On Arm the YVU to RGB conversions move constants into registers.
This change does the same for 64 bit intel builds where additional
registers are available.
The AVX2 saves 3 instructions by because the 2nd argument needs to be a register, so a vmovdqu was avoided.

x64 builds using memory:
AVX2  I420ToARGB_Opt (3059 ms)
SSSE3 I420ToARGB_Opt (3959 ms)

Now using registers
AVX2  I420ToARGB_Opt (2906 ms)
SSSE3 I420ToARGB_Opt (3928 ms)

TBR=harryjin@google.com
BUG=libyuv:520

Review URL: https://codereview.chromium.org/1407353010 .

using a stripped down gn file from webrtc.

BUG=libyuv:411,libyuv:519
R=kjellander@chromium.org

Review URL: https://codereview.chromium.org/1417613007 .

Add alpha version of YUV to RGB to neon code for ARMv7 and aarch64.
For other YUV to RGB conversions, hoist alpha set to 255 out of loop.

TBR=harryjin@google.com
BUG=libyuv:516

Review URL: https://codereview.chromium.org/1413763017 .

cpu flags of 1 disables SIMD and uses C.  This used to be 0, but the change
in auto init behavior means that 0 now means uninitialized, and will cause
auto detect to reinit the cpu info.  A value of 1 disables the auto init.

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1408753004 .

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1412373006 .

R=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1429693006 .

in order to compare C and Neon code, a new command line flag is added.
historically environment variables controlled cpu features, but on
android apk it is easier to pass a command line option to disable cpu
optimizations.

R=harryjin@google.com
BUG=libyuv:516

Review URL: https://codereview.chromium.org/1407193009 .

DSP code is not actually used, only DSPR2.  Remove the detect.

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1405043008 .

Add unittests that do 1 step conversion vs 2 step conversion.

Tests end swapping versions match direct conversions.

R=harryjin@google.com
BUG=libyuv:518

Review URL: https://codereview.chromium.org/1419103007 .

TBR=harryjin@google.com
BUG=libyuv:518

Review URL: https://codereview.chromium.org/1420033004 .

Removes low levels for I420ToBGRA and I420ToRAW and reimplements them as I420ToRGBA and I420ToRGB24 with transposed color matrix.

Adds unittests that do 1 step conversion vs 2 steps to test end swapping versions match direct conversions.

R=harryjin@google.com
BUG=libyuv:518

Review URL: https://codereview.chromium.org/1427993004 .

Using a transposed conversion matrix, I420ToARGB can output ABGR.

R=harryjin@google.com, xhwang@chromium.org
BUG=libyuv:473

Review URL: https://codereview.chromium.org/1413573010 .

R=harryjin@google.com
BUG=libyuv:517

Review URL: https://codereview.chromium.org/1428843003 .

In some methods with 7 arguments gcc fails to find enough registers
to compile the assembler code when compiling debug. Simplest solution
is to skip the assembler version in debug of those particular functions

(I422Alpha -> ARBG/ABGR)

R=harryjin@google.com,bratell@opera.com
BUG=libyuv:517

Review URL: https://codereview.chromium.org/1423283002 .

R=ajm@chromium.org, ajm@google.com
BUG=libyuv:513,webrtc:760

Review URL: https://codereview.chromium.org/1427643003 .

swap U and V and transpose conversion matrix, so I420AlphaToARGB and
I420AlphaToABGR share low level code.

Having less code with same performance allows more focused
optimization for future ARM versions.

R=harryjin@google.com
TBR=harryjin@chromium.org
BUG=libyuv:473,libyuv:516

Review URL: https://codereview.chromium.org/1422263002 .

U contributes to B and G.  V contributes to R and G.
By swapping U and V, they contribute to the opposite channels.  Adjust the matrix so the U contribution is in the matrix location such that it till contribute to the
new B channel and vice versa.
This allows ABGR versions of YUV conversion to use the same low level code as ARGB, just using a different matrix and swapping U and V pointers.

As a result the existing I444ToABGRRow functions are no longer needed and are removed.

Previously this function was only Intel AVX2 optimized for Windwos.  Now it is also optimized for Arm and GCC.

ARMv7 Neon
Was LibYUVConvertTest.I444ToABGR_Opt (75971 ms)
Now LibYUVConvertTest.I444ToABGR_Opt (3672 ms)
20.6 times faster.

R=xhwang@chromium.org
BUG=libyuv:515

Review URL: https://codereview.chromium.org/1414133006 .

TBR=harryjin@google.com
BUG=libyuv:515

Review URL: https://codereview.chromium.org/1423663007 .

