debian man page for rtf_create_downsampler

Query: rtf_create_downsampler

OS: debian

Section: 3

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RTF_CREATE_DOWNSAMPLER(3)					 rtfilter library					 RTF_CREATE_DOWNSAMPLER(3)

NAME
rtf_create_downsampler - Creates downsampling filter
SYNOPSIS
#include <rtfilter.h> hfilter rtf_create_downsampler(unsigned int nch, int type, unsigned int r);
DESCRIPTION
rtf_create_downsampler() creates a filter that downsamples signals coming from nch channels of type type (see rtf_create_filter(3)) by a decimation factor of r (i.e. the sampling frequency of the input will be r times the sampling frequency of the output). This is achieved internally by applying a lowpass 4-order Chebychev filter to the input data using a normalized cutoff frequency of 0.8/(2*r) and decimating the result every r samples.
RETURN VALUE
Returns the handle to the created filter in case of success, NULL otherwise.
NOTES
On the contrary of most other filters, the number of samples returned by rtf_filter(3) is different than the input (as expected) but also may vary at each call if the number of sample supplied in input is not a multiple of r.
SEE ALSO
rtf_filter(3), rtf_create_filter(3), rtf_destroy_filter(3)
EPFL
2010 RTF_CREATE_DOWNSAMPLER(3)