Filters an input waveform and produces a output waveform.

Synopsis

sigfilter [input file0] -o [output file] [-h ] [-itype string] [-n int] [-f int] [-ibo string] [-iswap ] [-istype string] [-c string] [-start float] [-end float] [-from int] [-to int] [-o ofile] [-otype string] [-F int] [-obo string] [-oswap ] [-ostype string] [-scale float] [-scaleN float] [-double ] [-lpfilter int] [-hpfilter int] [-forder int] [-lpcfilter ifile] [-firfilter ifile] [-inv_filter ]

Options

• -h: Options help

• -itype: string Input file type (optional). If set to raw, this indicates that the input file does not have a header. While this can be used to specify file types other than raw, this is rarely used for other purposes as the file type of all the existing supported types can be determined automatically from the file's header. If the input file is unheadered, files are assumed to be shorts (16bit). Supported types are nist, est, esps, snd, riff, aiff, audlab, raw, ascii

• -n: int Number of channels in an unheadered input file

• -f: int Sample rate in Hertz for an unheadered input file

• -ibo: string Input byte order in an unheadered input file: possibliities are: MSB , LSB, native or nonnative. Suns, HP, SGI Mips, M68000 are MSB (big endian) Intel, Alpha, DEC Mips, Vax are LSB (little endian)

• -iswap: Swap bytes. (For use on an unheadered input file)

• -istype: string Sample type in an unheadered input file: short, mulaw, byte, ascii

• -c: string Select a single channel (starts from 0). Waveforms can have multiple channels. This option extracts a single channel for progcessing and discards the rest.

• -start: float Extract sub-wave starting at this time, specified in seconds

• -end: float Extract sub-wave ending at this time, specified in seconds

• -from: int Extract sub-wave starting at this sample point

• -to: int Extract sub-wave ending at this sample point

• -o: ofile Output filename. If not specified output is to stdout.

• -otype: string Output file type, (optional). If no type is Specified the type of the input file is assumed. Supported types are: nist, est, esps, snd, riff, aiff, audlab, raw, ascii

• -F: int Output sample rate in Hz. If this is different from the input sample rate, resampling will occur

• -obo: string Output byte order: MSB, LSB, native, or nonnative. Suns, HP, SGI Mips, M68000 are MSB (big endian) Intel, Alpha, DEC Mips, Vax are LSB (little endian)

• -oswap: Swap bytes when saving to output

• -ostype: string Output sample type: short, mulaw, byte or ascii

• -scale: float Scaling factor. Increase or descrease the amplitude of the whole waveform by the factor given

• -scaleN: float Scaling factor with normalization. The waveform is scaled to its maximum level, after which it is scaled by the factor given

• -double: Perform double filtering by applying a forward filter, then a backward filter, leaving the filtered signla in phase with the original

• -lpfilter: int Low pass filter, with cutoff frequency in Hz Filtering is performed by a FIR filter which is built at run time. The order of the filter can be given by -forder. The default value is 199

• -hpfilter: int High pass filter, with cutoff frequency in Hz Filtering is performed by a FIR filter which is built at run time. The order of the filter can be given by -forder. The default value is 199.

• -forder: int Order of FIR filter used for lpfilter and hpfilter. This must be ODD. Sensible values range from 19 (quick but with a shallow rolloff) to 199 (slow but with a steep rolloff). The default is 199.

• -lpcfilter: ifile Track file containing lpc filter coefficients

• -firfilter: ifile File containing a single set of FIR filter coefficients

• -inv_filter: use filter coefficients for inverse filtering