Use pixel domain distortion metric in speed 0. This improves the
compression performance by 0.3% for both low and high resolution
test sets.
Change-Id: I5b5b7115960de73f0b5e5d0c69db305e490e6f1d
1. Skip golden non-zeromv and newmv-last for bsize >= 16x16 if the
temporal variance obtained from choose_partitioning is very low.
2. Skip horz and vert INTRA mode for speed 8.
This change works best on the clips with little noise and with some
motion (e.g. gips_motion which has > 5% speed up). PSNR drop is 1.78%
on rtc test set, no obvious visual quality regression found.
Change-Id: Ib43b5b20e67809d03c5a6890818ddff59e1fc94a
Skip intra-mode and some inter-modes (newmv, nearmv, nearestmv) for
golden frame if the variance got from choose_partitioning is very low.
Only for 1 pass real-time CBR mode and bsize >= 32x32, it has ~2.5%
speed up with less than 0.1% PSNR drop for rtc test set. Don't see
visual regression.
Change-Id: I70efbc95a1007231ae36f02c5b2fbf6cd35077ad
+5.857% BD-RATE on SCREEN_CONTENT
Leaving this off for non-screen content because:
+25.300% on TWITCH120
+37.833% BD-RATE on RTC
Change-Id: Ie0a312182d6cc859fb04298e4cd81d02b39e23fe
In inter mode search skip all modes except NEARESTMV and DC_PRED.
10% less encode latency for large frames using the chromium remoting_perftests.
+0.313% BDRATE on the screencast set at speed -6.
Change-Id: Ib97a39dd8bcdeab545509e0e02d78ce7033f8c63
Small changes to the best quality default speed trade off.
Some speedup settings are worth while even for best quality as they
have only a very small impact on quality but a significant impact on
encode time.
These changes give as much as a further 50-60% increase in encode
speed for my test animations clip with minimal impact on quality.
For this sequence these changes improve the best quality encode speed
to about the same level as good quality speed 0 in Q3 2015 whilst
retaining the large quality gain of over 1 db
For many natural videos though the quality difference from good 0
to best is much smaller.
Change-Id: I28b3840009d77e129817a78a7c41e29cb03e1132
This change alters the nature and use of exhaustive motion search.
Firstly any exhaustive search is preceded by a normal step search.
The exhaustive search is only carried out if the distortion resulting
from the step search is above a threshold value.
Secondly the simple +/- 64 exhaustive search is replaced by a
multi stage mesh based search where each stage has a range
and step/interval size. Subsequent stages use the best position from
the previous stage as the center of the search but use a reduced range
and interval size.
For example:
stage 1: Range +/- 64 interval 4
stage 2: Range +/- 32 interval 2
stage 3: Range +/- 15 interval 1
This process, especially when it follows on from a normal step
search, has shown itself to be almost as effective as a full range
exhaustive search with step 1 but greatly lowers the computational
complexity such that it can be used in some cases for speeds 0-2.
This patch also removes a double exhaustive search for sub 8x8 blocks
which also contained a bug (the two searches used different distortion
metrics).
For best quality in my test animation sequence this patch has almost
no impact on quality but improves encode speed by more than 5X.
Restricted use in good quality speeds 0-2 yields significant quality gains
on the animation test of 0.2 - 0.5 db with only a small impact on encode
speed. On most clips though the quality gain and speed impact are small.
Change-Id: Id22967a840e996e1db273f6ac4ff03f4f52d49aa
Changes to the breakout behavior for partition selection.
The biggest impact is on speed 0 where encode speed in
some cases more than doubles with typically less than 1%
impact on quality.
Speed 0 encode speed impact examples
Animation test clip: +128%
Park Joy: +59%
Old town Cross: + 109%
Change-Id: I222720657e56cede1b2a5539096f788ffb2df3a1
For non-rd mode (speed >=5): use mask based on prediction block size, and
(for non-screen content mode) allow for checking horiz and vert intra modes
for blocks sizes < 16x16.
Avg psnr/ssim metrics go up by about ~0.2%.
Only allowing H/V intra on block sizes below 16x16 for now, to keep
encoding time increase very small, and also when allowing H/V on 16x16 blocks,
metrics went down on a few clips which need to be further examined.
