added new files

core/src/dsp/convert/stereo_to_mono.h

@@ -9,7 +9,7 @@ namespace dsp::convert {
 
         StereoToMono(stream<stereo_t>* in) { base_type::init(in); }
         
-        inline int process(int count, const stereo_t* in, float* out) {
+        static inline int process(int count, const stereo_t* in, float* out) {
             for (int i = 0; i < count; i++) {
                 out[i] = (in[i].l + in[i].r) / 2.0f;
             }

core/src/dsp/noise_reduction/audio.h

@@ -0,0 +1,183 @@
+#pragma once
+#include "../processor.h"
+#include "../window/nuttall.h"
+#include <fftw3.h>
+#include "../convert/stereo_to_mono.h"
+
+namespace dsp::noise_reduction {
+    class Audio : public Processor<stereo_t, stereo_t> {
+        using base_type = Processor<stereo_t, stereo_t>;
+    public:
+        Audio() {}
+
+        Audio(stream<stereo_t>* in, int bins) { init(in, bins); }
+
+        ~Audio() {
+            if (!base_type::_block_init) { return; }
+            base_type::stop();
+            destroyBuffers();
+        }
+
+        void init(stream<stereo_t>* in, int bins) {
+            _bins = bins;
+            complexBins = (bins / 2) + 1;
+            normFactor = 1.0f / (float)_bins;
+            initBuffers();
+            base_type::init(in);
+        }
+
+        void setBins(int bins) {
+            assert(base_type::_block_init);
+            std::lock_guard<std::recursive_mutex> lck(base_type::ctrlMtx);
+            base_type::tempStop();
+            _bins = bins;
+            complexBins = (bins / 2) + 1;
+            normFactor = 1.0f / (float)_bins;
+            destroyBuffers();
+            initBuffers();
+            base_type::tempStart();
+        }
+
+        void setLevel(float level) {
+            _level = powf(10.0f, level * 0.1f);
+        }
+
+        void reset() {
+            assert(base_type::_block_init);
+            std::lock_guard<std::recursive_mutex> lck(base_type::ctrlMtx);
+            base_type::tempStop();
+            buffer::clear(buffer, _bins - 1);
+            buffer::clear(backFFTIn, _bins);
+            buffer::clear(noisePrint, _bins);
+            base_type::tempStart();
+        }
+
+        int process(int count, const stereo_t* in, stereo_t* out) {
+            // Write new input data to buffer
+            convert::StereoToMono::process(count, in, bufferStart);
+            
+            // Iterate the FFT
+            for (int i = 0; i < count; i++) {
+                // Apply windows
+                volk_32f_x2_multiply_32f(forwFFTIn, &buffer[i], fftWin, _bins);
+
+                // Do forward FFT
+                fftwf_execute(forwardPlan);
+
+                // Get bin amplitude and square to get power
+                volk_32fc_magnitude_32f(ampBuf, (lv_32fc_t*)forwFFTOut, complexBins);
+
+                // Update noise print using a running average
+                volk_32f_s32f_multiply_32f(scaledAmps, ampBuf, alpha, complexBins);
+                volk_32f_s32f_multiply_32f(noisePrint, noisePrint, beta, complexBins);
+                volk_32f_x2_add_32f(noisePrint, noisePrint, scaledAmps, complexBins);
+
+                // Clamp amplitudes
+                volk_32f_x2_max_32f(ampBuf, ampBuf, noisePrint, complexBins);
+
+                // Compute Wiener (funny) filter
+                volk_32f_x2_subtract_32f(scaledAmps, ampBuf, noisePrint, complexBins);
+                volk_32f_x2_divide_32f(scaledAmps, scaledAmps, ampBuf, complexBins);
+
+                // Apply wiener filter to bins
+                volk_32fc_32f_multiply_32fc((lv_32fc_t*)backFFTIn, (lv_32fc_t*)forwFFTOut, scaledAmps, complexBins);
+
+                // Do reverse FFT and get first element
+                fftwf_execute(backwardPlan);
+                out[i].l = backFFTOut[_bins / 2];
+                out[i].r = backFFTOut[_bins / 2];
+            }
+
+            // Correct amplitude
+            volk_32f_s32f_multiply_32f((float*)out, (float*)out, normFactor, count*2);
+
+            // Move buffer buffer
+            memmove(buffer, &buffer[count], (_bins - 1) * sizeof(float));
+
+            return count;
+        }
+
+        int run() {
+            int count = base_type::_in->read();
+            if (count < 0) { return -1; }
+
+            process(count, base_type::_in->readBuf, base_type::out.writeBuf);
+
+            // Swap if some data was generated
+            base_type::_in->flush();
+            if (!base_type::out.swap(count)) { return -1; }
+            return count;
+        }
+
+    protected:
+        void initBuffers() {
+            // Allocate FFT buffers
+            forwFFTIn = (float*)fftwf_malloc(_bins * sizeof(float));
+            forwFFTOut = (complex_t*)fftwf_malloc(_bins * sizeof(complex_t));
+            backFFTIn = (complex_t*)fftwf_malloc(_bins * sizeof(complex_t));
+            backFFTOut = (float*)fftwf_malloc(_bins * sizeof(float));
+
+            // Allocate and clear delay buffer
+            buffer = buffer::alloc<float>(STREAM_BUFFER_SIZE + 64000);
+            bufferStart = &buffer[_bins - 1];
+            buffer::clear(buffer, _bins - 1);
+
+            // Clear backward FFT input
+            buffer::clear(backFFTIn, _bins);
+
+            // Allocate amplitude buffer
+            ampBuf = buffer::alloc<float>(_bins);
+            scaledAmps = buffer::alloc<float>(_bins);
+            noisePrint = buffer::alloc<float>(_bins);
+            buffer::clear(noisePrint, _bins);
+
+            // Allocate and generate Window
+            fftWin = buffer::alloc<float>(_bins);
+            for (int i = 0; i < _bins; i++) { fftWin[i] = window::nuttall(i, _bins - 1); }
+
+            // Plan FFTs
+            forwardPlan = fftwf_plan_dft_r2c_1d(_bins, forwFFTIn, (fftwf_complex*)forwFFTOut, FFTW_ESTIMATE);
+            backwardPlan = fftwf_plan_dft_c2r_1d(_bins, (fftwf_complex*)backFFTIn, backFFTOut, FFTW_ESTIMATE);
+        }
+
+        void destroyBuffers() {
+            fftwf_destroy_plan(forwardPlan);
+            fftwf_destroy_plan(backwardPlan);
+            fftwf_free(forwFFTIn);
+            fftwf_free(forwFFTOut);
+            fftwf_free(backFFTIn);
+            fftwf_free(backFFTOut);
+            buffer::free(buffer);
+            buffer::free(ampBuf);
+            buffer::free(scaledAmps);
+            buffer::free(noisePrint);
+            buffer::free(fftWin);
+        }
+
+        float _level = 0.0f;
+
+        float* forwFFTIn;
+        complex_t* forwFFTOut;
+        complex_t* backFFTIn;
+        float* backFFTOut;
+
+        fftwf_plan forwardPlan;
+        fftwf_plan backwardPlan;
+
+        float* buffer;
+        float* bufferStart;
+
+        float* fftWin;
+
+        float* ampBuf;
+        float* scaledAmps;
+        float* noisePrint;
+
+        int _bins;
+        int complexBins;
+        float normFactor = 1.0f;
+
+        float alpha = 0.0001f;
+        float beta = 0.9999f;
+    }; 
+}

