From a52f9a19581901beabc9111917965b9817231014 Mon Sep 17 00:00:00 2001
From: jcorgan
Date: Tue, 15 Apr 2008 21:31:29 +0000
Subject: Merged r8195:8205 from jcorgan/ecc into trunk.  Adds convolutional
 encoder and decoder corresponding to the R=1/2, K=7 CCSDS standard
 ("Voyager").

This code is a GNU Radio wrapper around a 1995-era KA9Q portable-C 
implementation, and is designed for continuous streaming data, not packets.

The encoder takes MSB packed bytes and outputs channel symbols 0 or 1.

The decoder uses soft-decision Viterbi decoding on a floating point stream of
(possibly noise corrupted) [1.0, 1.0] symbols, and outputs MSB packed
decoded bytes.

Benchmarking on a 2.16 GHz Intel Core 2 Duo shows 4.7 Mbps decoding rate at 
100% CPU usage (single core).  (There is a newer KA9Q library that implements 
SIMD speed ups with correspondingly faster performance.)

The KA9Q library is placed into src/lib/viterbi.  It could use some cleanup,
file/function renaming, and refactoring, or even replacement with the newer
libfec code that is available.



git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@8206 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/Makefile.am |  41 ++++
 gnuradio-core/src/lib/viterbi/decode.cc   |  88 ++++++++
 gnuradio-core/src/lib/viterbi/encode.cc   |  54 +++++
 gnuradio-core/src/lib/viterbi/metrics.c   | 119 ++++++++++
 gnuradio-core/src/lib/viterbi/tab.c       |  57 +++++
 gnuradio-core/src/lib/viterbi/viterbi.c   | 355 ++++++++++++++++++++++++++++++
 gnuradio-core/src/lib/viterbi/viterbi.h   |  49 +++++
 7 files changed, 763 insertions(+)
 create mode 100644 gnuradio-core/src/lib/viterbi/Makefile.am
 create mode 100644 gnuradio-core/src/lib/viterbi/decode.cc
 create mode 100644 gnuradio-core/src/lib/viterbi/encode.cc
 create mode 100644 gnuradio-core/src/lib/viterbi/metrics.c
 create mode 100644 gnuradio-core/src/lib/viterbi/tab.c
 create mode 100644 gnuradio-core/src/lib/viterbi/viterbi.c
 create mode 100644 gnuradio-core/src/lib/viterbi/viterbi.h

