topic Could scaleFactor be negative? in Intel® Integrated Performance Primitives

Could scaleFactor be negative?

k_kun_wang — Fri, 29 Jul 2005 01:32:05 GMT

I am wondering whether I could setscaleFactor to be negative integer in the function

IppStatus ippsMul_16s_ISfs(const Ipp16s * pSrc, Ipp16s * pSrcDst, int len, int scaleFactor);

Thanks.

Re: Could scaleFactor be negative?

Intel_C_Intel — Fri, 12 Aug 2005 13:33:35 GMT

Hi,

Yes. The scale factor can be negative, positive, or zero. Scaling of an integer result is done by multiplying the output vector values by 2** (-scaleFactor ) before the function returns.

if (scaleFactor > 0) pDst = output >> scaleFactor

if (scaleFactor < 0) pDst = output<< ( - scaleFactor)

Thanks