R=harryjin@google.com
BUG=libyuv:514

Review URL: https://codereview.chromium.org/1413463004 .

R=harryjin@google.com
BUG=libyuv:512

Review URL: https://codereview.chromium.org/1418253002 .

R=harryjin@google.com
BUG=libyuv:512

Review URL: https://codereview.chromium.org/1422733003 .

R=harryjin@google.com
BUG=libyuv:511

Review URL: https://codereview.chromium.org/1412683005 .

TBR=harryjin@google.com
BUG=libyuv:510

Review URL: https://codereview.chromium.org/1415583003 .

A bug was introduced on arm when the code for 'any' width switch to
a temporary stack buffer and simd.
The C version handles odd width by doing 1 pixel, instead of averaging 2.
But the SIMD any version is supposed to replicate the last pixel, then
the subsampling in Neon will average the pixel with itself, producing
the same result.
The previous version did this, but only for ARGB 32 bit, which was to
avoid introducing issues with subsampled YUY2 source.  This CL adds
replication for RGB 16 bit values.

TBR=harryjin@google.com
BUG=libyuv:510

Review URL: https://codereview.chromium.org/1418983003 .

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1415213002 .

The any function for handling ARGBToI411 was not handling the pixel
replication correctly.  On 422 and odd width was handled by duplicating
a pixel of source.  411 needs replication for remainders of 1, 2 or 3
pixels.

The C version was handling odd width but with an average of the remainder
pixels, which does not match the SIMD 'any' handling off remainder.
This changes the odd width handling to mimic the any version.

TBR=harryjin@google.com
BUG=libyuv:491

Review URL: https://codereview.chromium.org/1411733004 .

Fix compile error on arm, mips etc due to undefined variable.

TBR=harryjin@google.com
BUG=none

Review URL: https://codereview.chromium.org/1403373008 .

To make init cpu flags thread safe, there can only be one write to the variable.

R=richard.winterton@intel.com, harryjin@google.com
BUG=libyuv:508

Review URL: https://codereview.chromium.org/1412793006 .

A fix for android -a was checked in, allowing libyuv gtest flags to be pass.
This CL rolls to the head version of chromium to pull in the change,
allowing better testing and benchmarking of libyuv on android.

TBR=harryjin@google.com
BUG=libyuv:507

Review URL: https://codereview.chromium.org/1416663006 .

Changelog: https://chromium.googlesource.com/chromium/src/+log/bb79186..5d149df

TBR=fbarchard@chromium.org

Review URL: https://codereview.chromium.org/1416823002 .

Allows us to ignore flags passed on to us by Chromium build bots
without having to explicitly disable them. (Thanks pbos!)

TESTED=webrtc ran modules_unittests with a bogus flag did not result in an
error.

R=kjellander@chromium.org
BUG=libyuv:507

Review URL: https://codereview.chromium.org/1417573002 .

The DEPS entry for gflags added in https://codereview.chromium.org/1413723002/
assumed the Chromium/WebRTC checkout layout with 'src' as the
top-directory name. That doesn't work for libyuv, since the top-directory
is named 'libyuv'.

BUG=libyuv:507

Review URL: https://codereview.chromium.org/1410673004 .

files needed for command line support with gtest.
These files are copied directly from webrtc.

TBR=kjellander@chromium.org
BUG=libyuv:507

Review URL: https://codereview.chromium.org/1414483002 .

Unit tests currently use environment variables to change behavior.
Using gflags this can be done via command line.

BUG=libyuv:507
TBR=fbarchard@chromium.org

Review URL: https://codereview.chromium.org/1413723002 .

This reverts commit 2dd3d923.

Reason: chromium_git is a missing variable, and to properly
add gflags, we need to check in GYP files in third_party/gflags
first, then add the DEPS entry.

BUG=libyuv:507
TBR=fbarchard@chromium.org

Review URL: https://codereview.chromium.org/1406323002 .

unittests currently use environment variables to change behavior.
using gflags this can be done via command line.

R=kjellander@chromium.org
BUG=libyuv:507

Review URL: https://codereview.chromium.org/1402313002 .

This test is just a printf, not a real test, but somehow
fails on arm.

TBR=harryjin@google.com
BUG=libyuv:506

Review URL: https://codereview.chromium.org/1409913002 .

R=harryjin@google.com
BUG=libyuv:507

Review URL: https://codereview.chromium.org/1410643002 .

YuvPixel for arm was miscomputing YG.

TBR=harryjin@google.com
BUG=libyuv:506

Review URL: https://codereview.chromium.org/1402333002 .

TBR=harryjin@google.com
BUG=libyuv:506

Review URL: https://codereview.chromium.org/1403183002 .