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
new file mode 100644
index 000000000..3eb1502ba
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/Makefile.am
@@ -0,0 +1,41 @@
+#
+# 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.
+# 
+
+INCLUDES = -Wall -Werror
+LIBS = -lm
+
+noinst_LTLIBRARIES = libviterbi.la
+
+libviterbi_la_SOURCES = \
+    metrics.c		\
+    tab.c		\
+    viterbi.c
+    
+noinst_HEADERS =	\
+    viterbi.h
+
+noinst_PROGRAMS = encode decode
+
+encode_SOURCES = encode.cc
+
+encode_LDADD = libviterbi.la
+
+decode_SOURCES = decode.cc
+
+decode_LDADD = libviterbi.la
diff --git a/gnuradio-core/src/lib/viterbi/decode.cc b/gnuradio-core/src/lib/viterbi/decode.cc
new file mode 100644
index 000000000..6580e4d66
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/decode.cc
@@ -0,0 +1,88 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 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.
+ */
+
+/*
+ * This is a minimal example demonstrating how to call the Viterbi decoder
+ * in continuous streaming mode.  It accepts data on stdin and writes to 
+ * stdout.
+ *
+ */
+
+extern "C" {
+#include "viterbi.h"
+}
+
+#include <cstdio>
+#include <cmath>
+
+#define MAXCHUNKSIZE 4096
+#define MAXENCSIZE MAXCHUNKSIZE*16
+
+int main()
+{
+  unsigned char data[MAXCHUNKSIZE];
+  signed char syms[MAXENCSIZE];
+  int count = 0;
+
+  // Initialize metric table
+  int mettab[2][256];
+  int amp = 100;
+  float RATE=0.5;
+  float ebn0 = 12.0;
+  float esn0 = RATE*pow(10.0, ebn0/10);
+  gen_met(mettab, amp, esn0, 0.0, 4);
+
+  // Initialize decoder state
+  struct viterbi_state state0[64];
+  struct viterbi_state state1[64];
+  unsigned char viterbi_in[16];
+  viterbi_chunks_init(state0);  
+
+  while (!feof(stdin)) {
+    unsigned int n = fread(syms, 1, MAXENCSIZE, stdin);
+    unsigned char *out = data;
+    
+    for (unsigned int i = 0; i < n; i++) {
+
+      // FIXME: This implements hard decoding by slicing the input stream
+      unsigned char sym = syms[i] > 0 ? -amp : amp;
+
+      // Write the symbol to the decoder input
+      viterbi_in[count % 4] = sym;
+
+      // Every four symbols, perform the butterfly2 operation
+      if ((count % 4) == 3) {
+        viterbi_butterfly2(viterbi_in, mettab, state0, state1);      
+
+	// Every sixteen symbols, perform the readback operation
+        if ((count > 64) && (count % 16) == 11) {
+          viterbi_get_output(state0, out);
+	  fwrite(out++, 1, 1, stdout);
+	}
+      }
+      
+      count++;
+    }    
+  }
+
+  return 0;
+}
diff --git a/gnuradio-core/src/lib/viterbi/encode.cc b/gnuradio-core/src/lib/viterbi/encode.cc
new file mode 100644
index 000000000..01acb3987
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/encode.cc
@@ -0,0 +1,54 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 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.
+ */
+
+/*
+ * This is a minimal example demonstrating how to call the ECC encoder
+ * in continuous streaming mode.  It accepts data on stdin and writes to 
+ * stdout.
+ * 
+ * FIXME: This does not flush the final bits out of the encoder.
+ *
+ */
+
+extern "C" {
+#include "viterbi.h"
+}
+
+#include <cstdio>
+
+#define MAXCHUNKSIZE 4096
+#define MAXENCSIZE MAXCHUNKSIZE*16
+
+int main()
+{
+  unsigned char encoder_state = 0;
+  unsigned char data[MAXCHUNKSIZE];
+  unsigned char syms[MAXENCSIZE];
+  
+  while (!feof(stdin)) {
+    unsigned int n = fread(data, 1, MAXCHUNKSIZE, stdin);
+    encoder_state = encode(syms, data, n, encoder_state);
+    fwrite(syms, 1, n*16, stdout);
+  }
+
+  return 0;
+}
diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
new file mode 100644
index 000000000..74f8ce09d
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright 1995 Phil Karn, KA9Q
+ * Copyright 2008 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.
+ */
+
+/* 
+ * Generate metric tables for a soft-decision convolutional decoder
+ * assuming gaussian noise on a PSK channel.
+ *
+ * Works from "first principles" by evaluating the normal probability
+ * function and then computing the log-likelihood function
+ * for every possible received symbol value
+ *
+ */
+
+/* Symbols are offset-binary, with 128 corresponding to an erased (no
+ * information) symbol
+ */
+#define	OFFSET	128
+
+#include <stdlib.h>
+#include <math.h>
+
+/* Normal function integrated from -Inf to x. Range: 0-1 */
+#define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
+
+/* Logarithm base 2 */
+#define	log2(x)	(log(x)*M_LOG2E)
+
+/* Generate log-likelihood metrics for 8-bit soft quantized channel
+ * assuming AWGN and BPSK
+ */
+void
+gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
+	int amp,		/* Signal amplitude, units */
+	double esn0,		/* Es/N0 ratio in dB */
+	double bias,		/* Metric bias; 0 for viterbi, rate for sequential */
+	int scale)		/* Scale factor */
+{
+  double noise;
+  int s,bit;
+  double metrics[2][256];
+  double p0,p1;
+  
+  /* Es/N0 as power ratio */
+  esn0 = pow(10.,esn0/10);
+  
+  noise = 0.5/esn0;	/* only half the noise for BPSK */
+  noise = sqrt(noise);	/* noise/signal Voltage ratio */
+  
+  /* Zero is a special value, since this sample includes all
+   * lower samples that were clipped to this value, i.e., it
+   * takes the whole lower tail of the curve 
+   */
+  p1 = normal(((0-OFFSET+0.5)/amp - 1)/noise);	/* P(s|1) */
+  
+  /* Prob of this value occurring for a 0-bit */	/* P(s|0) */
+  p0 = normal(((0-OFFSET+0.5)/amp + 1)/noise);
+  metrics[0][0] = log2(2*p0/(p1+p0)) - bias;
+  metrics[1][0] = log2(2*p1/(p1+p0)) - bias;
+  
+  for(s=1;s<255;s++){
+    /* P(s|1), prob of receiving s given 1 transmitted */
+    p1 = normal(((s-OFFSET+0.5)/amp - 1)/noise) -
+      normal(((s-OFFSET-0.5)/amp - 1)/noise);
+    
+    /* P(s|0), prob of receiving s given 0 transmitted */
+    p0 = normal(((s-OFFSET+0.5)/amp + 1)/noise) -
+      normal(((s-OFFSET-0.5)/amp + 1)/noise);
+    
+#ifdef notdef
+    printf("P(%d|1) = %lg, P(%d|0) = %lg\n",s,p1,s,p0);
+#endif
+    metrics[0][s] = log2(2*p0/(p1+p0)) - bias;
+    metrics[1][s] = log2(2*p1/(p1+p0)) - bias;
+  }
+  /* 255 is also a special value */
+  /* P(s|1) */
+  p1 = 1 - normal(((255-OFFSET-0.5)/amp - 1)/noise);
+  /* P(s|0) */
+  p0 = 1 - normal(((255-OFFSET-0.5)/amp + 1)/noise);
+  
+  metrics[0][255] = log2(2*p0/(p1+p0)) - bias;
+  metrics[1][255] = log2(2*p1/(p1+p0)) - bias;
+#ifdef	notdef
+  /* The probability of a raw symbol error is the probability
+   * that a 1-bit would be received as a sample with value
+   * 0-128. This is the offset normal curve integrated from -Inf to 0.
+   */
+  printf("symbol Pe = %lg\n",normal(-1/noise));
+#endif
+  for(bit=0;bit<2;bit++){
+    for(s=0;s<256;s++){
+      /* Scale and round to nearest integer */
+      mettab[bit][s] = floor(metrics[bit][s] * scale + 0.5);
+#ifdef	notdef
+      printf("metrics[%d][%d] = %lg, mettab = %d\n",
+	     bit,s,metrics[bit][s],mettab[bit][s]);
+#endif
+    }
+  }
+}
diff --git a/gnuradio-core/src/lib/viterbi/tab.c b/gnuradio-core/src/lib/viterbi/tab.c
new file mode 100644
index 000000000..1133c6308
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/tab.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright 1995 Phil Karn, KA9Q
+ * Copyright 2008 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.
+ */
+
+/* 8-bit parity lookup table, generated by partab.c */
+unsigned char Partab[] = {
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+};
diff --git a/gnuradio-core/src/lib/viterbi/viterbi.c b/gnuradio-core/src/lib/viterbi/viterbi.c
new file mode 100644
index 000000000..9f5c1e72a
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/viterbi.c
@@ -0,0 +1,355 @@
+/*
+ * Copyright 1995 Phil Karn, KA9Q
+ * Copyright 2008 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.
+ */
+
+/* 
+ * Viterbi decoder for K=7 rate=1/2 convolutional code
+ * Some modifications from original Karn code by Matt Ettus
+ */
+
+#include "viterbi.h"
+
+/* The two generator polynomials for the NASA Standard K=7 code.
+ * Since these polynomials are known to be optimal for this constraint
+ * length there is not much point in changing them. But if you do, you
+ * will have to regenerate the BUTTERFLY macro calls in viterbi()
+ */
+#define	POLYA	0x6d
+#define	POLYB	0x4f
+
+/* The basic Viterbi decoder operation, called a "butterfly"
+ * operation because of the way it looks on a trellis diagram. Each
+ * butterfly involves an Add-Compare-Select (ACS) operation on the two nodes
+ * where the 0 and 1 paths from the current node merge at the next step of
+ * the trellis.
+ *
+ * The code polynomials are assumed to have 1's on both ends. Given a
+ * function encode_state() that returns the two symbols for a given
+ * encoder state in the low two bits, such a code will have the following
+ * identities for even 'n' < 64:
+ *
+ * 	encode_state(n) = encode_state(n+65)
+ *	encode_state(n+1) = encode_state(n+64) = (3 ^ encode_state(n))
+ *
+ * Any convolutional code you would actually want to use will have
+ * these properties, so these assumptions aren't too limiting.
+ *
+ * Doing this as a macro lets the compiler evaluate at compile time the
+ * many expressions that depend on the loop index and encoder state and
+ * emit them as immediate arguments.
+ * This makes an enormous difference on register-starved machines such
+ * as the Intel x86 family where evaluating these expressions at runtime
+ * would spill over into memory.
+ */
+#define	BUTTERFLY(i,sym) { \
+	int m0,m1;\
+\
+	/* ACS for 0 branch */\
+	m0 = state[i].metric + mets[sym];	/* 2*i */\
+	m1 = state[i+32].metric + mets[3^sym];	/* 2*i + 64 */\
+	if(m0 > m1){\
+		next[2*i].metric = m0;\
+		next[2*i].path = state[i].path << 1;\
+	} else {\
+		next[2*i].metric = m1;\
+		next[2*i].path = (state[i+32].path << 1)|1;\
+	}\
+	/* ACS for 1 branch */\
+	m0 = state[i].metric + mets[3^sym];	/* 2*i + 1 */\
