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#ifndef DETECTOR_HPP__
#define DETECTOR_HPP__
#include "Audio/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, double periodLengthInSeconds, unsigned downSampleFactor = 4u,
QObject * parent = 0);
void setTRPeriod(double 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 m_frameRate;
double m_period;
unsigned m_downSampleFactor;
qint32 m_samplesPerFFT; // after any down sampling
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
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