Change-Id: I8ae0bc8cb2a964f9709612c76c5661acaab1381e
Impose a limit on the rd auto partition search based on
the image format. Smaller formats require that the search
includes includes a smaller minimum block size.
This change is intended to mitigate the visual impact of
ringing in some problem clips, for smaller image formats.
Change-Id: Ie039e5f599ee079bbef5d272f3e40e2e27d8f97b
Remove one of the auto partition size cases.
This case can behaves badly in some types of animated content
and was only used for the rd encode path. A subsequent patch
will add additional checks to help further improve visual quality.
Change-Id: I0ebd8da3d45ab8501afa45d7959ced8c2d60ee4e
This is to avoid redo the same calculation repeatly, and also allow
easier adjustments for further experiments.
This commit shall have no effect on quality/compression.
Change-Id: I4460acf5c808ff5518da18d21e002c5da58af857
This commit reworks the ONE_LOOP_REDUCED coefficient probability
model update process. It allows model update for every coefficient
across the spectrum at a coarser resolution, instead of performing
precise update only for certain subset of probability models.
The overall runtime remains nearly same (<1% change) for speed -6.
The compression performance is improved by 7.5% in PSNR for speed
-5 and 4.57% for speed -6, respectively.
Change-Id: Ifb17136382ee7e39a9f34ff4a4f09a753125c8d1
The max_partition_size and max_partition_size are set at the
beginning while setting speed features, and then adjusted at
SB level. Moving them to mb struct ensures there is a local
copy for each thread.
Change-Id: I7dd08dc918d9f772fcd718bbd6533e0787720ad4
Prepare for the introduction of frame-size change
logic into the recode loop.
Separated the speed dependent features into
separate static and dynamic parts, the latter being
those features that are dependent on the frame size.
Change-Id: Ia693e28c5cf069a1a7bf12e49ecf83e440e1d313
Its functionality has been replaced with choose_partitioning and
threshold based control on split mode check.
Change-Id: Ic9bb321df06b524f5c38ea5874dc6f6a8f93c5e3
This speed feature has been deprecated in both yt and rtc coding
modes. This commit removes the related operations.
Change-Id: I079c79c6adafe45581af2ebf8b98faebcface1ce
- Some fixes to surface fit.
- Returns variance function as cost rather than sad in the
pattern search and diamond search functions. Only
vp9_pattern_search_sad function used in bigdia search
uses sad as integer 1-away costs.
- Deploys SUBPEL_TREE_PRUNED_MORE for speed 4+.
Results:
derf [Speed 3]: About +0.036% in coding efficiency without any
discernible speed loss.
derf [Speed 4]: About 2-3% faster at -0.199% loss in coding efficiency.
derf [Speed 5]: About 3-4% faster at -0.149% loss in coding efficiency.
Change-Id: I8462f94f6adb46966ca964f2bd0400977357fd63
The concept:
There's too much noise in source pixels for variance and at low bitrate
the reconstructed looks nothing like the source so we have problems
getting good partitionings with either. This skirts the issue by using
a box blur scaled down version for variance calculations. To compare
against source_var_ moved keyframe to be rd based like source_var.
Change-Id: Ie3babdbfadae324b7b5a76bea192893af27f0624
One is a more aggressive version of the pruned subpel tree
search where only a single halfpel candidate is searched.
The search candidate is based on a surface fit result.
The other is a method to obtain the subpel position at one
shot based on the same surface fit.
The methods have not been deployed in any speed setting yet.
Change-Id: I34fef3f2e34f11396c9d1ba97f4be8c4ffca62d3
This patch re-enabled the feature in Pengchong's patch
(commit 1286126073). Originally, it
was turned on while use_lastframe_partitioning > 0(not used anymore).
Now it was added as a feature, and turned on while speed >= 2.
As described in the original patch, this feature helps speed up the
slideshows in YouTube.
Change-Id: I1b0f18d65da1ee1c8d1e117dabba910c5207c471
The speed feature that skips compound inter prediction modes was
subsumed by other speed features and effectively was not in use.
This commit removes it.
Change-Id: I22b0c71a8ddd15d93b25d86fa63a1dce2ba6a1a9
This commit refactor the rate-distortion optimization search for
regular block sizes to remove the speed feature dependency on mode
search order.