+	m1 = state[i+32].metric + mets[sym];	/* 2*i + 65 */\
+	if(m0 > m1){\
+		next[2*i+1].metric = m0;\
+		next[2*i+1].path = state[i].path << 1;\
+	} else {\
+		next[2*i+1].metric = m1;\
+		next[2*i+1].path = (state[i+32].path << 1)|1;\
+	}\
+}
+
+extern unsigned char Partab[];	/* Parity lookup table */
+
+/* Convolutionally encode data into binary symbols */
+unsigned char
+encode(unsigned char *symbols,
+       unsigned char *data,
+       unsigned int nbytes,
+       unsigned char encstate)
+{
+  int i;
+  
+  while(nbytes-- != 0){
+    for(i=7;i>=0;i--){
+      encstate = (encstate << 1) | ((*data >> i) & 1);
+      *symbols++ = Partab[encstate & POLYA];
+      *symbols++ = Partab[encstate & POLYB];
+    }
+    data++;
+  }
+  
+  return encstate;
+}
+
+/* Viterbi decoder */
+int
+viterbi(unsigned long *metric,	/* Final path metric (returned value) */
+	unsigned char *data,	/* Decoded output data */
+	unsigned char *symbols,	/* Raw deinterleaved input symbols */
+	unsigned int nbits,	/* Number of output bits */
+	int mettab[2][256]	/* Metric table, [sent sym][rx symbol] */
+	){
+  unsigned int bitcnt = 0;
+  int mets[4];
+  long bestmetric;
+  int beststate,i;
+  struct viterbi_state state0[64],state1[64],*state,*next;
+  
+  state = state0;
+  next = state1;
+  
+  /* Initialize starting metrics to prefer 0 state */
+  state[0].metric = 0;
+  for(i=1;i<64;i++)
+    state[i].metric = -999999;
+  state[0].path = 0;
+  
+  for(bitcnt = 0;bitcnt < nbits;bitcnt++){
+    /* Read input symbol pair and compute all possible branch
+     * metrics
+     */
+    mets[0] = mettab[0][symbols[0]] + mettab[0][symbols[1]];
+    mets[1] = mettab[0][symbols[0]] + mettab[1][symbols[1]];
+    mets[2] = mettab[1][symbols[0]] + mettab[0][symbols[1]];
+    mets[3] = mettab[1][symbols[0]] + mettab[1][symbols[1]];
+    symbols += 2;
+
+    /* These macro calls were generated by genbut.c */
+    BUTTERFLY(0,0);
+    BUTTERFLY(1,1);
+    BUTTERFLY(2,3);
+    BUTTERFLY(3,2);
+    BUTTERFLY(4,3);
+    BUTTERFLY(5,2);
+    BUTTERFLY(6,0);
+    BUTTERFLY(7,1);
+    BUTTERFLY(8,0);
+    BUTTERFLY(9,1);
+    BUTTERFLY(10,3);
+    BUTTERFLY(11,2);
+    BUTTERFLY(12,3);
+    BUTTERFLY(13,2);
+    BUTTERFLY(14,0);
+    BUTTERFLY(15,1);
+    BUTTERFLY(16,2);
+    BUTTERFLY(17,3);
+    BUTTERFLY(18,1);
+    BUTTERFLY(19,0);
+    BUTTERFLY(20,1);
+    BUTTERFLY(21,0);
+    BUTTERFLY(22,2);
+    BUTTERFLY(23,3);
+    BUTTERFLY(24,2);
+    BUTTERFLY(25,3);
+    BUTTERFLY(26,1);
+    BUTTERFLY(27,0);
+    BUTTERFLY(28,1);
+    BUTTERFLY(29,0);
+    BUTTERFLY(30,2);
+    BUTTERFLY(31,3);
+    
+    /* Swap current and next states */
+    if(bitcnt & 1){
+      state = state0;
+      next = state1;
+    } else {
+      state = state1;
+      next = state0;
+    }
+    // ETTUS
+    //if(bitcnt > nbits-7){
+    /* In tail, poison non-zero nodes */
+    //for(i=1;i<64;i += 2)
+    //	state[i].metric = -9999999;
+    //}
+    /* Produce output every 8 bits once path memory is full */
+    if((bitcnt % 8) == 5 && bitcnt > 32){
+      /* Find current best path */
+      bestmetric = state[0].metric;
+      beststate = 0;
+      for(i=1;i<64;i++){
+	if(state[i].metric > bestmetric){
+	  bestmetric = state[i].metric;
+	  beststate = i;
+	}
+      }
+#ifdef	notdef
+      printf("metrics[%d] = %d state = %lx\n",beststate,
+	     state[beststate].metric,state[beststate].path);
+#endif
+      *data++ = state[beststate].path >> 24;
+    }
+    
+  }
+  /* Output remaining bits from 0 state */
+  // ETTUS  Find best state instead
+  bestmetric = state[0].metric;
+  beststate = 0;
+  for(i=1;i<64;i++){
+    if(state[i].metric > bestmetric){
+      bestmetric = state[i].metric;
+      beststate = i;
+    }
+  }
+  if((i = bitcnt % 8) != 6)
+    state[beststate].path <<= 6-i;
+  
+  *data++ = state[beststate].path >> 24;
+  *data++ = state[beststate].path >> 16;
+  *data++ = state[beststate].path >> 8;
+  *data = state[beststate].path;
+  //printf ("BS = %d\tBSM = %d\tM0 = %d\n",beststate,state[beststate].metric,state[0].metric);
+  *metric = state[beststate].metric;
+  return 0;
+}
+
+
+void
+viterbi_chunks_init(struct viterbi_state* state) {
+  // Initialize starting metrics to prefer 0 state
+  int i;
+  state[0].metric = 0;
+  state[0].path = 0;
+  for(i=1;i<64;i++)
+    state[i].metric = -999999;
+}
+
+void
+viterbi_butterfly8(unsigned char *symbols, int mettab[2][256], struct viterbi_state *state0, struct viterbi_state *state1)
+{
+  unsigned int bitcnt;
+  int mets[4];
+  
+  struct viterbi_state *state, *next;
+  state = state0;
+  next = state1;
+  // Operate on 16 symbols (8 bits) at a time
+  for(bitcnt = 0;bitcnt < 8;bitcnt++){
+    // Read input symbol pair and compute all possible branch metrics
+    mets[0] = mettab[0][symbols[0]] + mettab[0][symbols[1]];
+    mets[1] = mettab[0][symbols[0]] + mettab[1][symbols[1]];
+    mets[2] = mettab[1][symbols[0]] + mettab[0][symbols[1]];
+    mets[3] = mettab[1][symbols[0]] + mettab[1][symbols[1]];
+    symbols += 2;
+    
+    // These macro calls were generated by genbut.c 
+    BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
+    BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
+    BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
+    BUTTERFLY(12,3);BUTTERFLY(13,2);BUTTERFLY(14,0);BUTTERFLY(15,1);
+    BUTTERFLY(16,2);BUTTERFLY(17,3);BUTTERFLY(18,1);BUTTERFLY(19,0);
+    BUTTERFLY(20,1);BUTTERFLY(21,0);BUTTERFLY(22,2);BUTTERFLY(23,3);
+    BUTTERFLY(24,2);BUTTERFLY(25,3);BUTTERFLY(26,1);BUTTERFLY(27,0);
+    BUTTERFLY(28,1);BUTTERFLY(29,0);BUTTERFLY(30,2);BUTTERFLY(31,3);
+    
+    // Swap current and next states
+    if(bitcnt & 1){
+      state = state0;
+      next = state1;
+    } else {
+      state = state1;
+      next = state0;
+    }
+  }
+}
+
+void
+viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], struct viterbi_state *state0, struct viterbi_state *state1)
+{
+  //unsigned int bitcnt;
+  int mets[4];
+  
+  struct viterbi_state *state, *next;
+  state = state0;
+  next = state1;
+  // Operate on 4 symbols (2 bits) at a time
+  
+  // Read input symbol pair and compute all possible branch metrics
+  mets[0] = mettab[0][symbols[0]] + mettab[0][symbols[1]];
+  mets[1] = mettab[0][symbols[0]] + mettab[1][symbols[1]];
+  mets[2] = mettab[1][symbols[0]] + mettab[0][symbols[1]];
+  mets[3] = mettab[1][symbols[0]] + mettab[1][symbols[1]];
+  
+  // These macro calls were generated by genbut.c 
+  BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
+  BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
+  BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
+  BUTTERFLY(12,3);BUTTERFLY(13,2);BUTTERFLY(14,0);BUTTERFLY(15,1);
+  BUTTERFLY(16,2);BUTTERFLY(17,3);BUTTERFLY(18,1);BUTTERFLY(19,0);
+  BUTTERFLY(20,1);BUTTERFLY(21,0);BUTTERFLY(22,2);BUTTERFLY(23,3);
+  BUTTERFLY(24,2);BUTTERFLY(25,3);BUTTERFLY(26,1);BUTTERFLY(27,0);
+  BUTTERFLY(28,1);BUTTERFLY(29,0);BUTTERFLY(30,2);BUTTERFLY(31,3);
+  
+  state = state1;
+  next = state0;
+  
+  // Read input symbol pair and compute all possible branch metrics
+  mets[0] = mettab[0][symbols[2]] + mettab[0][symbols[3]];
+  mets[1] = mettab[0][symbols[2]] + mettab[1][symbols[3]];
+  mets[2] = mettab[1][symbols[2]] + mettab[0][symbols[3]];
+  mets[3] = mettab[1][symbols[2]] + mettab[1][symbols[3]];
+  
+  // These macro calls were generated by genbut.c 
+  BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
+  BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
+  BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
+  BUTTERFLY(12,3);BUTTERFLY(13,2);BUTTERFLY(14,0);BUTTERFLY(15,1);
+  BUTTERFLY(16,2);BUTTERFLY(17,3);BUTTERFLY(18,1);BUTTERFLY(19,0);
+  BUTTERFLY(20,1);BUTTERFLY(21,0);BUTTERFLY(22,2);BUTTERFLY(23,3);
+  BUTTERFLY(24,2);BUTTERFLY(25,3);BUTTERFLY(26,1);BUTTERFLY(27,0);
+  BUTTERFLY(28,1);BUTTERFLY(29,0);BUTTERFLY(30,2);BUTTERFLY(31,3);
+}
+
+unsigned char
+viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf) {
+  // Produce output every 8 bits once path memory is full 
+  //  if((bitcnt % 8) == 5 && bitcnt > 32) {
+  
+  //  Find current best path
+  unsigned int i,beststate;
+  int bestmetric;
+  
+  bestmetric = state[0].metric;
+  beststate = 0;
+  for(i=1;i<64;i++)
+    if(state[i].metric > bestmetric) {
+      bestmetric = state[i].metric;
+      beststate = i;
+    }
+  *outbuf =  state[beststate].path >> 24;
+  return bestmetric;
+}
+
+
+//printf ("BS = %d\tBSM = %d\tM0 = %d\n",beststate,state[beststate].metric,state[0].metric);
+// In tail, poison non-zero nodes
+//if(bits_out > packet_size-7)
+//  for(i=1;i<64;i += 2)
+//    state[i].metric = -9999999;
+
diff --git a/gnuradio-core/src/lib/viterbi/viterbi.h b/gnuradio-core/src/lib/viterbi/viterbi.h
new file mode 100644
index 000000000..155b0d93a
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/viterbi.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2008 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.
+ */
+
+/* The path memory for each state is 32 bits. This is slightly shorter
+ * than we'd like for K=7, especially since we chain back every 8 bits.
+ * But it fits so nicely into a 32-bit machine word...
+ */
+struct viterbi_state {
+  unsigned long path;	/* Decoded path to this state */
+  long metric;		/* Cumulative metric to this state */
+};
+
+int gen_met(int mettab[2][256],	/* Metric table */
+	    int amp,		/* Signal amplitude */
+	    double esn0,	/* Es/N0 ratio in dB */
+	    double bias, 	/* Metric bias */
+	    int scale);		/* Scale factor */
+
+unsigned char
+encode(unsigned char *symbols, unsigned char *data,
+       unsigned int nbytes,unsigned char encstate);
+
+void 
+viterbi_chunks_init(struct viterbi_state* state);
+
+void 
+viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], 
+		   struct viterbi_state *state0, struct viterbi_state *state1);
+
+unsigned char
+viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf);
-- 
cgit 


