For large dynamic changes in target avg_frame_bandwidth, or
a change in resolution, via the update in change_config()),
reset the under/overshoot flags (rc_1_frame, rc_2_frame)
to prevent constraining the QP for the first few frames
following the change.
For SVC use the spatial stream avg_frame_bandwidth in
reset condition.
For the avg_frame_bandwidth condition, use fairly large
threshold (~50%) for now in reset.
This allows for better/faster QP response if, for example,
application dynamically changes bitrate by large amount.
Change-Id: Ib6e3761732d956949d79c9247e50dba744a535c0
Added command line control of Corpus VBR.
The new corpus vbr mode is a variant of standard
VBR (end-usage=0) where the complexity distribution
mid point is passed in rather than calculated for a specific
clip or chunk.
The new variant is enabled by setting a new command line
parameter --corpus-complexity to a zero value. Omitting
this parameter or setting it to 0 will cause the codec to use
standard vbr mode.
The correct value for a given corpus needs to be derived
experimentally using a training set such that the average
rate for the corpus is close to the target value.
For example our using our low res test set with upper and lower
vbr limits of 50%-150% and a corpus complexity value of 650
gives a similar average data rate across the set to using standard
vbr. However, with the corpus mode easier clips will be allocated
fewer bits and harder clips more bits rather than having the same
rate target for all.
Change-Id: I03f0fc8c6fb0ee32dc03720fea6a3f1949118589
The initial allocation of bits in the two pass code to each frame
should be within the min max limits on the command line. However,
when forming an ARF group the cost of the ARF is shared by frames
in that group such that the residual bits for a frame could drop below
the min value. This change prevents the minimum being re-applied
after the cost of the ARF has been deducted as this may otherwise
cause low rate sections to overshoot their target.
Test runs comparing to a baseline run with min and max section pct
0-2000% vs one closer to the YT use case (50-150%) suggest that
this fix not only results in better rate control but also gives a better
rd outcome.
For example the HD set vs 0-2000% baseline (opsnr, ssim).
Old code (50-150): +0.751, +1.099
New code(50-150): +0.241, -0.009
Change-Id: I715da7b130bf53ba8aa609532aa9e18b84f5e2ef
This patch makes further changes to support an experimental
corpus wide VBR mode that uses a corpus complexity
number as the midpoint of the distribution used to allocate bits
within a clip, rather than some average error score derived from the
clip itself.
At the moment the midpoint number is hard wired for testing and
the mode is enabled or disabled through a #ifdef. Ultimately this
would need to be controlled by command line parameters.
Change-Id: I9383b76ac9fc646eb35a5d2c5b7d8bc645bfa873
Add stats for past ARF usage, and use it to disable
ARF usage based on some conditions.
Overall improvement on ytlive set, reduces the regression
on the problem clips for this feature.
Only affects when sf->use_altref_onepass is enabled
(currently off by default).
Change-Id: I66267f227ea132dc86acb730e9882f85bead2cdb
Use the scene detection for CBR mode, and use it to reset the
rate control if large source sad is detected and rate
correctioni fact/QP is at minimum state.
Avoids large frame sizes after big content change following
low content period.
Only affects CBR mode for 1 pass at speeds 5, 6, 7.
Change-Id: I56dd853478cd5849b32db776e9221e258998d874
Refactor to split the 1 passs source sad computation into scene
detection (currently used for VBR and screen-content mode), and
superblock based source sad computation (used in non-rd CBR mode).
This allows the source sad computation for CBR mode to be
multi-threaded.
No change in compression.
Change-Id: I112f2918613ccbd37c1771d852606d3af18c1388
VBR method that allows a wider Q range for the first normal frame
in each ARF group and then centers the min - max range for the rest of
the arf group on the chosen Q value for that first frame.
This allows for quite rapid adjustment of the active Q range even if the
initial estimate is poor.
In some cases where the ARF frames themselves are tending to
undershoot but the normal frames are overshooting this can still give
net undershoot. This can be corrected by allowing a larger Q delta for
arf frames but is usually is a sign that the allocation to the arfs was to
high.
Change-Id: Icec87758925d8f7aeb2dca29aac0ff9496237469
The fix relaxes the max qindex based on the data from previous loop of
coding if output frame size is greater than maximum frame size allowed
Change-Id: Iac1f63ec67559d68766e090a7cbb80b812b2560f
For 1 pass vbr real-time mode:
Allow for the usage of alt-ref frame when non-zero lag-in-frames is used.
Use non-filtered alt-ref, and select usage based on fast scene/content
analysis/detection within the lag of frames.
Positive gains on ytlive set: overall avgPSNR ~3-4%.
Several clips are up between 5-14%, a few clips are neutral/small change.
Current speed decrease is about ~5-10%.
Use the flag USE_ALTREF_FOR_ONE_PASS to enable this feature
(off by default for now).
