Modifies the comp inter-intra expt

Uses a single 1D table to implement the weighting of the predictors
for the compound inter-intra experiment.

Change-Id: I204ffbe4f9fc79d5d43b6c724ad253d800461012
Remove buffer-to-buffer copy logic

This is the first in a series of commits to add additional reference
frames to the codec. Each frame will be able to update any of the
available references, but copying between references is not
supported.

Change-Id: I5945b5ce6cc3582c495102b4e7eed4f08c44d5a1
Update encoder to use fb_idx_ref_cnt

Do reference counting the same way on the encoder as the decoder does,
rather than maintaining the 'flags' member of YV12_BUFFER_CONFIG.

Change-Id: I91dc210ffca081acaf9d5c09a06e7461b3c3139c
Start to anonymize reference frames

Remove lst_fb_idx, gld_fb_idx, alt_fb_idx, refresh_last_frame,
refresh_golden_frame, refresh_alt_ref_frame from common. Gold/Alt are
encode side conventions. From the decoder's perspective, we want to be
dealing with numbered references.

Updates to active_ref 2 signal mode context switches, vestigial from
refresh_alt_ref_frame. This needs some clean up to make sense with
increased numbers of reference frames, as well as reimplementing the
swapping of alt/golden which was previously done using the
buffer-to-buffer copy mechanism removed in an earlier commit.

Change-Id: I7334445158b7666f9295d2a2dd22aa03f4485f58
Generalize and increase frame coding contexts

Previously there were two frame coding contexts tracked, one for normal
frames and one for alt-ref frames. Generalize this by signalling the
context to use in the bitstream, rather than tieing it to the alt ref
refresh bit. Also increase the number of contexts available to 4, which
may be useful for temporal scalability.

Change-Id: I7b66daaddd55c535c20cd16713541fab182b1662
Preserve the previous golden frame on golden updates

This commit restores the quality lost when the buffer-to-buffer copy
logic was removed. Note that this is specific to the current use of
golden frames and will need rework when RTC functionality is added.

Change-Id: I7324a75acd96eafd9e0f9b8633d782e390d5dc21
a minor change to a portion of loop filtering

The loop filtering used for MB edge or internal edge of a MB using 8x8
tranform was reading 5 pixel each side and writting 3 pixel each side.
With suggestion from Aki and Scott on hardware&software performance,
this commit changed to read 4 pixel each side and write 3 pixel each
side.

Change-Id: I584393906c4f5f948a581d6590959522572743bb
Use alt-ref frame context for keyframes

This matches the behavior prior to generalizing the frame context
selection, and intuitively makes sense in that the first forward ref
is immediately after the keyframe, so it's quality is improved a bit
by using the keyframe's entropy context rather than the default.

Change-Id: Ia82cef79382b9d8cfafdc44ba0533d4dc3e44053
Merge changes Ia82cef79,I7324a75a,I7b66daad,I73344451,I91dc210f,I5945b5ce into experimental

* changes:
  Use alt-ref frame context for keyframes
  Preserve the previous golden frame on golden updates
  Generalize and increase frame coding contexts
  Start to anonymize reference frames
  Update encoder to use fb_idx_ref_cnt
  Remove buffer-to-buffer copy logic
Intrinsic version of loopfilter now matches C code

Updated the instrinsic code to match Yaowu's latest loopfilter change.
(I584393906c4f5f948a581d6590959522572743bb)

The decoder performance improved by ~30% for the test clip used.

Change-Id: I026cfc75d5bcb7d8d58be6f0440ac9e126ef39d2
Merge "Modifies the comp inter-intra expt" into experimental
Support multiple codecs in test infrastructure

This commit starts to convert the tests to a system where the codec
to be used is provided by a factory object. Currently no tests are
instantiated for VP9 since they all fail for various reasons, but it
was verified that they're called and the correct codec is
instantiated.

Change-Id: Ia7506df2ca3a7651218ba3ca560634f08c9fbdeb
Merge "Support multiple codecs in test infrastructure" into experimental
Adds an error-resilient mode with test

Adds an error-resilient mode where frames can be continued
to be decoded even when there are errors (due to network losses)
on a prior frame. Specifically, backward updates are turned off
and probabilities of various symbols are reset to defaults at
the beginning of each frame. Further, the last frame's mvs are
not used for the mv reference list, and the sorting of the
initial list based on search on previous frames is turned off
as well.

Also adds a test where an arbitrary set of frames are skipped
from decoding to simulate errors. The test verifies (1) that if
the error frames are droppable - i.e. frame buffer updates have
been turned off - there are no mismatch errors for the remaining
frames after the error frames; and (2) if the error-frames are non
droppable, there are not only no decoding errors but the mismatch
PSNR between the decoder's version of the post-error frames and the
encoder's version is at least 20 dB.

Change-Id: Ie6e2bcd436b1e8643270356d3a930e8989ff52a5
Merge "Intrinsic version of loopfilter now matches C code" into experimental
MSVS compiler error

Visual Studio reports and error on the line
  static const int bsize2 = bsize >> 1;

"error C2099: initializer is not a constant"

Also warnings on signed/unsigned mismatch

Change-Id: I76cb06f736bd9c90107a26bfb3c130ec3f6c33de
Merge "MSVS compiler error" into experimental
Mvref speedup

Quality / decode speed trade off changes.
Simpler insert method without sort. Quality impact small.

Change-Id: Id0c0941bc508d985405abd06a13ffe7489170b62
Remove "update_context" variable from VP9_COMP context.

The variable is always zero.

Change-Id: Id5cdbecad543bca465a5b1d471badaec7e112c8d
Added eob == 0 check to vp9_dequant_idct_add_32x32_c

Added a quick eob == 0 check.  Once the integer version of the dct32x32 is
complete, we can check for other eob cases.

For the 1080p clip used, the decoder performance improved by 4%.

Change-Id: I9390b6ed3c8be0c0c0a0c44c578d9a031d6e026e