/* -*- c++ -*- */
/*
- * Copyright 2009 Free Software Foundation, Inc.
+ * Copyright 2009,2010 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
const std::vector<float> &taps,
unsigned int filter_size)
{
- return gr_pfb_arb_resampler_ccf_sptr (new gr_pfb_arb_resampler_ccf (rate, taps,
- filter_size));
+ return gnuradio::get_initial_sptr(new gr_pfb_arb_resampler_ccf (rate, taps,
+ filter_size));
}
gr_make_io_signature (1, 1, sizeof(gr_complex))),
d_updated (false)
{
+ d_acc = 0; // start accumulator at 0
+
/* The number of filters is specified by the user as the filter size;
this is also the interpolation rate of the filter. We use it and the
rate provided to determine the decimation rate. This acts as a
// Create an FIR filter for each channel and zero out the taps
std::vector<float> vtaps(0, d_int_rate);
- for(int i = 0; i < d_int_rate; i++) {
+ for(unsigned int i = 0; i < d_int_rate; i++) {
d_filters[i] = gr_fir_util::create_gr_fir_ccf(vtaps);
d_diff_filters[i] = gr_fir_util::create_gr_fir_ccf(vtaps);
}
// Now, actually set the filters' taps
std::vector<float> dtaps;
create_diff_taps(taps, dtaps);
- set_taps(taps, d_taps, d_filters);
- set_taps(dtaps, d_dtaps, d_diff_filters);
+ create_taps(taps, d_taps, d_filters);
+ create_taps(dtaps, d_dtaps, d_diff_filters);
+
+ set_relative_rate(rate);
}
gr_pfb_arb_resampler_ccf::~gr_pfb_arb_resampler_ccf ()
}
void
-gr_pfb_arb_resampler_ccf::set_taps (const std::vector<float> &newtaps,
- std::vector< std::vector<float> > &ourtaps,
- std::vector<gr_fir_ccf*> &ourfilter)
+gr_pfb_arb_resampler_ccf::create_taps (const std::vector<float> &newtaps,
+ std::vector< std::vector<float> > &ourtaps,
+ std::vector<gr_fir_ccf*> &ourfilter)
{
- int i,j;
-
unsigned int ntaps = newtaps.size();
d_taps_per_filter = (unsigned int)ceil((double)ntaps/(double)d_int_rate);
}
// Partition the filter
- for(i = 0; i < d_int_rate; i++) {
+ for(unsigned int i = 0; i < d_int_rate; i++) {
// Each channel uses all d_taps_per_filter with 0's if not enough taps to fill out
ourtaps[d_int_rate-1-i] = std::vector<float>(d_taps_per_filter, 0);
- for(j = 0; j < d_taps_per_filter; j++) {
+ for(unsigned int j = 0; j < d_taps_per_filter; j++) {
ourtaps[d_int_rate - 1 - i][j] = tmp_taps[i + j*d_int_rate];
}
gr_pfb_arb_resampler_ccf::create_diff_taps(const std::vector<float> &newtaps,
std::vector<float> &difftaps)
{
- float maxtap = 1e-20;
+ // Calculate the differential taps (derivative filter) by taking the difference
+ // between two taps. Duplicate the last one to make both filters the same length.
+ float tap;
difftaps.clear();
- difftaps.push_back(0); //newtaps[0]);
- for(unsigned int i = 1; i < newtaps.size()-1; i++) {
- float tap = newtaps[i+1] - newtaps[i-1];
+ for(unsigned int i = 0; i < newtaps.size()-1; i++) {
+ tap = newtaps[i+1] - newtaps[i];
difftaps.push_back(tap);
- if(tap > maxtap) {
- maxtap = tap;
- }
- }
- difftaps.push_back(0);//-newtaps[newtaps.size()-1]);
-
- // Scale the differential taps; helps scale error term to better update state
- // FIXME: should this be scaled this way or use the same gain as the taps?
- for(unsigned int i = 0; i < difftaps.size(); i++) {
- difftaps[i] /= maxtap;
}
+ difftaps.push_back(tap);
}
void
return 0; // history requirements may have changed.
}
- int i = 0, j, count = d_start_index;
+ int i = 0, count = d_start_index;
+ unsigned int j;
gr_complex o0, o1;
// Restore the last filter position
j = d_last_filter;
// produce output as long as we can and there are enough input samples
- while((i < noutput_items) && (count < ninput_items[0]-1)) {
+ int max_input = ninput_items[0]-(int)d_taps_per_filter;
+ while((i < noutput_items) && (count < max_input)) {
// start j by wrapping around mod the number of channels
while((j < d_int_rate) && (i < noutput_items)) {
- // Take the current filter output
+ // Take the current filter and derivative filter output
o0 = d_filters[j]->filter(&in[count]);
o1 = d_diff_filters[j]->filter(&in[count]);
- out[i] = o0 + o1*d_flt_rate; // linearly interpolate between samples
+ out[i] = o0 + o1*d_acc; // linearly interpolate between samples
i++;
-
- j += d_dec_rate;
+
+ // Adjust accumulator and index into filterbank
+ d_acc += d_flt_rate;
+ j += d_dec_rate + (int)floor(d_acc);
+ d_acc = fmodf(d_acc, 1.0);
}
if(i < noutput_items) { // keep state for next entry
float ss = (int)(j / d_int_rate); // number of items to skip ahead by