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
Current setting had active_worst_quality set too high (close to worst_quality)
for first frame(s) following first key frame. This changes that to be somewhat
more aggressive in allowing active_worst_quality to be lower following key frame.
Also remove the 4/5 reduction in active_worst for key frame as
this should be set by the user qp_max setting.
Change-Id: I0530b3ddcc85c00e3eb7568de1b14a31206c4a4c
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
Rate correction factor is used to correct the estimated rate for any
given quantizer, and feeds into rate control for quantizer selection.
We make use of the actual bits used to calculate this rate correction
factor with an adjustment limit to prevent over-adjustment.
This commit adapts the adjustment limit to the difference between the
estimated bits and the actual bits, allows the adjustment limit to vary
between 0.125 (when estimate is close to actual) and 0.625 (when there
is >10X factor off between estimated and actual bits). By doing this,
the commit appears to have largely corrected two observed issues:
1. Adjustment is too slow when the actual bits used is way off from
estimate due to the small adjustment limit.
2. Extreme oscillating quantizer choices due to the feedback loop.
Change-Id: I4ee148d2c9d26d173b6c48011313ddb07ce2d7d6
I0c5f010 changed to allow update golden reference buffer in CBR mode,
this commit changes the use of rate_correction_factor for those frames
to be aligned with the new usage. This commit attempts to solve two
issues:
a. Initialization of rate correction factor for Golden Frame
Prior to this patch, even the regular inter frame has been update
the rate correction factor based on content and encoding results,
the first golden frame would still use the ininitialized value
that can be way off.
b. Allowing rate correction factor update to be slightly faster
Prior to this patch, when the rate correction factor is off, the
update to the factor is too slow, the factor could not get close
to a semi-correct value even after many frames.
The commit helps all clips in psnr/ssim metric, but especially to
a few clip in RTC set that rate correction was way off. For example
thaloundeskmtgvga gained about .5dB for both overall/average psnr.
Change-Id: I0be5c41691be57891d824505348b64be87fa3545
This commit changes to allow the usage of golden reference frame in
VP9 CBR mode to improve quality. VP9 supports potentially up to 8
reference buffers, it has reference buffers available for this
purpose. This was not possible in VP8 as golden and alt-ref buffers
were used for temporal scalability purpose in CBR mode in WebRTC.
For frames that update golden frame, there can be a quality boost.
The amount of allowed bitrate boost can be controlled via parameter
rc_max_inter_bitrate_pct. The inital value of the boost ratior is
currently based on over_shoot_pct. Further experiments will work
out the adaption of this boost value.
Change-Id: I0c5f010c8fd8b7b598f69779c1b30e5b2ac30a4d
Add second level arf Q adjustment when using dual arfs
in constant Q mode.
Previously in constant Q mode enabling dual arf hurt by ~5%
but with this change the average benefit is ~1-1.5% with some
mid range data points up ~10%.
Note however that it still hurts on some clips including
some very low motion show content.
Change-Id: I5b7789a2f42a6127d9e801cc010c20a7113bdd9b
This removes an unnecessary restriction that causes
a problem (noticed by AWG) when the forced key frame
interval is set to a very small value, such as 10. In this case
we were being forced to code minimal length GF groups.
Change-Id: I76ef5861a09638ff51f61fea02359554184ada53
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
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
Adjustments to the GF interval choice and minimum boost.
Adjustment to the calculation of 2 pass worst q.
Compared to 09/29 head there is metrics hit on derf of
(-0.123%,-0.191%)
Compared to the September 29 head and a baseline on
September 18 baseline the accuracy of the VBR rate control
measured on the derf set is as follows:-
Mean error % / Mean abs(error %)
Sept 18 baseline (-7.0% / 14.76%)
Sept 29 head (-15.7%, 19.8%)
This check in (-1.5% / 14.4%)
The mean undershoot is reduced slightly but the
worst case overshoot on e.g. harbour/highway is
increased. This will be addressed in a later patch.
Change-Id: Iffd9b0ab7432a131c98fbaaa82d1e5b40be72b58
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
It's built based on current spatial svc code.
We only support one spatial two temporal layers at this time.
Change-Id: I1fdc8584354b910331e626bfae60473b3b701ba1
We had a very complicated way to initialize cpi->pass from
cfg->g_pass:
switch (cfg->g_pass) {
case VPX_RC_ONE_PASS:
oxcf->mode = ONE_PASS_GOOD;
break;
case VPX_RC_FIRST_PASS:
oxcf->mode = TWO_PASS_FIRST;
break;
case VPX_RC_LAST_PASS:
oxcf->mode = TWO_PASS_SECOND_BEST;
break;
}
cpi->pass = get_pass(oxcf->mode).
