Added a noise blanker for SSB and DSB

core/src/dsp/noise_reduction.h

@@ -267,7 +267,7 @@ namespace dsp {
     public:
         NoiseBlanker() {}
 
-        NoiseBlanker(stream<complex_t>* in, float attack, float decay, float threshold, float level, float sampleRate) { init(in, attack, decay, threshold, level, sampleRate); }
+        NoiseBlanker(stream<complex_t>* in, float level) { init(in, level); }
 
         ~NoiseBlanker() {
             if (!generic_block<NoiseBlanker>::_block_init) { return; }
@@ -275,16 +275,9 @@ namespace dsp {
             volk_free(ampBuf);
         }
 
-        void init(stream<complex_t>* in, float attack, float decay, float threshold, float level, float sampleRate) {
+        void init(stream<complex_t>* in, float level) {
             _in = in;
-            _attack = attack;
+            _level = powf(10.0f, level / 10.0f);;
-            _decay = decay;
-            _threshold = powf(10.0f, threshold / 10.0f);
-            _level = level;
-            _sampleRate = sampleRate;
-
-            _inv_attack = 1.0f - _attack;
-            _inv_decay = 1.0f - _decay;
 
             ampBuf = (float*)volk_malloc(STREAM_BUFFER_SIZE*sizeof(float), volk_get_alignment());
 
@@ -293,28 +286,8 @@ namespace dsp {
             generic_block<NoiseBlanker>::_block_init = true;
         }
 
-        void setAttack(float attack) {
-            _attack = attack;
-            _inv_attack = 1.0f - _attack;
-        }
-
-        void setDecay(float decay) {
-            _decay = decay;
-            _inv_decay = 1.0f - _decay;
-        }
-
-        void setThreshold(float threshold) {
-            _threshold = powf(10.0f, threshold / 10.0f);
-            spdlog::warn("Threshold {0}", _threshold);
-        }
-
         void setLevel(float level) {
-            _level = level;
+            _level = powf(10.0f, level / 10.0f);
-        }
-
-        void setSampleRate(float sampleRate) {
-            _sampleRate = sampleRate;
-            // TODO: Change parameters if the algo needs it
         }
 
         void setInput(stream<complex_t>* in) {
@@ -334,33 +307,13 @@ namespace dsp {
             // Get amplitudes
             volk_32fc_magnitude_32f(ampBuf, (lv_32fc_t*)_in->readBuf, count);
 
-            // Apply filtering and threshold
+            // Hard limit the amplitude
-            float val;
+            complex_t inVal;
             for (int i = 0; i < count; i++) {
-                // Filter using attack/threshold methode
+                inVal = _in->readBuf[i];
-                val = ampBuf[i];
+                out.writeBuf[i] = (ampBuf[i] > _level) ? inVal * (_level / inVal.amplitude()) : inVal;
-                if (val > lastValue) {
-                    lastValue = (_inv_attack*lastValue) + (_attack*val);
-                }
-                else {
-                    lastValue = (_inv_decay*lastValue) + (_decay*val);
-                }
-
-                // Apply threshold and invert
-                if (lastValue > _threshold) {
-                    ampBuf[i] = _threshold / (lastValue * _level);
-                    if (ampBuf[i] == 0) {
-                        spdlog::warn("WTF???");
-                    }
-                }
-                else {
-                    ampBuf[i] = 1.0f;
-                }
             }
 
-            // Multiply
-            volk_32fc_32f_multiply_32fc((lv_32fc_t*)out.writeBuf, (lv_32fc_t*)_in->readBuf, ampBuf, count);
-
             _in->flush();
             if (!out.swap(count)) { return -1; }
             return count;
@@ -371,15 +324,7 @@ namespace dsp {
     private:
         float* ampBuf;
 
