Performance improvement to the FFT + code cleanup + Added an option to select the FFT window

core/src/core.cpp

@@ -118,6 +118,7 @@ int sdrpp_main(int argc, char *argv[]) {
     defConfig["fastFFT"] = false;
     defConfig["fftHeight"] = 300;
     defConfig["fftSize"] = 65536;
+    defConfig["fftWindow"] = 0;
     defConfig["frequency"] = 100000000.0;
     defConfig["fullWaterfallUpdate"] = false;
     defConfig["max"] = 0.0;

core/src/gui/main_window.cpp

@@ -40,8 +40,8 @@ void MainWindow::init() {
     gui::waterfall.init();
     gui::waterfall.setRawFFTSize(fftSize);
 
-    tempFFT = new float[fftSize];
-    FFTdata = new float[fftSize];
+    appliedWindow = new float[fftSize];
+    generateFFTWindow(selectedWindow, fftSize);
 
     credits::init();
 
@@ -201,21 +201,23 @@ void MainWindow::fftHandler(dsp::complex_t* samples, int count, void* ctx) {
     std::lock_guard<std::mutex> lck(_this->fft_mtx);
     if (count != _this->fftSize) { return; }
 
-    memcpy(_this->fft_in, samples, count * sizeof(dsp::complex_t));
-    fftwf_execute(_this->fftwPlan);
-    int half = count / 2;
+    // Apply window
+    volk_32fc_32f_multiply_32fc((lv_32fc_t*)_this->fft_in, (lv_32fc_t*)samples, _this->appliedWindow, count);
 
+    // Execute FFT
+    fftwf_execute(_this->fftwPlan);
+
+    // Get the FFT buffer
     float* fftBuf = gui::waterfall.getFFTBuffer();
     if (fftBuf == NULL) {
         gui::waterfall.pushFFT();
         return;
     }
 
-    volk_32fc_s32f_power_spectrum_32f(_this->tempFFT, (lv_32fc_t*)_this->fft_out, count, count);
-
-    memcpy(fftBuf, &_this->tempFFT[half], half * sizeof(float));
-    memcpy(&fftBuf[half], _this->tempFFT, half * sizeof(float));
+    // Take power of spectrum
+    volk_32fc_s32f_power_spectrum_32f(fftBuf, (lv_32fc_t*)_this->fft_out, count, count);
 
+    // Push back data
     gui::waterfall.pushFFT();
 }
 
@@ -619,6 +621,30 @@ void MainWindow::setFFTSize(int size) {
     fft_in = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * fftSize);
     fft_out = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * fftSize);
     fftwPlan = fftwf_plan_dft_1d(fftSize, fft_in, fft_out, FFTW_FORWARD, FFTW_ESTIMATE);
+
+    delete appliedWindow;
+
+    appliedWindow = new float[fftSize];
+    generateFFTWindow(selectedWindow, fftSize);
+}
+
+void MainWindow::setFFTWindow(int win) {
+    std::lock_guard<std::mutex> lck(fft_mtx);
+    selectedWindow = win;
+    generateFFTWindow(selectedWindow, fftSize);
+}
+
+void MainWindow::generateFFTWindow(int win, int size) {
+    if (win == FFT_WINDOW_RECTANGULAR) {
+        for (int i = 0; i < size; i++) {
+            appliedWindow[i] = (i%2) ? 1 : -1;
+        }
+    }
+    else if (win == FFT_WINDOW_BLACKMAN) {
+        for (int i = 0; i < size; i++) {
+            appliedWindow[i] = ((i%2) ? dsp::window_function::blackman(i, size) : -dsp::window_function::blackman(i, size))*2;
+        }
+    }
 }
 
 bool MainWindow::isPlaying() {

core/src/gui/main_window.h

@@ -11,6 +11,12 @@
 
 #define WINDOW_FLAGS    ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoBringToFrontOnFocus | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoBackground
 
+enum {
+    FFT_WINDOW_RECTANGULAR,
+    FFT_WINDOW_BLACKMAN,
+    _FFT_WINDOW_COUNT
+};
+
 class MainWindow {
 public:
     void init();
@@ -18,6 +24,7 @@ public:
     void setViewBandwidthSlider(float bandwidth);
     bool sdrIsRunning();
     void setFFTSize(int size);
+    void setFFTWindow(int win);
 