From 07383f3191c80c2d59535d72d5dc1c92075b0f49 Mon Sep 17 00:00:00 2001
From: eb
Date: Thu, 8 May 2008 03:57:47 +0000
Subject: fix for ticket:243

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@8318 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/metrics.c | 3 ---
 1 file changed, 3 deletions(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 74f8ce09d..3351ff403 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -41,9 +41,6 @@
 /* Normal function integrated from -Inf to x. Range: 0-1 */
 #define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
 
-/* Logarithm base 2 */
-#define	log2(x)	(log(x)*M_LOG2E)
-
 /* Generate log-likelihood metrics for 8-bit soft quantized channel
  * assuming AWGN and BPSK
  */
-- 
cgit 


From 593a87ce2254a7966d33fa88e2efa9cbbdb4f7f0 Mon Sep 17 00:00:00 2001
From: eb
Date: Thu, 8 May 2008 06:17:55 +0000
Subject: better fix for ticket:243

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@8324 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/metrics.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 3351ff403..2dd4279aa 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -30,6 +30,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 /* Symbols are offset-binary, with 128 corresponding to an erased (no
  * information) symbol
  */
@@ -41,6 +45,12 @@
 /* Normal function integrated from -Inf to x. Range: 0-1 */
 #define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
 
+/* Logarithm base 2 */ 
+double log2(double);		/* declaration seems to be missing from some math.h's */
+#if !defined(HAVE_LOG2)
+#define log2(x) (log(x)*M_LOG2E)
+#endif
+
 /* Generate log-likelihood metrics for 8-bit soft quantized channel
  * assuming AWGN and BPSK
  */
-- 
cgit 


From 0da73b85fc0a8bf49e84c46e29b045d76defa984 Mon Sep 17 00:00:00 2001
From: eb
Date: Sat, 23 Aug 2008 18:46:04 +0000
Subject: fix for ticket:243

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9381 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/metrics.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 2dd4279aa..9f958cab7 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -46,10 +46,7 @@
 #define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
 
 /* Logarithm base 2 */ 
-double log2(double);		/* declaration seems to be missing from some math.h's */
-#if !defined(HAVE_LOG2)
-#define log2(x) (log(x)*M_LOG2E)
-#endif
+#define gr_log2(x) (log(x)*M_LOG2E)
 
 /* Generate log-likelihood metrics for 8-bit soft quantized channel
  * assuming AWGN and BPSK
@@ -80,8 +77,8 @@ gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
   
   /* Prob of this value occurring for a 0-bit */	/* P(s|0) */
   p0 = normal(((0-OFFSET+0.5)/amp + 1)/noise);
-  metrics[0][0] = log2(2*p0/(p1+p0)) - bias;
-  metrics[1][0] = log2(2*p1/(p1+p0)) - bias;
+  metrics[0][0] = gr_log2(2*p0/(p1+p0)) - bias;
+  metrics[1][0] = gr_log2(2*p1/(p1+p0)) - bias;
   
   for(s=1;s<255;s++){
     /* P(s|1), prob of receiving s given 1 transmitted */
@@ -95,8 +92,8 @@ gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
 #ifdef notdef
     printf("P(%d|1) = %lg, P(%d|0) = %lg\n",s,p1,s,p0);
 #endif
-    metrics[0][s] = log2(2*p0/(p1+p0)) - bias;
-    metrics[1][s] = log2(2*p1/(p1+p0)) - bias;
+    metrics[0][s] = gr_log2(2*p0/(p1+p0)) - bias;
+    metrics[1][s] = gr_log2(2*p1/(p1+p0)) - bias;
   }
   /* 255 is also a special value */
   /* P(s|1) */
@@ -104,8 +101,8 @@ gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
   /* P(s|0) */
   p0 = 1 - normal(((255-OFFSET-0.5)/amp + 1)/noise);
   