core/src/dsp/noise_reduction/noise_blanker.h

@@ -37,21 +37,17 @@ namespace dsp::noise_reduction {
 
         inline int process(int count, complex_t* in, complex_t* out) {
             for (int i = 0; i < count; i++) {
-                // Get signal amplitude
+                // Get signal amplitude and pass value if null
                 float inAmp = in[i].amplitude();
-
-                // Update average amplitude
-                float gain = 1.0f;
-                if (inAmp != 0.0f) {
-                    amp = (amp * _invRate) + (inAmp * _rate);
-                    float excess = inAmp / amp;
-                    if (excess > _level) {
-                        gain = 1.0f / excess;
-                    }
+                if (!inAmp) {
+                    out[i] = in[i];
                 }
 
-                // Scale output by gain
-                out[i] = in[i] * gain;
+                // Update running average of amplitude
+                amp = (_rate*inAmp) + (_invRate*amp);
+
+                // Null out if spike (Note: ideally, it should try to guess the real data)
+                out[i] = (inAmp > _level*amp) ? complex_t{0.0f,0.0f} : in[i];
             }
             return count;
         }

decoder_modules/radio/src/demod.h

@@ -45,6 +45,7 @@ namespace demod {
         virtual int getDefaultDeemphasisMode() = 0;
         virtual bool getFMIFNRAllowed() = 0;
         virtual bool getNBAllowed() = 0;
+        virtual bool getAFNRAllowed() = 0;
         virtual dsp::stream<dsp::stereo_t>* getOutput() = 0;
     };
 }

decoder_modules/radio/src/demodulators/am.h

@@ -86,6 +86,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return false; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/cw.h

@@ -92,6 +92,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return false; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/dsb.h

@@ -79,6 +79,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return true; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/lsb.h

@@ -79,6 +79,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return true; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/nfm.h

@@ -75,6 +75,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return true; }
         bool getNBAllowed() { return false; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/raw.h

@@ -59,6 +59,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return true; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &c2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/usb.h

