The original library from Phil Karn needs a few patches to be used in C++ code on a modern x64 processor. A completely patched copy with CMake project files is available at https://gitlab.lrz.de/sdr/libfec.git
***** Fork of above referenced "completely patched copy" has been placed at https://github.com/K4KDR/libfec.git and will automatically be pulled as a dependency via the listing in .gitmodules file *****
!!! Below steps not needed if normal install w/ dependencies is done (-- K4KDR)
The following document describes how to get the library running from the original files.
You can download the base library from Phil Karns website: http://ka9q.net/code/fec Or directly download the library from the command line with
wget --quiet http://ka9q.net/code/fec/fec-3.0.1.tar.bz2;
In order to use libfec with GNURadio on modern systems two patches are needed.
The first one is from http://lodge.glasgownet.com/2011/11/07/making-opendab-fec-and-the-psion-wavefinder-work-on-x64/ and it will disable all attempts to detect and run assembly code (which is for 32bit processors and thus incompatible)
It can be downloaded from the command line with
wget --quiet http://lodge.glasgownet.com/bitsnbobs/kg_fec-3.0.1.patch
The second patch if from us and will insert the extern "C" { ... } block around the header file to be able to use this C library from within C++.
Save the following code into a file called extern_c_header.patch
diff -Naur fec-3.0.1-origpatch/fec.h fec-3.0.1/fec.h
--- fec-3.0.1-origpatch/fec.h 2013-02-28 10:30:42.175998400 +0100
+++ fec-3.0.1/fec.h 2013-02-28 10:32:48.987994820 +0100
@@ -6,6 +6,11 @@
#ifndef _FEC_H_
#define _FEC_H_
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
/* r=1/2 k=7 convolutional encoder polynomials
* The NASA-DSN convention is to use V27POLYA inverted, then V27POLYB
* The CCSDS/NASA-GSFC convention is to use V27POLYB, then V27POLYA inverted
@@ -341,6 +346,10 @@
int cpu_features(void);
+#ifdef __cplusplus
+} /* END extern "C" */
+#endif
+
#endif /* _FEC_H_ */
Make sure you have the fec archive and the two patches in the cwd. Their md5sums should be
52846b9eac4080e68ade7d2bd13eb504 fec-3.0.1.tar.bz2
78eee9c211fc2a8ca4d11c515f7fe194 kg_fec-3.0.1.patch
7cb15410de10125f2ba69593a295029e extern_c_header.patch
Extract libfec
tar -xjf fec-3.0.1.tar.bz2
cd fec-3.0.1
Apply patches
patch < ../kg_fec-3.0.1.patch
patch < ../extern_c_header.patch
Install
./configure --prefix=/usr/local
make
sudo make install