unit uIQConverter;

interface

uses Forms, Graphics, uFFTasm, uLayers, uFunctions, uInitCalc, uCalc16;

procedure FFTIQ2Real(fBPF: Boolean);

implementation

uses uMain, uWavIO;

procedure FFTIQ2Real(fBPF: Boolean);
var i,j,k,n            : LongInt;
    t                  : Double;
    SizeS,SizeA,SizeQ  : LongInt;
    ip,jp,pe           : Int64;
    ComplexArray1A     : TAsmComplexArray;
    ComplexArray1B     : TAsmComplexArray;
    ComplexArray2A     : TAsmComplexArray;
    ComplexArray2B     : TAsmComplexArray;
    AudioA             : Array of Single;
    AmpWindowingArr    : Array [0..8191] of Single;
    BPFWindowingArr    : Array [0..83] of Single;
    fFFTSize, fBPFSize : Longint;
    Label                FIN;
begin
     if not LockBlock then EXIT;
     MainForm.sbStopLoad.Enabled:= True;
     MainForm.StatusBar.Panels[3].Text:= ' Converting I/Q to Real...';
     MainForm.ProgressBar.BackColor:= clWhite;

     fFFTSize:= 16384;
     fBPFSize:= 84;

     SizeA:= fFFTSize div 2;
     SizeS:= SizeA     *  2;
     SizeQ:= SizeA    div 2;

     for i := 0 to 8191 do
     begin
          t := i / 8192 - 0.5;
          AmpWindowingArr[i] := abs(0.5+0.5*Cos(2*Pi*t));
     end;
     for i := 0 to 83 do
     begin
          t := i / 84 - 0.5;
          BPFWindowingArr[i] := abs(0.5+0.5*Cos(2*Pi*t));
     end;

     SetLength(AudioA, SizeA);

     ip:= -SizeA; jp:= ip; pe:= wf32DataSize + SizeA * 2;

     while ip < wf32DataSize + SizeA do
     Begin
          j:= 0; k:=0;
          for i:= 0 to SizeS - 1 do
          begin
               if i and 1 = 0 then
               begin
                    if (ip < wf32DataSize) and (ip >= 0) then
                    ComplexArray1A[j].Re:= DATA32[ip] * AmpWindowingArr[j]
                    else ComplexArray1A[j].Re:= 0.0;
                    if (ip < wf32DataSize - SizeA) and (ip + SizeA >= 0) then
                    ComplexArray1B[j].Re:= DATA32[ip + SizeA] * AmpWindowingArr[j]
                    else ComplexArray1B[j].Re:= 0.0;
                    Inc(j);
               end else
               begin
                    if (ip < wf32DataSize) and (ip >= 0) then
                    ComplexArray1A[k].Im:= DATA32[ip] * AmpWindowingArr[k]
                    else ComplexArray1A[k].Im:= 0.0;
                    if (ip < wf32DataSize - SizeA) and (ip + SizeA >= 0) then
                    ComplexArray1B[k].Im:= DATA32[ip + SizeA] * AmpWindowingArr[k]
                    else ComplexArray1B[k].Im:= 0.0;
                    Inc(k);
               end;
               Inc(ip)
          end;

          dspDoFFT(@ComplexArray1A, SizeA, False, True, True);
          dspDoFFT(@ComplexArray1B, SizeA, False, True, True);

          for k:= 0 to SizeQ - 1 do
          begin
               ComplexArray2A[k].Re:= ComplexArray1A[k+SizeQ].Re;
               ComplexArray2A[k].Im:= ComplexArray1A[k+SizeQ].Im;
               ComplexArray2B[k].Re:= ComplexArray1B[k+SizeQ].Re;
               ComplexArray2B[k].Im:= ComplexArray1B[k+SizeQ].Im;
          end;

          for k:= SizeQ to SizeA - 1 do
          begin
               ComplexArray2A[k].Re:= ComplexArray1A[k-SizeQ].Re;
               ComplexArray2A[k].Im:= ComplexArray1A[k-SizeQ].Im;
               ComplexArray2B[k].Re:= ComplexArray1B[k-SizeQ].Re;
               ComplexArray2B[k].Im:= ComplexArray1B[k-SizeQ].Im;
          end;

          if fBPF then
          begin
               i:= fBPFSize div 2;
               for k:= SizeA - fBPFSize div 2 to SizeA do //HF Filter
               begin
                    ComplexArray2A[k].Re:= ComplexArray2A[k].Re * BPFWindowingArr[i];
                    ComplexArray2A[k].Im:= ComplexArray2A[k].Im * BPFWindowingArr[i];
                    ComplexArray2B[k].Re:= ComplexArray2B[k].Re * BPFWindowingArr[i];
                    ComplexArray2B[k].Im:= ComplexArray2B[k].Im * BPFWindowingArr[i];
                    dec(i)
               end;
               for k:= 0 to fBPFSize div 2 - 1 do //LF Filter
               begin
                    ComplexArray2A[k].Re:= ComplexArray2A[k].Re * BPFWindowingArr[k];
                    ComplexArray2A[k].Im:= ComplexArray2A[k].Im * BPFWindowingArr[k];
                    ComplexArray2B[k].Re:= ComplexArray2B[k].Re * BPFWindowingArr[k];
                    ComplexArray2B[k].Im:= ComplexArray2B[k].Im * BPFWindowingArr[k];
               end;
          end;

          for k:= 1 to SizeA - 1 do
          begin
               ComplexArray2A[k+SizeA].Re:=  ComplexArray2A[SizeA-k].Re;
               ComplexArray2A[k+SizeA].Im:= -ComplexArray2A[SizeA-k].Im;
               ComplexArray2B[k+SizeA].Re:=  ComplexArray2B[SizeA-k].Re;
               ComplexArray2B[k+SizeA].Im:= -ComplexArray2B[SizeA-k].Im;
          end;

          dspDoFFT(@ComplexArray2A, SizeS, True, True, True);
          dspDoFFT(@ComplexArray2B, SizeS, True, True, True);

          i:= 0; j:= 0;
          for k:= 0 to SizeS -1 do
          begin
               if jp < wf32DataSize then
               begin
                    if k < SizeS div 2 then
                    begin
                         if jp >= 0 then
                         DATA32[jp]:= ComplexArray2A[k].re + AudioA[i];
                         AudioA[i]:= ComplexArray2B[i + SizeA].re;
                         Inc(i);
                    end else
                    begin
                         if jp >= 0 then
                         DATA32[jp]:= ComplexArray2A[k].re + ComplexArray2B[j].re;
                         Inc(j);
                    end;
               end;
               Inc(jp);
          end;

          if ip mod 256 = 0 then
          begin
               MainForm.ProgressBar.Position:= Round( ( ip / pe ) * 100 );
               Application.ProcessMessages;
          end;
          if STOPLoad then GoTo Fin;
     End;

     FIN:

     if wfCHANNELS = 2 then
     begin
          wfCHANNELS  :=  1;
          wfSAMPLERATE:= wfSAMPLERATE * 2;
          MainForm.DrawBigRuler(wfSAMPLERATE);
          MainForm.mnu1Channel.Checked:= True;
          DeleteStereoLayer;
     end;

     MainForm.mnuInvertChannel1L.Enabled:= wfCHANNELS = 2;
     MainForm.mnuInvertChannel2R.Enabled:= wfCHANNELS = 2;
     LockControl := False;
end;


end.