Format of filter files
The filter files are line oriented, that means there is one
information entry per line. Blank lines are not allowed ! The
format of the filter files is as follows:
FFT filter
- All lines at the beginning of the file starting with exclamation
sign ! are comments
and ignored by the program.
- The first data line is a magic number and must be 1357913578
- The next data line contains the number 1,
which is an ID for FFT filters.
- Normalization value (real number), which is multiplied to
the output samples of the filter.
- Number of zeros z (integer)
- z lines following with one zero each in the format
(<real-part>,<imag-part>).
Both parts of a complex conjugate pair must be specified.
- Number of poles p
- p lines following with one pole each in the same format as
zeros.
Example of an FFT filter file.
Recursive filters
- All lines at the beginning of the file starting with exclamation
sign ! are comments
and ignored by the program.
- The first data line is a magic number and must be 1357913578.
- The next data line contains the number 3,
which is an ID for recursive filters.
- Sample rate for which this file is valid (real number)
- Normalization value (real number), which is multiplied to
the output samples of the filter.
- Number of numerator coefficients n (integer)
- n lines following, one coefficient (real number) in each.
- Number of denominator coefficients d (integer)
- d lines following, one coefficient per line.
- Optional following other stages of the filter, new stage
indicated by a line containing a single @.
- Additional stages are repeating the entries 'ID number
3' until denominator
coefficients.
Example of a recursive filter
file.
This page last modifed 10-Jul-2000