diff --git a/sdrbase/CMakeLists.txt b/sdrbase/CMakeLists.txt
index 050c289aa..9a55e6dd8 100644
--- a/sdrbase/CMakeLists.txt
+++ b/sdrbase/CMakeLists.txt
@@ -130,9 +130,10 @@ set(sdrbase_HEADERS
     dsp/inthalfbandfilter.h
     dsp/inthalfbandfilterdb.h
     dsp/inthalfbandfilterdbf.h
-    dsp/inthalfbandfiltereo1.h
-    dsp/inthalfbandfiltereo1i.h
-    dsp/inthalfbandfiltereo2.h
+    dsp/inthalfbandfiltereo.h
+    # dsp/inthalfbandfiltereo1.h
+    # dsp/inthalfbandfiltereo1i.h
+    # dsp/inthalfbandfiltereo2.h
     dsp/inthalfbandfiltereof.h
     dsp/inthalfbandfilterst.h
     dsp/inthalfbandfiltersti.h
diff --git a/sdrbase/dsp/decimators.h b/sdrbase/dsp/decimators.h
index 9d413e948..50fb6b97b 100644
--- a/sdrbase/dsp/decimators.h
+++ b/sdrbase/dsp/decimators.h
@@ -18,12 +18,7 @@
 #define INCLUDE_GPL_DSP_DECIMATORS_H_
 
 #include "dsp/dsptypes.h"
-
-#ifdef SDR_RX_SAMPLE_24BIT
-#include "dsp/inthalfbandfiltereo2.h"
-#else // SDR_RX_SAMPLE_24BIT
-#include "dsp/inthalfbandfiltereo1.h"
-#endif // SDR_RX_SAMPLE_24BIT
+#include "dsp/inthalfbandfiltereo.h"
 
 #define DECIMATORS_HB_FILTER_ORDER 64
 
@@ -329,20 +324,20 @@ public:
 
 private:
 #ifdef SDR_RX_SAMPLE_24BIT
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator2;  // 1st stages
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator4;  // 2nd stages
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator8;  // 3rd stages
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator16; // 4th stages
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator32; // 5th stages
-    IntHalfbandFilterEO2<DECIMATORS_HB_FILTER_ORDER> m_decimator64; // 6th stages
-#else // SDR_RX_SAMPLE_24BIT
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator2;  // 1st stages
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator4;  // 2nd stages
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator8;  // 3rd stages
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator16; // 4th stages
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator32; // 5th stages
-    IntHalfbandFilterEO1<DECIMATORS_HB_FILTER_ORDER> m_decimator64; // 6th stages
-#endif // SDR_RX_SAMPLE_24BIT
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator2;  // 1st stages
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator4;  // 2nd stages
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator8;  // 3rd stages
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator16; // 4th stages
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator32; // 5th stages
+    IntHalfbandFilterEO<qint64, qint64, DECIMATORS_HB_FILTER_ORDER> m_decimator64; // 6th stages
+#else
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator2;  // 1st stages
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator4;  // 2nd stages
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator8;  // 3rd stages
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator16; // 4th stages
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator32; // 5th stages
+    IntHalfbandFilterEO<qint32, qint32, DECIMATORS_HB_FILTER_ORDER> m_decimator64; // 6th stages
+#endif
 };
 
 template<typename StorageType, typename T, uint SdrBits, uint InputBits>
diff --git a/sdrbase/dsp/inthalfbandfiltereo.h b/sdrbase/dsp/inthalfbandfiltereo.h
new file mode 100644
index 000000000..8d6af22ff
--- /dev/null
+++ b/sdrbase/dsp/inthalfbandfiltereo.h
@@ -0,0 +1,815 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 F4EXB                                                      //
+// written by Edouard Griffiths                                                  //
+//                                                                               //
+// Integer half-band FIR based interpolator and decimator                        //
+// This is the even/odd double buffer variant. Really useful only when SIMD is   //
+// used                                                                          //
+//                                                                               //
+// 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                  //
+//                                                                               //
+// 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/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_INTHALFBANDFILTEREO_H_
+#define SDRBASE_DSP_INTHALFBANDFILTEREO_H_
+
+#include <stdint.h>
+#include <cstdlib>
+#include "dsp/dsptypes.h"
+#include "dsp/hbfiltertraits.h"
+#include "export.h"
+
+template<typename EOStorageType, typename AccuType, uint32_t HBFilterOrder>
+class SDRBASE_API IntHalfbandFilterEO {
+public:
+    IntHalfbandFilterEO();
+
+    // downsample by 2, return center part of original spectrum
+    bool workDecimateCenter(Sample* sample)
+    {
+        // insert sample into ring-buffer
