[DSK6713] issue with FFT and IFFT of C67x dsp library

With DSK6713 (TMS320C6713), customer is using FFT and IFFT of C67x dsp library (dsp67x.lib).

They did below things.

   * Audio Capture

   * FFT [ gen_w_r2(w, N); bit_rev(w, N>>1); DSPF_sp_cfftr2_dit(x, w, N); ]

   * IFFT [ DSPF_sp_icfftr2_dif(x, w, N); divide(x, N); ]

   * Audio Playback

With above FFT - IFFT, original captured audio should be output, right?

But, actually there is no sound output.

Is there anything more required to do?

Thanks and regards,

Hayden