在信号重采样的时候，滤波器设计的指标怎么确定？

Question

尝试把44.1kHz的信号转换成96kHz的信号。
把L/M=320/147 分解成 （8/7）（4/3）（10/7）的形式，可以知道截至频率应该等于
π/max（L,M）。

1. 但是具体每个滤波器应该怎么设计呢？

2. 还有我看了下matlab的resample函数的处理方法，不太明白这一段：

 % Need to delay output so that downsampling by q hits center tap of filter.
nz = floor(q-mod(Lhalf,q));
z = zeros(1,nz);
h = [z h(:).'];  % ensure that h is a row vector.
Lhalf = Lhalf + nz;

% Number of samples removed from beginning of output sequence 
% to compensate for delay of linear phase filter:
delay = floor(ceil(Lhalf)/q);

% Need to zero-pad so output length is exactly ceil(Lx*p/q).
nz1 = 0;
while ceil( ((Lx-1)*p+length(h)+nz1 )/q ) - delay < ceil(Lx*p/q)
    nz1 = nz1+1;
end
h = [h zeros(1,nz1)];