This restores d9dce2f48e
Switched to using signed shift-and-narrow. Instead of saturating
negative results to 0, it was saturating them to 255.
BUG=webm:817
BUG=webm:1273
Change-Id: I571095336aa4182e3288b17924fcaaece42b0a49
On 32 bit machines 'new' does not always appear to allocate sufficiently
aligned buffers, causing intermittent test failures.
Change-Id: I0db4fc73782012e4eef71dc0fb540e74fdbfcebe
The code only has issues when xoffset == 0 and yoffset == 0 which
represents a simple copy. Presumably this case does not need to be
handled because the issue has existed since 2010.
BUG=webm:1287
Change-Id: Ic47e2653f3b729e99b40e53d8d2d8d1501edaaa9
Build out the sixtap_predict test because the filters are
interchangeable. Add verbose failures and border checking.
Change-Id: I962f50041750dca6f8d0cd35a943424cf82ddcb1
