Added a complex sample center half band decimator

sdrbase/CMakeLists.txt

@@ -86,6 +86,7 @@ set(sdrbase_SOURCES
     dsp/decimatorsif.cpp
     dsp/decimatorsff.cpp
     dsp/decimatorsfi.cpp
+    dsp/decimatorc.cpp
     dsp/dspcommands.cpp
     dsp/dspengine.cpp
     dsp/dspdevicesourceengine.cpp
@@ -211,6 +212,7 @@ set(sdrbase_HEADERS
     dsp/decimatorsff.h
     dsp/decimatorsfi.h
     dsp/decimatorsu.h
+    dsp/decimatorc.h
     dsp/interpolators.h
     dsp/interpolatorsif.h
     dsp/dspcommands.h

sdrbase/dsp/decimatorc.cpp

@@ -0,0 +1,221 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "decimatorc.h"
+
+DecimatorC::DecimatorC() :
+    m_log2Decim(0),
+    m_decim(1)
+{}
+
+void DecimatorC::setLog2Decim(unsigned int log2Decim)
+{
+    m_log2Decim = log2Decim;
+    m_decim = 1 << log2Decim;
+}
+
+bool DecimatorC::decimate(Complex c, Complex& cd)
+{
+    if (m_log2Decim == 0) { // no decimation hence no translation possible
+        return true;
+    }
+
+    if (m_log2Decim == 1) {
+        return decimate2(c, cd);
+    } else if (m_log2Decim == 2) {
+        return decimate4(c, cd);
+    } else if (m_log2Decim == 3) {
+        return decimate8(c, cd);
+    } else if (m_log2Decim == 4) {
+        return decimate16(c, cd);
+    } else if (m_log2Decim == 5) {
+        return decimate32(c, cd);
+    } else if (m_log2Decim == 6) {
+        return decimate64(c, cd);
+    }
+}
+
+bool DecimatorC::decimate2(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        cd.real(x);
+        cd.imag(y);
+    }
+
+    return done2;
+}
+
+bool DecimatorC::decimate4(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            cd.real(x);
+            cd.imag(y);
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate8(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                cd.real(x);
+                cd.imag(y);
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate16(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    cd.real(x);
+                    cd.imag(y);
+                    return true;
+                }
+            }
+        }
+    }
+
+    return false;
+}
+
+
+bool DecimatorC::decimate32(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    bool done32 = m_decimator32.workDecimateCenter(&x, &y);
+
+                    if (done32)
+                    {
+                        cd.real(x);
+                        cd.imag(y);
+                        return true;
+                    }
+                }
+            }
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate64(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    bool done32 = m_decimator32.workDecimateCenter(&x, &y);
+
+                    if (done32)
+                    {
+                        bool done64 = m_decimator32.workDecimateCenter(&x, &y);
+
+                        if (done64)
+                        {
+                            cd.real(x);
+                            cd.imag(y);
+                            return true;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return false;
+}

sdrbase/dsp/decimatorc.h

@@ -0,0 +1,55 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+// Half-band centered decimators with Complex (i.e. omplex<float>) input/output
+// Decimates by a power of two using centered half-band filters
+
+#ifndef INCLUDE_DSP_DECIMATORC_H_
+#define INCLUDE_DSP_DECIMATORC_H_
+
+#include "dsp/dsptypes.h"
+#include "dsp/inthalfbandfiltereof.h"
+
+#define DECIMATORSXS_HB_FILTER_ORDER 64
+
+class DecimatorC
+{
+public:
+    DecimatorC();
+    void setLog2Decim(unsigned int log2Decim);
+    bool decimate(Complex c, Complex& cd);
+    unsigned int getDecim() const { return m_decim; }
+
+private:
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator2; // 1st stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator4; // 2nd stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator8; // 3rd stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator16; // 4th stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator32; // 5th stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator64; // 6th stages
+    unsigned int m_log2Decim;
+    unsigned int m_decim;
+
+    bool decimate2(Complex c, Complex& cd);
+    bool decimate4(Complex c, Complex& cd);
+    bool decimate8(Complex c, Complex& cd);
+    bool decimate16(Complex c, Complex& cd);
+    bool decimate32(Complex c, Complex& cd);
+    bool decimate64(Complex c, Complex& cd);
+};
+
+#endif // INCLUDE_DSP_DECIMATORC_H_