data为一个16位的数
p=floor(log2((2^16-1)/(data)));
k=7-p;
k(k<0)=0;
x=floor(data/(2^k));
x(x==0)=1;
B=floor(3400*log10(x))+floor(3400*log10(2^k));
396abf98bf 396abf98bf
