Before encoding a frame, calculate and store each 16x16 block's
variance of source difference between last and current frame.
Find partitioning threshold T for the frame from its variance
histogram, and then use T to make partition decisions.

Comparing with fixed 16x16 partitioning, rtc set test showed an
overall psnr gain of 3.242%, and ssim gain of 3.751%. The best
psnr gain is 8.653%.

The overall encoding speed didn't change much. It got faster for
some clips(for example, 12% speedup for vidyo1), and a little
slower for others.

Also, a minor modification was made in datarate unit test.

Change-Id: Ie290743aa3814e83607b93831b667a2a49d0932c

Change-Id: I38bb2801ad3f059d5e2eb6513eec92397c67abcd

Change-Id: I86451ddfa90d871e46e5b4c97794dbef65293c6c

Change-Id: Id51468f99f8970b8795ce2d254344f4b8d7817d0

Change-Id: I7f989d197444d166133ad91eb23ac1033109f58d

Change-Id: Ia9ac079d65fbd0a134e8d69c1f4ce171fe94bf64

x32 would never be detected unless an explicit CC= was used
fixes:
...: -E: command not found

Change-Id: I465fd7b0979f782053bdda240ad68edbca5658e5

the buffer is only used in encoding and only when
CONFIG_INTERNAL_STATS or CONFIG_VP9_POSTPROC is enabled.
a future change should decouple this from the frame buffer allocation
and make it conditional based on runtime flags when the above config
options are enabled.
reduces decode heap usage by at least 12%

Change-Id: Id0b97620d4936afefa538d3aadf32106743d9caf

This reverts commit b3363561.

This causes a hang in:
VP9/InvalidFileTest.ReturnCode/3

the change to test/user_priv_test.cc remains with a minor update

Change-Id: I4a8a272ca37ea329b0f413f0b1cd827a238bd9fd

As a way to speed-up rtc encoding at speed 7.

Change-Id: Ie36a010392cf7b741dc130df21a4e733622a75b7

To experiment with different speed/quality compromises.

Change-Id: Ia9d4b85243554d620498a327da37c356e752b07f

Encoding screen content exercises various fast skip paths that are
missed by natural video content.

Change-Id: Ie359884ef9be89cbe5dda6d82f1f79360604a090

Change-Id: Ib94ee638eb486f1368f2e3098d25c1d3d28fc265

This patch checks that a decoder never tries to reference frame that's
outside the range of 2x to 1/16th the size of this frame.  Any attempt
to do so causes a failure.

Change-Id: I5c98fa7bb95ac4f29146f29dd92b62fe96164e4c

Set the proper number of mb_rows/cols.
Also remove warnings (unused variable) when configured with temporal-denoising disabled.

Change-Id: I8abd2372394ee55295feb87a66efd294ea6989d0

Change-Id: Iee21eb0ecc5a1fe2c56fb3df0cee0ead6d139ed1

Bug introduced in I930dced169c9d53f8044d2754a04332138347409. If
svc.number_temporal_layers == 1 and svc.number_spatial_layers == 1, the system
attempt to do spatial SVC. It no longer does that.

Change-Id: Ie6b130a72b1eea40c547c9a64447e40695f811c5

Also added reset_frame_stats()

Change-Id: I8e6ca00dbd5fa85cd39485d81c9343c0ff207d6c