Working interrupted noise

src/lasp/dsp/lasp_siggen.cpp

@@ -22,15 +22,46 @@ vd Siggen::genSignal(const us nframes) {
 
   if (!_muted) {
     vd signal_dynamic = _level_linear * genSignalUnscaled(nframes);
+
+    // Filter signal
     for (auto f : _filters) {
       assert(f.second);
       f.second->filter(signal_dynamic);
     }
-    signal += signal_dynamic;
+
+    // Check whether we are running / not for signal interruption.
+    bool activated = false;
+    if (_interrupt_period_s < 0) {
+      activated = true;
+    } else {
+      if (_interruption_frame_count < _interrupt_period_s*_fs) {
+        activated = true;
+      }
+      _interruption_frame_count += nframes;
+
+      if (_interruption_frame_count >=  2 * _interrupt_period_s*_fs) {
+        _interruption_frame_count = 0;
+      }
     }
 
+    if (activated) {
+      signal += signal_dynamic;
+    }
+  } // end if(!_muted)
+
   return signal;
 }
+void Siggen::setInterruptPeriod(const d newPeriod) {
+  mutexlock lck(_mtx);
+  if (newPeriod == 0) {
+    throw rte("Interruption period cannot be 0");
+  }
+  if (newPeriod < 0) {
+    _interrupt_period_s = -1;
+  } else {
+    _interrupt_period_s = newPeriod;
+  }
+}
 void Siggen::setFilter(const std::string &name,
                        std::shared_ptr<Filter> filter) {
   DEBUGTRACE_ENTER;

src/lasp/dsp/lasp_siggen.h

@@ -29,6 +29,13 @@ private:
 protected:
   std::mutex _mtx;
   d _fs = 0;
+  /**
+   * @brief Interuption of period the signal. If set, the signal will be
+   * periodically turned on / off. This is useful for measuring reverberation
+   * times using the "interrupted noise method".
+   */
+  int _interrupt_period_s = -1;
+  int _interruption_frame_count = 0;
 
   virtual void resetImpl() = 0;
   virtual vd genSignalUnscaled(const us nframes) = 0;
@@ -36,6 +43,15 @@ protected:
 public:
   virtual ~Siggen() = default;
 
+  /**
+   * @brief Set the interruption period for interrupted signals. 
+   *
+   * @param newPeriod If < 0, the interruption is disabled. If > 0, an
+   * approximate interruption number of *buffers* is computed, rounded upwards
+   * for which the signal generator is turned off.
+   */
+  void setInterruptPeriod(const d newPeriod);
+
   /**
    * @brief Set a filter on the signal. For example to EQ the signal, or
    * otherwise to shape the spectrum. Filters are stored in a map, and

src/lasp/pybind11/lasp_siggen.cpp

@@ -30,6 +30,7 @@ void init_siggen(py::module &m) {
   siggen.def("setLevel", &Siggen::setLevel, py::arg("newLevel"),
              py::arg("dB") = true);
   siggen.def("reset", &Siggen::reset);
+  siggen.def("setInterruptPeriod", &Siggen::setInterruptPeriod);
 
   siggen.def("setFilter", &Siggen::setFilter);