Change-Id: Ied033ee484c2957e17baa7b6450b720fe7dd0e7d
This commit allows encoder to skip intra coding mode test, when
the known inter residual is less than the source variance. It
reduces the runtime of speed 3 for test clips:
bus cif 1000 kbps: 8587 ms -> 8260 ms, 3.8% speed-up
pedestrian 1080p 2000 kbps: 161381 ms -> 155241 ms, 3.7% speed-up.
The compression performance is down by
derf -0.36%
stdhd -0.25%
Change-Id: I75ce1e035b4da2153cb1ac14111d1a07c05a735d
In the partition search, the encoder checks all possible
partitionings in the superblock's partition search tree.
This patch proposed a set of criteria for partition search
early termination, which effectively decided whether or
not to terminate the search in current branch based on the
"skippable" result of the quantized transform coefficients.
The "skippable" information was gathered during the
partition mode search, and no overhead calculations were
introduced.
This patch gives significant encoding speed gains without
sacrificing the quality.
Borg test results:
1. At speed 1,
stdhd set: psnr: +0.074%, ssim: +0.093%;
derf set: psnr: -0.024%, ssim: +0.011%;
2. At speed 2,
stdhd set: psnr: +0.033%, ssim: +0.100%;
derf set: psnr: -0.062%, ssim: +0.003%;
3. At speed 3,
stdhd set: psnr: +0.060%, ssim: +0.190%;
derf set: psnr: -0.064%, ssim: -0.002%;
4. At speed 4,
stdhd set: psnr: +0.070%, ssim: +0.143%;
derf set: psnr: -0.104%, ssim: +0.039%;
The speedup ranges from several percent to 60+%.
speed1 speed2 speed3 speed4
(1080p, 100f):
old_town_cross: 48.2% 23.9% 20.8% 16.5%
park_joy: 11.4% 17.8% 29.4% 18.2%
pedestrian_area: 10.7% 4.0% 4.2% 2.4%
(720p, 200f):
mobcal: 68.1% 36.3% 34.4% 17.7%
parkrun: 15.8% 24.2% 37.1% 16.8%
shields: 45.1% 32.8% 30.1% 9.6%
(cif, 300f)
bus: 3.7% 10.4% 14.0% 7.9%
deadline: 13.6% 14.8% 12.6% 10.9%
mobile: 5.3% 11.5% 14.7% 10.7%
Change-Id: I246c38fb952ad762ce5e365711235b605f470a66
Updates the vp9_pattern_search function to return integer one-away
neighbors' sad values, for subsequent use in speeding up the
sub-pel search. Also, removes code for the do_refine option
which is not being used currently.
Updates the integer and subpel functions to pass in a 5-element
sad list for output or input.
A new pruned sub-pel search algorithm is implemented that uses
the sad returned from the integer pel search. But it is not
deployed yet.
Change-Id: Ifa9f5ad024b5b660570366d2bd900343e1891520
This commit addes a new strategy to reduce the search for optimal
interpolation filter type. The encoder counts and store how many each
filter type is selected and used for each of the reference frames.
A filter type that is rarely used for all three reference frames is
masked out to avoid computation.
The impact on compression is neglectible:
-0.02% on derf
+0.02% on stdhd
Encoding time is seen to reduce by 2~3%.
Change-Id: Ibafa92291b51185de40da513716222db4b230383
In the full-rd transform size search, we go through all transform
sizes to choose the one with best rd score. In this patch, an
early termination is added to stop the search once we see that the
smaller size won't give better rd score than the larger size. Also,
the search starts from largest transform size, then goes down to
smallest size.
A speed feature tx_size_search_breakout is added, which is turned off
at speed 0, and on for other speeds. The transform size search is
turned on at speed 1.
Borg test results:
1. At speed 1,
derf set: psnr gain: 0.618%, ssim gain: 0.377%;
stdhd set: psnr gain: 0.594%, ssim gain: 0.162%;
No noticeable speed change.
3. At speed 2,
derf set: psnr loss: 0.157%, ssim loss: 0.175%;
stdhd set: psnr loss: 0.090%, ssim loss: 0.101%;
speed gain: ~4%.