Now pass is moved to VP9EncoderConfig and initialization is simple:
switch (cfg->g_pass) {
case VPX_RC_ONE_PASS:
oxcf->pass = 0;
break;
case VPX_RC_FIRST_PASS:
oxcf->pass = 1;
break;
case VPX_RC_LAST_PASS:
oxcf->pass = 2;
break;
}
Change-Id: I8f582203a4575f5e39b071598484a8ad2b72e0d9
1. Remove last reference flag for first frame upper layers in one pass mode.
2. Disable refresh golden frame flag for key frames.
Change-Id: I44ac1bd2c795169e4fbfdd078ea79a1d33a204d6
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
Add indirection to the section of buffer indices.
This is to help simplify things in the future if we
have other codec features that switch indices.
Limit the max GF interval for static sections to fit
the gf_group structures.
Change-Id: I38310daaf23fd906004c0e8ee3e99e15570f84cb
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
If we are already saving a lot in bits from the target (maximum)
bitrate in the constrained quality mode, allow the quantizer
to go lower than the cq level. This hopefully will solve issues
with getting too low a bitrate and consequently poor quality for
certain videos in cq mode.
Change-Id: I1c4e8b0171fcf58f95198b3add85eea5f3c8f19f
Allow slightly larger minq-maxq range for P frames. This improves
the compression performance of speed -5 for rtc set by 2.7% in psnr.
Change-Id: I438653d52d0fe51111509c6092e2334bac2de0cf
tx_mode supercedes whatever mechanism is used to push for 16x16
allowing for the use of the 4x4 transform.
Change-Id: I6c3f05ab9fe52050e40cc6303de9334653763289
Merged minq tables for arf and gf cases.
These tables were almost the same and for
VBR the arf table was not used at all.
Change-Id: Ie3c87e91dab613cf06f6945ac1ace0e0e4213d34
Small adjustment to the active Q range calculations.
These changes should slightly extend the available Q range
for KF/GF/ARF and narrow it for other frames.
The results for this change in isolation are broadly positive
for SSIM and average PSNR and slightly up but mixed for opsnr.
derf +0.293% opsnr, +1.286% SSIM
std-hd + 0.528% opsnr, + 1.746% SSIM
yt +0.056% opsnr, +0.457% SSIM
yt-hd -0.147% opsnr, + 0.226% SSIM
Change-Id: If065280342027ecc5d44b49fc1d440dfef041002
This member of VP9_COMP seemed unnecessary since it
only shadowed VP9EncoderConfig.key_freq that is
accessible through VP9_COMP.
Change-Id: Ib751bb1cf1b0b3c50a2a527d7c34f6829dd6fee3
The end_useage parameter is confusingly named since it
now actually defines the rate control method used.
Change-Id: I98912caabfe556b7af0b939a645d1336409e4d71
To make direct side by side testing this patch combines two
VBR corrections schemes to allow more direct side by side testing.
(The other patch was by Debargha chg id I0cd1f7...)
Change-Id: I271c45e5c4ccf8de8305589000218b80d9dc3a25
Add code to monitor over and under spend and
apply limited correction to the data rate of subsequent
frames. To prevent the problem of starvation or overspend
on individual frames (especially near the end of a clip) the
maximum adjustment on a single frame is limited to a %
of its un-modified allocation.
Change-Id: I6e1ca035ab8afb0c98eac4392115d0752d9cbd7f
Fix rate control bug whereby the rate factor heuristics
were being updated on arf overlays causing a rate surge
for a few frames followed by a corrective drop.
This fix eliminates many of the overshoot problems that
we were seeing on hard clips (even without applying
stricter vbr rate control) and also helps quality on
almost all clips with some hard clips improving by >5%.
Overall quality results measured at speed 2.
Derf +1.78% opsnr , +2.44% SSIM
Stdhd +2.41% opsnr, +2.85% SSIM
Change-Id: I2369df6295c2705963fa6307877f6acb304bcc39
This increases the range of Q values available to
normal inter frames to allow encoder a better chance
to hit the target rate.
Change-Id: I33cd96469a46577fdcea631e26d3355710909e6d
The limits applied under the flag
"LIMIT_QRANGE_FOR_ALTREF_AND_KEY"
behaved in an undesirable way if the gap between
active_worst_quality and active_best_quality was
changed.
In this patch, the adjustment is made using the
vp9_compute_qdelta_by_rate() function and fixed
rate multiplier values. Hence it is not impacted by
the relative value of active_best_quality.
Change-Id: I93b3308e04ade1e4eb5af63edf64f91cd3700249
ARF overlays now use the same rate correction factor as regular inter
frames, further testing would be needed to see if it makes sense to use
a completely separate rate correction factor for ARF overlays.
$ vpxenc --cpu-used=5 --fps=50/1 --target-bitrate=2000
parkjoy.y4m -o out.webm
=> Before: 3356 kb/s
=> After: 2271 kb/s
Change-Id: I73e4defa615ba7a8a2bdb845864f4b1721cbbffe
Turns off the DISABLE_RC_LONG_TERM_MEM macro and makes other changes
in the way the bits are updated, to make 2-pass rate control track
target bitrates closer.
Change-Id: I5f3be4b11c2908e6a9a9a1dd4fcf4e65531c44d8
