sdrangel/plugins/channeltx/moddatv/dvb-s2/dvb2_ldpc_encode.cpp

158 lines
4.5 KiB
C++

#include "memory.h"
#include "DVB2.h"
/*
for( int row = 0; row < rows; row++ )
{
for( int n = 0; n < 360; n++ )
{
for( int col = 1; col <= table_name[row][0]; col++ )
{
// parity bit location, position from start of block
m_ldpc_encode.p[index] = m_format.kldpc + (table_name[row][col] + (n*m_format.q_val))%pbits;
// data bit to be accumulated
m_ldpc_encode.d[index] = im;
index++;
}
im++;
}
}
*/
#define LDPC_BF( TABLE_NAME, ROWS ) \
for( int row = 0; row < ROWS; row++ ) \
{ \
for( int n = 0; n < 360; n++ ) \
{ \
for( int col = 1; col <= TABLE_NAME[row][0]; col++ ) \
{ \
m_ldpc_encode.p[index] = (TABLE_NAME[row][col] + (n*q))%pbits; \
m_ldpc_encode.d[index] = im; \
index++; \
} \
im++; \
} \
}
/*
//
// Generate the lookup tables for the ldpc mode
//
void DVBS2::ldpc_lookup_generate( void )
{
int im;
int index;
int pbits;
int uc;
int rows;
index = 0;
im = 0;
if(m_format.frame_type == FRAME_NORMAL)
{
if(m_format.code_rate == CR_2_3)
{
uc = m_format.kldpc;
pbits = m_format.nldpc - m_format.kldpc; //number of parity bits
rows = 120;
for( int row = 0; row < rows; row++ )// for each row
{
for( int n = 0; n < 360; n++ )
{
for( int col = 1; col <= ldpc_tab_2_3N[row][0]; col++ )
{
// parity bit location, position from start of block
m_ldpc_encode.p[index] = m_format.kldpc + (ldpc_tab_2_3N[row][col] + (n*m_format.q_val))%pbits;
// data bit to be accumulated
m_ldpc_encode.d[index] = im;
index++;
}
im++;
}
}
}
}
m_ldpc_encode.length = index;
}
*/
void DVB2::ldpc_lookup_generate( void )
{
int im;
int index;
int pbits;
int q;
index = 0;
im = 0;
pbits = m_format[0].nldpc - m_format[0].kldpc; //number of parity bits
q = m_format[0].q_val;
if(m_format[0].frame_type == FRAME_NORMAL)
{
if( m_format[0].code_rate == CR_1_4 ) LDPC_BF( ldpc_tab_1_4N, 45 );
if( m_format[0].code_rate == CR_1_3 ) LDPC_BF( ldpc_tab_1_3N, 60 );
if( m_format[0].code_rate == CR_2_5 ) LDPC_BF( ldpc_tab_2_5N, 72 );
if( m_format[0].code_rate == CR_1_2 ) LDPC_BF( ldpc_tab_1_2N, 90 );
if( m_format[0].code_rate == CR_3_5 ) LDPC_BF( ldpc_tab_3_5N, 108 );
if( m_format[0].code_rate == CR_2_3 ) LDPC_BF( ldpc_tab_2_3N, 120 );
if( m_format[0].code_rate == CR_3_4 ) LDPC_BF( ldpc_tab_3_4N, 135 );
if( m_format[0].code_rate == CR_4_5 ) LDPC_BF( ldpc_tab_4_5N, 144 );
if( m_format[0].code_rate == CR_5_6 ) LDPC_BF( ldpc_tab_5_6N, 150 );
if( m_format[0].code_rate == CR_8_9 ) LDPC_BF( ldpc_tab_8_9N, 160 );
if( m_format[0].code_rate == CR_9_10) LDPC_BF( ldpc_tab_9_10N, 162 );
}
if(m_format[0].frame_type == FRAME_SHORT)
{
if( m_format[0].code_rate == CR_1_4 ) LDPC_BF( ldpc_tab_1_4S, 9 );
if( m_format[0].code_rate == CR_1_3 ) LDPC_BF( ldpc_tab_1_3S, 15 );
if( m_format[0].code_rate == CR_2_5 ) LDPC_BF( ldpc_tab_2_5S, 18 );
if( m_format[0].code_rate == CR_1_2 ) LDPC_BF( ldpc_tab_1_2S, 20 );
if( m_format[0].code_rate == CR_3_5 ) LDPC_BF( ldpc_tab_3_5S, 27 );
if( m_format[0].code_rate == CR_2_3 ) LDPC_BF( ldpc_tab_2_3S, 30 );
if( m_format[0].code_rate == CR_3_4 ) LDPC_BF( ldpc_tab_3_4S, 33 );
if( m_format[0].code_rate == CR_4_5 ) LDPC_BF( ldpc_tab_4_5S, 35 );
if( m_format[0].code_rate == CR_5_6 ) LDPC_BF( ldpc_tab_5_6S, 37 );
if( m_format[0].code_rate == CR_8_9 ) LDPC_BF( ldpc_tab_8_9S, 40 );
}
m_ldpc_encode.table_length = index;
}
void DVB2::ldpc_encode( void )
{
Bit *d,*p;
// Calculate the number of parity bits
int plen = m_format[0].nldpc - m_format[0].kldpc;
d = m_frame;
p = &m_frame[m_format[0].kldpc];
// First zero all the parity bits
memset( p, 0, sizeof(Bit)*plen);
// now do the parity checking
for( int i = 0; i < m_ldpc_encode.table_length; i++ )
{
p[m_ldpc_encode.p[i]] ^= d[m_ldpc_encode.d[i]];
}
for (int i = 1; i < plen; i++)
{
p[i] ^= p[i - 1];
}
}
void DVB2::ldpc_encode_test( void )
{
if(1)// m_format.code_rate == CR_1_2 )
{
printf("\n\nEncode length %d\n",m_ldpc_encode.table_length);
printf("Parity start %d\n",m_format[0].kldpc);
for( int i = 0; i < m_ldpc_encode.table_length; i++ )
{
if(m_ldpc_encode.d[i] == 0 )
{
printf("%d+%d\n",m_ldpc_encode.p[i],m_ldpc_encode.d[i]);
}
}
printf("Encode test end\n\n");
}
}