API for deinterlacing YUV420 output on Android

Add libyuv:Android420ToI420 function which takes 3 pointers
to Y,U,V and a pixel stride for U and V.  The pixel stride is expected to be 1 or 2.

TEST=LibYUVConvertTest.Android420ToI420_Opt
BUG=libyuv:604
R=braveyao@chromium.org

Committed: https://chromium.googlesource.com/libyuv/libyuv/+/84e04699c2da42e8868a13944a242ac54656ffa3

[fbarchard1, 2016-07-12 18:24:46]

fbarchard@google.com changed reviewers:
+ braveyao@chromium.org

[fbarchard1, 2016-07-12 18:24:47]

Initial Android420 support

[fbarchard1, 2016-07-12 21:06:17]

Description was changed from

==========
proto android conversion

BUG=libyuv:604
==========

to

==========
Add libyuv:Android420ToI420 function which takes 3 pointers
to Y,U,V and a pixel stride for U and V.  The pixel stride is expected to be 1
or 2.

TEST=LibYUVConvertTest.Android420ToI420_Opt
BUG=libyuv:604
==========

[braveyao, 2016-07-12 21:42:05]

lgtm with nits.

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc
File source/convert.cc (right):

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:230: // width and height are plane sizes (typically half pixel
width)
s/width/Width?

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:445: 
why added 2 white lines?

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:1458: uint8* dst_u, int width) {
Maybe indent more to align with arguments above?

[fbarchard1, 2016-07-12 23:19:38]

x86 C
I420ToI420_Opt (174 ms)
I422ToI420_Opt (164 ms)
Android420ToI420_Opt (319 ms)
NV12ToI420_Opt (360 ms)
NV21ToI420_Opt (322 ms)
YUY2ToI420_Opt (762 ms)

x86 SSE2
I420ToI420_Opt (116 ms)
I422ToI420_Opt (119 ms)
Android420ToI420_Opt (110 ms)
NV12ToI420_Opt (135 ms)
NV21ToI420_Opt (133 ms)
RGB24ToI420_Opt (491 ms)
YUY2ToI420_Opt (194 ms)

Arm C
I420ToI420_Opt (286 ms)
I422ToI420_Opt (343 ms)
Android420ToI420_Opt (889 ms)
NV12ToI420_Opt (521 ms)
NV21ToI420_Opt (520 ms)
RGB24ToI420_Opt (4496 ms)
YUY2ToI420_Opt (1310 ms)

Arm NEON
I420ToI420_Opt (403 ms)
I422ToI420_Opt (370 ms)
Android420ToI420_Opt (299 ms)
NV12ToI420_Opt (279 ms)
NV21ToI420_Opt (290 ms)
RGB24ToI420_Opt (1102 ms)
YUY2ToI420_Opt (542 ms)

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc
File source/convert.cc (right):

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:230: // width and height are plane sizes (typically half pixel
width)
On 2016/07/12 21:42:04, braveyao wrote:
> s/width/Width?

Done.

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:445: 
On 2016/07/12 21:42:05, braveyao wrote:
> why added 2 white lines?

Done.

https://codereview.chromium.org/2114843002/diff/60001/source/convert.cc#newco...
source/convert.cc:1458: uint8* dst_u, int width) {
On 2016/07/12 21:42:05, braveyao wrote:
> Maybe indent more to align with arguments above?

Done.

[fbarchard1, 2016-07-12 23:23:53]

Description was changed from

==========
Add libyuv:Android420ToI420 function which takes 3 pointers
to Y,U,V and a pixel stride for U and V.  The pixel stride is expected to be 1
or 2.

TEST=LibYUVConvertTest.Android420ToI420_Opt
BUG=libyuv:604
==========

to

==========
Add libyuv:Android420ToI420 function which takes 3 pointers
to Y,U,V and a pixel stride for U and V.  The pixel stride is expected to be 1
or 2.

TEST=LibYUVConvertTest.Android420ToI420_Opt
BUG=libyuv:604
R=braveyao@chromium.org

Committed:
https://chromium.googlesource.com/libyuv/libyuv/+/84e04699c2da42e8868a13944a2...
==========

[fbarchard1, 2016-07-12 23:23:55]

Committed patchset #6 (id:100001) manually as
84e04699c2da42e8868a13944a242ac54656ffa3 (presubmit successful).