Previously when a frame was being overlaid on a previously coded
alt ref frame we only checked the alt ref 0,0 mode. Where there is
a possibility that the alt ref buffer is a filtered frame we should allow
the other prediction modes as normal or at the least allow use of
the last frame buffer.

Change-Id: I4d6227223d125c96b4f3066ec6ec9484fee7768c

Allow use of other reference frames for the ARF overlay frame
when ARNR filtering is enabled

Change-Id: Icd6a9fb38977a88fbe7cc9b9c18198eb454c0273

Moved ref frame calculations to outside of the
mode_index loop.

Change-Id: I06103fc7e8af88b54b84443acf6691d29b1272ac

Add a flag to always enable block4x4 search for speed=0 (good
quality) to guarantee no quality loss for speed0.

Change-Id: Ie04bbc25f7e6a33a7bfa30e05775d33148731c81

The maximum possible MV in 1/8 pel units is (1<<11), which could
cause mvcost out of its range that is 1023. Change maximum
possible MV in 1/8 pel units to (1<<11)-8 will fix this problem.

Change-Id: I5788ed1de773f66658c14f225fb4ab5b1679b74b

cpi->target_bits_per_mb is currently not being used,
so delete it.  Also removed other unused code in rdopt.c.

Change-Id: I98449f9030bcd2f15451d9b7a3b9b93dd1409923

Add limits to avoid MV going out of range.

Change-Id: I8a5deb40bf393488d29f694b5a56804d578e68b5

1. Search for block8x16/block16x8 uses block8x8's search results.
2. Check block4x4 only if block8x8 is chosen. (This hurts quality,
   which will be improved in another check-in.)
3. In block4x4 search, the previous block's result is used as
   MV predictor for next block.

This change improves performance.

Change-Id: I9dc089007ca08129fb6c11fe7692777ebb8647b0

Re-calibrated sad_per_bit16 and sad_per_bit4 tables to linearly
correlated to quantizer values, these two variables are used in
motion search for costing motion vectors. This change has an small
positive effect on compression.

Change-Id: Ic9b5ea6fb8d5078ef663ba4899db019cc51f4166

In SPLITMV, the 8x8 segment will be checked first.  If the 8x8 rd
is better than the best, we check the other segments.  Otherwise
bail.  Adjustments to the thresh_mult were necessary to make
up for the initial quality loss.
The performance improved by 20% (average) for good quality,
speed 0 and speed 1, while the overall quality remained the same.

Change-Id: I717aef401323c8a254fba3e9777d2a316c774cc3

vp8_rd_pick_best_mbsegmentation looks at y only.  The new
breakout does not include the frame cost, the prob_skip_false
cost, or the uv rate.  Performance improved by a few percent
and the quality remained the same.

Change-Id: I94ff013998ac51e8ecce7130870f7b6600758e15

This fix added MV range checks for NEWMV mode as suggested by Jim.
To reduce unnecessary MV range checks, I tried Yaowu's suggestion.
Update UMV borders in NEWMV mode to also cover MV range check.
Also, in this way, every MV that is valid gets checked in diamond
search function.

Change-Id: I95a89ce0daf6f178c454448f13d4249f19b30f3a

The MV's range is 256. Since the new motion search uses a different
starting MV than the center ref MV, a MV range checking needs to
be done to avoid corruption.

Change-Id: I8ae0721d1bd203639e13891e2e54a2e87276f306

Change I3430820b performed an uninitialized read when
encode_breakout == 0, since the sum and sse wouldn't be set:

   if(x->encode_breakout)
       VARIANCE_INVOKE(..., get16x16var)(..., &sum, &sse);
   if (cpi->active_map_enabled && x->active_ptr[0] == 0) {
       ...
   } else if (sse < x->encode_breakout)

Change-Id: I915eb76d1227b4b6d1137a0dedf2c143860098a2

Realized no need for new assembly code sum is already
calculated.

Change-Id: Ie2d94feb4b7c1f77c5359bca29b66228e41638c9

Moved the code from the segmentation loop into a function
which is now called for each segment. This will allow us
to change the segment order checking more easily.

Change-Id: I9510d26f0acae5a73043fcca8f1984b121d3e052

Add vp8_mv_pred() to better predict starting MV for NEWMV
mode in vp8_rd_pick_inter_mode(). Set different search
ranges according to MV prediction accuracy, which improves
encoder performance without hurting the quality. Also,
as Yaowu suggested, using diamond search result as full
search starting point and therefore adjusting(reducing)
full search range helps the performance.

Change-Id: Ie4a3c8df87e697c1f4f6e2ddb693766bba1b77b6

only do the variance calculation if necessary
( eg needed for breakout test)

macro_block_yrd and vp8_rdcost_mby are not called for SPLITMV.

Change-Id: I2224d3c8725df526d48426447482768d543752f1

Small changes to the default zero bin and rounding tables.
Though the tables are currently the same for the Y1 and Y2 cases
I have left them as separate tables in case we want to tune this later.

There is now some adjustment of the zbin based on the prediction mode.
Previously this was restricted to an adjustment for gf/arf 0,0 MV.

The exact quantizer now marginal outperforms and is the default.

The overall average gain is about 0.5%

Change-Id: I5e4353f3d5326dde4e86823684b236a1e9ea7f47

Using tables for the label count and label offset.

Change-Id: Iac3d5b292c37341a881be0af282f5cac3b3e01eb

NEON has optimized 16x16 half-pixel variance functions, but they
were not part of the RTCD framework. Add these functions to RTCD,
so that other platforms can make use of this optimization in the
future and special-case ARM code can be removed.