+        storeSample((FixReal) sample->real(), (FixReal) sample->imag());
+
+        switch(m_state)
+        {
+            case 0:
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 1;
+                // tell caller we don't have a new sample
+                return false;
+
+            default:
+                // save result
+                doFIR(sample);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 0;
+
+                // tell caller we have a new sample
+                return true;
+        }
+    }
+
+    // upsample by 2, return center part of original spectrum - double buffer variant
+    bool workInterpolateCenterZeroStuffing(Sample* sampleIn, Sample *SampleOut)
+    {
+        switch(m_state)
+        {
+            case 0:
+                // insert sample into ring-buffer
+                storeSample((FixReal) 0, (FixReal) 0);
+                // save result
+                doFIR(SampleOut);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 1;
+                // tell caller we didn't consume the sample
+                return false;
+
+            default:
+                // insert sample into ring-buffer
+                storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
+                // save result
+                doFIR(SampleOut);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 0;
+                // tell caller we consumed the sample
+                return true;
+        }
+    }
+
+    /** Optimized upsampler by 2 not calculating FIR with inserted null samples */
+    bool workInterpolateCenter(Sample* sampleIn, Sample *SampleOut)
+    {
+        switch(m_state)
+        {
+        case 0:
+            // return the middle peak
+            SampleOut->setReal(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]);
+            SampleOut->setImag(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]);
+            m_state = 1;  // next state
+            return false; // tell caller we didn't consume the sample
+
+        default:
+            // calculate with non null samples
+            doInterpolateFIR(SampleOut);
+
+            // insert sample into ring double buffer
+            m_samples[m_ptr][0] = sampleIn->real();
+            m_samples[m_ptr][1] = sampleIn->imag();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
+
+            // advance pointer
+            if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+                m_ptr++;
+            } else {
+                m_ptr = 0;
+            }
+
+            m_state = 0; // next state
+            return true; // tell caller we consumed the sample
+        }
+    }
+
+    bool workDecimateCenter(int32_t *x, int32_t *y)
+    {
+        // insert sample into ring-buffer
+        storeSample32(*x, *y);
+
+        switch(m_state)
+        {
+            case 0:
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 1;
+                // tell caller we don't have a new sample
+                return false;
+
+            default:
+                // save result
+                doFIR(x, y);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 0;
+                // tell caller we have a new sample
+                return true;
+        }
+    }
+
+    // downsample by 2, return lower half of original spectrum
+    bool workDecimateLowerHalf(Sample* sample)
+    {
+        switch(m_state)
+        {
+            case 0:
+                // insert sample into ring-buffer
+                storeSample((FixReal) -sample->imag(), (FixReal) sample->real());
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 1;
+                // tell caller we don't have a new sample
+                return false;
+
+            case 1:
+                // insert sample into ring-buffer
+                storeSample((FixReal) -sample->real(), (FixReal) -sample->imag());
+                // save result
+                doFIR(sample);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 2;
+                // tell caller we have a new sample
+                return true;
+
+            case 2:
+                // insert sample into ring-buffer
+                storeSample((FixReal) sample->imag(), (FixReal) -sample->real());
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 3;
+                // tell caller we don't have a new sample
+                return false;
+
+            default:
+                // insert sample into ring-buffer
+                storeSample((FixReal) sample->real(), (FixReal) sample->imag());
+                // save result
+                doFIR(sample);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 0;
+                // tell caller we have a new sample
+                return true;
+        }
+    }
+
+    // upsample by 2, from lower half of original spectrum - double buffer variant
