SPKitButterworthFilter
User's Guide
SPKitButterworthFilter a base class for butterworth filters.
It implements functions common to the four Butterworth filter variant
classes:
Note: SPKitButterworthFilter serves only as a base class
for the filters listed above. It is
not intended for direct use.
For a more detailed description of Butterworth filters,
see Dodge & Jerse (1985:186-193).
Programmer's Reference
Defined in <spkit/butterwo.h>
Inherits from SPKitProcessor
SPKitButterworthFilter
overrides
getSample()
and
setInput().
It also defines a destructor for releasing
local buffers allocated by setInput().
Public Members
- SPKitError setInput(SPKitProcessor* newInput)
- connect an input to the object and initialize it.
Allocates a delay buffer for each audio channel of the input object.
Calls
SPKitProcessor::setInput().
- int getSample(SPKitSample& outputSample)
- retrieve a processed audio sample
getSample() multiplies each input sample by the product of
previously read and written samples and coefficients.
getSample() stores the processed sample in outputSample.
The function returns 0 on end of signal, 1 otherwise.
Protected Members
- SPKitFloat C
- a temporary variable for calculating filter coefficients
- SPKitFloat D
- a temporary variable for calculating filter coefficients
- SPKitFloat a[3]
- coefficients for the current input and previously read samples
- SPKitFloat b[2]
- coefficients for the previously written samples
- BWBuffer* chBuf[]
- buffers for previously read and written samples