The previous implementation visited each node in the tree multiple times
because it used each symbol's encoding to revisit the branches taken and
increment its count. Instead, we can traverse the tree depth first and
calculate the probabilities and branch counts as we walk back up. The
complexity goes from somewhere between O(nlogn) and O(n^2) (depending on
how balanced the tree is) to O(n).

Only tested one clip (256kbps, CIF), saw 13% decoding perf improvement.

Note that this optimization should port trivially to VP8 as well. In VP8,
the decoder doesn't use this function, but it does routinely show up
on the profile for realtime encoding.

Change-Id: I4f2848e4f41dc9a7694f73f3e75034bce08d1b12

Split macroblock and superblock tokenization and detokenization
functions and coefficient-related data structs so that the bitstream
layout and related code of superblock coefficients looks less like it's
a hack to fit macroblocks in superblocks.

In addition, unify chroma transform size selection from luma transform
size (i.e. always use the same size, as long as it fits the predictor);
in practice, this means 32x32 and 64x64 superblocks using the 16x16 luma
transform will now use the 16x16 (instead of the 8x8) chroma transform,
and 64x64 superblocks using the 32x32 luma transform will now use the
32x32 (instead of the 16x16) chroma transform.

Lastly, add a trellis optimize function for 32x32 transform blocks.

HD gains about 0.3%, STDHD about 0.15% and derf about 0.1%. There's
a few negative points here and there that I might want to analyze
a little closer.

Change-Id: Ibad7c3ddfe1acfc52771dfc27c03e9783e054430

Wrote a SSE2 vp9_short_idct4x4llm to improve the decoder
performance.

Change-Id: I90b9d48c4bf37aaf47995bffe7e584e6d4a2c000

Fixed a couple of variable/function definitions, as well as header
handling to support 16K sequence coding at high bit-rates.

The width and height are each specified by two bytes in the header.
Use an extra byte to explicitly indicate the scaling factors in
both directions, each ranging from 0 to 15.

Tested coding up to 16400x16400 dimension.

Change-Id: Ibc2225c6036620270f2c0cf5172d1760aaec10ec

Update the function prototypes to match between VP9 and VP8.

Change-Id: If58965073989e87df3b62b67a030ec6ce23ca04f

Change-Id: Iab0176f058045181821ded95ff1cf423af1625f9

Removing redundant 'extern' keyword, lowercase variable names.

Change-Id: I608e8d8579aba8981f5fac3493f77b4481b13808

to be a fixed value of 15.

Test results:
cif:  .124%, .068%, .081%
std-hd: 2.809%, 3.174%, 2.705%

Change-Id: I380c8152c973506094da15eab59e3aa22b75a983

Simplified idct32x32 calculation when there are only 10 or less
non-zero coefficients in 32x32 block. This helps the decoder
performance.

Change-Id: If7f8893d27b64a9892b4b2621a37fdf4ac0c2a6d

gf_group_bits is int64_t remove casts to int.

Change-Id: I3b4225905041fac9af9fdfcbcb6f1c357ea4b593

Lower case variable names, converting while loops to for loops.

Change-Id: Ic3b973391eef7472a99d18d02fe79cfef5e04e62

Provided a wrapper and removed duplicate code.

Change-Id: Iaef842226ec348422e459202793b001d0983ea30

Change-Id: Ie89bd00d58e30bf4094cb748a282f1dfa81a31d8

Change-Id: Id786be31da3c91d95d2955aa569ecdc6e66650df

The ABOVESPREFMV experiment uses four pixels to the left of the
current block, which don't exist for the left-most column.

Change-Id: I4cf0b42ae8f54c0b3e7b1ed8755704b74fafc39c

Removing redundant variables, using x *= y instead x = x * y, moving
variable declarations into inner blocks.

Change-Id: I884f95c755f55d51b7c1c6585f10296919063e41

Removing redundant 'extern' keyword, better formatting, code
simplification.

Change-Id: I132fea14f08c706ee9ea147d19464d03f833f25b

The width and height stored in the reference frames are padded out to
a multiple of 16. The Width and Height variables in common are the
displayed size, which may be smaller. The incorrect comparison was
causing scaling related code to be called when it shouldn't have
been. A notable case where this happens is 1080p, since 1088 != 1080.

Change-Id: I55f743eeeeaefbf2e777e193bc9a77ff726e16b5

sse4_1 code used uint16_t for returning sad, but that
won't work for 32x32 or 64x64.   This code fixes the
assembly for those and also reenables sse4_1 on linux

Change-Id: I5ce7288d581db870a148e5f7c5092826f59edd81

Change-Id: I919e2dd72292fe44f2e53ada56bd42287d50cdeb
Signed-off-by: Jim Bankoski <jimbankoski@google.com>

Scalar path is about 1.4x faster (4% overall encoder speedup).
SSE2 path is about 7x faster (13% overall encoder speedup).