Change-Id: I802d2bf3d44f9cf01f6d15c76be9c90192314769
Allow usage of lookahead for VBR in real-time mode, for 1 pass vbr.
Current usage is for fast checking of future scene cuts/changes,
and adjusting rate control (gf interval and active_worst/target size).
Added unittests (datarate) for 1 pass vbr mode, with non-zero lag.
Added an experimental option to limit QP based on lookahead.
Overall positive gain in metrics on ytlive set:
avgPNSR/SSIM up on average ~1-3%; several clips up by 5, 7%.
Change-Id: I960d57dfc89de121c4824b9a9bf88d2814e74b56
Modify the gfu_boost and af_ratio setting based on the
average frame motion level.
Change only affects 1 pass vbr.
Metrics overall positive on ytlive set.
On average up by ~1%, several clips up by 2-4%.
Change-Id: Ic18c49eb2df74cb4986b63cdb11be36d86ab5e8d
Code cleaup, use existing rolling_actual/target metrics instead,
set threshold to get same/similar effect.
Little/no change in metrics on ytlive set.
Change-Id: I74f3c3d0a143a9cf20dc9c3dee54c0f7e6a97a51
Rename and change to how its updated.
Only affects 1 pass vbr.
Small change in metrics (< ~0.1%) on ytlive set.
Change-Id: Ibb1fe485699b6c4a8194951c8f229abe2f64b9a5
For 1 pass vbr mode.
Increase the gf interval for case where average Q is close to
max and high overshoot is detected.
Small increase in overall avg_psnr/sssim metrics (~0.2/0.1%) for ytlive,
but improves the low-end (low bitrate) for several clips (less overshoot).
Change-Id: Ifba40f25b4861b2e0d9832c82d5359a6a3dce9f2
Change recursive weight for average_source_sad and
put some constraint on spacing between detected scene-cuts.
Change only affects 1 pass real-time mode.
Change-Id: I1917e748d845e244812d11aec2a9d755372ec182
For testing implemented a fixed pattern and delta, 1 pass,
fixed Q, low delay mode.
This has not in any way been tuned or optimized.
Change-Id: Idf5ee179b277fa15d07a97f14f2ce5bbaae80a04
Dynamic resizing now support two-steps scaling: first go down to
3/4 and then 1/2. This feature is under a flag which controls the
switch between two-steps scaling and one-step scaling (1/2 only).
Change-Id: I3a6c1d3d5668cf8e016a0a02aeca737565604a0f
For 1 pass CBR mode under screen content mode:
if pre-analysis (source temporal-sad) indicates significant
change in content, then check the projected frame size after
encode_frame(), and if size is above threshold, force re-encode
of that frame at max QP.
Change-Id: I91e66d9f3167aff2ffcc6f16f47f19f1c21dc688
Adds two new vp9 parameters --min-gf-interval and --max-gf-interval
to enable testing based on frequency of alt-ref frames.
Also adds a unit-test to test enforcement of min-gf-interval.
For both these parameters the default value is 0, which indicates
they are picked by the encoder, based on resolution and framerate
considerations. If they are greater than zero, the specified
parameter is honored.
(Additional note by paulwilkins)
Note that there is a slight oddity in that key frames are also GFs and
considered part of GF only group. However they are treated as not
being part of an arf group because for arf groups the previous GF is
assumed to be the terminal or overlay frame for the previous group.
(end note)
Change-Id: Ibf0c30b72074b3f71918ab278ccccc02a95a70a0
Decision to scale down/up is based on buffer state and average QP
over previous time window. Limit the total amount of down-scaling
to be at most one scale down for now.
Reset certain quantities after resize (buffer level, cyclic refresh,
rate correction factor).
Feature is enable via the setting rc_resize_allowed = 1.
Change-Id: I9b1a53024e1e1e953fb8a1e1f75d21d160280dc7
This patch provides a partial rapid feedback of bits
resulting from extreme undershoot.
Some improvement on some problem animated material
but in its current form only a small impact on the metrics results
of our standard test sets.
Change-Id: Ie03036ea8123bc2553437cb8c8c9e7a9fc5dac5d
Previously limit on max interval set to 0.5 seconds.
Though this helped some low frame rate material it
appears to be a bit too aggressive for some 24 and 25 fps
content. This patch relaxes the limit to 0.75 seconds.
The patch also adds a new minimum interval variable
to replace the current hard wired value. This allows us
to impose a limit on the maximum number of primary
arfs per second for high frame rate (e.g. 50 & 60fps)
content. This is to address concerns regarding playback
performance on some platforms if there is a high base
frame rate and very frequent arfs.
Change-Id: I373e8b6b2a8ef522eced6c6d2cceb234ff763fcf
Note: This feature is still in development.
Add an option for the encoder to decide the resolution
at which to encode each frame.