+    bool workInterpolateLowerHalfZeroStuffing(Sample* sampleIn, Sample *sampleOut)
+    {
+        Sample s;
+
+        switch(m_state)
+        {
+        case 0:
+            // insert sample into ring-buffer
+            storeSample((FixReal) 0, (FixReal) 0);
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(s.imag());
+            sampleOut->setImag(-s.real());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 1;
+
+            // tell caller we didn't consume the sample
+            return false;
+
+        case 1:
+            // insert sample into ring-buffer
+            storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(-s.real());
+            sampleOut->setImag(-s.imag());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 2;
+
+            // tell caller we consumed the sample
+            return true;
+
+        case 2:
+            // insert sample into ring-buffer
+            storeSample((FixReal) 0, (FixReal) 0);
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(-s.imag());
+            sampleOut->setImag(s.real());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 3;
+
+            // tell caller we didn't consume the sample
+            return false;
+
+        default:
+            // insert sample into ring-buffer
+            storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(s.real());
+            sampleOut->setImag(s.imag());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 0;
+
+            // tell caller we consumed the sample
+            return true;
+        }
+    }
+
+    /** Optimized upsampler by 2 not calculating FIR with inserted null samples */
+    bool workInterpolateLowerHalf(Sample* sampleIn, Sample *sampleOut)
+    {
+        Sample s;
+
+        switch(m_state)
+        {
+        case 0:
+            // return the middle peak
+            sampleOut->setReal(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]);  // imag
+            sampleOut->setImag(-m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]); // - real
+            m_state = 1;  // next state
+            return false; // tell caller we didn't consume the sample
+
+        case 1:
+            // calculate with non null samples
+            doInterpolateFIR(&s);
+            sampleOut->setReal(-s.real());
+            sampleOut->setImag(-s.imag());
+
+            // insert sample into ring double buffer
+            m_samples[m_ptr][0] = sampleIn->real();
+            m_samples[m_ptr][1] = sampleIn->imag();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
+
+            // advance pointer
+            if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+                m_ptr++;
+            } else {
+                m_ptr = 0;
+            }
+
+            m_state = 2; // next state
+            return true; // tell caller we consumed the sample
+
+        case 2:
+            // return the middle peak
+            sampleOut->setReal(-m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]);  // - imag
+            sampleOut->setImag(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]); // real
+            m_state = 3;  // next state
+            return false; // tell caller we didn't consume the sample
+
+        default:
+            // calculate with non null samples
+            doInterpolateFIR(&s);
+            sampleOut->setReal(s.real());
+            sampleOut->setImag(s.imag());
+
+            // insert sample into ring double buffer
+            m_samples[m_ptr][0] = sampleIn->real();
+            m_samples[m_ptr][1] = sampleIn->imag();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
+
+            // advance pointer
+            if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+                m_ptr++;
+            } else {
+                m_ptr = 0;
+            }
+
+            m_state = 0; // next state
+            return true; // tell caller we consumed the sample
+        }
+    }
+
+    // downsample by 2, return upper half of original spectrum
+    bool workDecimateUpperHalf(Sample* sample)
+    {
+        switch(m_state)
+        {
+            case 0:
+                // insert sample into ring-buffer
+                storeSample((FixReal) sample->imag(), (FixReal) -sample->real());
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 1;
+                // tell caller we don't have a new sample
+                return false;
+
+            case 1:
+                // insert sample into ring-buffer
+                storeSample((FixReal) -sample->real(), (FixReal) -sample->imag());
+                // save result
+                doFIR(sample);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 2;
+                // tell caller we have a new sample
+                return true;
+
+            case 2:
+                // insert sample into ring-buffer