@@ -80,6 +80,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_NONE; }
         bool getFMIFNRAllowed() { return false; }
         bool getNBAllowed() { return true; }
+        bool getAFNRAllowed() { return true; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/wfm.h

@@ -130,6 +130,7 @@ namespace demod {
         int getDefaultDeemphasisMode() { return DEEMP_MODE_50US; }
         bool getFMIFNRAllowed() { return true; }
         bool getNBAllowed() { return false; }
+        bool getAFNRAllowed() { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
         // ============= DEDICATED FUNCTIONS =============

decoder_modules/radio/src/radio_module.h

@@ -9,6 +9,7 @@
 #include <dsp/noise_reduction/noise_blanker.h>
 #include <dsp/noise_reduction/fm_if.h>
 #include <dsp/noise_reduction/squelch.h>
+#include <dsp/noise_reduction/audio.h>
 #include <dsp/multirate/rational_resampler.h>
 #include <dsp/filter/deephasis.h>
 #include <core.h>
@@ -83,9 +84,11 @@ public:
 
         resamp.init(NULL, 250000.0, 48000.0);
         deemp.init(NULL, 50e-6, 48000.0);
+        afNR.init(NULL, 1024);
 
         afChain.addBlock(&resamp, true);
         afChain.addBlock(&deemp, false);
+        afChain.addBlock(&afNR, false);
 
         // Initialize the sink
         srChangeHandler.ctx = this;
@@ -247,6 +250,12 @@ private:
             if (!_this->nbEnabled && _this->enabled) { style::endDisabled(); }
         }
         
+        // Noise reduction
+        if (_this->afNRAllowed) {
+            if (ImGui::Checkbox(("Audio Noise Reduction##_radio_afnr_ena_" + _this->name).c_str(), &_this->afNREnabled)) {
+                _this->setAFNREnabled(_this->afNREnabled);
+            }
+        }
 
         // Squelch
         if (ImGui::Checkbox(("Squelch##_radio_sqelch_ena_" + _this->name).c_str(), &_this->squelchEnabled)) {
@@ -370,6 +379,8 @@ private:
         fmIFPresetId = ifnrPresets.valueId(IFNR_PRESET_VOICE);
         nbAllowed = selectedDemod->getNBAllowed();
         nbEnabled = false;
+        afNRAllowed = selectedDemod->getAFNRAllowed();
+        afNREnabled = false;
         nbLevel = 0.0f;
         double ifSamplerate = selectedDemod->getIFSampleRate();
         config.acquire();
@@ -411,6 +422,9 @@ private:
         if (config.conf[name][selectedDemod->getName()].contains("noiseBlankerLevel")) {
             nbLevel = config.conf[name][selectedDemod->getName()]["noiseBlankerLevel"];
         }
+        if (config.conf[name][selectedDemod->getName()].contains("audioNoiseReductionEnabled")) {
+            nbEnabled = config.conf[name][selectedDemod->getName()]["audioNoiseReductionEnabled"];
+        }
         config.release();
 
         // Configure VFO
@@ -446,7 +460,10 @@ private:
             afChain.enableBlock(&resamp, [=](dsp::stream<dsp::stereo_t>* out){ stream.setInput(out); });
 
             // Configure deemphasis
-            setDeemphasisMode(deempModes[deempId]);
+            setDeemphasisMode(deempAllowed ? deempModes[deempId] : DEEMP_MODE_NONE);
+
+            // Configure AF NR
+            setAFNREnabled(afNRAllowed && afNREnabled);
         }
         else {
             // Disable everything if post processing is disabled
@@ -508,6 +525,17 @@ private:
         config.release(true);
     }
 
+    void setAFNREnabled(bool enable) {
+        afNREnabled = enable;
+        if (!postProcEnabled || !selectedDemod) { return; }
+        afChain.setBlockEnabled(&afNR, afNREnabled, [=](dsp::stream<dsp::stereo_t>* out){ stream.setInput(out); });
+
+        // Save config
+        config.acquire();
+        config.conf[name][selectedDemod->getName()]["audioNoiseReductionEnabled"] = nbEnabled;
+        config.release(true);
+    }
+
     void setNBEnabled(bool enable) {
         nbEnabled = enable;
         if (!selectedDemod) { return; }
@@ -660,6 +688,7 @@ private:
     dsp::chain<dsp::stereo_t> afChain;
     dsp::multirate::RationalResampler<dsp::stereo_t> resamp;
     dsp::filter::Deemphasis<dsp::stereo_t> deemp;
+    dsp::noise_reduction::Audio afNR;
 
     SinkManager::Stream stream;
 
@@ -683,6 +712,9 @@ private:
     int deempId = 0;
     bool deempAllowed;
 
+    bool afNREnabled = false;
+    bool afNRAllowed;
+
     bool FMIFNRAllowed;
     bool FMIFNREnabled = false;
     int fmIFPresetId;