This is an initial attempt to allow variable block size partition
in non-RD coding flow. It tests 8x8, 16x16 and 32x32 block size per
64x64 block, all using non-RD mode decision and the associated rate
distortion costs from modeling, then selects the best block size to
encode the entire 64x64 block. Such operations are triggered every
other 3 frames. The blocks of intermediate frames will reuse the
collocated block's partition type.

It improves the compression performance by 13.2%. Note that the gains
are not evenly distributed. For many hard clips, the compression
performance is improved by 20% to 28%. Local speed test shows that
it will also increase runtime by 50%, as compared to speed -7. It is
now enabled in speed -6 setting.

Change-Id: Ib4fb8659d21621c9075b3c369ddaa9ecb0a4b204

The use of uninitialized skip flag will trigger inconsistency in
coding statistics, when alternate RD and non-RD coding modes are
enabled. This commit fixes this issue and removes unnecessary if
statements from update_state_rt.

Change-Id: I7d549dcb0e3ef48b999e5bbc78174ba84502cfcf

Activated using aq_mode=3.

Change-Id: Ied628b9e7bd0e88b0c75790276bca75b19eb5c07

Change-Id: Ia561dda53f2dd10e3a10a2df2adb8027ab19397a

Change-Id: Ibfccee5e35c235c02843e1c1fbd3c39034619cf5

Hash and license details are found in README.webm

Change-Id: I52192abe8eba8ec413f6bccd479e8e2256a8f617

Change-Id: Ib5cbf77052bc03495ae135b3cdcd39c2452c2b34

Change-Id: I0d39bdbb8166ee44561f1008d1a2e76e70b36f30

Change-Id: Ic130a77cb77c780bea9d5a3fc7c7dccd3c77f0dd

The comment made it look like the condition code was dropped from
the extra add instruction, while it actually was handled properly.

Thus, the comment was misleading while the code itself did the right
thing.

Also clarify the comment indicating that we use the full three-operand
form of the add instruction.

Change-Id: I2c1ac6ac4fedf262d104ea30a6c005febc74de9c

This is for the purpose to test variable partition choices for the
same 64x64 block.

Change-Id: I0fab7351a62e7d3dfccd667e908bccb996ee677e

vp8_vpxyv12_copy_y_neon is slower than vp8_vpxyv12_copy_y_c.

Change-Id: I7ba860619dc0714d700f232242ce915620461587

Modified the non-rd rate_mv calculation and moved it after sub-pixel
motion search is done.

Change-Id: I6a5cbd3d67ff0a86b3693e25ecf1fd77b16d708c

Change-Id: Iec885af58c95e65814fcb6ab528ce4e0874eb573

Adding a --(enable|disable)-webm-io flag to control WebM container input and
output support. For now, enabling WebM IO by default only when there is a C++
compiler. Doing so because eventually we will move WebM IO to libwebm and it
is built using C++.

Change-Id: I210ac36c23528e382ed41d3c4322291720481492

The block coding skip flags are assigned in the normal RD mode
decision loop. They are then used in the final encoding stage.
In the non-RD mode decision, the forward transform and quantization
stages are replaced by modeling based on SSE and variance of
prediction residues. This commit applies reset to this array in
the non-RD coding mode.

Change-Id: I66584669b035e9c8ac23e95047849ff277472742

This commit moves the position where rdmult is saved to make sure it
is the correct value. Prior, an uninitialized value may be saved and
restored.

This addresses issue:
https://code.google.com/p/webm/issues/detail?id=733

Change-Id: I436407f289169bc63da3c5a6bf609bed16cb71b5