+                storeSample((FixReal) -sample->imag(), (FixReal) sample->real());
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 3;
+                // tell caller we don't have a new sample
+                return false;
+
+            default:
+                // insert sample into ring-buffer
+                storeSample((FixReal) sample->real(), (FixReal) sample->imag());
+                // save result
+                doFIR(sample);
+                // advance write-pointer
+                advancePointer();
+                // next state
+                m_state = 0;
+                // tell caller we have a new sample
+                return true;
+        }
+    }
+
+    // upsample by 2, move original spectrum to upper half - double buffer variant
+    bool workInterpolateUpperHalfZeroStuffing(Sample* sampleIn, Sample *sampleOut)
+    {
+        Sample s;
+
+        switch(m_state)
+        {
+        case 0:
+            // insert sample into ring-buffer
+            storeSample((FixReal) 0, (FixReal) 0);
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(-s.imag());
+            sampleOut->setImag(s.real());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 1;
+
+            // tell caller we didn't consume the sample
+            return false;
+
+        case 1:
+            // insert sample into ring-buffer
+            storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(-s.real());
+            sampleOut->setImag(-s.imag());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 2;
+
+            // tell caller we consumed the sample
+            return true;
+
+        case 2:
+            // insert sample into ring-buffer
+            storeSample((FixReal) 0, (FixReal) 0);
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(s.imag());
+            sampleOut->setImag(-s.real());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 3;
+
+            // tell caller we didn't consume the sample
+            return false;
+
+        default:
+            // insert sample into ring-buffer
+            storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
+
+            // save result
+            doFIR(&s);
+            sampleOut->setReal(s.real());
+            sampleOut->setImag(s.imag());
+
+            // advance write-pointer
+            advancePointer();
+
+            // next state
+            m_state = 0;
+
+            // tell caller we consumed the sample
+            return true;
+        }
+    }
+
+    /** Optimized upsampler by 2 not calculating FIR with inserted null samples */
+    bool workInterpolateUpperHalf(Sample* sampleIn, Sample *sampleOut)
+    {
+        Sample s;
+
+        switch(m_state)
+        {
+        case 0:
+            // return the middle peak
+            sampleOut->setReal(-m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]); // - imag
+            sampleOut->setImag(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]); // + real
+            m_state = 1;  // next state
+            return false; // tell caller we didn't consume the sample
+
+        case 1:
+            // calculate with non null samples
+            doInterpolateFIR(&s);
+            sampleOut->setReal(-s.real());
+            sampleOut->setImag(-s.imag());
+
+            // insert sample into ring double buffer
+            m_samples[m_ptr][0] = sampleIn->real();
+            m_samples[m_ptr][1] = sampleIn->imag();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
+
+            // advance pointer
+            if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+                m_ptr++;
+            } else {
+                m_ptr = 0;
+            }
+
+            m_state = 2; // next state
+            return true; // tell caller we consumed the sample
+
+        case 2:
+            // return the middle peak
+            sampleOut->setReal(m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]);  // + imag
+            sampleOut->setImag(-m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]);   // - real
+            m_state = 3;  // next state
+            return false; // tell caller we didn't consume the sample
+
+        default:
+            // calculate with non null samples
+            doInterpolateFIR(&s);
+            sampleOut->setReal(s.real());
+            sampleOut->setImag(s.imag());
+
+            // insert sample into ring double buffer
+            m_samples[m_ptr][0] = sampleIn->real();
+            m_samples[m_ptr][1] = sampleIn->imag();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
+            m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
+
+            // advance pointer
+            if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+                m_ptr++;
+            } else {
+                m_ptr = 0;
+            }
+
