Related to waveforms

int get_next_sig_frame(sigstream_t *f, int c, int l, int d, float a, sample_t *s)
return in s the next frame after pre-emphasis by $1-az^{-1}$, reading channel c in the waveform stream f and assuming a frame length of l samples and a frame shift of d samples; the sample array s must remain unchanged between two successive calls to the function; returns 1 upon succes and 0 otherwise.

float sig_normalize(spsig_t *s, int flag)
returns the energy in signal s and, if flag is not null, normalize the waveform samples to unit energy.

double *set_sig_win(unsigned long n, int type)
allocate and initialize memory for the specified window of length n samples, returning a pointer to the allocated vector or NULL in case of error; the valid window types are SPRO_XXX_WINDOW where XXX is one of HAMMING, HANNING and BLACKMAN.

int sig_weight(spsig_t *s, double *w, sample_t *p)
apply the specified window to the signal, storing the result in p..