FIR filter cache class. More...
#include <CDSPFIRFilter.h>
Inheritance diagram for r8b::CDSPFIRFilterCache:
Collaboration diagram for r8b::CDSPFIRFilterCache:
Static Public Member Functions | |
| static int | getObjCount () |
| static CDSPFIRFilter & | getLPFilter (const double ReqNormFreq, const double ReqTransBand, const double ReqAtten, const EDSPFilterPhaseResponse ReqPhase, const double ReqGain, const double *const AttenCorrs=NULL) |
| Function calculates or returns reference to a previously calculated (cached) low-pass FIR filter. More... | |
Friends | |
| class | CDSPFIRFilter |
Detailed Description
FIR filter cache class.
Class that implements cache for calculated FIR filters. The required FIR filter should be obtained via the getLPFilter() static function.
Member Function Documentation
◆ getLPFilter()
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inlinestatic |
Function calculates or returns reference to a previously calculated (cached) low-pass FIR filter.
Note that the real transition band and attenuation achieved by the filter varies with the magnitude of the required attenuation, and are never 100% exact.
- Parameters
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ReqNormFreq Required normalized frequency, in the range 0 to 1, inclusive. This is the point after which the stop-band spans. ReqTransBand Required transition band, in percent of the 0 to ReqNormFreq spectral bandwidth, in the range CDSPFIRFilter::getLPMinTransBand() to CDSPFIRFilter::getLPMaxTransBand(), inclusive. The transition band specifies the part of the spectrum between the -3 dB and ReqNormFreq points. The real resulting -3 dB point varies in the range from -3.00 to -3.05 dB, but is generally very close to -3 dB. ReqAtten Required stop-band attenuation in decibel, in the range CDSPFIRFilter::getLPMinAtten() to CDSPFIRFilter::getLPMaxAtten(), inclusive. Note that the actual stop-band attenuation of the resulting filter may be 0.40-4.46 dB higher. ReqPhase Required filter's phase response. ReqGain Required overall filter's gain (1.0 for unity gain). AttenCorrs Attentuation correction table, to pass to the filter generation function. For internal use.
- Returns
- A reference to a new or a previously calculated low-pass FIR filter object with the required characteristics. A reference count is incremented in the returned filter object which should be released after use via the CDSPFIRFilter::unref() function.
◆ getObjCount()
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inlinestatic |
- Returns
- The number of filters present in the cache now. This value can be monitored for debugging "forgotten" filters.
The documentation for this class was generated from the following files:
- src/r8brain/CDSPFIRFilter.h
- src/r8brain/r8bbase.cpp
