This allows for faster SIMD implementations in the future (currently
there is no speed impact).

Change-Id: I732647e9148b5dcb44e6bc8728138f0141218329

Change-Id: I8508f1a3d3430f998bb9295f849e88e626a52a24

7.5% faster overall encoding.

Change-Id: Ie9bb7f9fdf93659eda106404cb342525df1ba02f

Indentation was off by 2 spaces for this particular block.

Change-Id: I1e587b7ad3eff77ade5521252d20c7bb2daa0f6d

      Unreachable code
  that does nothing anyway
      removed forever.

Change-Id: I14105d2dd9dbc9d558f36464055e350dbeb45488

Change-Id: I8ecc178b4d4069e721c7fec6d7631c00e4a3e5d5

This patch adds column-based tiling. The idea is to make each tile
independently decodable (after reading the common frame header) and
also independendly encodable (minus within-frame cost adjustments in
the RD loop) to speed-up hardware & software en/decoders if they used
multi-threading. Column-based tiling has the added advantage (over
other tiling methods) that it minimizes realtime use-case latency,
since all threads can start encoding data as soon as the first SB-row
worth of data is available to the encoder.

There is some test code that does random tile ordering in the decoder,
to confirm that each tile is indeed independently decodable from other
tiles in the same frame. At tile edges, all contexts assume default
values (i.e. 0, 0 motion vector, no coefficients, DC intra4x4 mode),
and motion vector search and ordering do not cross tiles in the same
frame.
t log

Tile independence is not maintained between frames ATM, i.e. tile 0 of
frame 1 is free to use motion vectors that point into any tile of frame
0. We support 1 (i.e. no tiling), 2 or 4 column-tiles.

The loopfilter crosses tile boundaries. I discussed this briefly with Aki
and he says that's OK. An in-loop loopfilter would need to do some sync
between tile threads, but that shouldn't be a big issue.

Resuls: with tiling disabled, we go up slightly because of improved edge
use in the intra4x4 prediction. With 2 tiles, we lose about ~1% on derf,
~0.35% on HD and ~0.55% on STD/HD. With 4 tiles, we lose another ~1.5%
on derf ~0.77% on HD and ~0.85% on STD/HD. Most of this loss is
concentrated in the low-bitrate end of clips, and most of it is because
of the loss of edges at tile boundaries and the resulting loss of intra
predictors.

TODO:
- more tiles (perhaps allow row-based tiling also, and max. 8 tiles)?
- maybe optionally (for EC purposes), motion vectors themselves
  should not cross tile edges, or we should emulate such borders as
  if they were off-frame, to limit error propagation to within one
  tile only. This doesn't have to be the default behaviour but could
  be an optional bitstream flag.

Change-Id: I5951c3a0742a767b20bc9fb5af685d9892c2c96f

Overall encoding about 15% faster.

Change-Id: I176a775c704317509e32eee83739721804120ff2

This commit changes the 4x4 iDCT to use same algorithm & constants as
other iDCTs. The 4x4 fDCT is also changed to be based on the new iDCT.

Change-Id: Ib1a902693228af903862e1f5a08078c36f2089b0

This commit makes the NearestMV match the chosen
best reference MV. It can be a 0,0 or non zero vector
which means the the compound nearest mv mode can
combine a 0,0 and a non zero vector.

Change-Id: I2213d09996ae2916e53e6458d7d110350dcffd7a

and called this function in vp9_dequant_idct_add_32x32_c when
eob == 1.  For the test clip used, the decoder performance improved
by 21+%.  Based on Yaowu's 16 point idct work.

Change-Id: Ib579a90fed531d45777980e04bf0c9b23c093c43

Separate out code to set the main encode speed
related rd thresholds. Some values changed from
the initial defaults for various new modes.

Quality test results pending but even the addition
of some further non-zero defaults helps encode speed
somewhat in limited testing on derf clips.

Adjustment of thresholds for quality / speed tradeoff
to follow.

Change-Id: I117ee473157e151a1b93193d5f393449328de20d

to be consistent with idct16 and idct32.

