gr-fft: creates a gr-fft top-level component.

1 files changed, 147 insertions, 0 deletions

diff --git a/gr-fft/lib/fft_vcc_fftw.cc b/gr-fft/lib/fft_vcc_fftw.cc
new file mode 100644
index 000000000..92441f0d3
--- /dev/null
+++ b/gr-fft/lib/fft_vcc_fftw.cc
@@ -0,0 +1,147 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2004,2007,2008,2010,2012 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "fft_vcc_fftw.h"
+#include <gr_io_signature.h>
+#include <math.h>
+#include <string.h>
+
+namespace gr {
+  namespace fft {
+    
+    fft_vcc::sptr fft_vcc::make(int fft_size, bool forward,
+				const std::vector<float> &window,
+				bool shift, int nthreads)
+    {
+      return gnuradio::get_initial_sptr(new fft_vcc_fftw
+					(fft_size, forward, window,
+					 shift, nthreads));
+    }
+
+    fft_vcc_fftw::fft_vcc_fftw(int fft_size, bool forward,
+			       const std::vector<float> &window,
+			       bool shift, int nthreads)
+      : gr_sync_block("fft_vcc_fftw",
+		      gr_make_io_signature(1, 1, fft_size * sizeof(gr_complex)),
+		      gr_make_io_signature(1, 1, fft_size * sizeof(gr_complex))),
+	d_fft_size(fft_size), d_forward(forward), d_shift(shift)
+    {
+      d_fft = new fft_impl_fft_complex(d_fft_size, forward, nthreads);
+    }
+
+    fft_vcc_fftw::~fft_vcc_fftw()
+    {
+      delete d_fft;
+    }
+
+    void
+    fft_vcc_fftw::set_nthreads(int n)
+    {
+      d_fft->set_nthreads(n);
+    }
+
+    int
+    fft_vcc_fftw::nthreads() const
+    {
+      return d_fft->nthreads();
+    }
+
+    bool
+    fft_vcc_fftw::set_window(const std::vector<float> &window)
+    {
+      if(window.size()==0 || window.size()==d_fft_size) {
+	d_window=window;
+	return true;
+      }
+      else
+	return false;
+    }
+
+    int
+    fft_vcc_fftw::work(int noutput_items,
+		       gr_vector_const_void_star &input_items,
+		       gr_vector_void_star &output_items)
+    {
+      const gr_complex *in = (const gr_complex *) input_items[0];
+      gr_complex *out = (gr_complex *) output_items[0];
+      
+      unsigned int input_data_size = input_signature()->sizeof_stream_item (0);
+      unsigned int output_data_size = output_signature()->sizeof_stream_item (0);
+      
+      int count = 0;
+      
+      while(count++ < noutput_items) {
+	
+	// copy input into optimally aligned buffer
+	if(d_window.size()) {
+	  gr_complex *dst = d_fft->get_inbuf();
+	  if(!d_forward && d_shift) {
+	    unsigned int offset = (!d_forward && d_shift)?(d_fft_size/2):0;
+	    int fft_m_offset = d_fft_size - offset;
+	    for(unsigned int i = 0; i < offset; i++)		// apply window
+	      dst[i+fft_m_offset] = in[i] * d_window[i];
+	    for(unsigned int i = offset; i < d_fft_size; i++)	// apply window
+	      dst[i-offset] = in[i] * d_window[i];
+	  } 
+	  else {
+	    for(unsigned int i = 0; i < d_fft_size; i++)		// apply window
+	      dst[i] = in[i] * d_window[i];
+	  }
+	}
+	else {
+	  if(!d_forward && d_shift) {  // apply an ifft shift on the data
+	    gr_complex *dst = d_fft->get_inbuf();
+	    unsigned int len = (unsigned int)(floor(d_fft_size/2.0)); // half length of complex array
+	    memcpy(&dst[0], &in[len], sizeof(gr_complex)*(d_fft_size - len));
+	    memcpy(&dst[d_fft_size - len], &in[0], sizeof(gr_complex)*len);
+	  }
+	  else {
+	    memcpy(d_fft->get_inbuf(), in, input_data_size);
+	  }
+	}
+	
+	// compute the fft
+	d_fft->execute();
+	
+	// copy result to our output
+	if(d_forward && d_shift) {  // apply a fft shift on the data
+	  unsigned int len = (unsigned int)(ceil(d_fft_size/2.0));
+	  memcpy(&out[0], &d_fft->get_outbuf()[len], sizeof(gr_complex)*(d_fft_size - len));
+	  memcpy(&out[d_fft_size - len], &d_fft->get_outbuf()[0], sizeof(gr_complex)*len);
+	}
+	else {
+	  memcpy (out, d_fft->get_outbuf (), output_data_size);
+	}
+	
+	in  += d_fft_size;
+	out += d_fft_size;
+      }
+      
+      return noutput_items;
+    }
+
+  } /* namespace fft */
+} /* namespace gr */