FT8 early decoding is now working.

lib/decoder.f90

@@ -105,7 +105,7 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
      newdat=params%newdat
      call my_ft8%decode(ft8_decoded,id2,params%nQSOProgress,params%nfqso,    &
           params%nftx,newdat,params%nutc,params%nfa,params%nfb,              &
-          params%ndepth,ncontest,logical(params%nagain),                     &
+          params%nzhsym,params%ndepth,ncontest,logical(params%nagain),       &
           logical(params%lft8apon),logical(params%lapcqonly),                &
           params%napwid,mycall,hiscall,hisgrid)
      call timer('decft8  ',1)

lib/ft8/ft8b.f90

@@ -1,6 +1,7 @@
-subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly,    &
+subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,nzhsym,lapon,     &
-     napwid,lsubtract,nagain,ncontest,iaptype,mycall12,hiscall12,             &
+     lapcqonly,napwid,lsubtract,nagain,ncontest,iaptype,mycall12,hiscall12, &
-     sync0,f1,xdt,xbase,apsym,aph10,nharderrors,dmin,nbadcrc,ipass,iera,msg37,xsnr)  
+     sync0,f1,xdt,xbase,apsym,aph10,nharderrors,dmin,nbadcrc,ipass,iera,    &
+     msg37,xsnr,itone)
 
   use crc
   use timer_module, only: timer
@@ -236,7 +237,8 @@ subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly,    &
   else
      npasses=3
   endif
-
+  if(nzhsym.lt.50) npasses=1
+  
   do ipass=1,npasses 
      llrd=llra
      if(ipass.eq.2) llrd=llrb
@@ -405,7 +407,10 @@ subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly,    &
      endif
      nbadcrc=0  ! If we get this far: valid codeword, valid (i3,n3), nonquirky message.
      call get_ft8_tones_from_77bits(message77,itone)
-     if(lsubtract) call subtractft8(dd0,itone,f1,xdt) 
+     if(lsubtract) call subtractft8(dd0,itone,f1,xdt)
+!     write(*,3001) nzhsym,npasses,nqsoprogress,ipass,iaptype,lsubtract,   &
+!          f1,xdt,msg37(1:22); flush(6)
+!3001 format('A',5i3,L3,f7.1,f7.2,2x,a22)
      xsig=0.0
      xnoi=0.0
      do i=1,79

lib/ft8_decode.f90

@@ -33,14 +33,14 @@ module ft8_decode
 contains
 
   subroutine decode(this,callback,iwave,nQSOProgress,nfqso,nftx,newdat,  &
-       nutc,nfa,nfb,ndepth,ncontest,nagain,lft8apon,lapcqonly, &
+       nutc,nfa,nfb,nzhsym,ndepth,ncontest,nagain,lft8apon,lapcqonly,    &
        napwid,mycall12,hiscall12,hisgrid6)
     use timer_module, only: timer
     include 'ft8/ft8_params.f90'
 
     class(ft8_decoder), intent(inout) :: this
     procedure(ft8_decode_callback) :: callback
-    parameter (MAXCAND=300)
+    parameter (MAXCAND=300,MAX_EARLY=100)
     real s(NH1,NHSYM)
     real sbase(NH1)
     real candidate(3,MAXCAND)
@@ -55,7 +55,12 @@ contains
 !   character message*22
     character*37 allmessages(100)
     integer allsnrs(100)
-    save s,dd
+    integer itone(NN)
+    integer itone_save(NN,MAX_EARLY)
+    real f1_save(MAX_EARLY)
+    real xdt_save(MAX_EARLY)
+
+    save s,dd,ndec_early,itone_save,f1_save,xdt_save
 
     this%callback => callback
     write(datetime,1001) nutc        !### TEMPORARY ###
@@ -63,9 +68,18 @@ contains
 
     call ft8apset(mycall12,hiscall12,ncontest,apsym2,aph10)
     dd=iwave
-    ndecodes=0
+    if(nzhsym.lt.50) then
-    allmessages='                                     '
+       ndecodes=0
-    allsnrs=0
+       allmessages='                                     '
+       allsnrs=0
+    else
+       ndecodes=ndec_early
+    endif
+    if(nhsym.eq.50 .and. ndec_early.ge.1) then
+       do i=1,ndec_early
+          call subtractft8(dd,itone_save(1,i),f1_save(i),xdt_save(i))
+       enddo
+    endif
     ifa=nfa
     ifb=nfb
     if(nagain) then
@@ -104,10 +118,10 @@ contains
         xdt=candidate(2,icand)
         xbase=10.0**(0.1*(sbase(nint(f1/3.125))-40.0))
         call timer('ft8b    ',0)
-        call ft8b(dd,newdat,nQSOProgress,nfqso,nftx,ndepth,lft8apon,      &
+        call ft8b(dd,newdat,nQSOProgress,nfqso,nftx,ndepth,nzhsym,lft8apon, &
              lapcqonly,napwid,lsubtract,nagain,ncontest,iaptype,mycall12,   &
              hiscall12,sync,f1,xdt,xbase,apsym2,aph10,nharderrors,dmin,     &
-             nbadcrc,iappass,iera,msg37,xsnr)
+             nbadcrc,iappass,iera,msg37,xsnr,itone)
         call timer('ft8b    ',1)
         nsnr=nint(xsnr) 
         xdt=xdt-0.5
@@ -121,6 +135,9 @@ contains
               ndecodes=ndecodes+1
               allmessages(ndecodes)=msg37
               allsnrs(ndecodes)=nsnr
+              f1_save(ndecodes)=f1
+              xdt_save(ndecodes)=xdt
+              itone_save(1:NN,ndecodes)=itone
            endif
 !           write(81,1004) nutc,ncand,icand,ipass,iaptype,iappass,        &
 !                nharderrors,dmin,hd,min(sync,999.0),nint(xsnr),          &
@@ -133,8 +150,11 @@ contains
            endif
         endif
       enddo
-  enddo
+   enddo
+   ndec_early=0
+   if(nzhsym.lt.50) ndec_early=ndecodes
+   
   return
-  end subroutine decode
+end subroutine decode
 
