Filters and decimates the input signal $x[n]$ with the polyphase FIR filter.

Parameters:¶

x: ArrayLike¶

The input signal $x[n]$ with sample rate $f_s$ and length $L$.

mode: 'rate' | 'full' = 'rate'¶

The non-streaming convolution mode.

• "rate": The output signal $y[n]$ has length $L/r$ proportional to the decimation rate $r$. Output sample 0 aligns with input sample 0.

• "full": The full convolution is performed. The output signal $y[n]$ has length $(L+N)r$, where $N$ is the order of the multirate filter. Output sample delay aligns with input sample 0.

In streaming mode, the "full" convolution is performed. However, for each $L$ input samples only $L/r$ output samples are produced per call. A final call with input zeros is required to flush the filter state.

Returns:¶

The filtered signal $y[n]$ with sample rate $f_s/r$. The output length is dictated by the mode argument.