-  metrics[0][255] = log2(2*p0/(p1+p0)) - bias;
-  metrics[1][255] = log2(2*p1/(p1+p0)) - bias;
+  metrics[0][255] = gr_log2(2*p0/(p1+p0)) - bias;
+  metrics[1][255] = gr_log2(2*p1/(p1+p0)) - bias;
 #ifdef	notdef
   /* The probability of a raw symbol error is the probability
    * that a 1-bit would be received as a sample with value
-- 
cgit 


From 48ce0c39329017f236d148bb067d15026f6d5ce9 Mon Sep 17 00:00:00 2001
From: jcorgan
Date: Thu, 2 Oct 2008 23:11:10 +0000
Subject: Removed extraneous flags

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9703 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/Makefile.am | 1 -
 1 file changed, 1 deletion(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
index 3eb1502ba..4b434cb4b 100644
--- a/gnuradio-core/src/lib/viterbi/Makefile.am
+++ b/gnuradio-core/src/lib/viterbi/Makefile.am
@@ -17,7 +17,6 @@
 # Boston, MA 02110-1301, USA.
 # 
 
-INCLUDES = -Wall -Werror
 LIBS = -lm
 
 noinst_LTLIBRARIES = libviterbi.la
-- 
cgit 


From 18f685853b2bf1914148cb07a9c6df76f5063ff3 Mon Sep 17 00:00:00 2001
From: eb
Date: Wed, 13 May 2009 05:29:11 +0000
Subject: Fixes ticket:364, ticket:365.  Merged eb/t364 -r11015:11017 to trunk.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@11018 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/Makefile.am | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
index 4b434cb4b..8384c52f0 100644
--- a/gnuradio-core/src/lib/viterbi/Makefile.am
+++ b/gnuradio-core/src/lib/viterbi/Makefile.am
@@ -17,6 +17,8 @@
 # Boston, MA 02110-1301, USA.
 # 
 
+include $(top_srcdir)/Makefile.common
+
 LIBS = -lm
 
 noinst_LTLIBRARIES = libviterbi.la
@@ -25,7 +27,7 @@ libviterbi_la_SOURCES = \
     metrics.c		\
     tab.c		\
     viterbi.c
-    
+
 noinst_HEADERS =	\
     viterbi.h
 
-- 
cgit 


From 253018c6cdb114f5662a2d7ba8ed748c6e68e3a7 Mon Sep 17 00:00:00 2001
From: git
Date: Fri, 14 Aug 2009 18:10:11 +0000
Subject: Added git ignore files auto created from svn:ignore properties.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@11592 221aa14e-8319-0410-a670-987f0aec2ac5
---
 gnuradio-core/src/lib/viterbi/.gitignore | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 gnuradio-core/src/lib/viterbi/.gitignore

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/.gitignore b/gnuradio-core/src/lib/viterbi/.gitignore
new file mode 100644
index 000000000..85bb5cc04
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/.gitignore
@@ -0,0 +1,6 @@
+/Makefile
+/Makefile.in
+/.libs
+/.deps
+/encode
+/decode
-- 
cgit 


From 1e1798393381fe7472a7cdb5b2c3c90d7ae753fb Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Wed, 20 Jul 2011 18:06:44 -0700
Subject: core: declare erf in case it was missing in math.h and provided for
 by the build system

---
 gnuradio-core/src/lib/viterbi/metrics.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 9f958cab7..77c6a63c8 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -42,6 +42,9 @@
 #include <stdlib.h>
 #include <math.h>
 
+//declare erf in case it was missing in math.h and provided for by the build system
+extern double erf(double x);
+
 /* Normal function integrated from -Inf to x. Range: 0-1 */
 #define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
 
-- 
cgit 


From f914499f4a96fe69ab9cd8dba48f8e3bfc7a54e5 Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Wed, 20 Jul 2011 18:38:36 -0700
Subject: core: API declaration macros for core class and function symbols

---
 gnuradio-core/src/lib/viterbi/Makefile.am |  2 ++
 gnuradio-core/src/lib/viterbi/viterbi.h   | 14 +++++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
index 8384c52f0..1b86a86f8 100644
--- a/gnuradio-core/src/lib/viterbi/Makefile.am
+++ b/gnuradio-core/src/lib/viterbi/Makefile.am
@@ -21,6 +21,8 @@ include $(top_srcdir)/Makefile.common
 
 LIBS = -lm
 
+AM_CPPFLAGS = -I$(top_srcdir)/gnuradio-core/src/lib/general
+
 noinst_LTLIBRARIES = libviterbi.la
 
 libviterbi_la_SOURCES = \
diff --git a/gnuradio-core/src/lib/viterbi/viterbi.h b/gnuradio-core/src/lib/viterbi/viterbi.h
index 155b0d93a..5bb8b357a 100644
--- a/gnuradio-core/src/lib/viterbi/viterbi.h
+++ b/gnuradio-core/src/lib/viterbi/viterbi.h
@@ -23,27 +23,31 @@
  * than we'd like for K=7, especially since we chain back every 8 bits.
  * But it fits so nicely into a 32-bit machine word...
  */
-struct viterbi_state {
+
+#include <gr_core_api.h>
+
+struct GR_CORE_API viterbi_state {
   unsigned long path;	/* Decoded path to this state */
   long metric;		/* Cumulative metric to this state */
 };
 
+GR_CORE_API
 int gen_met(int mettab[2][256],	/* Metric table */
 	    int amp,		/* Signal amplitude */
 	    double esn0,	/* Es/N0 ratio in dB */
 	    double bias, 	/* Metric bias */
 	    int scale);		/* Scale factor */
 
-unsigned char
+GR_CORE_API unsigned char
 encode(unsigned char *symbols, unsigned char *data,
        unsigned int nbytes,unsigned char encstate);
 
-void 
+GR_CORE_API void
 viterbi_chunks_init(struct viterbi_state* state);
 
-void 
+ GR_CORE_API void
 viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], 
 		   struct viterbi_state *state0, struct viterbi_state *state1);
 
-unsigned char
+GR_CORE_API unsigned char
 viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf);
-- 
cgit 


From accb9f2fe8fd8f6a1e114adac5b15304b0e0012d Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Wed, 20 Jul 2011 19:04:32 -0700
Subject: gr: squashed cmakelists.txt into one commit

---
 gnuradio-core/src/lib/viterbi/CMakeLists.txt | 63 ++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 gnuradio-core/src/lib/viterbi/CMakeLists.txt

