The existing test was triggering a lot of false positives on some types
of animated material with very plain backgrounds. These were triggering
code designed to catch key frames in letter box format clips.
This patch tightens up the criteria and imposes a minimum requirement
on the % blocks coded intra in the first pass and the ratio between the
% coded intra and the modified inter % after discounting neutral (flat)
blocks that are coded equally well either way.
On a particular problem animation clip this change eliminated a large
number of false positives including some cases where the old code
selected kf several times in a row. Marginal false negatives are less
damaging typically to compression and in the problem clip there are now
a couple of cases where "visual" scene cuts are ignored because of well
correlated content across the scene cut.
Replaced some magic numbers related to this with #defines and added
explanatory comments.
Change-Id: Ia3d304ac60eb7e4323e3817eaf83b4752cd63ecf
This patch limits the maximum arf interval length to
approximately half a second. In some low fps animations in
particular the existing code was selecting an overly long interval
which was hurting visual quality. For a sample problem test clip
(360P animation , 15fps, ~200Kbit/s) this change also improved
metrics by >0.5 db.
There may be some clips where this hurts metrics a little, but the
worst case impact visually is likely to be less than having an
interval that is much too long. On more normal material at 24
fps or higher, the impact is likely to be nil/minimal.
Change-Id: Id8b57413931a670c861213ea91d7cc596375a297
Modifies a special handling that improves rate control accuracy in
the constrained quality mode, when the undershoot and overshoot
limits are set tighter.
Change-Id: If62103f0ef3ed1cac92807400678c93da50cf046
the sse4 code expects 16-byte aligned arrays; vp8 already had a similar
change applied:
b2aa401 Align SAD output array to be 16-byte aligned
Change-Id: I5e902035e5a87e23309e151113f3c0d4a8372226
Skip redundant prediction filter type cost in filter search loop,
if the rate value will be reset in Hadamard transform based rate
distortion estimate.
Change-Id: Ie5221f4bc8da9461c449df367251aeeac52c6e5d
This commit turns on the Hadamard transform based rate distortion
estimate for all block sizes in RTC coding mode. It conditionally
skips the rate distortion estimation if all zero block flag is set
on. No significant encoding speed change is observed. The
compression performance of speed -6 is improved by 1.7% over using
it only for block sizes of 32x32 and below.
Change-Id: I768145e6f05c737b05b5b5f1ee674e929532cafb
The threshold scaling factor was calculated wrong using partition
size "bsize". Thank Yaowu for pointing it out. It was fixed and no
speed change was seen.
Change-Id: If7a5564456f0f68d6957df3bd2d1876bbb8dfd27
This commit accounts for the transform block end of coefficient flag
cost in the RTC mode decision process. This allows a more precise
rate estimate. It also turns on the model to block sizes up to 32x32.
The test sequences shows about 3% - 5% speed penalty for speed -6.
The average compression performance improvement for speed -6 is
1.58% in PSNR. The compression gains for hard clips like jimredvga,
mmmoving, and tacomascmv at low bit-rate range are 1.8%, 2.1%, and
3.2%, respectively.
Change-Id: Ic2ae211888e25a93979eac56b274c6e5ebcc21fb
The vbp thresholds are set seperately for boosted/non-boosted
superblocks according to their segment_id. This way we don't
have to force the boosted blocks to split to 32x32.
Speed 6 RTC set borg test result showed some quality gains.
Overall PSNR: +0.199%; Avg PSNR: +0.245%; SSIM: +0.802%.
No speed change was observed.
Change-Id: I37c6643a3e2da59c4b7dc10ebe05abc8abf4026a
This commit separates Hadamard transform/quantization operations
from rate and distortion computation in block_yrd. This allows one
to skip SATD computation when all transform blocks are quantized
to zero. It also uses a new block error function that skips
repeated computation of sum of squared residuals. It reduces the
CPU cycles spent on block error calculation in block_yrd by 40%.
Change-Id: I726acb2454b44af1c3bd95385abecac209959b10
This commit allows the quantizer to compare the AC coefficients to
the quantization step size to determine if further multiplication
operations are needed. It makes the quantization process 20% faster
without coding statistics change.
Change-Id: I735aaf6a9c0874c82175bb565b20e131464db64a
For large partition blocks(block_size > 32x32), the variance
calculation is modified so that every 8x8 block's variance
is stored during the calculation, which is used in the
following transform skipping test. Also, the variance for
every tx block is calculated. The skipping test checks all tx
blocks in the partition, and sets the skip flag only if all tx
blocks are skippable. If the skip flag of Y plane is 1, a
quick evaluation is done on UV planes. If the current partition
block is skippable in YUV planes, the mode search checks fewer
inter modes and doesn't check intra modes.
The rtc set borg test(at speed 6) showed that:
Overall psnr: -0.527%; Avg psnr: -0.510%; ssim: -0.573%.
Average single-thread speedup on rtc set was 3.5%.
For 720p clips, more speedups were seen.
gipsrecmotion: 13%
gipsrestat: 12%
vidyo: 5 - 9%
dark: 15%
niklas: 6%
Change-Id: I8d8ebec0cb305f1de016516400bf007c3042666e
This commit allows the encoder to check the eob per transform
block to decide how to compute the SATD rate cost. If the entire
block is quantized to zero, there is no need to add anything; if
only the DC coefficient is non-zero, add its absolute value;
otherwise, sum over the block. This reduces the CPU cycles spent
on vp9_satd_sse2 to one third.
Change-Id: I0d56044b793b286efc0875fafc0b8bf2d2047e32