Each KF/GF/ARF goup is tested to see if it would be
better encoded at a lower resolution. At present, each
KF/GF/ARF is coded first at full-size and if the coded
size exceeds a threshold (twice target data rate) at
the maximum active Q then the entire group is encoded
at lower resolution.
This feature is enabled in vpxenc by setting:
--resize-allowed=1
In addition, if the vpxenc command line also specifies
valid frame dimensions using:
--resize-width=XXXX & --resize_height=YYYY
then *all* frames will be encoded at this resolution.
Change-Id: I13f341e0a82512f9e84e144e0f3b5aed8a65402b
Just before a forced key frame we often get a foreshortened
arf/gf group. In such a case, we do not want to update
rc->last_boosted_qindex, which is used to define the Q range
for the forced key frame itself.
This gives a small average metrics gain for the YT and YT-HD sets
(eg. YT SSIM +0.141%).
Change-Id: Ie06698bc4f249e87183b8f8fb27ff8f3fde216d9
Incorporate segment delta-q into estimated bits.
This generally improves the rate control under cyclic refresh (aq=3) mode.
Change-Id: I1dc60fb230e7d08357fae18909d8ed27bf58e037
In rare cases, the interaction between rate correction factor and Q
choices may cause severe oscillating frame sizes that are way off
target bandwidth. This commit adds tracking of rate control results
for last two frames, and use the information to prevent oscillating
Q choices.
Change-Id: I9a6d125a15652b9bcac0e1fec6d7a1aedc4ed97e
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
Allow min and maxQ to creep when the undershoot
or overshoot exceeds thresholds controlled by the
command line under_shoot_pct and over_shoot_pct
values.
Default is 100%,100% which ~disables adaptation.
Derf results for example undershoot% / overshoot%:-
Head:- Mean abs (%rate error) = 14.4%
This check in:-
25%/25% - Mean abs (%rate error) = 6.7%
PSNR hit -1% SSIM -0.1%
5% / 5% - Mean abs (%rate error) = 2.2%
PSNR hit -3.3% SSIM - 1.1%
Most of the remaining error and most of the quality hit is
at extreme data rates. The adaptation code still has an
exception for material that is in effect static so that we
don't over adjust and over spend on YT slide show type
content.
(Rebase of If25a2449a415449c150acff23df713e9598d64c9
to resolve a auto-merge error)
Change-Id: Iec4e1613ef0d067454751d8220edb7058dfbd816
This reverts commit 869d4ca51957614dcf5093ebb9e322cc8a8405ca.
This breaks the build via conflict with
e18edd5eb651f9b7563cbd829744807402bfe0d8.
Change-Id: If544b99e367a449452834eb8cce600f58c34ec0d
Allow min and maxQ to creep when the undershoot
or overshoot exceeds thresholds controlled by the
command line under_shoot_pct and over_shoot_pct
values.
Default is 100%,100% which ~disables adaptation.
Derf results for example undershoot% / overshoot%:-
Head:- Mean abs (%rate error) = 14.4%
This check in:-
25%/25% - Mean abs (%rate error) = 6.7%
PSNR hit -1% SSIM -0.1%
5% / 5% - Mean abs (%rate error) = 2.2%
PSNR hit -3.3% SSIM - 1.1%
Most of the remaining error and most of the quality hit is
at extreme data rates. The adaptation code still has an
exception for material that is in effect static so that we
don't over adjust and over spend on YT slide show type
content.
Change-Id: If25a2449a415449c150acff23df713e9598d64c9
Substantial restructuring of the way we estimate
the rate of decay in prediction quality and determine
the arf interval and amount of boost used.
Also other changes to support moving to a lower first pass
Q which exposes some new features and allows us to better
distinguish genuinely static blocks from low motion or noisy
blocks.
Net gains now visible on all the test sets with std-hd PSNR up
1.87%. There are still some bad outlier cases but most of these
are low motion or slide show type content where the metrics
are already high at any given rate. The best + case is up by
more than 10%.
Change-Id: I18e25170053bdf3188f493ff8062f48a74515815
All changes are for spatial svc only.
1. Enable encoding hidden frames in each layer and use alt reference idex to reference the hidden frame in each layer
2. Use golden reference idx for spatial reference
3. For those layers that don't have hidden frames (caused by lack of frame buffers), reference a hidden frame in lower layers
4. Add "auto-alt-refs" in svc options
Change-Id: Idf27d1fd2fb5f3ffd9e86d2119235e3dad36c178
This patch implements a mechanism for inserting a second
arf at the mid position of arf groups.
It is currently disabled by default using the flag multi_arf_enabled.
Results are currently down somewhat in initial testing if
multi-arf is enabled. Most of the loss is attributable to the
fact that code to preserve the previous golden frame
(in the arf buffer) in cases where we are coding an overlay
frame, is currently disabled in the multi-arf case.
Change-Id: I1d777318ca09f147db2e8c86d7315fe86168c865
