For 8-bit the subtrahend is small enough to fit into uint32_t.
This is the same that was done for:
c0241664a Resolve -Wshorten-64-to-32 in variance.
For 10/12-bit apply:
63a37d16f Prevent negative variance
Change-Id: Iab35e3f3f269035e17c711bd6cc01272c3137e1d
This function only exists as a shortcut to subpixel variance with
predefined offsets. xoffset = 4 for horizontal, yoffset = 4 for vertical
and both for "hv"
Removing this allows the existing optimizations for the variance
functions to be called. Instead of having only sse2 optimizations, this
gives sse2, ssse3, msa and neon.
BUG=webm:1273
Change-Id: Ieb407b423b91b87d33c4263c6a1ad5e673b0efd6
Due to rounding used computation, HDB variance computation may produce
slightly negative values. This commit adds clamping to make sure
output variance values for 10 and 12 to be non-negative.
Change-Id: Id679aa55a4c201958c4c7d28cd8733b9246a71c8
This commit change to use int64_t to represent the sum of pixel
differences, which can be negative.
This fixes a number of ubsan warnings.
BUG=webm:1219
Change-Id: I885f245ae895ab92ca5f3b9848d37024b07aac98
This reverts commit ea48370a50, reversing
changes made to 15939cb2d7.
The commit was insufficiently tested and causes failures.
Change-Id: I623d6fc2cd3ae6fd42d0abab1f8eada465ae57a7
Always round sum error and sum square error toward zero in variance
calculations. This prevents variance from becoming negative.
Avoiding rounding variance at all might be better but would be far
more invasive.
Change-Id: Icf24e0e75ff94952fc026ba6a4d26adf8d373f1c