Change-Id: I22535cd2017b5e54f2a62bb6a38231aea4268b3f
This commit enables the encoder to record the location of the
center frame to generate alter reference frame. It then allows to
skip checking prediction modes of other reference frame types when
it comes to encode this frame.
The speed 3 runtime is reduced for the test sequences:
bus at CIF 1000 kbps, 9791 ms -> 9446 ms, i.e., 3.5% speed-up,
pedestrian at 1080p 2000 kbps, 184043 ms -> 175730 ms, i.e., 4.5%
speed-up.
No compression performance change observed.
Change-Id: Iacfde3bcc1445964e7a241f239bd6ea11cb94bd1
Add a speed feature to give the tighter partition search
range. Before partition search, calculate the histogram
of the partition sizes of the left, above and previous
co-located blocks of the current block. If the variance of
observed partition sizes is small enough, adjust the search
range around the mean partition size, which will be tigher.
The feature is currently turned on at speed 2. Experiments on
sample youtube clips show on average the runtime is reduced
by 3-7%.
For hard stdhd clips:
park_joy_1080p @ 15000kbps: 509251 ms -> 491953 ms (3.3%)
pedestrian_area_1080p @ 2000kbps: 223941 ms -> 214226 ms (4.3%)
The PSNR performance is changed:
derf: -0.112%
yt: -0.099%
hd: -0.090%
stdhd:-0.102%
Change-Id: Ie205ec5325bf92ec5676c243e30ba9d0adca10f2
This commit allows the encoder to check the above and left neighbor
blocks' reference frames and motion vectors. If they are all
consistent, skip checking the NEARMV and ZEROMV modes. This is
enabled in speed 3. The coding performance is improved:
pedestrian area 1080p at 2000 kbps,
from 74773 b/f, 41.101 dB, 198064 ms
to 74795 b/f, 41.099 dB, 193078 ms
park joy 1080p at 15000 kbps,
from 290727 b/f, 30.640 dB, 609113 ms
to 290558 b/f, 30.630 dB, 592815 ms
Overall compression performance of speed 3 is changed
derf -0.171%
stdhd -0.168%
Change-Id: I8d47dd543a5f90d7a1c583f74035b926b6704b95
This commit enables a chessboard pattern constrained partition
search for 720p and above resolutions. The scheme applies stricter
partition search to alternative blocks based on its above/left
neighboring blocks' partition range, as well as that of the
collocated blocks in the previous frame. It is currently turned
on at 16x16 block size level. The chessboard pattern is flipped
per coding frame.
The speed 3 runtime is reduced:
park_joy_1080p, 652832 ms -> 607738 ms (7% speed-up)
pedestrian_area_1080p, 215998 ms -> 200589 ms (8% speed-up)
The compression performance is changed:
hd -0.223%
stdhd -0.295%
Change-Id: I2d4d123ae89f7171562f618febb4d81789575b19
This commit enables a chessboard pattern prediction filter type
search scheme for rate-distortion optimization speed-up. For the
inferred motion vector modes, the encoder can re-use its above/left
neighbor blocks' prediction filter type and skip a full test on
all possible filter types. Such operation is turned on/off
alternatively in a chessboard manner.
It is turned on in speed 3. For test clip pedestrian 1080p, the
runtime is reduced from 231500 ms -> 221700 ms. The compression
performance is changed:
derf: -0.147%
yt: -0.134%
hd: -0.079%
stdhd: -0.220%
Change-Id: I1912f278e7576c2dc632688e3ad7a257410c605a
This commit changed the hard-coded DEFAULT_INTERP_FILTER to a speed
feature with the same default value: SWITCHABLE.
Change-Id: I7f54f40f1bd3f5277841d04b85db7a84e47313f1
* Replace max_step_search_steps with constant MAX_MVSEARCH_STEPS
* Fold (reduce_first_step_size + speed > 5) into reduce_first_step_size
replacing uses of reduce_first_step_size that don't add the speed
check with zero.
Change-Id: Iae46395dbf3eaca138bf4d18b838a9e364b5a198
This commit added a speed feature to control the step_param used in
full pixel motion search. The intention is to reduced the search
steps for high speed real time coding.
Change-Id: I21d2f0105c2b647783a6688615da7fcf2b6d670b