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/CMakeLists.txt b/gnuradio-core/src/lib/viterbi/CMakeLists.txt
new file mode 100644
index 000000000..aeb8a012d
--- /dev/null
+++ b/gnuradio-core/src/lib/viterbi/CMakeLists.txt
@@ -0,0 +1,63 @@
+# Copyright 2010-2011 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.
+
+########################################################################
+# This file included, use CMake directory variables
+########################################################################
+
+SET(viterbi_sources
+    ${CMAKE_CURRENT_SOURCE_DIR}/metrics.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/tab.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/viterbi.c
+)
+
+########################################################################
+# define missing erf function with C linkage (hack for metrics.c)
+########################################################################
+IF(MSVC)
+FILE(WRITE ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc "
+#include <boost/math/special_functions/erf.hpp>
+extern \"C\" double erf(double x){
+    return boost::math::erf(x);
+}
+")
+LIST(APPEND viterbi_sources ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc)
+ENDIF(MSVC)
+
+########################################################################
+# Append gnuradio-core library sources
+########################################################################
+LIST(APPEND gnuradio_core_sources ${viterbi_sources})
+
+########################################################################
+# Install runtime headers
+########################################################################
+INSTALL(
+    FILES ${CMAKE_CURRENT_SOURCE_DIR}/viterbi.h
+    DESTINATION ${GR_INCLUDE_DIR}/gnuradio
+    COMPONENT "core_devel"
+)
+
+########################################################################
+# Create some text executables (not registered tests)
+# Its not much to build so the sources are just re-listed,
+# rather than create a new library just for these two apps.
+########################################################################
+#ADD_EXECUTABLE(viterbi_encode ${CMAKE_CURRENT_SOURCE_DIR}/encode.cc ${viterbi_sources})
+#ADD_EXECUTABLE(viterbi_decode ${CMAKE_CURRENT_SOURCE_DIR}/decode.cc ${viterbi_sources})
-- 
cgit 


From 71c0f14a46f85027b95f2f5f6d3d219cc9e3783e Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Sat, 8 Oct 2011 17:11:12 -0700
Subject: gr: the CMakeLists.txt took a chill pill

---
 gnuradio-core/src/lib/viterbi/CMakeLists.txt | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/CMakeLists.txt b/gnuradio-core/src/lib/viterbi/CMakeLists.txt
index aeb8a012d..add5c77e8 100644
--- a/gnuradio-core/src/lib/viterbi/CMakeLists.txt
+++ b/gnuradio-core/src/lib/viterbi/CMakeLists.txt
@@ -21,7 +21,7 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-SET(viterbi_sources
+set(viterbi_sources
     ${CMAKE_CURRENT_SOURCE_DIR}/metrics.c
     ${CMAKE_CURRENT_SOURCE_DIR}/tab.c
     ${CMAKE_CURRENT_SOURCE_DIR}/viterbi.c
@@ -30,25 +30,25 @@ SET(viterbi_sources
 ########################################################################
 # define missing erf function with C linkage (hack for metrics.c)
 ########################################################################
-IF(MSVC)
-FILE(WRITE ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc "
+if(MSVC)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc "
 #include <boost/math/special_functions/erf.hpp>
 extern \"C\" double erf(double x){
     return boost::math::erf(x);
 }
 ")
-LIST(APPEND viterbi_sources ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc)
-ENDIF(MSVC)
+list(APPEND viterbi_sources ${CMAKE_CURRENT_BINARY_DIR}/boost_math_erf.cc)
+endif(MSVC)
 
 ########################################################################
 # Append gnuradio-core library sources
 ########################################################################
-LIST(APPEND gnuradio_core_sources ${viterbi_sources})
+list(APPEND gnuradio_core_sources ${viterbi_sources})
 
 ########################################################################
 # Install runtime headers
 ########################################################################
-INSTALL(
+install(
     FILES ${CMAKE_CURRENT_SOURCE_DIR}/viterbi.h
     DESTINATION ${GR_INCLUDE_DIR}/gnuradio
     COMPONENT "core_devel"
-- 
cgit 


From 8dec45ada7e92f425a876494d5daf85fd3825e98 Mon Sep 17 00:00:00 2001
From: Tom Rondeau
Date: Thu, 20 Oct 2011 11:19:33 -0700
Subject: core: fixing AM_CPPFLAGS in viterbi/Makefile.am

---
 gnuradio-core/src/lib/viterbi/Makefile.am | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
index 1b86a86f8..7e65880b3 100644
--- a/gnuradio-core/src/lib/viterbi/Makefile.am
+++ b/gnuradio-core/src/lib/viterbi/Makefile.am
@@ -21,7 +21,9 @@ include $(top_srcdir)/Makefile.common
 
 LIBS = -lm
 
-AM_CPPFLAGS = -I$(top_srcdir)/gnuradio-core/src/lib/general
+AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(GRUEL_INCLUDES) \
+	-I$(top_srcdir)/gnuradio-core/src/lib/general \
+	$(WITH_INCLUDES)
 
 noinst_LTLIBRARIES = libviterbi.la
 
-- 
cgit 


From ab6f8142da17ee70effd469f20a41821b4bc4513 Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Thu, 20 Oct 2011 14:00:14 -0700
Subject: removes gcc warning, dont need symbol export on plain c structs

---
 gnuradio-core/src/lib/viterbi/viterbi.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/viterbi.h b/gnuradio-core/src/lib/viterbi/viterbi.h
index 5bb8b357a..3a3ea5615 100644
--- a/gnuradio-core/src/lib/viterbi/viterbi.h
+++ b/gnuradio-core/src/lib/viterbi/viterbi.h
@@ -26,7 +26,7 @@
 
 #include <gr_core_api.h>
 
-struct GR_CORE_API viterbi_state {
+struct viterbi_state {
   unsigned long path;	/* Decoded path to this state */
   long metric;		/* Cumulative metric to this state */
 };
-- 
cgit 


From 00420d32081d8252bb37142b2be19a8a7c4dc4c4 Mon Sep 17 00:00:00 2001
From: Johnathan Corgan
Date: Thu, 8 Dec 2011 13:48:48 -0800
Subject: Removed autotools, gr-waveform, some cleanup

Nick Foster owes Nick Corgan a six-pack of beer!
---
 gnuradio-core/src/lib/viterbi/.gitignore  |  6 ----
 gnuradio-core/src/lib/viterbi/Makefile.am | 46 -------------------------------
 2 files changed, 52 deletions(-)
 delete mode 100644 gnuradio-core/src/lib/viterbi/.gitignore
 delete mode 100644 gnuradio-core/src/lib/viterbi/Makefile.am

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/.gitignore b/gnuradio-core/src/lib/viterbi/.gitignore
deleted file mode 100644
index 85bb5cc04..000000000
--- a/gnuradio-core/src/lib/viterbi/.gitignore
+++ /dev/null
@@ -1,6 +0,0 @@
-/Makefile
-/Makefile.in
-/.libs
-/.deps
-/encode
-/decode
diff --git a/gnuradio-core/src/lib/viterbi/Makefile.am b/gnuradio-core/src/lib/viterbi/Makefile.am
deleted file mode 100644
index 7e65880b3..000000000
--- a/gnuradio-core/src/lib/viterbi/Makefile.am
+++ /dev/null
@@ -1,46 +0,0 @@
-#
-# 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.
-# 
-
-include $(top_srcdir)/Makefile.common
-
-LIBS = -lm
-
-AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(GRUEL_INCLUDES) \
-	-I$(top_srcdir)/gnuradio-core/src/lib/general \
-	$(WITH_INCLUDES)
-
-noinst_LTLIBRARIES = libviterbi.la
-
-libviterbi_la_SOURCES = \
-    metrics.c		\
-    tab.c		\
-    viterbi.c
-
-noinst_HEADERS =	\
-    viterbi.h
-
-noinst_PROGRAMS = encode decode
-
-encode_SOURCES = encode.cc
-
-encode_LDADD = libviterbi.la
-
-decode_SOURCES = decode.cc
-
-decode_LDADD = libviterbi.la
-- 
cgit 


From f919f9dcbb54a08e6e26d6c229ce92fb784fa1b2 Mon Sep 17 00:00:00 2001
From: Tom Rondeau
Date: Fri, 13 Apr 2012 18:36:53 -0400
Subject: Removed whitespace and added dtools/bin/remove-whitespace as a tool
 to do this in the future.