-        float _attack;
-        float _decay;
-        float _inv_attack;
-        float _inv_decay;
-        float _threshold;
         float _level;
-        float _sampleRate;
-
-        float lastValue = 0.0f;
         
         stream<complex_t>* _in;
 

decoder_modules/radio/src/demod.h

@@ -38,6 +38,7 @@ namespace demod {
         virtual int getDefaultDeemphasisMode() = 0;
         virtual double getAFBandwidth(double bandwidth) = 0;
         virtual bool getFMIFNRAllowed() = 0;
+        virtual bool getNBAllowed() = 0;
         
         virtual bool getDynamicAFBandwidth() = 0;
         virtual dsp::stream<dsp::stereo_t>* getOutput() = 0;

decoder_modules/radio/src/demodulators/am.h

@@ -68,6 +68,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth / 2.0; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &m2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/cw.h

@@ -69,6 +69,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return (bandwidth / 2.0) + 1000.0; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &m2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/dsb.h

@@ -70,6 +70,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth / 2.0; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return true; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &m2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/lsb.h

@@ -70,6 +70,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return true; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &m2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/nfm.h

@@ -62,6 +62,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth / 2.0; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return true; }
+        bool getNBAllowed()                     { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &demod.out; }
 
     private:

decoder_modules/radio/src/demodulators/raw.h

@@ -63,6 +63,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth; }
         bool getDynamicAFBandwidth()            { return false; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return true; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &c2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/usb.h

@@ -70,6 +70,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return bandwidth; }
         bool getDynamicAFBandwidth()            { return true; }
         bool getFMIFNRAllowed()                 { return false; }
+        bool getNBAllowed()                     { return true; }
         dsp::stream<dsp::stereo_t>* getOutput() { return &m2s.out; }
 
     private:

decoder_modules/radio/src/demodulators/wfm.h

@@ -86,6 +86,7 @@ namespace demod {
         double getAFBandwidth(double bandwidth) { return 16000.0; }
         bool getDynamicAFBandwidth()            { return false; }
         bool getFMIFNRAllowed()                 { return true; }
+        bool getNBAllowed()                     { return false; }
         dsp::stream<dsp::stereo_t>* getOutput() { return stereo ? demodStereo.out : &demod.out; }
 
         // ============= DEDICATED FUNCTIONS =============

decoder_modules/radio/src/radio_module.h

@@ -62,10 +62,12 @@ public:
         fmnr.block.init(NULL, 32);
         notch.block.init(NULL, 0.5, 0, 250000); // TODO: The rate has to depend on IF sample rate so the width is always the same
         squelch.block.init(NULL, MIN_SQUELCH);
+        nb.block.init(NULL, -100.0f);
 
         ifChain.add(&notch);
         ifChain.add(&squelch);
         ifChain.add(&fmnr);
+        ifChain.add(&nb);
 
         // Load configuration for and enabled all demodulators
         EventHandler<dsp::stream<dsp::stereo_t>*> _demodOutputChangeHandler;
@@ -258,6 +260,21 @@ private:
         }
         if (!_this->squelchEnabled && _this->enabled) { style::endDisabled(); }
 
+        // Noise blanker
+        if (_this->nbAllowed) {
+            if (ImGui::Checkbox(("Noise Blanker##_radio_nb_ena_" + _this->name).c_str(), &_this->nbEnabled)) {
+                _this->setNoiseBlankerEnabled(_this->nbEnabled);
+            }
+            if (!_this->nbEnabled && _this->enabled) { style::beginDisabled(); }
+            ImGui::SameLine();
+            ImGui::SetNextItemWidth(menuWidth - ImGui::GetCursorPosX());
+            if (ImGui::SliderFloat(("##_radio_nb_lvl_" + _this->name).c_str(), &_this->nbLevel, 0.0f, -100.0f, "%.3fdB")) {
+                _this->setNoiseBlankerLevel(_this->nbLevel);
+            }
+            if (!_this->nbEnabled && _this->enabled) { style::endDisabled(); }
+        }
+        
+
         // // Notch filter
         // if (ImGui::Checkbox("Notch##_radio_notch_ena_", &_this->notchEnabled)) {
         //     _this->ifChain.setState(&_this->notch, _this->notchEnabled);
@@ -324,6 +341,10 @@ private:
         postProcEnabled = selectedDemod->getPostProcEnabled();
         FMIFNRAllowed = selectedDemod->getFMIFNRAllowed();
         FMIFNREnabled = false;
+        nbAllowed = selectedDemod->getNBAllowed();
+        nbEnabled = false;
+        nbLevel = 0.0f;
+        config.acquire();
         if (config.conf[name][selectedDemod->getName()].contains("bandwidth")) {
             bandwidth = config.conf[name][selectedDemod->getName()]["bandwidth"];
             bandwidth = std::clamp<double>(bandwidth, minBandwidth, maxBandwidth);
@@ -343,6 +364,16 @@ private:
         if (config.conf[name][selectedDemod->getName()].contains("FMIFNREnabled")) {
             FMIFNREnabled = config.conf[name][selectedDemod->getName()]["FMIFNREnabled"];
         }
+        if (config.conf[name][selectedDemod->getName()].contains("noiseBlankerEnabled")) {
+            nbEnabled = config.conf[name][selectedDemod->getName()]["noiseBlankerEnabled"];
+        }
+        if (config.conf[name][selectedDemod->getName()].contains("noiseBlankerEnabled")) {
+            nbEnabled = config.conf[name][selectedDemod->getName()]["noiseBlankerEnabled"];
+        }
+        if (config.conf[name][selectedDemod->getName()].contains("noiseBlankerLevel")) {
+            nbLevel = config.conf[name][selectedDemod->getName()]["noiseBlankerLevel"];
+        }
+        config.release();
         deempMode = std::clamp<int>(deempMode, 0, _DEEMP_MODE_COUNT-1);
 