     // TODO: Replace with it's own class 
     void setVFO(double freq);
@@ -27,6 +34,7 @@ public:
     bool lockWaterfallControls = false;
 
 private:
+    void generateFFTWindow(int win, int size);
     static void fftHandler(dsp::complex_t* samples, int count, void* ctx);
     static void vfoAddedHandler(VFOManager::VFO* vfo, void* ctx);
 
@@ -35,8 +43,7 @@ private:
     std::mutex fft_mtx;
     fftwf_complex *fft_in, *fft_out;
     fftwf_plan fftwPlan;
-    float* tempFFT;
-    float* FFTdata;
+    float* appliedWindow;
     
     // GUI Variables
     bool firstMenuRender = true;
@@ -56,6 +63,7 @@ private:
     int tuningMode = tuner::TUNER_MODE_NORMAL;
     dsp::stream<dsp::complex_t> dummyStream;
     bool demoWindow = false;
+    int selectedWindow = 0;
 
     EventHandler<VFOManager::VFO*> vfoCreatedHandler;
 

core/src/gui/menus/display.cpp

@@ -14,6 +14,7 @@ namespace displaymenu {
     std::vector<std::string> colorMapNames;
     std::string colorMapNamesTxt = "";
     std::string colorMapAuthor = "";
+    int selectedWindow = 0;
 
     const int FFTSizes[] = {
         65536,
@@ -70,6 +71,8 @@ namespace displaymenu {
         }
         gui::mainWindow.setFFTSize(FFTSizes[fftSizeId]);
 
+        selectedWindow = std::clamp<int>((int)core::configManager.conf["fftWindow"], 0, _FFT_WINDOW_COUNT-1);
+        gui::mainWindow.setFFTWindow(selectedWindow);
     }
 
     void draw(void* ctx) {
@@ -99,13 +102,23 @@ namespace displaymenu {
         ImGui::Text("FFT Size");
         ImGui::SameLine();
         ImGui::SetNextItemWidth(menuWidth - ImGui::GetCursorPosX());
-        if (ImGui::Combo("##test_fft_size", &fftSizeId, FFTSizesStr)) {
+        if (ImGui::Combo("##sdrpp_fft_size", &fftSizeId, FFTSizesStr)) {
             gui::mainWindow.setFFTSize(FFTSizes[fftSizeId]);
             core::configManager.aquire();
             core::configManager.conf["fftSize"] = FFTSizes[fftSizeId];
             core::configManager.release(true);
         }
 
+        ImGui::Text("FFT Window");
+        ImGui::SameLine();
+        ImGui::SetNextItemWidth(menuWidth - ImGui::GetCursorPosX());
+        if (ImGui::Combo("##sdrpp_fft_window", &selectedWindow, "Rectangular\0Blackman\0")) {
+            gui::mainWindow.setFFTWindow(selectedWindow);
+            core::configManager.aquire();
+            core::configManager.conf["fftWindow"] = selectedWindow;
+            core::configManager.release(true);
+        }
+
         if (colorMapNames.size() > 0) {
             ImGui::Text("Color Map");
             ImGui::SameLine();

frequency_manager/src/main.cpp

@@ -15,7 +15,7 @@
 SDRPP_MOD_INFO {
     /* Name:            */ "frequency_manager",
     /* Description:     */ "Frequency manager module for SDR++",
-    /* Author:          */ "Ryzerth;zimm",
+    /* Author:          */ "Ryzerth;Zimm",
     /* Version:         */ 0, 3, 0,
     /* Max instances    */ 1
 };
@@ -125,8 +125,9 @@ private:
             if (core::modComManager.interfaceExists(vfoName)) {
                 if (core::modComManager.getModuleName(vfoName) == "radio") {
                     int mode = bm.mode;
+                    float bandwidth = bm.bandwidth;
                     core::modComManager.callInterface(vfoName, RADIO_IFACE_CMD_SET_MODE, &mode, NULL);
-                    // TODO: Set bandwidth as well
+                    core::modComManager.callInterface(vfoName, RADIO_IFACE_CMD_SET_BANDWIDTH, &bandwidth, NULL);
                 }
             }
             tuner::tune(tuner::TUNER_MODE_NORMAL, vfoName, bm.frequency);
@@ -594,6 +595,9 @@ private:
         }
 
