Merged master 8748

.svn/pristine/45/45075fdf59d9a179725ab915d757459453c338d1.svn-base

@@ -0,0 +1,59 @@
+#ifndef DETECTOR_HPP__
+#define DETECTOR_HPP__
+#include "AudioDevice.hpp"
+#include <QScopedArrayPointer>
+
+//
+// output device that distributes data in predefined chunks via a signal
+//
+// the underlying device for this abstraction is just the buffer that
+// stores samples throughout a receiving period
+//
+class Detector : public AudioDevice
+{
+  Q_OBJECT;
+
+public:
+  //
+  // if the data buffer were not global storage and fixed size then we
+  // might want maximum size passed as constructor arguments
+  //
+  // we down sample by a factor of 4
+  //
+  // the samplesPerFFT argument is the number after down sampling
+  //
+  Detector (unsigned frameRate, unsigned periodLengthInSeconds, unsigned downSampleFactor = 4u, QObject * parent = 0);
+
+  void setTRPeriod(unsigned p) {m_period=p;}
+  bool reset () override;
+
+  Q_SIGNAL void framesWritten (qint64) const;
+  Q_SLOT void setBlockSize (unsigned);
+
+protected:
+  qint64 readData (char * /* data */, qint64 /* maxSize */) override
+  {
+    return -1;			// we don't produce data
+  }
+
+  qint64 writeData (char const * data, qint64 maxSize) override;
+
+private:
+  void clear ();		// discard buffer contents
+  unsigned secondInPeriod () const;
+
+  unsigned m_frameRate;
+  unsigned m_period;
+  unsigned m_downSampleFactor;
+  qint32 m_samplesPerFFT;	// after any down sampling
+  qint32 m_ns;
+  static size_t const max_buffer_size {7 * 512};
+  QScopedArrayPointer<short> m_buffer; // de-interleaved sample buffer
+  // big enough for all the
+  // samples for one increment of
+  // data (a signals worth) at
+  // the input sample rate
+  unsigned m_bufferPos;
+};
+
+#endif