         // Configure VFO
@@ -363,6 +394,10 @@ private:
         squelch.block.setLevel(squelchLevel);
         setSquelchEnabled(squelchEnabled);
 
+        // Configure noise blanker
+        nb.block.setLevel(nbLevel);
+        setNoiseBlankerEnabled(nbEnabled);
+
         // Configure AF chain
         if (postProcEnabled) {
             // Configure resampler
@@ -483,6 +518,28 @@ private:
         config.release(true);
     }
 
+    void setNoiseBlankerEnabled(bool enabled) {
+        nbEnabled = enabled;
+        if (!selectedDemod) { return; }
+        ifChain.setState(&nb, nbEnabled);
+
+        // Save config
+        config.acquire();
+        config.conf[name][selectedDemod->getName()]["noiseBlankerEnabled"] = nbEnabled;
+        config.release(true);
+    }
+
+    void setNoiseBlankerLevel(float level) {
+        nbLevel = level;
+        if (!selectedDemod) { return; }
+        nb.block.setLevel(nbLevel);
+
+        // Save config
+        config.acquire();
+        config.conf[name][selectedDemod->getName()]["noiseBlankerLevel"] = nbLevel;
+        config.release(true);
+    }
+
     static void vfoUserChangedBandwidthHandler(double newBw, void* ctx) {
         RadioModule* _this = (RadioModule*)ctx;
         _this->setBandwidth(newBw);
@@ -568,6 +625,7 @@ private:
     dsp::ChainLink<dsp::FMIFNoiseReduction, dsp::complex_t> fmnr;
     dsp::ChainLink<dsp::NotchFilter, dsp::complex_t> notch;
     dsp::ChainLink<dsp::Squelch, dsp::complex_t> squelch;
+    dsp::ChainLink<dsp::NoiseBlanker, dsp::complex_t> nb;
 
     // Audio chain
     dsp::stream<dsp::stereo_t> dummyAudioStream;
@@ -587,12 +645,15 @@ private:
     float bandwidth;
     bool bandwidthLocked;
     int snapInterval;
+    int selectedDemodID = 1;
+    bool postProcEnabled;
+
     bool squelchEnabled = false;
     float squelchLevel;
-    int selectedDemodID = 1;
+
     int deempMode = DEEMP_MODE_NONE;
     bool deempAllowed;
-    bool postProcEnabled;
+
     bool FMIFNRAllowed;
     bool FMIFNREnabled = false;
 
@@ -600,6 +661,10 @@ private:
     float notchPos = 0;
     float notchWidth = 500;
 
+    bool nbAllowed;
+    bool nbEnabled;
+    float nbLevel = -100.0f;
+
     const double MIN_SQUELCH = -100.0;
     const double MAX_SQUELCH = 0.0;