Matlab v_filterbank函数参数详解（英文附例）
请注意，“v_”开头的函数均在voicebox中使用，将此工具箱添加至路径即可。
函数解释
v_filterbank appply v_filterbank to a signal: [y,zo]=(b,a,x,gd)
Inputs:
b numerator coefficients, one row per filter
a denominator coefficients, one row per filter
x input signal
gd group delay of each filter in samples [default=0]. The filter outputs will be advanced to compensate for the group delays.
Alternatively, this input can be the zo output from a previous call.
Outputs:
y output signals, one column per filter
zo output filter state