Change-Id: I7e85d8225a914a74c61ea370210414696560094d

Fixing code style, using array lookup instead of switch statements for
forward hybrid transforms (in the same way as for their inverses).
Consistent usage of ROUND_POWER_OF_TWO macro in appropriate places.

Change-Id: I0d3822ae11f928905fdbfbe4158f91d97c71015f

Fixing indentation, removing redundant parenthesis, deciphering single
letter variable names, better spacing.

Change-Id: I1d447a7d69eddbf1e94e0820423615f40ea2d591

Removed vp9/decoder/x86/vp9_idct_blk_mmx.c

Change-Id: I07ab06382a394cf556fa5a8e3c98b91f6e4f9ce8

Removed vp9_idctllm_mmx.asm

Change-Id: I7152756f23a5a09ed69e8fb40edb2ab3237290fe

Consistent with VP8.

Change-Id: I8c316ee49f072e15abbb033a80e9c36617891f07

This function was part of an optimization used in VP8 that required
caching two macroblocks. This is unused in VP9, and might not
survive refactoring to support superblocks, so removing it for now.

Change-Id: I744e585206ccc1ef9a402665c33863fc9fb46f0d

s/movd/movq/

Change-Id: Id1a56de91551f8dc796f14f1056c565dfc1ba626

This patch makes the encoder's use of ref_frame_map and active_ref_idx
consistent with the decoder. ref_frame_map[] maps a reference buffer
index to its actual location in the yv12_fb array, since many
references may share an underlying buffer. active_ref_idx[] mirrors
cpi->{lst,gld,alt}_fb_idx, holding the active references in each
slot.

This also fixes a bug in setup_buffer_inter() where the incorrect
reference was used to populate the scaling factors.

Change-Id: Id3728f6d77cffcd27c248903bf51f9c3e594287e

Fixes a bug in vp9_set_internal_size() that prevented returning to
the unscaled state. Updated the ResizeInternalTest to scale both
down and up. Added a check that all frames are within 2.5% of the
quality of the initial keyframe.

Change-Id: I3b7ef17cdac144ed05b9148dce6badfa75cff5c8

This avoids duplicating all the filters twice. Includes fixups to the
convolve routines and associated tests to make this work.

Change-Id: I922f86021594e55072ddb63b42b2313605db6e00

This patch extends the previous support for using references of a
different resolution in ZEROMV mode to all inter prediction modes.
Subpixel based best-mv scoring is disabled when the reference frame
differs in resolution from the current frame.

Change-Id: Id4dc3e5e6692de98d9857fd56bfad3ac57e944ac

This commit updates the 4x4 prediction to consistently use the
build_2x1_inter_predictor() method. That function is updated to
calculate the scale offset, rather than relying on the caller
to calculate it. In the case that the 2x1 prediction can not
be used, the scale offset is recalculated for each 1x1 block.
The idea here is that the offsets are calculated before each
call to vp9_build_scaled_inter_predictor().

Change-Id: I0ac3343dd54e2846efa3c4195fcd328b709ca04d

This patch allows coding frames using references of different
resolution, in ZEROMV mode. For compound prediction, either
reference may be scaled.

To test, I use the resize_test and enable WRITE_RECON_BUFFER
in vp9_onyxd_if.c. It's also useful to apply this patch to
test/i420_video_source.h:

  --- a/test/i420_video_source.h
  +++ b/test/i420_video_source.h
  @@ -93,6 +93,7 @@ class I420VideoSource : public VideoSource {

     virtual void FillFrame() {
       // Read a frame from input_file.
  +    if (frame_ != 3)
       if (fread(img_->img_data, raw_sz_, 1, input_file_) == 0) {
         limit_ = frame_;
       }

This forces the frame that the resolution changes on to be coded
with no motion, only scaling, and improves the quality of the
result.

Change-Id: I1ee75d19a437ff801192f767fd02a36bcbd1d496

Wrote SSE2 version of vp9_dc_only_idct_add_c function. In order to
improve performance, clipped the absolute diff values to [0, 255].
This allowed us to keep the additions/subtractions in 8 bits.
Test showed an over 2% decoder performance increase.

Change-Id: Ie1a236d23d207e4ffcd1fc9f3d77462a9c7fe09d

Change-Id: I893fa36297b9bd9cff93d082f1736f6860b15c0d

Change-Id: I35e64998b25694a3bb4a62164bba3c03c1db4bc7

Change-Id: I17e2d2f6a4da86d9e4af7bebdea0bf5d154da084

Change-Id: I62497dcf2074b4bb4787bf660e727e5cf1bf3472

Ensure that all inter prediction goes through a common code path
that takes scaling into account. Removes a bunch of duplicate
1st/2nd predictor code. Also introduces a 16x8 mode for 8x8
MVs, similar to the 8x4 trick we were doing before. This has an
unexpected effect with EIGHTTAP_SMOOTH, so it's disabled in that
case for now.

Change-Id: Ia053e823a8bc616a988a0af30452e1e75a739cba