Developer Reference

  • 2021
  • 03/26/2021
  • Public Content
Contents

IIRSparse

Filters a source vector through a sparse IIR filter.

Syntax

IppStatus ippsIIRSparse_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, int
len
, IppsIIRSparseState_32f*
pState
);
Include Files
ipps.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
Libraries:
ippcore.lib
,
ippvm.lib
Parameters
pState
Pointer to the sparse IIR filter state structure.
pSrc
Pointer to the source vector.
pDst
Pointer to the destination vector.
len
Number of elements that will be filtered.
Description
This function applies the sparse IIR filter to the
len
elements of the source vector
pSrc
, and stores the results in
pDst
. The filter parameters - the number of non-zero taps
nzTapsLen1
,
nzTapsLen2
, their values
pNZTaps
and their positions
pNZTapPos
, and the delay line values
pDlyLine
- are specified in the sparse IIR filter structure
pState
that should be previously initialized the function
ippsIIRSparseInit
.
In the following definition of the sparse IIR filter, the sample to be filtered is denoted
x
(n)
, the non-zero taps are denoted B
i
and A
i
, their positions are denoted BP
i
and AP
i
.
The non-zero taps are arranged in the array as follows:
B
0
, B
1
, . . ., B
nzTapsLen1
-1
, A
0
, A
1
, . . ., A
nzTapsLen2
-1.
The non-zero tap positions are arranged in the array as follows:
BP
0
, BP
1
, . . ., BP
nzTapsLen1
-1
, AP
0
, AP
1
, . . ., AP
nzTapsLen2
-1,
AP
0
≠ 0
The return value is
y
(n)
is defined by the formula for a sparse IIR filter:
After the function has performed calculations, it updates the delay line values stored in the filter state structure.
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error if one of the specified pointers is
NULL
.
ippStsSizeErr
Indicates an error if
len
is less than or equal to 0.

Example

The example below shows how to use the sparse IIR filter functions.
int buflen; Ipp8u *buf; int nzTapsLen1 = 5; //number of non-zero taps in the FIR part of the formula int nzTapsLen2 = 3; //number of non-zero taps in the IIR part of the formula Ipp32f nzTaps [] = {0.5, 0.4, 0.3, 0.2, 0.1, 0.8, 0.7, 0.6}; //non-zero taps values (FIR+IIR) Ipp32s nzTapsPos[] = {0, 10, 20, 30, 40, 1, 5, 15}; //non-zero tap positions (FIR+IIR) IppsIIRSparseState_32f* iirState; Ipp32f *src, *dst; /* ............................................. */ ippsIIRSparseGetStateSize_32f(nzTapsLen1, nzTapsLen2, nzTapsPos [nzTapsLen1 - 1], nzTapsPos [nzTapsLen1 + nzTapsLen2 - 1], &buflen); buf = ippsMalloc_8u(buflen); ippsIIRSparseInit_32f(&iirState, nzTaps, nzTapsPos, nzTapsLen1, nzTapsLen2, NULL, buf); /* . . . . initializing src somehow . . . . */ ippsIIRSparse_32f(src, dst, len, iirState); /* dst[i] = src[i] * 0.5 + src[i-10] * 0.4 + src[i-20] * 0.3 + src[i-30] * 0.2 + src[i-40] * 0.1 + dst[i-1] * 0.8 + dst[i-5] * 0.7 + dst[i-15] * 0.6 */ /* ................................................... */ ippsFree(buf);

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.