leansdr::spectrum< T, NFFT > Struct Template Reference

#include <sdr.h>

Inheritance diagram for leansdr::spectrum< T, NFFT >:

Collaboration diagram for leansdr::spectrum< T, NFFT >:

Public Member Functions
	spectrum (scheduler *sch, pipebuf< complex< T >> &_in, pipebuf< float[NFFT]> &_out)
void	run ()
Public Member Functions inherited from leansdr::runnable
	runnable (scheduler *_sch, const char *name)
Public Member Functions inherited from leansdr::runnable_common
	runnable_common (const char *_name)
virtual	~runnable_common ()
virtual void	shutdown ()

Public Attributes
int	decimation
float	kavg
int	decim
Public Attributes inherited from leansdr::runnable_common
const char *	name

Private Member Functions
void	do_spectrum ()

Private Attributes
pipereader< complex< T > >	in
pipewriter< float[NFFT]>	out
cfft_engine< T >	fft
T *	avgpower
int	phase

Additional Inherited Members
Protected Attributes inherited from leansdr::runnable
scheduler *	sch

Detailed Description

template<typename T, int NFFT>
struct leansdr::spectrum< T, NFFT >

Definition at line 1813 of file sdr.h.

Constructor & Destructor Documentation

spectrum()

template<typename T , int NFFT>

leansdr::spectrum< T, NFFT >::spectrum ( scheduler *  sch, pipebuf< complex< T >> &  _in, pipebuf< float[NFFT]> &  _out  )

inline

Definition at line 1815 of file sdr.h.

                                         : runnable(sch, "spectrum"),
                                           decimation(1048576),
                                           kavg(0.1),
                                           decim(1), in(_in),
                                           out(_out),
                                           fft(NFFT),
                                           avgpower(NULL),
                                           phase(0)
    {
    }

Member Function Documentation

do_spectrum()

template<typename T , int NFFT>

void leansdr::spectrum< T, NFFT >::do_spectrum ( )

inlineprivate

Definition at line 1849 of file sdr.h.

References leansdr::auto_notch< T >::fft, leansdr::auto_notch< T >::slot::i, leansdr::auto_notch< T >::in, leansdr::cfft_engine< T >::inplace(), leansdr::cfft_engine< T >::n, leansdr::auto_notch< T >::out, and leansdr::complex< T >::re.

    {
        complex<T> data[fft.n];

        if (decim == 1)
        {
            memcpy(data, in.rd(), fft.n * sizeof(data[0]));
        }
        else
        {
            complex<T> *pin = in.rd();

            for (int i = 0; i < fft.n; ++i, pin += decim)
                data[i] = *pin;
        }

        fft.inplace(data, true);
        float power[NFFT];

        for (int i = 0; i < fft.n; ++i)
            power[i] = (float)data[i].re * data[i].re + (float)data[i].im * data[i].im;

        if (!avgpower)
        {
            // Initialize with first spectrum
            avgpower = new float[fft.n];
            memcpy(avgpower, power, fft.n * sizeof(avgpower[0]));
        }

        // Accumulate and low-pass filter
        for (int i = 0; i < fft.n; ++i)
            avgpower[i] = avgpower[i] * (1 - kavg) + power[i] * kavg;

        // Reuse power[]
        for (int i = 0; i < fft.n / 2; ++i)
        {
            power[i] = 10 * log10f(avgpower[NFFT / 2 + i]);
            power[NFFT / 2 + i] = 10 * log10f(avgpower[i]);
        }

        memcpy(out.wr(), power, sizeof(power[0]) * NFFT);
        out.written(1);
    }

Here is the call graph for this function:

run()

template<typename T , int NFFT>

void leansdr::spectrum< T, NFFT >::run ( )

inlinevirtual

Reimplemented from leansdr::runnable_common.

Definition at line 1832 of file sdr.h.

References leansdr::auto_notch< T >::decimation, leansdr::auto_notch< T >::fft, leansdr::auto_notch< T >::in, leansdr::cfft_engine< T >::n, leansdr::auto_notch< T >::out, and leansdr::auto_notch< T >::phase.

    {
        while (in.readable() >= fft.n * decim && out.writable() >= 1)
        {
            phase += fft.n * decim;

            if (phase >= decimation)
            {
                phase -= decimation;
                do_spectrum();
            }

            in.read(fft.n * decim);
        }
    }

Member Data Documentation

avgpower

template<typename T , int NFFT>

T* leansdr::spectrum< T, NFFT >::avgpower

private

Definition at line 1896 of file sdr.h.

decim

template<typename T , int NFFT>

int leansdr::spectrum< T, NFFT >::decim

Definition at line 1830 of file sdr.h.

decimation

template<typename T , int NFFT>

int leansdr::spectrum< T, NFFT >::decimation

Definition at line 1828 of file sdr.h.

fft

template<typename T , int NFFT>

cfft_engine<T> leansdr::spectrum< T, NFFT >::fft

private

Definition at line 1895 of file sdr.h.

in

template<typename T , int NFFT>

pipereader<complex<T> > leansdr::spectrum< T, NFFT >::in

private

Definition at line 1893 of file sdr.h.

kavg

template<typename T , int NFFT>

float leansdr::spectrum< T, NFFT >::kavg

Definition at line 1829 of file sdr.h.

out

template<typename T , int NFFT>

pipewriter<float[NFFT]> leansdr::spectrum< T, NFFT >::out

private

Definition at line 1894 of file sdr.h.

phase

template<typename T , int NFFT>

int leansdr::spectrum< T, NFFT >::phase

private

Definition at line 1897 of file sdr.h.

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The documentation for this struct was generated from the following file:

• plugins/channelrx/demoddatv/leansdr/sdr.h