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

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

Pitch now means the number of elements, not the number of bytes.

Change-Id: Idb9f2f012e39b09d596a3cc1802305a80b7c13af

Change-Id: Ia15f4244595fab49bffda0c651a750a8a9481d28

Removing switch statements for inverse hybrid transforms. Making code style
consistent for all similar transform implementations. Renaming shortpitch
and short_pitch variables to half_pitch.

Change-Id: I875f7a82aae4e8063a58777bf1cc3f1e67b48582

Removing redundant parentheses, better code formatting, introducing
ROUND_POWER_OF_TWO macro to replace repeated expression.

Change-Id: I91aad7a53ed03482428b2419de4bb99fd92c6771

Lower case names of variables. Removing redundant spaces, parentheses,
casts, and variables.

Change-Id: I55b80c55b7d5adca44c1e8adb40a124c0680f229

avoids signed integer overflow

Change-Id: I9ffcdba90b21edb324d1b173fd11d613e0592931

Increase the first stage dynamic range by 4 times, and reduce it
back with proper rounding before applying the second stage. Hence
it still fits in the given dynamic range and slightly improves
the key frame coding performance.

Change-Id: Ia4c5907446f20a95dc3de079c314b3ad1221d8aa

Rebased.

Remove the old matrix multiplication transform computation. The 16x16
ADST/DCT can be switched on/off and evaluated by setting ACTIVE_HT16
300/0 in vp9/common/vp9_blockd.h.

Change-Id: Icab2dbd18538987e1dc4e88c45abfc4cfc6e133f

Some minor refactoring code relating to estimates of
bits per MB at a given Q and estimating the allowed Q range.

Most of the changes here were included in a previous commit.
This commit seeks to separate out the refactoring from more
the material changes.

Two #define control flags have been added for experimentation.

ONE_SHOT_Q_ESTIMATE force the two pass encoder to
use its initial Q range estimate for the whole clip even if this results
in a miss on the target data rate. In effect this tightens the Q range
seen at the expense of rate control accuracy.

DISABLE_RC_LONG_TERM_MEM is a related flag that disables the
long term memory in the rate control. Local adjustments are still
made to try and better hit the rate target on a per frame basis but
the impact of rate control misses is not propagated to the remainder
of the clip. This means that for example an overshoot early on will not
cause frames later in the clip to be starved of bits. Again the result
of this relaxation amy be less rate control accuracy especially on short
clips.

The flags are disabled by default for now.

Change-Id: I7482f980146d8ea033b5d50cc689f772e4bd119e

This commit added pre/post scaling for first half of fDCT16x16 to
reduce error, by simulation of 100,000 blocks for random inputs,
the average sse reduced from 2.1/block to 0.0498/block.

also enabled tests for 16x16 fDCT and iDCT

Change-Id: Id2a95f0464c6dd4118797d456237ae90274c0f02

Change-Id: I5416455f8f129ca0f450d00e48358d2012605072

This patch alters the balance of context between the
coefficient bands (reflecting the position of coefficients
within a transform blocks) and the energy of the previous
token (or tokens) within a block.

In this case the number of coefficient bands is reduced
but more previous token energy bands are supported.

Some initial rebalancing of the default tables has been
by running multiple derf clips at multiple data rates using
the ENTOPY_STATS macro. Further balancing needs to be
done using larger image formatsd especially in regard to
the bigger transform sizes which are not as well represented
in encodings of smaller image formats.

Change-Id: If9736e95c391e711b04aef6393d26f60f36e1f8a

The commit added a final rounding choice for 8x8 forward dct to get
rid of a sign bias at DC position and improve the accuracry in term
of round trip error for 8x8 fDCT/iDCT.

This commit also enabled forward 8x8 dct test.

Change-Id: Ib67f99b0a24d513e230c7812bc04569d472fdc50

Removing redundant 'extern' keywords and parentheses, fixing indentation,
making variable names lower case, using short expressions x *= c
instead of x = x * c, minor code simplifications.

Change-Id: If6a25fcf306d1db26e90d27e3c24a32735c607de

1. changed 4x4 test name to Vp9Fdct4x4Test to be consistent
2. remove forward 8x8 dct test code from idct8x8_test.cc
3. temporarily disable other forward dct tests to allow fdct work in
progress

Change-Id: I566aeed9c7c34da5a206190aa7d0e847a4008b36

The over quant code was added in VP8 post
bitstream freeze to allow compression to lower
data rates

In VP9 the real qualtizer range has been greatly
extended anyway.

Change-Id: I5d384fa5e9a83ef75a3df34ee30627bd21901526

This patch includes 4x4, 8x8, and 16x16 forward butterfly ADST/DCT
hybrid transform. The kernel of 4x4 ADST is sin((2k+1)*(n+1)/(2N+1)).
The kernel of 8x8/16x16 ADST is of the form sin((2k+1)*(2n+1)/4N).

Change-Id: I8f1ab3843ce32eb287ab766f92e0611e1c5cb4c1