Imported Upstream version 3.2.2

[debian/gnuradio] / gnuradio-core / src / lib / general / gr_decode_ccsds_27_fb.cc

diff --git a/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.cc b/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.cc
new file mode 100644 (file)
index 0000000..add036f
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.cc
@@ -0,0 +1,86 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ * 
+ * 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 <gr_decode_ccsds_27_fb.h>
+#include <gr_io_signature.h>
+
+gr_decode_ccsds_27_fb_sptr 
+gr_make_decode_ccsds_27_fb()
+{
+  return gr_decode_ccsds_27_fb_sptr(new gr_decode_ccsds_27_fb());
+}
+
+gr_decode_ccsds_27_fb::gr_decode_ccsds_27_fb()
+  : gr_sync_decimator("decode_ccsds_27_fb",
+                     gr_make_io_signature(1, 1, sizeof(float)),
+                     gr_make_io_signature(1, 1, sizeof(char)),
+                     2*8)  // Rate 1/2 code, unpacked to packed translation
+{
+    float RATE = 0.5;
+    float ebn0 = 12.0;
+    float esn0 = RATE*pow(10.0, ebn0/10);
+
+    gen_met(d_mettab, 100, esn0, 0.0, 256);
+    viterbi_chunks_init(d_state0);
+}
+
+gr_decode_ccsds_27_fb::~gr_decode_ccsds_27_fb()
+{
+}
+
+int 
+gr_decode_ccsds_27_fb::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];
+  unsigned char *out = (unsigned char *)output_items[0];
+
+  for (int i = 0; i < noutput_items*16; i++) {
+    // Translate and clip [-1.0..1.0] to [28..228]
+    float sample = in[i]*100.0+128.0;
+    if (sample > 255.0)
+       sample = 255.0;
+    else if (sample < 0.0)
+       sample = 0.0;
+    unsigned char sym = (unsigned char)(floor(sample));
+    
+    d_viterbi_in[d_count % 4] = sym;
+    if ((d_count % 4) == 3) {
+      // Every fourth symbol, perform butterfly operation
+      viterbi_butterfly2(d_viterbi_in, d_mettab, d_state0, d_state1);
+      
+      // Every sixteenth symbol, read out a byte
+      if (d_count % 16 == 11) {
+       // long metric = 
+       viterbi_get_output(d_state0, out++);
+       // printf("%li\n", *(out-1), metric);
+      }
+    }
+    
+    d_count++;
+  }
+
+  return noutput_items;
+}