README change

1 files changed, 64 insertions, 0 deletions

diff --git a/gr-blocks/lib/nlog10_ff_impl.cc b/gr-blocks/lib/nlog10_ff_impl.cc
new file mode 100644
index 000000000..f662b8fd5
--- /dev/null
+++ b/gr-blocks/lib/nlog10_ff_impl.cc
@@ -0,0 +1,64 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 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 "nlog10_ff_impl.h"
+#include <gr_io_signature.h>
+
+namespace gr {
+  namespace blocks {
+
+    nlog10_ff::sptr nlog10_ff::make(float n, size_t vlen, float k)
+    {
+      return gnuradio::get_initial_sptr(new nlog10_ff_impl(n, vlen, k));
+    }
+
+    nlog10_ff_impl::nlog10_ff_impl(float n, size_t vlen, float k)
+      : gr_sync_block("nlog10_ff",
+		      gr_make_io_signature (1, 1, sizeof(float)*vlen),
+		      gr_make_io_signature (1, 1, sizeof(float)*vlen)),
+	d_n(n), d_vlen(vlen), d_k(k)
+    {
+    }
+
+    int
+    nlog10_ff_impl::work(int noutput_items,
+			      gr_vector_const_void_star &input_items,
+			      gr_vector_void_star &output_items)
+    {
+      const float *in = (const float *) input_items[0];
+      float *out = (float *) output_items[0];
+      int noi = noutput_items * d_vlen;
+      float n = d_n;
+      float k = d_k;
+
+      for (int i = 0; i < noi; i++)
+	out[i] = n * log10(std::max(in[i], (float) 1e-18)) + k;
+
+      return noutput_items;
+    }
+
+  } /* namespace blocks */
+}/* namespace gr */