         ImGui::BeginTooltip();
+        ImGui::Text(hoveredBookmarkName.c_str());
+        ImGui::Separator();
+        ImGui::Text("Frequency: %s", freqToStr(hoveredBookmark.frequency).c_str());
         ImGui::Text("Bandwidth: %s", freqToStr(hoveredBookmark.bandwidth).c_str());
         ImGui::Text("Mode: %s", demodModeList[hoveredBookmark.mode]);
         ImGui::EndTooltip();

radio/src/am_demod.h

@@ -162,8 +162,8 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
         float audioBW = std::min<float>(audioSampRate / 2.0f, bw / 2.0f);
@@ -173,6 +173,7 @@ private:
         resamp.updateWindow(&win);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/cw_demod.h

@@ -169,12 +169,13 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/dsb_demod.h

@@ -162,12 +162,13 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/fm_demod.h

@@ -154,14 +154,15 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
         demod.setDeviation(bw / 2.0f);
         setAudioSampleRate(audioSampRate);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/lsb_demod.h

@@ -161,8 +161,8 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
         demod.setBandWidth(bw);
@@ -173,6 +173,7 @@ private:
         resamp.updateWindow(&win);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/main.cpp

@@ -174,6 +174,10 @@ private:
             int* _in = (int*)in;
             if (*_in != _this->demodId) { _this->selectDemodById(*_in); }
         }
+        else if (code == RADIO_IFACE_CMD_SET_BANDWIDTH) {
+            float* _in = (float*)in;
+            _this->currentDemod->setBandwidth(*_in, true);
+        }
     }
 
     void selectDemod(Demodulator* demod) {

radio/src/radio_demod.h

@@ -12,6 +12,7 @@ public:
     virtual VFOManager::VFO* getVFO() = 0;
     virtual void setAudioSampleRate(float sampleRate) = 0;
     virtual float getAudioSampleRate() = 0;
+    virtual void setBandwidth(float bandWidth, bool updateWaterfall = true) = 0;
     virtual dsp::stream<dsp::stereo_t>* getOutput() = 0;
     virtual void showMenu() = 0;
 };

radio/src/raw_demod.h

@@ -116,6 +116,10 @@ public:
         }
 
         // TODO: Allow selection of the bandwidth
+    }
+
+    void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        // Do nothing
     } 
 
 private:

radio/src/usb_demod.h

@@ -161,8 +161,8 @@ public:
         }
     } 
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
         demod.setBandWidth(bw);
@@ -173,6 +173,7 @@ private:
         resamp.updateWindow(&win);
     }
 
+private:
     void setSnapInterval(float snapInt) {
         snapInterval = snapInt;
         _vfo->setSnapInterval(snapInterval);

radio/src/wfm_demod.h

@@ -192,13 +192,15 @@ public:
         _vfo->setSnapInterval(snapInterval);
     }
 
-private:
     void setBandwidth(float bandWidth, bool updateWaterfall = true) {
+        bandWidth = std::clamp<float>(bandWidth, bwMin, bwMax);
         bw = bandWidth;
         _vfo->setBandwidth(bw, updateWaterfall);
         demod.setDeviation(bw / 2.0f);
     }
 
+private:
+
     const float bwMax = 250000;
     const float bwMin = 50000;
     const float bbSampRate = 250000;

readme.md

@@ -1,6 +1,6 @@
 # SDR++, The bloat-free SDR software
 
-![Screenshot](https://i.imgur.com/EFOqwQQ.png)
+![Screenshot](https://i.imgur.com/Ter2MQJ.png)
 SDR++ is a cross-platform and open source SDR software with the aim of being bloat free and simple to use.
 
 ![Build](https://github.com/AlexandreRouma/SDRPlusPlus/workflows/Build%20Binaries/badge.svg)