MPIFilterPostFilterSectionType

Definition

typedef enum {
    MPIFilterPostFilterSectionTypeINVALID = -1,
    MPIFilterPostFilterSectionTypeUNITY_GAIN,            /* B0 = 1    B1=B2=A1=A2 = 0   (effectively acting as no filter) */
    MPIFilterPostFilterSectionTypeSINGLE_ORDER,
    MPIFilterPostFilterSectionTypeLOW_PASS,
    MPIFilterPostFilterSectionTypeHIGH_PASS,
    MPIFilterPostFilterSectionTypeNOTCH,
    MPIFilterPostFilterSectionTypeRESONATOR,
    MPIFilterPostFilterSectionTypeLEAD_LAG,
    MPIFilterPostFilterSectionTypeZERO_GAIN,             /* b0=b1=b2=a1=a2 = 0   (this does act as a filter.... zeroing the output) */
    MPIFilterPostFilterSectionTypeBIQUAD,                /* Only valid for setting.  Reading will not return these types */
    MPIFilterPostFilterSectionTypeDIGITAL_BIQUAD,
    MPIFilterPostFilterSectionTypePOLES_ZEROS,
    MPIFilterPostFilterSectionTypeDIGITAL_POLES_ZEROS,
    MPIFilterPostFilterSectionTypeUNKNOWN,               /* algorithm couldn't figure out what this filter was from the coeffs! */
    MPIFilterPostFilterTypeEND,
    MPIFilterPostFilterTypeFIRST = MPIFilterPostFilterTypeINVALID + 1
} MPIFilterPostFilterSectionType;

Description

Note: The MPI will attempt to return analog & digital biquad and pole/zero information from mpiFilterPostFilterGet(...) and mpiFilterPostFilterSectionGet(...). However, the filter types MPIFilterPostFilterSectionTypeDIGITAL_BIQUAD, MPIFilterPostFilterSectionTypePOLES_ZEROS, and MPIFilterPostFilterSectionTypeDIGITAL_POLES_ZEROS are never returned by get() calls -- they are used only for setting postfilters. MPIFilterPostFilterSectionTypeBIQUAD will only be returned by mpiFilterPostFilterGet(...) and mpiFilterPostFilterSectionGet(...) if the analog coefficients can be calculated (there is no division by 0) and the section cannot be identified as one of the other analog filter types.

MPIFilterPostFilterSectionTypeUNITY_GAIN A unity gain filter. This effectively performs no filtering.
MPIFilterPostFilterSectionTypeSINGLE_ORDER A single order filter
MPIFilterPostFilterSectionTypeLOW_PASS A low pass filter
MPIFilterPostFilterSectionType_HIGH_PASS A high pass filter.
MPIFilterPostFilterSectionTypeNOTCH A notch filter
MPIFilterPostFilterSectionTypeRESONATOR A resonator filter.
MPIFilterPostFilterSectionTypeLEAD_LAG A lead or lag filter.
MPIFilterPostFilterSectionTypeZERO_GAIN Zeros the output of a filter.
MPIFilterPostFilterSectionTypeBIQUAD An analog biquad filter. When reading postfilter data, this type means that the postfilter section could not be identified as a standard filter type.
MPIFilterPostFilterSectionTypeDIGITAL_BIQUAD A digital biquad filter. This is only used for setting postfilter sections.
MPIFilterPostFilterSectionTypePOLES_ZERO Analog poles and zeros filter (maximum of two poles and zeros) with unity zero-frequency amplitude. This is only used for setting postfilter sections.
MPIFilterPostFilterSectionTypeDIGITAL_POLES_ZEROS Digital poles and zeros filter (maximum of two poles and zeros) with unity zero-frequency amplitude. This is only used for setting postfilter sections.
MPIFilterPostFilterSectionTypeUNKNOWN Returned by mpiFilterPostFilterGet(...) and mpiFilterPostFilterSectionGet(...) if analog coefficients cannot be found. only digital data will be available.
MPIFilterPostFilterTypeEND Need info.
MPIFilterPostFilterTypeFIRST Need info.

See Also

MPIFilterPostFilterSection | mpiFilterPosterfilterGet | mpiFilterPosterfilterSet | mpiFilterPosterfilterSectionGet | mpiFilterPosterfilterSectionSet