Реалізація ідеї арифметичного кодування, Детальна інформація

static code_value low, high;

static long bits_to_follow;

/* Ii/aoie eiaeoaaiiy iioiea neiaie\x00B3a */

start_encoding()

{ low = 0;

high = Top_value;

bits_to_follow = 0;

}

/* Eiaeoaaiiy neiaieo */

encode_symbol(symbol,cum_freq)

int symbol;

int cum_freq[];

{ long range;

range = (long)(high-low)+1;

high = low + (range*cum_freq[symbol-1])/cum_freq[0]-1;

low = low + (range*cum_freq[symbol])/cum_freq[0];

for (;;) {

if (high
bit_plus_follow(0);

}

else if (low>=Half) {

bit_plus_follow(1);

low -= Half;

high -= Half;

}

else if (low>=First_qtr && high
{ bits_to_follow +=1;

low -= First_qtr;

high -= First_qtr;

}