tree 7523d45cf314381256ed513c17a5798a86fbacf3
parent bacaf9ab3b43f740bac629fed1df1220b9d6888e
author Yunqing Wang <yunqingwang@google.com> 1570738178 -0700
committer Yunqing Wang <yunqingwang@google.com> 1570770324 -0700

Eliminate temporal filtering for INTNL_ARF_UPDATE type

For INTNL_ARF_UPDATE type, temporal filtering isn't done. However,
in current code it still goes through temporal filtering, and
unchanged image is copied to alt_ref_buffer for encoding. This patch
eliminates the unnecessary temporal filtering and frame copying, and
uses the lookahead buffer image directly.

Ran Borg test on midres set for several speeds:
         avg_psnr: ovr_psnr:  ssim:
speed 0: -0.003    -0.001     0.005
speed 1:  0.001     0.000    -0.004
speed 4: -0.001    -0.001    -0.001
speed 5:  0.004     0.004     0.002

Sped up 2% - 2.3% for all speeds(speed 0 to speed 5).

STATS_CHANGED

Change-Id: If6467a324e2c2e4bd38600ce62cdecf26b8c561d