The sed script was provided by Moritz Fischer.
---
 gnuradio-core/src/lib/viterbi/decode.cc | 20 ++++++------
 gnuradio-core/src/lib/viterbi/encode.cc | 14 ++++-----
 gnuradio-core/src/lib/viterbi/metrics.c | 30 +++++++++---------
 gnuradio-core/src/lib/viterbi/tab.c     |  8 ++---
 gnuradio-core/src/lib/viterbi/viterbi.c | 56 ++++++++++++++++-----------------
 gnuradio-core/src/lib/viterbi/viterbi.h | 10 +++---
 6 files changed, 69 insertions(+), 69 deletions(-)

(limited to 'gnuradio-core/src/lib/viterbi')

diff --git a/gnuradio-core/src/lib/viterbi/decode.cc b/gnuradio-core/src/lib/viterbi/decode.cc
index 6580e4d66..368e69713 100644
--- a/gnuradio-core/src/lib/viterbi/decode.cc
+++ b/gnuradio-core/src/lib/viterbi/decode.cc
@@ -1,19 +1,19 @@
 /* -*- c++ -*- */
 /*
  * Copyright 2008 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,
@@ -22,7 +22,7 @@
 
 /*
  * This is a minimal example demonstrating how to call the Viterbi decoder
- * in continuous streaming mode.  It accepts data on stdin and writes to 
+ * in continuous streaming mode.  It accepts data on stdin and writes to
  * stdout.
  *
  */
@@ -55,12 +55,12 @@ int main()
   struct viterbi_state state0[64];
   struct viterbi_state state1[64];
   unsigned char viterbi_in[16];
-  viterbi_chunks_init(state0);  
+  viterbi_chunks_init(state0);
 
   while (!feof(stdin)) {
     unsigned int n = fread(syms, 1, MAXENCSIZE, stdin);
     unsigned char *out = data;
-    
+
     for (unsigned int i = 0; i < n; i++) {
 
       // FIXME: This implements hard decoding by slicing the input stream
@@ -71,7 +71,7 @@ int main()
 
       // Every four symbols, perform the butterfly2 operation
       if ((count % 4) == 3) {
-        viterbi_butterfly2(viterbi_in, mettab, state0, state1);      
+        viterbi_butterfly2(viterbi_in, mettab, state0, state1);
 
 	// Every sixteen symbols, perform the readback operation
         if ((count > 64) && (count % 16) == 11) {
@@ -79,9 +79,9 @@ int main()
 	  fwrite(out++, 1, 1, stdout);
 	}
       }
-      
+
       count++;
-    }    
+    }
   }
 
   return 0;
diff --git a/gnuradio-core/src/lib/viterbi/encode.cc b/gnuradio-core/src/lib/viterbi/encode.cc
index 01acb3987..83a85fcac 100644
--- a/gnuradio-core/src/lib/viterbi/encode.cc
+++ b/gnuradio-core/src/lib/viterbi/encode.cc
@@ -1,19 +1,19 @@
 /* -*- c++ -*- */
 /*
  * Copyright 2008 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,
@@ -22,9 +22,9 @@
 
 /*
  * This is a minimal example demonstrating how to call the ECC encoder
- * in continuous streaming mode.  It accepts data on stdin and writes to 
+ * in continuous streaming mode.  It accepts data on stdin and writes to
  * stdout.
- * 
+ *
  * FIXME: This does not flush the final bits out of the encoder.
  *
  */
@@ -43,7 +43,7 @@ int main()
   unsigned char encoder_state = 0;
   unsigned char data[MAXCHUNKSIZE];
   unsigned char syms[MAXENCSIZE];
-  
+
   while (!feof(stdin)) {
     unsigned int n = fread(data, 1, MAXCHUNKSIZE, stdin);
     encoder_state = encode(syms, data, n, encoder_state);
diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 77c6a63c8..0d91c301f 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -1,26 +1,26 @@
 /*
  * Copyright 1995 Phil Karn, KA9Q
  * Copyright 2008 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.
  */
 
-/* 
+/*
  * Generate metric tables for a soft-decision convolutional decoder
  * assuming gaussian noise on a PSK channel.
  *
@@ -48,7 +48,7 @@ extern double erf(double x);
 /* Normal function integrated from -Inf to x. Range: 0-1 */
 #define	normal(x)	(0.5 + 0.5*erf((x)/M_SQRT2))
 
-/* Logarithm base 2 */ 
+/* Logarithm base 2 */
 #define gr_log2(x) (log(x)*M_LOG2E)
 
 /* Generate log-likelihood metrics for 8-bit soft quantized channel
@@ -65,33 +65,33 @@ gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
   int s,bit;
   double metrics[2][256];
   double p0,p1;
-  
+
   /* Es/N0 as power ratio */
   esn0 = pow(10.,esn0/10);
-  
+
   noise = 0.5/esn0;	/* only half the noise for BPSK */
   noise = sqrt(noise);	/* noise/signal Voltage ratio */
-  
+
   /* Zero is a special value, since this sample includes all
    * lower samples that were clipped to this value, i.e., it
-   * takes the whole lower tail of the curve 
+   * takes the whole lower tail of the curve
    */
   p1 = normal(((0-OFFSET+0.5)/amp - 1)/noise);	/* P(s|1) */
-  
+
   /* Prob of this value occurring for a 0-bit */	/* P(s|0) */
   p0 = normal(((0-OFFSET+0.5)/amp + 1)/noise);
   metrics[0][0] = gr_log2(2*p0/(p1+p0)) - bias;
   metrics[1][0] = gr_log2(2*p1/(p1+p0)) - bias;
-  
+
   for(s=1;s<255;s++){
     /* P(s|1), prob of receiving s given 1 transmitted */
     p1 = normal(((s-OFFSET+0.5)/amp - 1)/noise) -
       normal(((s-OFFSET-0.5)/amp - 1)/noise);
-    
+
     /* P(s|0), prob of receiving s given 0 transmitted */
     p0 = normal(((s-OFFSET+0.5)/amp + 1)/noise) -
       normal(((s-OFFSET-0.5)/amp + 1)/noise);
-    
+
 #ifdef notdef
     printf("P(%d|1) = %lg, P(%d|0) = %lg\n",s,p1,s,p0);
 #endif
@@ -103,7 +103,7 @@ gen_met(int mettab[2][256],	/* Metric table, [sent sym][rx symbol] */
   p1 = 1 - normal(((255-OFFSET-0.5)/amp - 1)/noise);
   /* P(s|0) */
   p0 = 1 - normal(((255-OFFSET-0.5)/amp + 1)/noise);
-  
+
   metrics[0][255] = gr_log2(2*p0/(p1+p0)) - bias;
   metrics[1][255] = gr_log2(2*p1/(p1+p0)) - bias;
 #ifdef	notdef
diff --git a/gnuradio-core/src/lib/viterbi/tab.c b/gnuradio-core/src/lib/viterbi/tab.c
index 1133c6308..1c135acfe 100644
--- a/gnuradio-core/src/lib/viterbi/tab.c
+++ b/gnuradio-core/src/lib/viterbi/tab.c
@@ -1,19 +1,19 @@
 /*
  * Copyright 1995 Phil Karn, KA9Q
  * Copyright 2008 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,
diff --git a/gnuradio-core/src/lib/viterbi/viterbi.c b/gnuradio-core/src/lib/viterbi/viterbi.c
index 9f5c1e72a..fc8886603 100644
--- a/gnuradio-core/src/lib/viterbi/viterbi.c
+++ b/gnuradio-core/src/lib/viterbi/viterbi.c
@@ -1,26 +1,26 @@
 /*
  * Copyright 1995 Phil Karn, KA9Q
  * Copyright 2008 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.
  */
 