 end module ft8_decode

widgets/mainwindow.cpp

@@ -1411,7 +1411,7 @@ void MainWindow::dataSink(qint64 frames)
     m_dialFreqRxWSPR=m_freqNominal;
   }
 
-  if(m_ihsym == m_hsymStop) {
+  if(m_ihsym==m_hsymStop or (m_mode=="FT8" and m_ihsym==m_earlyDecode and !m_diskData)) {
     if(m_mode=="Echo") {
       float snr=0;
       int nfrit=0;
@@ -1448,9 +1448,11 @@ void MainWindow::dataSink(qint64 frames)
     dec_data.params.newdat=1;
     dec_data.params.nagain=0;
     dec_data.params.nzhsym=m_hsymStop;
+    if(m_mode=="FT8" and m_ihsym==m_earlyDecode and !m_diskData) dec_data.params.nzhsym=m_earlyDecode;
     QDateTime now {QDateTime::currentDateTimeUtc ()};
     m_dateTime = now.toString ("yyyy-MMM-dd hh:mm");
     if(!m_mode.startsWith ("WSPR")) decode(); //Start decoder
+    if(m_mode=="FT8" and m_ihsym==m_earlyDecode and !m_diskData) return;
 
     if(!m_diskData) {                        //Always save; may delete later
       if(m_mode=="FT8" or m_mode=="FT4") {
@@ -1458,8 +1460,6 @@ void MainWindow::dataSink(qint64 frames)
         if(n<(m_TRperiod/2)) n=n+m_TRperiod;
         auto const& period_start=now.addSecs(-n);
         m_fnameWE=m_config.save_directory().absoluteFilePath (period_start.toString("yyMMdd_hhmmss"));
-//        qDebug() << "datasink 2" << QDateTime::currentDateTimeUtc().toString("ss.zzz")
-//                 << n << period_start.toString("ss.zzz");
       } else {
         auto const& period_start = now.addSecs (-(now.time ().minute () % (int(m_TRperiod) / 60)) * 60);
         m_fnameWE=m_config.save_directory ().absoluteFilePath (period_start.toString ("yyMMdd_hhmm"));
@@ -2843,6 +2843,8 @@ void MainWindow::decode()                                       //decode()
     if(m_mode=="ISCAT" or m_mode=="MSK144" or m_bFast9 or m_mode=="FT8" or m_mode=="FT4") {
       qint64 ms=1000.0*(2.0-m_TRperiod);
       if(m_mode=="FT4") ms=1000.0*(2.0-m_TRperiod);
+      //Adjust for FT8 early decode:
+      if(m_mode=="FT8" and m_ihsym==m_earlyDecode and !m_diskData) ms+=(m_hsymStop-m_earlyDecode)*288;
       QDateTime t=QDateTime::currentDateTimeUtc().addMSecs(ms);
       ihr=t.toString("hh").toInt();
       imin=t.toString("mm").toInt();
@@ -2983,6 +2985,7 @@ void MainWindow::decode()                                       //decode()
   } else {
     memcpy(to, from, qMin(mem_jt9->size(), size));
     QFile {m_config.temp_dir ().absoluteFilePath (".lock")}.remove (); // Allow jt9 to start
+//    qDebug() << "aa" << QDateTime::currentDateTimeUtc().toString("hh:mm:ss.s") << m_ihsym;
     decodeBusy(true);
   }
 }
@@ -3041,6 +3044,7 @@ void MainWindow::decodeDone ()
   decodeBusy(false);
   m_RxLog=0;
   m_blankLine=true;
+  if(m_mode=="FT8" and dec_data.params.nzhsym==m_earlyDecode) m_blankLine=false;
   if(SpecOp::FOX == m_config.special_op_id()) houndCallers();
 }
 
@@ -3048,6 +3052,7 @@ void MainWindow::readFromStdout()                             //readFromStdout
 {
   while(proc_jt9.canReadLine()) {
     auto line_read = proc_jt9.readLine ();
+//    qDebug() << "cc" << line_read;
     if (auto p = std::strpbrk (line_read.constData (), "\n\r"))
       {
         // truncate before line ending chars

widgets/mainwindow.h

@@ -467,6 +467,7 @@ private:
   qint32  m_nFoxFreq;          //Audio freq at which Hound received a call from Fox
   qint32  m_nSentFoxRrpt=0;    //Serial number for next R+rpt Hound will send to Fox
   qint32  m_kin0=0;
+  qint32  m_earlyDecode=35;
 
   bool    m_btxok;		//True if OK to transmit
   bool    m_diskData;