This commit enables an adaptive transform size selection method
for speed -6. It uses largest transform size when the sse is more
than 4 times of variance, i.e., most energy is compacted in the
DC coefficient. Otherwise, use the default TX_8X8. It improves
the compression efficiency for rtc set of speed -6 by 0.8%, no
speed change observed.
Change-Id: Ie6ed1e728ff7bf88ebe940a60811361cdd19969c
This commit fixes the potential issue in the non-RD mode decision
flow that only checks part of the block to estimate the cost. It
was due to the use of fixed transform size, in replacing the
largest transform block size. This commit enables per transform
block cost estimation of the intra prediction mode in the non-RD
mode decision.
Change-Id: I14ff92065e193e3e731c2bbf7ec89db676f1e132
In real-time speed 6, no partition search is done. The inter
prediction results got from picking mode can be reused in the
following encoding process. A speed feature reuse_inter_pred_sby
is added to only enable the resue in speed 6.
This patch doesn't change encoding result. RTC set tests showed
that the encoding speed gain is 2% - 5%.
Change-Id: I3884780f64ef95dd8be10562926542528713b92c
Fix some bugs relating to the use of buffers
in the overlay frames.
Fix bug where a mid sequence overlay was
propagating large partition and transform sizes into
the subsequent frame because of :-
sf->last_partitioning_redo_frequency > 1 and
sf->tx_size_search_method == USE_LARGESTALL
Change-Id: Ibf9ef39a5a5150f8cbdd2c9275abb0316c67873a
This commit allows the key frame to search through more prediction
modes and more flexible block sizes. No speed change observed. The
coding performance for rtc set is improved by 1.7% for speed -5 and
3.0% for speed -6.
Change-Id: Ifd1bc28558017851b210b4004f2d80838938bcc5
Speed 6 uses small tx size, namely 8x8. max_intra_bsize needs to
be modified accordingly to ensure valid intra mode checking.
Borg test on RTC set showed an overall PSNR gain of 0.335% in speed
-6.
This also changes speed -5 encoding by allowing DC_PRED checking
for block32x32. Borg test on RTC set showed a slight PSNR gain of
0.145%, and no noticeable speed change.
Change-Id: I1502978d8fbe265b3bb235db0f9c35ba0703cd45
In non-rd real-time mode, choosing smaller transform size in
encoding gives better video quality and good speed gain than
choosing larger transform size. This patch set tx size search
method to ALLOW_8X8, which is better than using 4x4 or other
larger sizes.
Borg tests on rtc set at speed 6 showed significant gain on quality.
PSNR gain: 11.034% and SSIM gain: 15.466%.
The speed gain is 5% - 12% for <720p clips, and 2% - 7% for
720p clips.
Change-Id: If4dc74ed2df359346b059f47fb73b4a0193ec548
Right now there is just one place to check: xd->lossless and for the first
pass there is a function is_lossless_requested().
Change-Id: I949a6834e64ce51e422e2892f097f2b871b5429a
Making this consistent with intra mode masks: you need to specify
allowed inter/intra modes to use.
Change-Id: Iaecd28bf79047259707d8e7a59a57bb7b856383e
This commit changed to enable the encoder to adjust motion dection
speed threshold based on picture size. In addition, cpu-used 1 now
does a partition search every other frame instead of every third
frame for low resolution inputs.
The change has no quality/speed impact for 720p and above. Test
showed the change increase encoding time by between 3% to 6% for
cpu-used 2 encodiong of 360p sequences. It also has a compression
gain about .3%.
For cpu-used 2, the change resolved some very disturbing visual
artifacts in certain sequences when large block partitionings and
transforms are used as a result of copying the partition from a
previous frame.
Change-Id: Ic7fd22508cdb811d4ca935655adbf20109286cfa
Added a skipping test in non-rd inter-mode. After interpolation
prediction step, the residuals are tested to see if they will be
quantized to 0 based on modeling between spatial domain and
frequency domain.
Set static-thresh to 800 for >=720p and 300 for <720p, rtc set
tests showed
1. Speed 5, psnr: -0.514%; ssim: -1.748%;
speedup on related clips: 5% -11%
2. Speed 6, psbr: -0.628%; ssim: -1.637%;
speedup on related clips: 4% - 9%
Change-Id: I62fbf26bc043ecd2b584f255f1a4ee5ab52bfcf3
This commit introduces a chessboard pattern search for the prediction
filter type search. It runs extensive search in alternate blocks and
allows the rest blocks to refer coding decisions of their nearby
neighbors.
For pedestrian 1080p at 4000 kbps, the runtime of speed -5 goes down
from 43990 ms to 42200 ms. The overall compression performance for
RTC set is changed by -1.37%.
Change-Id: Icfe220c49451cda796f0ca91d935c9ed01e56c9d
For speed 3 and above, such search is only allowed at speed 3.
The change helped cif and stdhd set by 1.2% and .7% in compression,
but increased the encoding time by around 5%.
Change-Id: Ifa4832327f1c1bef3decb032ceb769cbf50e059f
A previous path improved speed 2 quality a little but
more extensive testing showed that it slowed encode
by a few %.
The change will have a similar effect for speed 3 but
should not impact speeds 4+;
This experiment should reverse that and give a speed
up at the cost of a small quality loss.
Borg results pending.
Change-Id: I4493fc1541aaf44587f1a41ff219f7088da9252c
Calculate the difference variance between last source frame and
current source frame. The variance is calculated at 16x16 block
level. The variances are compared to several thresholds to decide
final partition sizes.
An adaptive strategy is implemented to decide using
SOURCE_VAR_BASED_PARTITION or FIXED_PARTITION based on motions
in the video. The switching test is done once every
search_type_check_frequency frames.
The selection of source_var_thresh needs to be investigated
further later.
RTC set Borg test showed 0.424% overall psnr gain, and 0.357%
ssim gain. For clips with large enough static area, the
encoding speedup is around 2% to 15%.
Change-Id: Id7d268f1d8cbca7fb8026aa4a53b3c77459dc156
Copy up to a certain bsize, otherwise set to a fixed bsize.
This helsp to reduce artifact near moving boundary caused by full partition
copy without checking motion of super-block.
This artifact can occur at speeds 3,4 in real-time mode.
Issue: https://code.google.com/p/webm/issues/detail?id=738.
Change-Id: I05812521fd38816a467f72eb6a951cae4c227931
This commit slightly increases the bit allocation for key frame. This
improves speed -5 coding performance by 2.77% with aq-mode=0 and by
2.78% with aq-mode=3.
Change-Id: Iaa3e777f80b9706306606af06e89852bac146659
This commit reduces the frequency of frames using finer quantizer
in non-RD coding flow, and slightly tune up the quantizer resolution
when used. It provides 1.7% compression gains in speed -5 at no speed
difference.
Change-Id: I430249a51260a841a0402666e5ec1566e4f7d5a6
The new tolerance is a little higher than before (especially
for kf/gf/arf) so this change gives an encode speed up
for some clips up for speeds 0-2.
Change-Id: I63f7d6c9cc11c7f58742f41e250dcd3eab1741eb
This commit adjusted the speed steps in rt mode to make the steps
more evenly spaced on speed and quality, specifically:
1. Merged 3 and 4 into one single step 3 and removed confilicting
features.
2. Move 8, 7, 6, 5 to be 7, 6, 5, 4 repsectively.
Change-Id: I38d56d61531f3561d772aef953c411c8fb38c063