Change-Id: Ie89dbd32b65c33274b7fecb4b41160fcf1962204

fixed a function prototypes to prevent compiler warnings;
removed a function not in use;
un-capitialize "Refstride" to ref_stride

Change-Id: Ib4472b6084f357d96328c6a06e795b6813a9edba

This commit changes the inverse 16 point dct to use the same algorithm
as the one for 32 point idct. In fact, now 16 point dct uses the exact
version of the souce code for even portion of the 32 point idct.

Tests showed current implementation has significant better accuracy
than the previous version. With this implementation and the minor bug
fix on forward 16 point dct, encoding tests showed about 0.2% better
compression of CIF set, test results on std-hd setting pending.

Change-Id: I68224b60c816ba03434e9f08bee147c7e344fb63

The commit fixes a minor error in 16 point fdct where in a rotation can
produce result of -1 instead of 0.

Change-Id: I45aac4a52bcd06225c6d04e643547a13e1c1aade

This commit changes the 32x32 idct to use integer only. The algorithm
was taken directly from "A Fast Computational Algorithm for the
Discrete Cosine Tranform" by W. Chen, et al., which was published in
IEEE Transaction on Communication Vol. Com.-25 No. 9, 1977. The signal
flow graph in the original paper is for a 32 point forward dct, the
current implementation of inverse DCT was done by follow the graph in
reversed direction.

With this implementation, the 32 point inverse dct contains a 16 point
inverse dct in its even portion, similarly the 16 point idct further
contains 8 point and 4 point inverse dcts.

As of patch 4, encoding tests showed there is no compression loss when
compared against the floating point baseline. Numbers even showed very
small postives. (cif: .01%, std-hd: .05%).

Change-Id: I2d2d17a424b0b04b42422ef33ec53f5802b0f378

Change-Id: Icb6e21dc0c2d9918faa33c8bf70943660df7ad88

This is identical to the later decisions made in encode_superblock().
This commit doesn't actually change anything, but makes the mbmi state
more consistent between the RD loop and the final encode result.

Change-Id: I9e735afb7c5a52e5b61728cb88c67ef9b9bf59be

This is the superblock equivalent of commit 290b83ab.

Change-Id: Ib3945dd9e992fa9ec1fdea5a11e17a3cc0e37637

Change-Id: I32bf4ee532a15af78619cbcd8a193224029fab50

The RD loop would change the pointer after the first mode (DC) was tested,
leading to corrupt block objects being provided for the others. This
would essentially render the i8x8 predictor useless.

Change-Id: I16c5906ca64fb34878ac32ce59af8974e4582bb8

Remove eob_max_offset markers and replace
with the generic skip_block flag to indicate
to the quantizer that all coeffs to be set to 0
and eob position set to 0;

Change-Id: Id477e8f8d4ec1a5562758904071013c24b76bfd7

Adds a special combination mode specific to intra prediciton
mode D45.

Current results with the compound inter/intra experiment:
derf: 0.2%
yt: 0.55%
std-hd: 0.75%
hd: 0.74%

Change-Id: I8976bdf3b9b0b66ab8c5c628bbc62c14fc72ca86

First step in simplifying the segment mode and
segment EOB flags into a simpler segment skip
flag that implies 0,0 mv and EOB at position 0.

Change-Id: Ib750cac31a7a02dc21082580498efd9f7d8d72a5

Simplification to eliminate a number of very large data
data structures. All zero run, zbin boosts for different
transform sizes are now limited to a maximum run length
of 15 before they max out the boost.

Some further work still needs be done to refactor, rationalize
and optimize the multiple quantizer functions.

The simplification coupled with tweaks to the 16 element array
now used for all transform sizes, has minimal effect on quality.

Change-Id: I6f3948b8ca0418b60d4db9030ff19026a34ed423

We'd backup and restore all cols for a 64x64 SB, but the array wouldn't
be big enough to hold all that data.

Change-Id: Ic68ea721bf07e0b2f3937bd16b0b734bcc743ce1

Adds a flag to disable features that would inhibit frame parallel
decoding. This includes backward adaptation and MV sorting based
on search in ref frame buffer.

Also includes some minor clean-ups.

Change-Id: I434846717a47b7bcb244b37ea670c5cdf776f14d

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

The variable is always zero.

Change-Id: Id5cdbecad543bca465a5b1d471badaec7e112c8d

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

Change-Id: Id0c0941bc508d985405abd06a13ffe7489170b62

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

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

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

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

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

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

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

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

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