The array size is equal to the length of the FIR multiplied by number of channels and divided equally by AI Engine kernels used, i.e.:
TapsPerRtpPort = (TP_FIR_LEN) / (TP_SSR * TP_CASC_LEN)
For example, if TP_FIR_LEN = 6 , if TP_SSR = 2 and TP_CASC_LEN = 3, the coefficient array will be divided into 2 * 3 = 6 parts.
FIR graph class provides a helper method: getTapsPerRtpPort(int kernelNo) to get number of FIR taps per RTP port. For more details, refer to: API Reference Overview.