VPP sharpen artifacts at bottom edge of output

[uartie]

VPP sharpen for all levels produces a line artifact at the bottom of output image. This happens with all media middleware (libyami, gstreamer-vaapi, ffmpeg-vaapi) on i965 driver for any YUV input. This does not happen on iHD driver.

On gst-vaapi, this can be reproduced with:

LIBVA_DRIVER_NAME=i965 GST_VAAPI_ALL_DRIVERS=1 gst-launch-1.0 -vf videotestsrc \
 pattern=black num-buffers=10 ! video/x-raw,format=NV12,width=1920,height=1080 \
 ! vaapipostproc sharpen=1.0 ! checksumsink2 file-checksum=false frame-checksum=false \
 plane-checksum=false dump-output=true dump-location=output.yuv

"black" pattern result:

"smpte" pattern result:

[uartie]

Reproduced on KBL. Other platforms not tested.