add oversampler

oversampling/HIIR/FPUUpsampler2x.h

@@ -0,0 +1,168 @@
+/*
+FPUUpsampler2x.h
+Copyright (c) 2005 Laurent de Soras
+
+Upsamples by a factor 2 the input signal, using FPU.
+
+Template parameters:
+- NC: number of coefficients, > 0
+
+--- Legal stuff ---
+
+This program is free software. It comes without any warranty, to
+the extent permitted by applicable law. You can redistribute it
+and/or modify it under the terms of the Do What The Fuck You Want
+To Public License, Version 2, as published by Sam Hocevar. See
+http://sam.zoy.org/wtfpl/COPYING for more details.
+
+*/
+
+#pragma once
+
+#include <array>
+#include "FPUStageProc.h"
+
+namespace hiir
+{
+
+template <int NC, typename T>
+class Upsampler2xFPU
+{
+public:
+
+  enum { NBR_COEFS = NC };
+
+  Upsampler2xFPU ();
+
+  /*
+  Name: set_coefs
+  Description:
+  Sets filter coefficients. Generate them with the PolyphaseIir2Designer
+  class.
+  Call this function before doing any processing.
+  Input parameters:
+  - coef_arr: Array of coefficients. There should be as many coefficients as
+  mentioned in the class template parameter.
+  */
+  void set_coefs (const double coef_arr [NBR_COEFS]);
+
+  /*
+  Name: process_sample
+  Description:
+    Upsamples (x2) the input sample, generating two output samples.
+  Input parameters:
+    - input: The input sample.
+  Output parameters:
+    - out_0: First output sample.
+    - out_1: Second output sample.
+  */
+  inline void process_sample (T &out_0, T &out_1, T input);
+
+  /*
+  Name: process_block
+  Description:
+    Upsamples (x2) the input sample block.
+    Input and output blocks may overlap, see assert() for details.
+  Input parameters:
+    - in_ptr: Input array, containing nbr_spl samples.
+    - nbr_spl: Number of input samples to process, > 0
+  Output parameters:
+    - out_0_ptr: Output sample array, capacity: nbr_spl * 2 samples.
+  */
+  void process_block (T out_ptr [], const T in_ptr [], long nbr_spl);
+
+  /*
+  Name: clear_buffers
+  Description:
+    Clears filter memory, as if it processed silence since an infinite amount
+    of time.
+  */
+  void clear_buffers ();
+
+private:
+  std::array<T, NBR_COEFS> _coef;
+  std::array<T, NBR_COEFS> _x;
+  std::array<T, NBR_COEFS> _y;
+
+private:
+  bool operator == (const Upsampler2xFPU &other);
+  bool operator != (const Upsampler2xFPU &other);
+
+};  // class Upsampler2xFPU
+
+template <int NC, typename T>
+Upsampler2xFPU <NC, T>::Upsampler2xFPU ()
+: _coef ()
+, _x ()
+, _y ()
+{
+  for (int i = 0; i < NBR_COEFS; ++i)
+  {
+    _coef [i] = 0;
+  }
+  clear_buffers ();
+}
+
+template <int NC, typename T>
+void Upsampler2xFPU <NC, T>::set_coefs (const double coef_arr [NBR_COEFS])
+{
+  assert (coef_arr != 0);
+
+  for (int i = 0; i < NBR_COEFS; ++i)
+  {
+    _coef [i] = static_cast <T> (coef_arr [i]);
+  }
+}
+
+template <int NC, typename T>
+void Upsampler2xFPU <NC, T>::process_sample (T &out_0, T &out_1, T input)
+{
+//  assert (&out_0 != 0);
+//  assert (&out_1 != 0);
+
+  T even = input;
+  T odd = input;
+  StageProcFPU <NBR_COEFS, T>::process_sample_pos (
+    NBR_COEFS,
+    even,
+    odd,
+    &_coef [0],
+    &_x [0],
+    &_y [0]
+  );
+  out_0 = even;
+  out_1 = odd;
+}
+
+template <int NC, typename T>
+void Upsampler2xFPU <NC, T>::process_block (T out_ptr [], const T in_ptr [], long nbr_spl)
+{
+//  assert (out_ptr != 0);
+//  assert (in_ptr != 0);
+//  assert (out_ptr >= in_ptr + nbr_spl || in_ptr >= out_ptr + nbr_spl);
+//  assert (nbr_spl > 0);
+
+  long pos = 0;
+  do
+  {
+    process_sample (
+      out_ptr [pos * 2],
+      out_ptr [pos * 2 + 1],
+      in_ptr [pos]
+    );
+    ++ pos;
+  }
+  while (pos < nbr_spl);
+}
+
+template <int NC, typename T>
+void Upsampler2xFPU <NC, T>::clear_buffers ()
+{
+  for (int i = 0; i < NBR_COEFS; ++i)
+  {
+    _x [i] = 0;
+    _y [i] = 0;
+  }
+}
+
+} // namespace hiir