From 21b3c7ed135c7c6e8a7ebae167bd73bc0963d141 Mon Sep 17 00:00:00 2001
From: Joe Taylor <k1jt@arrl.org>
Date: Wed, 3 Oct 2012 00:41:07 +0000
Subject: [PATCH] Add the decode9 routine.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2631 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
---
 libm65/decode9.f90 | 54 ++++++++++++++++++++++++++++++++++++++++++++++
 mainwindow.cpp     |  2 +-
 2 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 libm65/decode9.f90

diff --git a/libm65/decode9.f90 b/libm65/decode9.f90
new file mode 100644
index 000000000..c415b5dc4
--- /dev/null
+++ b/libm65/decode9.f90
@@ -0,0 +1,54 @@
+subroutine decode9(i1SoftSymbols,msg)
+
+! Decoder for JT9
+! Input:   i1SoftSymbols(207) - Single-bit soft symbols
+! Output:  msg                - decoded message (blank if erasure)
+
+  character*22 msg
+  integer*4 i4DecodedBytes(9)
+  integer*4 i4Decoded6BitWords(12)
+  integer*1 i1DecodedBytes(13)   !72 bits and zero tail as 8-bit bytes
+  integer*1 i1SoftSymbols(207)
+  integer*1 i1DecodedBits(72)
+
+  integer*1 i1
+  logical first
+  integer*4 mettab(0:255,0:1)
+  equivalence (i1,i4)
+  data first/.true./
+  save
+
+  if(first) then
+! Get the metric table
+     bias=0.37                          !To be optimized, in decoder program
+     scale=10                           !  ... ditto ...
+     open(19,file='met8.21',status='old')
+     do i=0,255
+        read(19,*) x00,x0,x1
+        mettab(i,0)=nint(scale*(x0-bias))
+        mettab(i,1)=nint(scale*(x1-bias))    !### Check range, etc.  ###
+     enddo
+     close(19)
+     first=.false.
+  endif
+
+  msg='                      '
+  nbits=72
+  ndelta=17
+  limit=1000
+  call fano232(i1SoftSymbols,nbits+31,mettab,ndelta,limit,i1DecodedBytes,   &
+       ncycles,metric,ierr,maxmetric,maxnp)
+
+  if(ncycles.lt.(nbits*limit)) then
+     nbytes=(nbits+7)/8
+     do i=1,nbytes
+        n=i1DecodedBytes(i)
+        i4DecodedBytes(i)=iand(n,255)
+     enddo
+     call unpackbits(i4DecodedBytes,nbytes,8,i1DecodedBits)
+     call packbits(i1DecodedBits,12,6,i4Decoded6BitWords)
+     call unpackmsg(i4Decoded6BitWords,msg)                !Unpack decoded msg
+  endif
+
+  return
+end subroutine decode9
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 48d16902e..b4b246613 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1,4 +1,4 @@
-//-------------------------------------------------------------- MainWindow
+//--------------------------------------------------------------- MainWindow
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
 #include "devsetup.h"