leansdr::gf2x_p< Te, Tp, P, N, ALPHA > Struct Template Reference

#include <rs.h>

Public Member Functions
	gf2x_p ()
Te	add (Te x, Te y)
Te	sub (Te x, Te y)
Te	mul (Te x, Te y)
Te	div (Te x, Te y)
Te	inv (Te x)
Te	exp (Te x)
Te	log (Te x)

Static Public Attributes
static const Te	alpha = ALPHA

Private Attributes
Te	lut_exp [(1<< N) *2]
Te	lut_log [1<< N]

Detailed Description

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>
struct leansdr::gf2x_p< Te, Tp, P, N, ALPHA >

Definition at line 48 of file rs.h.

Constructor & Destructor Documentation

gf2x_p()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::gf2x_p ( )

inline

Definition at line 50 of file rs.h.

    {
        if (ALPHA != 2)
            fail("alpha!=2 not implemented");
        // Precompute log and exp tables.
        Tp alpha_i = 1;
        for (Tp i = 0; i < (1 << N); ++i)
        {
            lut_exp[i] = alpha_i;
            lut_exp[((1 << N) - 1) + i] = alpha_i;
            lut_log[alpha_i] = i;
            alpha_i <<= 1; // Multiply by alpha=[X] i.e. increase degrees
            if (alpha_i & (1 << N))
                alpha_i ^= P; // Modulo P iteratively
        }
    }

Member Function Documentation

add()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::add ( Te  x, Te  y  )

inline

Definition at line 67 of file rs.h.

Referenced by leansdr::rs_engine::eval_poly(), and leansdr::rs_engine::eval_poly_rev().

{ return x ^ y; } // Addition modulo 2

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div()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::div ( Te  x, Te  y  )

inline

Definition at line 75 of file rs.h.

Referenced by leansdr::rs_engine::correct(), and leansdr::rs_engine::encode().

    {
        //if ( ! y ) fail("div"); // TODO
        if (!x)
            return 0;
        return lut_exp[lut_log[x] + ((1 << N) - 1) - lut_log[y]];
    }

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exp()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::exp ( Te  x )

inline

Definition at line 87 of file rs.h.

Referenced by leansdr::rs_engine::correct(), leansdr::rs_engine::rs_engine(), and leansdr::rs_engine::syndromes().

{ return lut_exp[x]; }

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inv()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::inv ( Te  x )

inline

Definition at line 82 of file rs.h.

Referenced by leansdr::rs_engine::correct().

    {
        //    if ( ! x ) fail("inv");
        return lut_exp[((1 << N) - 1) - lut_log[x]];
    }

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log()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::log ( Te  x )

inline

Definition at line 88 of file rs.h.

{ return lut_log[x]; }

mul()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::mul ( Te  x, Te  y  )

inline

Definition at line 69 of file rs.h.

Referenced by leansdr::rs_engine::correct(), leansdr::rs_engine::encode(), leansdr::rs_engine::eval_poly(), leansdr::rs_engine::eval_poly_rev(), and leansdr::rs_engine::rs_engine().

    {
        if (!x || !y)
            return 0;
        return lut_exp[lut_log[x] + lut_log[y]];
    }

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sub()

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::sub ( Te  x, Te  y  )

inline

Definition at line 68 of file rs.h.

Referenced by leansdr::rs_engine::encode(), and leansdr::rs_engine::rs_engine().

{ return x ^ y; } // Subtraction modulo 2

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Member Data Documentation

alpha

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

const Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::alpha = ALPHA

static

Definition at line 66 of file rs.h.

lut_exp

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::lut_exp[(1<< N) *2]

private

Definition at line 91 of file rs.h.

Referenced by leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::div(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::exp(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::gf2x_p(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::inv(), and leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::mul().

lut_log

template<typename Te, typename Tp, Tp P, int N, Te ALPHA>

Te leansdr::gf2x_p< Te, Tp, P, N, ALPHA >::lut_log[1<< N]

private

Definition at line 92 of file rs.h.

Referenced by leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::div(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::gf2x_p(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::inv(), leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::log(), and leansdr::gf2x_p< unsigned char, unsigned short, 0x11d, 8, 2 >::mul().

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

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