+            m_state = 0; // next state
+            return true; // tell caller we consumed the sample
+        }
+    }
+
+    void myDecimate(const Sample* sample1, Sample* sample2)
+    {
+        storeSample((FixReal) sample1->real(), (FixReal) sample1->imag());
+        advancePointer();
+
+        storeSample((FixReal) sample2->real(), (FixReal) sample2->imag());
+        doFIR(sample2);
+        advancePointer();
+    }
+
+    void myDecimate(int32_t x1, int32_t y1, int32_t *x2, int32_t *y2)
+    {
+        storeSample32(x1, y1);
+        advancePointer();
+
+        storeSample32(*x2, *y2);
+        doFIR(x2, y2);
+        advancePointer();
+    }
+
+    /** Simple zero stuffing and filter */
+    void myInterpolateZeroStuffing(Sample* sample1, Sample* sample2)
+    {
+        storeSample((FixReal) sample1->real(), (FixReal) sample1->imag());
+        doFIR(sample1);
+        advancePointer();
+
+        storeSample((FixReal) 0, (FixReal) 0);
+        doFIR(sample2);
+        advancePointer();
+    }
+
+    /** Simple zero stuffing and filter */
+    void myInterpolateZeroStuffing(int32_t *x1, int32_t *y1, int32_t *x2, int32_t *y2)
+    {
+        storeSample32(*x1, *y1);
+        doFIR(x1, y1);
+        advancePointer();
+
+        storeSample32(0, 0);
+        doFIR(x2, y2);
+        advancePointer();
+    }
+
+    /** Optimized upsampler by 2 not calculating FIR with inserted null samples */
+    void myInterpolate(qint32 *x1, qint32 *y1, qint32 *x2, qint32 *y2)
+    {
+        // insert sample into ring double buffer
+        m_samples[m_ptr][0] = *x1;
+        m_samples[m_ptr][1] = *y1;
+        m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = *x1;
+        m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = *y1;
+
+        // advance pointer
+        if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
+            m_ptr++;
+        } else {
+            m_ptr = 0;
+        }
+
+        // first output sample calculated with the middle peak
+        *x1 = m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0];
+        *y1 = m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1];
+
+        // second sample calculated with the filter
+        doInterpolateFIR(x2, y2);
+    }
+
+protected:
+    EOStorageType m_even[2][HBFIRFilterTraits<HBFilterOrder>::hbOrder];
+    EOStorageType m_odd[2][HBFIRFilterTraits<HBFilterOrder>::hbOrder];
+    int32_t m_samples[HBFIRFilterTraits<HBFilterOrder>::hbOrder][2];
+
+    int m_ptr;
+    int m_size;
+    int m_state;
+
+    void storeSample(const FixReal& sampleI, const FixReal& sampleQ)
+    {
+        if ((m_ptr % 2) == 0)
+        {
+            m_even[0][m_ptr/2] = sampleI;
+            m_even[1][m_ptr/2] = sampleQ;
+            m_even[0][m_ptr/2 + m_size] = sampleI;
+            m_even[1][m_ptr/2 + m_size] = sampleQ;
+        }
+        else
+        {
+            m_odd[0][m_ptr/2] = sampleI;
+            m_odd[1][m_ptr/2] = sampleQ;
+            m_odd[0][m_ptr/2 + m_size] = sampleI;
+            m_odd[1][m_ptr/2 + m_size] = sampleQ;
+        }
+    }
+
+    void storeSample32(int32_t x, int32_t y)
+    {
+        if ((m_ptr % 2) == 0)
+        {
+            m_even[0][m_ptr/2] = x;
+            m_even[1][m_ptr/2] = y;
+            m_even[0][m_ptr/2 + m_size] = x;
+            m_even[1][m_ptr/2 + m_size] = y;
+        }
+        else
+        {
+            m_odd[0][m_ptr/2] = x;
+            m_odd[1][m_ptr/2] = y;
+            m_odd[0][m_ptr/2 + m_size] = x;
+            m_odd[1][m_ptr/2 + m_size] = y;
+        }
+    }
+
+    void advancePointer()
+    {
+        m_ptr = m_ptr + 1 < 2*m_size ? m_ptr + 1: 0;
+    }
+
+    void doFIR(Sample* sample)
+    {
+        AccuType iAcc = 0;
+        AccuType qAcc = 0;
+
+        int a = m_ptr/2 + m_size; // tip pointer
+        int b = m_ptr/2 + 1; // tail pointer
+
+        for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
+        {
+            if ((m_ptr % 2) == 0)
+            {
+                iAcc += (m_even[0][a] + m_even[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+                qAcc += (m_even[1][a] + m_even[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            }
+            else
+            {
+                iAcc += (m_odd[0][a] + m_odd[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+                qAcc += (m_odd[1][a] + m_odd[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            }
+
+            a -= 1;
+            b += 1;
+        }
+
+        if ((m_ptr % 2) == 0)
+        {
+            iAcc += ((int32_t)m_odd[0][m_ptr/2 + m_size/2]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+            qAcc += ((int32_t)m_odd[1][m_ptr/2 + m_size/2]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+        }
+        else
+        {
