1 files changed, 150 insertions, 0 deletions
diff --git a/demos/spectrum/3rdparty/fftreal/testapp.dpr b/demos/spectrum/3rdparty/fftreal/testapp.dpr
new file mode 100644
index 0000000000..54f2eb99a1
--- /dev/null
+++ b/demos/spectrum/3rdparty/fftreal/testapp.dpr
@@ -0,0 +1,150 @@
+program testapp;
+{$APPTYPE CONSOLE}
+uses
+  SysUtils,
+  fftreal in 'fftreal.pas',
+  Math,
+  Windows;
+
+var
+   nbr_points  : longint;
+   x, f        : pflt_array;
+   fft         : TFFTReal;
+   i           : longint;
+   PI          : double;
+   areal, img  : double;
+   f_abs       : double;
+   buffer_size : longint;
+   nbr_tests   : longint;
+   time0, time1, time2 : int64;
+   timereso    : int64;
+   offset      : longint;
+   t0, t1      : double;
+   nbr_s_chn   : longint;
+   tempp1, tempp2 : pflt_array;
+
+begin
+  (*______________________________________________
+   *
+   * Exactness test
+   *______________________________________________
+   *)
+
+  WriteLn('Accuracy test:');
+  WriteLn;
+
+  nbr_points := 16;       // Power of 2
+  GetMem(x, nbr_points * sizeof_flt);
+  GetMem(f, nbr_points * sizeof_flt);
+  fft := TFFTReal.Create(nbr_points);    // FFT object initialized here
+
+  // Test signal
+  PI := ArcTan(1) * 4;
+  for i := 0 to nbr_points-1 do
+  begin
+    x^[i] := -1 + sin (3*2*PI*i/nbr_points)
+                + cos (5*2*PI*i/nbr_points) * 2
+                - sin (7*2*PI*i/nbr_points) * 3
+                + cos (8*2*PI*i/nbr_points) * 5;
+  end;
+
+  // Compute FFT and IFFT
+  fft.do_fft(f, x);
+  fft.do_ifft(f, x);
+  fft.rescale(x);
+
+  // Display the result
+  WriteLn('FFT:');
+  for i := 0 to nbr_points div 2 do
+  begin
+    areal := f^[i];
+    if (i > 0) and (i < nbr_points div 2) then
+      img := f^[i + nbr_points div 2]
+    else
+      img := 0;
+
+    f_abs := Sqrt(areal * areal + img * img);
+    WriteLn(Format('%5d: %12.6f %12.6f (%12.6f)', [i, areal, img, f_abs]));
+  end;
+
+  WriteLn;
+  WriteLn('IFFT:');
+  for i := 0 to nbr_points-1 do
+    WriteLn(Format('%5d: %f', [i, x^[i]]));
+
+  WriteLn;
+
+  FreeMem(x);
+  FreeMem(f);
+  fft.Free;
+
+
+  (*______________________________________________
+   *
+   * Speed test
+   *______________________________________________
+   *)
+
+  WriteLn('Speed test:');
+  WriteLn('Please wait...');
+  WriteLn;
+
+  nbr_points := 1024;	          // Power of 2
+  buffer_size := 256*nbr_points;  // Number of flt_t (float or double)
+  nbr_tests := 10000;
+
+  assert(nbr_points <= buffer_size);
+  GetMem(x, buffer_size * sizeof_flt);
+  GetMem(f, buffer_size * sizeof_flt);
+  fft := TFFTReal.Create(nbr_points);					// FFT object initialized here
+
+  // Test signal: noise
+  for i := 0 to nbr_points-1 do
+    x^[i] := Random($7fff) - ($7fff shr 1);
+
+  // timing
+  QueryPerformanceFrequency(timereso);
+  QueryPerformanceCounter(time0);
+
+  for i := 0 to nbr_tests-1 do
+  begin
+    offset := (i * nbr_points) and (buffer_size - 1);
+    tempp1 := f;
+    inc(tempp1, offset);
+    tempp2 := x;
+    inc(tempp2, offset);
+    fft.do_fft(tempp1, tempp2);
+  end;
+
+  QueryPerformanceCounter(time1);
+
+  for i := 0 to nbr_tests-1 do
+  begin
+    offset := (i * nbr_points) and (buffer_size - 1);
+    tempp1 := f;
+    inc(tempp1, offset);
+    tempp2 := x;
+    inc(tempp2, offset);
+    fft.do_ifft(tempp1, tempp2);
+    fft.rescale(x);
+  end;
+
+  QueryPerformanceCounter(time2);
+
+  t0 := ((time1-time0) / timereso) / nbr_tests;
+  t1 := ((time2-time1) / timereso) / nbr_tests;
+
+  WriteLn(Format('%d-points FFT           : %.0f us.', [nbr_points, t0 * 1000000]));
+  WriteLn(Format('%d-points IFFT + scaling: %.0f us.', [nbr_points, t1 * 1000000]));
+
+  nbr_s_chn := Floor(nbr_points / ((t0 + t1) * 44100 * 2));
+  WriteLn(Format('Peak performance: FFT+IFFT on %d mono channels at 44.1 KHz (with overlapping)', [nbr_s_chn]));
+  WriteLn;
+
+  FreeMem(x);
+  FreeMem(f);
+  fft.Free;
+
+  WriteLn('Press [Return] key to terminate...');
+  ReadLn;
+end.