ifft example

Author: pschatzmann

src/AudioTools/AudioLibs/AudioFFT.h

@@ -312,6 +312,12 @@ class AudioFFTBase : public AudioStream {
   size_t readBytes(uint8_t *data, size_t len) override {
     TRACED();
     if (rfft_data.size() == 0) return 0;
+
+    // get data via callback if there is no more data
+    if (cfg.rxtx_mode == RX_MODE && cfg.callback != nullptr && rfft_data.available() == 0) {
+      cfg.callback(*this);
+    }
+   
     // execute rfft when we consumed all data
     if (has_rfft_data && rfft_data.available() == 0) {
       rfft();
@@ -443,6 +449,14 @@ class AudioFFTBase : public AudioStream {
   /// gets the value of a bin
   bool getBin(int pos, FFTBin &bin) { return p_driver->getBin(pos, bin); }
 
+  /// clears the fft data
+  void clearBins(){
+    FFTBin empty{0,0};
+    for (int j=0; j< size(); j++){
+      setBin(j, empty);
+    }  
+  }
+
   /// Provides the actual configuration
   AudioFFTConfig &config() { return cfg; }
 

tests-cmake/ifft/CMakeLists.txt

@@ -0,0 +1,35 @@
+cmake_minimum_required(VERSION 3.20)
+
+
+# set the project name
+project(ifft)
+set (CMAKE_CXX_STANDARD 11)
+set (DCMAKE_CXX_FLAGS "-Werror")
+set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0 -ldl -lpthread -lm")
+set (CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0 -ldl -lpthread -lm")
+
+# Emulator is not necessary for -DIS_MIN_DESKTOP
+set(ADD_ARDUINO_EMULATOR OFF CACHE BOOL "Add Arduino Emulator Library") 
+set(ADD_PORTAUDIO OFF CACHE BOOL "No Portaudio") 
+
+# Build with arduino-audio-tools
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/../.. ${CMAKE_CURRENT_BINARY_DIR}/arduino-audio-tools )
+endif()
+
+# Download miniaudio.h
+file(DOWNLOAD https://raw.githubusercontent.com/mackron/miniaudio/master/miniaudio.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/miniaudio.h)
+
+
+# build sketch as executable
+add_executable (ifft ifft.cpp)
+
+# set preprocessor defines
+target_compile_definitions(ifft PUBLIC -DIS_MIN_DESKTOP)
+
+# specify libraries
+target_link_libraries(ifft arduino-audio-tools)
+
+# access to miniaudio in sketch directory
+target_include_directories(ifft PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})

tests-cmake/ifft/ifft.cpp

@@ -0,0 +1,38 @@
+#include "AudioTools.h"
+#include "AudioTools/AudioLibs/AudioRealFFT.h" // using RealFFT
+#include "AudioTools/AudioLibs/MiniAudioStream.h"
+
+AudioInfo info(44100, 2, 16);
+AudioRealFFT afft; // or AudioKissFFT
+//CsvOutput<int16_t> out(Serial);
+MiniAudioStream out;
+StreamCopy copier(out, afft);
+int bin_idx = 0;
+
+// privide fft data
+void fftFillData(AudioFFTBase &fft) {
+  fft.clearBins();
+  FFTBin bin{1,1};
+  fft.setBin(bin_idx, bin);
+
+  // restart from first bin
+  if (++bin_idx>=fft.size()) bin_idx = 0;
+}
+
+void setup() {
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Warning);
+
+  // Setup FFT
+  auto tcfg = afft.defaultConfig(RX_MODE);
+  tcfg.copyFrom(info);
+  tcfg.length = 1024;
+  tcfg.callback = fftFillData;
+  afft.begin(tcfg);
+
+  // setup output
+  auto ocfg = out.defaultConfig(TX_MODE);
+  ocfg.copyFrom(info);
+  out.begin(ocfg);
+}
+
+void loop() { copier.copy(); }