+            iAcc += ((int32_t)m_even[0][m_ptr/2 + m_size/2 + 1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+            qAcc += ((int32_t)m_even[1][m_ptr/2 + m_size/2 + 1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+        }
+
+        sample->setReal(iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
+        sample->setImag(qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
+    }
+
+    void doFIR(int32_t *x, int32_t *y)
+    {
+        AccuType iAcc = 0;
+        AccuType qAcc = 0;
+
+        int a = m_ptr/2 + m_size; // tip pointer
+        int b = m_ptr/2 + 1; // tail pointer
+
+        for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
+        {
+            if ((m_ptr % 2) == 0)
+            {
+                iAcc += (m_even[0][a] + m_even[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+                qAcc += (m_even[1][a] + m_even[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            }
+            else
+            {
+                iAcc += (m_odd[0][a] + m_odd[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+                qAcc += (m_odd[1][a] + m_odd[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            }
+
+            a -= 1;
+            b += 1;
+        }
+
+        if ((m_ptr % 2) == 0)
+        {
+            iAcc += ((int32_t)m_odd[0][m_ptr/2 + m_size/2]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+            qAcc += ((int32_t)m_odd[1][m_ptr/2 + m_size/2]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+        }
+        else
+        {
+            iAcc += ((int32_t)m_even[0][m_ptr/2 + m_size/2 + 1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+            qAcc += ((int32_t)m_even[1][m_ptr/2 + m_size/2 + 1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
+        }
+
+        *x = iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1); // HB_SHIFT incorrect do not loose the gained bit
+        *y = qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
+    }
+
+    void doInterpolateFIR(Sample* sample)
+    {
+        AccuType iAcc = 0;
+        AccuType qAcc = 0;
+
+        qint16 a = m_ptr;
+        qint16 b = m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder / 2) - 1;
+
+        // go through samples in buffer
+        for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
+        {
+            iAcc += (m_samples[a][0] + m_samples[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            qAcc += (m_samples[a][1] + m_samples[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            a++;
+            b--;
+        }
+
+        sample->setReal(iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
+        sample->setImag(qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
+    }
+
+    void doInterpolateFIR(qint32 *x, qint32 *y)
+    {
+        AccuType iAcc = 0;
+        AccuType qAcc = 0;
+
+        qint16 a = m_ptr;
+        qint16 b = m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder / 2) - 1;
+
+        // go through samples in buffer
+        for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
+        {
+            iAcc += (m_samples[a][0] + m_samples[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            qAcc += (m_samples[a][1] + m_samples[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
+            a++;
+            b--;
+        }
+
+        *x = iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
+        *y = qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
+    }
+};
+
+template<typename EOStorageType, typename AccuType, uint32_t HBFilterOrder>
+IntHalfbandFilterEO<EOStorageType, AccuType, HBFilterOrder>::IntHalfbandFilterEO()
+{
+    m_size = HBFIRFilterTraits<HBFilterOrder>::hbOrder/2;
+
+    for (int i = 0; i < 2*m_size; i++)
+    {
+        m_even[0][i] = 0;
+        m_even[1][i] = 0;
+        m_odd[0][i] = 0;
+        m_odd[1][i] = 0;
+        m_samples[i][0] = 0;
+        m_samples[i][1] = 0;
+    }
+
+    m_ptr = 0;
+    m_state = 0;
+}
+
+#endif /* SDRBASE_DSP_INTHALFBANDFILTEREO_H_ */
diff --git a/sdrbase/dsp/inthalfbandfiltereo1.h b/sdrbase/dsp/inthalfbandfiltereo1.h
index 7a1539afc..21bc112de 100644
--- a/sdrbase/dsp/inthalfbandfiltereo1.h
+++ b/sdrbase/dsp/inthalfbandfiltereo1.h
@@ -19,8 +19,8 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.          //
 ///////////////////////////////////////////////////////////////////////////////////
 
-#ifndef SDRBASE_DSP_INTHALFBANDFILTEREO_H_
-#define SDRBASE_DSP_INTHALFBANDFILTEREO_H_
+#ifndef SDRBASE_DSP_INTHALFBANDFILTEREO1_H_
+#define SDRBASE_DSP_INTHALFBANDFILTEREO1_H_
 
 #include <stdint.h>
 #include <cstdlib>
@@ -837,4 +837,4 @@ IntHalfbandFilterEO1<HBFilterOrder>::IntHalfbandFilterEO1()
     m_state = 0;
 }
 
-#endif /* SDRBASE_DSP_INTHALFBANDFILTEREO_H_ */
+#endif /* SDRBASE_DSP_INTHALFBANDFILTEREO1_H_ */