A number of functions were taking two variance functions as
parameters. These functions were changed to take a single
parameter, a pointer to a struct containing all the variance
functions for that block size. This provides additional flexibility
for calling additional variance functions (the half-pixel special
case, for example) and by initializing the table for all block sizes,
we don't have to construct this function pointer table for each
macroblock.

Change-Id: I78289ff36b2715f9a7aa04d5f6fbe3d23acdc29c

Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.

Fixes issue #97.

Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba

Moved partition_bmi and partition_count out of MB_MODE_INFO and
placed into MACROBLOCK.  Also reduced the size of other members
of the MB_MODE_INFO struct.  For 1080p, the memory was reduced
by 1,209,516 bytes.  The decoder performance appeared to improve
by 3% for the clip used.
Note:  The main goal for this change is to improve the decoder
performance.  The encoder will be revisited at a later date for
further structure cleanup.

Change-Id: I4733621292ee9cc3fffa4046cb3fd4d99bd14613

The main reason for the change was to reduce cycles in the token
decoder. (~1.5% gain for 32 bit)  This layout should be more
cache friendly.

As a result of this change, the encoder had to be updated.

Change-Id: Id5e804169d8889da0378b3a519ac04dabd28c837
Note: dixie uses a similar layout

These copies occurred for each macroblock in the encoder and decoder.
Thetemp MB_MODE_INFO mbmi was removed from MACROBLOCKD.  As a result,
a large number compile errors had to be fixed.

Change-Id: I4cf0ffae3ce244f6db04a4c217d52dd256382cf3

The mv_ref and sub_mv_ref token encodings are indexed from NEARESTMV
and LEFT4X4, respectively, rather than being zero-based like the
other token encodings.

Change-Id: I3699c3f84111209ecfb91097c4b900773e9a3ad5

Replace the exponential search for optimal rounding during
 quantization with a linear Viterbi trellis and enable it
 by default when using --best.
Right now this operates on top of the output of the adaptive
 zero-bin quantizer in vp8_regular_quantize_b() and gives a small
 gain.
It can be tested as a replacement for that quantizer by
 enabling the call to vp8_strict_quantize_b(), which uses
 normal rounding and no zero bin offset.
Ultimately, the quantizer will have to become a function of lambda
 in order to take advantage of activity masking, since there is
 limited ability to change the quantization factor itself.
However, currently vp8_strict_quantize_b() plus the trellis
 quantizer (which is lambda-dependent) loses to
 vp8_regular_quantize_b() alone (which is not) on my test clip.

Patch Set 3:

Fix an issue related to the cost evaluation of successor
states when a coefficient is reduced to zero. With this
issue fixed, now the trellis search almost exactly matches
the exponential search.

Patch Set 2:

Overall, the goal of this patch set is to make "trellis"
search to produce encodings that match the exponential
search version. There are three main differences between
Patch Set 2 and 1:
a. Patch set 1 did not properly account for the scale of
2nd order error, so patch set 2 disable it all together
for 2nd blocks.
b. Patch set 1 was not consistent on when to enable the
the quantization optimization. Patch set 2 restore the
condition to be consistent.
c. Patch set 1 checks quantized level L-1, and L for any
input coefficient was quantized to L. Patch set 2 limits
the candidate coefficient to those that were rounded up
to L. It is worth noting here that a strategy to check
L and L+1 for coefficients that were truncated down to L
might work.

(a and b get trellis quant to basically match the exponential
search on all mid/low rate encodings on cif set, without
a, b, trellis quant can hurt the psnr by 0.2 to .3db at
200kbps for some cif clips)
(c gets trellis quant  to match the exponential search
to match at Q0 encoding, without c, trellis quant can be
1.5 to 2db lower for encodings with fixed Q at 0 on most
derf cif clips)

Change-Id:	Ib1a043b665d75fbf00cb0257b7c18e90eebab95e

At the end of the decode, frame buffers were being copied.
The frames are not updated after the copy, they are just
for reference on later frames.  This change allows multiple
references to the same frame buffer instead of copying it.

Changes needed to be made to the encoder to handle this.  The
encoder is still doing frame buffer copies in similar places
where pointer reference could be done.

Change-Id: I7c38be4d23979cc49b5f17241ca3a78703803e66

Following conversations with Tim T (Derf) I ran a large number of
tests comparing the existing polynomial expression with a simpler
^2 variant. Though the polynomial was sometimes a little better at
the extremes of Q it was possible to get close for most clips and
even a little better on some.

This code also changes the way the RD multiplier is calculated
when the ZBIN is extended to use a variant of the same ^2
expression.

I hope that this simpler expression will be easier to tune further
as we expand our test set and consider adjustments based on content.

Change-Id: I73b2564346e74d1332c33e2c1964ae093437456c

The new fdct lowers the round trip sum squared error for a
4x4 block ~0.12. or ~0.008/pixel. For reference, the old
matrix multiply version has average round trip error 1.46
for a 4x4 block.

Thanks to "derf" for his suggestions and references.

Change-Id: I5559d1e81d333b319404ab16b336b739f87afc79

When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.

Change-Id: I236c05fade06589e417179c0444cb39b09e4200d

Change-Id: I2a97f08cc3c7808ce5be39e910cc5147ecf03a1d

 low and high Q ends.

Change-Id: I944035e720ef834561a9da0d723879a4f787312c

Change-Id: Ieebea089095d9073b3a94932791099f614ce120c