[Speex-dev] MDF filter coefficients

[Jean-Marc Valin]

David Giguet a écrit :
> I would like to compute the inverse FFT of the MDF coefficients. 

See SPEEX_ECHO_GET_IMPULSE_RESPONSE (and
SPEEX_ECHO_GET_IMPULSE_RESPONSE). It's all been done for you.

> I have
> noticed that some coefficients are obviously missing since I do not see
> the mirror effect, neither find the purely real frequency 0 coefficent
> that have to be found for a "real" signal.
> I guess the frequency 0 coefficient is 0 (average energy 0), but how
> should I do the mirroring and how many coefficients should I expect ?

FYI, the DC (aka coef 0) is there. There's no symmetry because I'm using
a real to half-complex FFT.

Cheer,

	Jean-Marc