only called when output flag is on. Hence
removing the conditional branch on it therein.
Change-Id: Ib709f47f23f39ca05a695faf86fa3377f11f2dd0
This commit optimizes the tokenization and detokenization operational
flow for speed-up. It makes the coding process about 0.3% faster at
speed 0.
Change-Id: I28008df7482874e4b5f237f2d418ff82a249dd56
This commit makes the encoder skip the redundant tokenization process
in the rate-distortion optimization search loop, while updating the
entropy contexts accordingly. It makes the speed 0 encoding process
about 0.5% faster at no performance change.
Change-Id: I34a4155a0b5332afeb45c93a51c7f35a294d685c
This commit provides special handle on 16x16 inverse 2D-DCT, where
only DC coefficient is quantized to be non-zero value.
Change-Id: I7bf71be7fa13384fab453dc8742b5b50e77a277c
Fixes a warning on MSVS 2012 where the alignment of vp9_default_iscan_8x8
didn't match between its declaration and definition.
Change-Id: I1466a15635f4b22594d705d570b7e399bfb6cf21
This allows us to increment the position at the band-level only as
we go from one band to the next; more importantly, that allows us to
use an add instead of multiply instruction, and omit the instruction
altogether if the band doesn't change from one coef to the next, thus
being slightly faster (probably more noticeable on systems where a
multiply is expensive, like arm).
Change-Id: I4343fe35b9f9a47fa00b217bdcbf5f91ff96c381
This commit brought back the shortcut implementation of 8x8/16x16
inverse 2D-DCT. When the eob <= 10, it skips the inverse transform
operations on row 4:7/4:15 in the first round. For bus_cif at 1000
kbps, this provides about 2% speed-up at speed 0.
Change-Id: I453e2d72956467d75be4ad8c04b4482ab889d572
This commit enables a special handle for the 8x8 inverse 2D-DCT,
where only DC coefficient is quantized to be non-zero. For bus_cif
at 2000 kbps, it provides about 1% speed-up at speed 0.
Change-Id: I2523222359eec26b144cf8fd4c63a4ad63b1b011
Speed feature experiment to set an upper and lower
partition size limit based on what has been seen
in spatial neighbors.
This seems to gives quite reasonable speed gains in local
(10-15%) and when used with speed 0 the losses are small
(0.25% derf, 0.35% stdhd). However, for now I am only
enabling it on speed 1 as there may be clashes with the existing
temporal partition selection in speed 2.
Using a tighter min / max around the range derived from the
neighbors increases speed further but at the cost of a
bigger quality loss. However, I think this spatial method could
be combined with data from either the last frame or a variance
method (or both) to refine the range of minimum and maximum
partition size. I.e. consider the min and max from spatial and
temporal neighbors and the variance recommendation.
Change-Id: I1b96bf8b84368d6aad0c7aa600fe141b4f07435f
Used 3 * standard_deviation in internal threshold calculation
instead of fit curve. This actually approached the algorithm
better.
For comparison, similar tests were done:
The overall psnr loss is less than before.
1. derf set:
when static-thresh = 1, psnr loss is 0.329%;
when static-thresh = 500, psnr loss is 0.970%;
2. stdhd set:
when static-thresh = 1, psnr loss is 0.922%;
when static-thresh = 500, psnr loss is 1.307%;
Similar speedup is achieved. For example,
clip bitrate static-thresh psnr time
akiyo(cif) 500 0 48.952 5.077s(50f)
akiyo 500 500 48.866 4.169s(50f)
parkjoy(1080p) 4000 0 30.388 78.20s(30f)
parkjoy 4000 500 30.367 70.85s(30f)
sunflower(1080p) 4000 0 44.402 74.55s(30f)
sunflower 4000 500 44.414 68.69s(30f)
Change-Id: Ic78833642ce1911dbbd1cb6c899a2d7e2dfcc1f3
Now read_inter_mode_info calls read_intra_block_part (renamed from
read_intra_block_modes) or read_inter_block_part (just added).
Change-Id: I541badea6b663e0ae692ec158665efb90ed20c03
This option exists in VP8, and it was rewritten in VP9 to support
skipping on different partition levels. After prediction is done,
we can check if the residuals in the partition block will be all
quantized to 0. If this is true, the skip flag is set, and only
prediction data are needed in reconstruction. Based on DCT's energy
conservation property, the skipping check can be estimated in
spatial domain.
The prediction error is calculated and compared to a threshold.
The threshold is determined by the dequant values, and also
adjusted by partition sizes. To be precise, the DC and AC parts
for Y, U, and V planes are checked to decide skipping or not.
Test showed that
1. derf set:
when static-thresh = 1, psnr loss is 0.666%;
when static-thresh = 500, psnr loss is 1.162%;
2. stdhd set:
when static-thresh = 1, psnr loss is 1.249%;
when static-thresh = 500, psnr loss is 1.668%;
For different clips, encoding speedup range is between several
percentage and 20+% when static-thresh <= 500. For example,
clip bitrate static-thresh psnr time
akiyo(cif) 500 0 48.923 5.635s(50f)
akiyo 500 500 48.863 4.402s(50f)
parkjoy(1080p) 4000 0 30.380 77.54s(30f)
parkjoy 4000 500 30.384 69.59s(30f)
sunflower(1080p) 4000 0 44.461 85.2s(30f)
sunflower 4000 500 44.418 78.1s(30f)
Higher static-thresh values give larger speedup with larger
quality loss.
Change-Id: I857031ceb466ff314ab580ac5ec5d18542203c53
