Added FM CMD example.

examples/CMakeLists.txt

@@ -15,3 +15,6 @@ ENDIF(SDR_WITH_QT5 AND SDR_WITH_FFTW AND SDR_WITH_PORTAUDIO)
 
 add_executable(sdr_psk31 sdr_psk31.cc)
 target_link_libraries(sdr_psk31 ${LIBS} ${QT_LIBRARIES} libsdr libsdr-gui)
+
+add_executable(sdr_fm sdr_fm.cc)
+target_link_libraries(sdr_fm ${LIBS} libsdr)

examples/sdr_fm.cc

@@ -0,0 +1,73 @@
+#include "demod.hh"
+#include "rtlsource.hh"
+#include "baseband.hh"
+#include "autocast.hh"
+#include "portaudio.hh"
+#include "wavfile.hh"
+
+#include <iostream>
+#include <csignal>
+
+using namespace sdr;
+
+static void __sigint_handler(int signo) {
+  std::cerr << "Stop Queue..." << std::endl;
+  // On SIGINT -> stop queue properly
+  Queue::get().stop();
+  Queue::get().wait();
+}
+
+
+int main(int argc, char *argv[]) {
+  if (2 > argc) { std::cout << "USAGE: sdr_fm FREQUENCY [OUTPUT.wav]" << std::endl; return -1; }
+
+  // get frequency
+  double freq = atof(argv[1]);
+  // Get output file (if given)
+  std::string outFile;
+  if (3 <= argc) { outFile = argv[2]; }
+
+  sdr::Logger::get().addHandler(
+        new sdr::StreamLogHandler(std::cerr, sdr::LOG_DEBUG));
+
+  // Register handler:
+  signal(SIGINT, __sigint_handler);
+
+  PortAudio::init();
+
+  RTLSource src(freq-100e3, 1e6);
+  AutoCast< std::complex<int16_t> > cast;
+  IQBaseBand<int16_t> baseband(100e3, 12.5e3, 21, 1, 8000.0);
+  baseband.setCenterFrequency(100e3);
+  baseband.setFilterFrequency(100e3);
+  FMDemod<int16_t>    demod;
+  FMDeemph<int16_t>   deemph;
+  PortSink            audio;
+  WavSink<int16_t>    *wav_sink = 0;
+
+  // Assemble processing chain:
+  src.connect(&cast, true);
+  cast.connect(&baseband);
+  baseband.connect(&demod, true);
+  demod.connect(&deemph, true);
+  deemph.connect(&audio);
+
+  if (outFile.size()) {
+    wav_sink = new WavSink<int16_t>(outFile);
+    deemph.connect(wav_sink);
+  }
+
+  Queue::get().addStart(&src, &RTLSource::start);
+  Queue::get().addStop(&src, &RTLSource::stop);
+
+  Queue::get().start();
+  Queue::get().wait();
+
+  if (wav_sink) {
+    delete wav_sink;
+  }
+
+  PortAudio::terminate();
+
+  return 0;
+}