Advanced Calculations
BIQUAD OutputArray(OUT),InputArray(IN),FilterCoefficientArray(FP) 
Apply biquadratic filter
・The following calculation is performed on all elements of the specified array. (0 <= t < len(IN))
OUT[t]=FP[0]*IN[t]+FP[1]*IN[t-1]+FP[2]*IN[t-2]-FP[3]*OUT[t-1]-FP[4]*OUT[t-2]
・If a 1D array is specified, it will be handled as monaural and if a 2D array is specified, it will be handled as stereo.
・If the array index is negative, use monaural or the value of FP[5..8] for the left channel and FP[9..12] for the right channel.
FP[5..12] value is updated at each execution.
・The filter coefficient array of the main characteristics such as a low-pass filter can be obtained with the BQPARAM command.
Arguments
OutputArray
Array that stores the results of applying the filter
InputArray
Array containing the signals to which the filter is applied
FilterCoefficientArray
Array containing filter coefficient
・The number of elements in the array must be 13 or more.
Example
DIM OD[2,1000],ID[2,1000],FP[13] BQPARAM FP,#BQLPF,48000,8000,1/SQR(2) BIQUAD OD,ID,FP
BQPARAM FilterCoefficientArray,FilterType,SamplingFrequency,CutoffFrequency,QValueOrBandwidth[, AmplificationFactor]
Calculate filter coefficients of biquadratic filter
Arguments
FilterCoefficientArray
Array to store filter coefficient (length must be 13 or more)
・ [5..12] of the specified array is not changed even if this command is executed.
FilterType
| 0 | #BQAPF | All-Pass Filter | Only the phase near the cutoff frequency changes |
| 1 | #BQLPF | Low-Pass Filter | Passes below the cutoff frequency |
| 2 | #BQHPF | High-Pass Filter | Passes frequencies above the cutoff frequency |
| 3 | #BQBPF | Bandpass Filter | Passes a specified frequency band centered on the cutoff frequency |
| 4 | #BQBSF | Bandstop Filter | Blocks the specified frequency band centered on the cutoff frequency |
| 5 | #BQLSF | Low-Shelf Filter | Amplifies the frequency below the cutoff frequency with the specified amplification factor |
| 6 | #BQHSF | High-Shelf Filter | Amplifies the frequency above the cutoff frequency with the specified amplification factor |
| 7 | #BQPEQ | Peaking Equalizer | Amplifies a specified frequency band centered on the cutoff frequency with a specified amplification factor |
SamplingFrequency
Sampling frequency of input signal
・0 is an error.
CutoffFrequency
Filter cutoff frequency
QValueOrBandwidth
Handle filter types, BPF/BSF/PEQ as bandwidth (unit: octave), and otherwise, QValue as smoothness of filter characteristics.
・0 is an error.
AmplificationFactor
Amplification factor of filter (unit: db). The descriptions must be needed when the filter types, #BQLSF, #BQHSF and #BQPEQ, are used.
Example
DIM OD[1000],ID[1000],FP[13] BQPARAM FP,#BQLSF,48000,8000,1/SQR(2),3.0 BIQUAD OD,ID,FP
FFT OutputRealPartArray,OutputImaginaryPartArray,InputRealPartArray,InputImaginaryPartArray[,WindowFunctionValueArray]
Perform Fourier transform on complex array
・All specified arrays must have the same number of elements, and the number of elements must be 2 to the power of n.
・The output and input arrangement may be the same.
Arguments
OutputRealPartArray,OutputImaginaryPartArray
Complex array of real and imaginary parts containing the result of the operation
InputRealPartArray,InputImaginaryPartArray
Complex array of real and imaginary parts to operate on
WindowFunctionValueArray
Array containing the window function values
・If specified, the input complex number array is multiplied by the element value of the same index, and then the Fourier transform is performed.
・The window function value array can also be obtained with the FFTTWFN command.
Example
DIM iR[1024],iI[1024],WF[1024] DIM oR[1024],oI[1024] FFTWFN WF,3 FFT oR,oI,iR,iI,WF
IFFT OutputRealPartArray,OutputImaginaryPartArray,InputRealPartArray,InputImaginaryPartArray
Perform inverse Fourier transform on complex array
・All specified arrays must have the same number of elements, and the number of elements must be 2 to the power of n.
・The output and input arrangement may be the same.
Arguments
OutputRealPartArray,OutputImaginaryPartArray
Complex array of real and imaginary parts containing the result of the operation
InputRealPartArray,InputImaginaryPartArray
Complex array of real and imaginary parts to operate on
Example
DIM iR[1024],iI[1024] DIM oR[1024],oI[1024] IFFT oR,oI,iR,iI
FFTWFN Array,WindowFunctionType
Obtain window function value array
Arguments
Array
Array containing the window function values
WindowFunctionType
| 0 | #WFRECT | Rectangular Window |
| 1 | #WFHAMM | Humming Window |
| 2 | #WFHANN | Hanning Window |
| 3 | #WFBLKM | Blackman Window |
Example
DIM WF[1024] FFTWFN WF,#WFHAMM
ARYOP OperationType,ResultStorageArray,Parameter1,Parameter2[,Parameter3]
Perform a batch operation on elements in an array
・From the beginning of the array to the end of the result storage array, the operation specified by the operation type is performed between each element, and the operation result is stored in the result storage array.
・If the number of elements in the parameter array is different from the number of elements in the result storage array, when it reaches the end of the array, return to the top of the array and refer to it repeatedly.
Argument
Operation type
| 0 | #AOPADD | Addition (p1+p2) |
| 1 | #AOPSUB | Subtraction (p1-p2) |
| 2 | #AOPMUL | Multiplication (p1*p2) |
| 3 | #AOPDIV | Division (p1/p2) |
| 4 | #AOPMAD | Sum of Products (p1*p2+p3) |
| 5 | #AOPLIP | Linear Interpolation （p1*p3+p2*（1-p3）） |
| 6 | #AOPCLP | Clamp (Rounds the value of p1 within the range of p2<=x<=p3) |
ResultStorageArray
Numeric array for storing operation results
Parameter1,Parameter2,Parameter3
Parameters 1, 2, and 3 can be specified as a numeric array or normal numeric value
・If a normal numerical value is specified, that numerical value is used for all element operations.