commit be6cc07d82d99e1a778084fecdeb102fabe769a2
author David Barker <david.barker@argondesign.com> Thu Dec 15 15:39:10 2016 +0000
committer Debargha Mukherjee <debargha@google.com> Tue Jan 03 17:15:29 2017 +0000
tree 744f697121d382dba173970ad4e8c2ad7396ae6d
parent 469a5c80fca715acfe6d7390f54ec9c8966b7f13

Add new convolve variant for loop-restoration

The convolve filters generated by loop_wiener_filter_tile
are not compatible with some existing convolve implementations
(they can have coefficients >128, sums of (certain subsets of)
coefficients >128, etc.)

So we implement a new variant, which takes a filter with 128
subtracted from its central element and which adds an extra copy
of the source just before clipping to a pixel (reinstating the
128 we subtracted). This should be easy to adapt from the existing
convolve functions, and this patch includes SSE2 highbd and
SSSE3 lowbd implementations.

Change-Id: I0abf4c2915f0665c49d88fe450dbc77b783f69e1