-/* 
+/*
  * Viterbi decoder for K=7 rate=1/2 convolutional code
  * Some modifications from original Karn code by Matt Ettus
  */
@@ -94,7 +94,7 @@ encode(unsigned char *symbols,
        unsigned char encstate)
 {
   int i;
-  
+
   while(nbytes-- != 0){
     for(i=7;i>=0;i--){
       encstate = (encstate << 1) | ((*data >> i) & 1);
@@ -103,7 +103,7 @@ encode(unsigned char *symbols,
     }
     data++;
   }
-  
+
   return encstate;
 }
 
@@ -120,16 +120,16 @@ viterbi(unsigned long *metric,	/* Final path metric (returned value) */
   long bestmetric;
   int beststate,i;
   struct viterbi_state state0[64],state1[64],*state,*next;
-  
+
   state = state0;
   next = state1;
-  
+
   /* Initialize starting metrics to prefer 0 state */
   state[0].metric = 0;
   for(i=1;i<64;i++)
     state[i].metric = -999999;
   state[0].path = 0;
-  
+
   for(bitcnt = 0;bitcnt < nbits;bitcnt++){
     /* Read input symbol pair and compute all possible branch
      * metrics
@@ -173,7 +173,7 @@ viterbi(unsigned long *metric,	/* Final path metric (returned value) */
     BUTTERFLY(29,0);
     BUTTERFLY(30,2);
     BUTTERFLY(31,3);
-    
+
     /* Swap current and next states */
     if(bitcnt & 1){
       state = state0;
@@ -205,7 +205,7 @@ viterbi(unsigned long *metric,	/* Final path metric (returned value) */
 #endif
       *data++ = state[beststate].path >> 24;
     }
-    
+
   }
   /* Output remaining bits from 0 state */
   // ETTUS  Find best state instead
@@ -219,7 +219,7 @@ viterbi(unsigned long *metric,	/* Final path metric (returned value) */
   }
   if((i = bitcnt % 8) != 6)
     state[beststate].path <<= 6-i;
-  
+
   *data++ = state[beststate].path >> 24;
   *data++ = state[beststate].path >> 16;
   *data++ = state[beststate].path >> 8;
@@ -245,7 +245,7 @@ viterbi_butterfly8(unsigned char *symbols, int mettab[2][256], struct viterbi_st
 {
   unsigned int bitcnt;
   int mets[4];
-  
+
   struct viterbi_state *state, *next;
   state = state0;
   next = state1;
@@ -257,8 +257,8 @@ viterbi_butterfly8(unsigned char *symbols, int mettab[2][256], struct viterbi_st
     mets[2] = mettab[1][symbols[0]] + mettab[0][symbols[1]];
     mets[3] = mettab[1][symbols[0]] + mettab[1][symbols[1]];
     symbols += 2;
-    
-    // These macro calls were generated by genbut.c 
+
+    // These macro calls were generated by genbut.c
     BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
     BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
     BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
@@ -267,7 +267,7 @@ viterbi_butterfly8(unsigned char *symbols, int mettab[2][256], struct viterbi_st
     BUTTERFLY(20,1);BUTTERFLY(21,0);BUTTERFLY(22,2);BUTTERFLY(23,3);
     BUTTERFLY(24,2);BUTTERFLY(25,3);BUTTERFLY(26,1);BUTTERFLY(27,0);
     BUTTERFLY(28,1);BUTTERFLY(29,0);BUTTERFLY(30,2);BUTTERFLY(31,3);
-    
+
     // Swap current and next states
     if(bitcnt & 1){
       state = state0;
@@ -284,19 +284,19 @@ viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], struct viterbi_st
 {
   //unsigned int bitcnt;
   int mets[4];
-  
+
   struct viterbi_state *state, *next;
   state = state0;
   next = state1;
   // Operate on 4 symbols (2 bits) at a time
-  
+
   // Read input symbol pair and compute all possible branch metrics
   mets[0] = mettab[0][symbols[0]] + mettab[0][symbols[1]];
   mets[1] = mettab[0][symbols[0]] + mettab[1][symbols[1]];
   mets[2] = mettab[1][symbols[0]] + mettab[0][symbols[1]];
   mets[3] = mettab[1][symbols[0]] + mettab[1][symbols[1]];
-  
-  // These macro calls were generated by genbut.c 
+
+  // These macro calls were generated by genbut.c
   BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
   BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
   BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
@@ -305,17 +305,17 @@ viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], struct viterbi_st
   BUTTERFLY(20,1);BUTTERFLY(21,0);BUTTERFLY(22,2);BUTTERFLY(23,3);
   BUTTERFLY(24,2);BUTTERFLY(25,3);BUTTERFLY(26,1);BUTTERFLY(27,0);
   BUTTERFLY(28,1);BUTTERFLY(29,0);BUTTERFLY(30,2);BUTTERFLY(31,3);
-  
+
   state = state1;
   next = state0;
-  
+
   // Read input symbol pair and compute all possible branch metrics
   mets[0] = mettab[0][symbols[2]] + mettab[0][symbols[3]];
   mets[1] = mettab[0][symbols[2]] + mettab[1][symbols[3]];
   mets[2] = mettab[1][symbols[2]] + mettab[0][symbols[3]];
   mets[3] = mettab[1][symbols[2]] + mettab[1][symbols[3]];
-  
-  // These macro calls were generated by genbut.c 
+
+  // These macro calls were generated by genbut.c
   BUTTERFLY(0,0);BUTTERFLY(1,1);BUTTERFLY(2,3);BUTTERFLY(3,2);
   BUTTERFLY(4,3);BUTTERFLY(5,2);BUTTERFLY(6,0);BUTTERFLY(7,1);
   BUTTERFLY(8,0);BUTTERFLY(9,1);BUTTERFLY(10,3);BUTTERFLY(11,2);
@@ -328,13 +328,13 @@ viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], struct viterbi_st
 
 unsigned char
 viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf) {
-  // Produce output every 8 bits once path memory is full 
+  // Produce output every 8 bits once path memory is full
   //  if((bitcnt % 8) == 5 && bitcnt > 32) {
-  
+
   //  Find current best path
   unsigned int i,beststate;
   int bestmetric;
-  
+
   bestmetric = state[0].metric;
   beststate = 0;
   for(i=1;i<64;i++)
diff --git a/gnuradio-core/src/lib/viterbi/viterbi.h b/gnuradio-core/src/lib/viterbi/viterbi.h
index 3a3ea5615..bcdbe116d 100644
--- a/gnuradio-core/src/lib/viterbi/viterbi.h
+++ b/gnuradio-core/src/lib/viterbi/viterbi.h
@@ -1,18 +1,18 @@
 /*
  * Copyright 2008 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,
@@ -46,7 +46,7 @@ GR_CORE_API void
 viterbi_chunks_init(struct viterbi_state* state);
 
  GR_CORE_API void
-viterbi_butterfly2(unsigned char *symbols, int mettab[2][256], 
+viterbi_butterfly2(unsigned char *symbols, int mettab[2][256],
 		   struct viterbi_state *state0, struct viterbi_state *state1);
 
 GR_CORE_API unsigned char
-- 
cgit