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//
// repack_bytes_example.c
//
// This example demonstrates the repack_bytes() interface by packing a
// sequence of three 3-bit symbols into five 2-bit symbols. The results
// are printed to the screen. Because the total number of bits in the
// input is 9 and not evenly divisible by 2, the last of the 5 output
// symbols has a zero explicitly padded to the end.
//
#include <stdio.h>
#include "liquid.h"
// print symbol to screen, one bit at a time
void print_symbol(unsigned char _sym,
unsigned int _bits_per_symbol)
{
unsigned int i;
unsigned int n; // shift amount
for (i=0; i<_bits_per_symbol; i++) {
n = _bits_per_symbol - i - 1;
printf("%c", (_sym >> n) & 0x01 ? '1' : '0');
}
}
// print symbol array to screen
void print_symbol_array(unsigned char * _sym,
unsigned int _bits_per_symbol,
unsigned int _num_symbols)
{
unsigned int i;
for (i=0; i<_num_symbols; i++) {
print_symbol(_sym[i], _bits_per_symbol);
printf("%c", i < _num_symbols-1 ? ',' : '\n');
}
}
int main() {
// input symbols: 111 000 111
// expected output: 11 10 00 11 1(0)
unsigned char input[3] = {
0x07, // 111
0x00, // 000
0x07 // 111(0)
};
// allocate memory for output array
unsigned char output[5];
unsigned int N;
// print input symbol array
printf("input symbols: ");
print_symbol_array(input,3,3);
// repack bytes into output array
liquid_repack_bytes( input, 3, 3, output, 2, 5, &N );
// print output array
printf("output symbols: ");
print_symbol_array(output,2,5);
return 0;
}
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