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

Remove damping parameter and use the damping
formula introduced by Yaowu Xu in all cases.

Change-Id: I18db7e0d0f262d5140102f259ab07821d374d285

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

ioc found a potential integer overflow in the rate control.

This is related to https://code.google.com/p/webm/issues/detail?id=821

Change-Id: Ib6c4acd6e964972f932fce7490592eb134f2b7ea

For a few refresh periods after key frame, use large qp-delta
to increase quality ramp-up.

Change-Id: Ib5a150fb2dfa6bafd0d4e6b5d28dfd0724b61319

Incorporate segment delta-q into estimated bits.
This generally improves the rate control under cyclic refresh (aq=3) mode.

Change-Id: I1dc60fb230e7d08357fae18909d8ed27bf58e037

When the golden frame is boosted, the rate correction factor is not
correlated well with other inter frames even in CBR mode. This commit
changes to use GF specific rate_correction_factor when gf_cbr_boost
is greater than 20%.

Change-Id: I6312c1564387bcacc11f4c5e8a9cfdc781b5c3ab

VP9/DatarateTestVP9Large.ChangingDropFrameThresh/[34] fails post the
merge of commit#ffa06b37. This commit adds reset of rc tracking info
when frame is dropped, and fixes the causes of the bad interaction
between the tests and the previous commit.

Change-Id: I848acfd9fcb336359662274325190f94aac76eae

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

Change-Id: I205de3611622cff7f751ea8baf9f82784581730a

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

This reverts commit 869d4ca5.

This breaks the build via conflict with
e18edd5e.

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

Change-Id: Ie69a164bc166b6a8819777038d65a7d9f9c3361f

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

Adds various high bitdepth quantization functions.

Change-Id: I36fc0bf75a1bd15128ed271df8723de0ac134b0c

It's built based on current spatial svc code.
We only support one spatial two temporal layers at this time.
Change-Id: I1fdc8584354b910331e626bfae60473b3b701ba1

Change-Id: Iacc0b5c58032bde372ed9f99b87712547c4d8454

Alter way in which we identify static scenes.
Remove some redundant code.

Change-Id: I883c2ea2e341770648a8663d8881f720ed099b61

Framerate changes over time, VP9EncoderConfig supposed to have static
read-only data.

Change-Id: I36580a7ee71243c1eabb57691089691731d03e67

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

Change-Id: Ice5376100d8e27cbdaddfd3cd06898cedd2720fe

[spatial svc]Enabl golden frame for base layer and fix wrong ref_frame_flag for upper layers in first frame

Change-Id: I1fec9c084b499b2f445b79726066d01b136b59fa

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

Change-Id: I53db06acf5bc434f9584136b848322f5870300b3

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

Adjust enforced minimum arf Q deltas for non primary arfs
in the middle of an arf/gf group.

Change-Id: Ie8034ffb3ac00f887d74ae1586d4cac91d6cace2

Remove the old experimental multi arf code that was under
the flag CONFIG_MULTIPLE_ARF.

Change-Id: Ib24865abc11691d6ac8cb0434ada1da674368a61

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

Both enums are identical.
Change-Id: I06653f9c90a2d3a2dd5c741e75b17ee7d066a56f

Change-Id: I54cdb4ce11590511e6f86bc2fd55771f1c18a20a