mlib_SignalLPC2Cepstral_S1mediaLibLLibramlib_SignalLPC2Cepstral_S16_Adp(3MLIB)NAMEmlib_SignalLPC2Cepstral_S16_Adp - convert linear prediction coeffi‐
cients to cepstral coefficients
SYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>
mlib_status mlib_SignalLPC2Cepstral_S16_Adp(mlib_s16 *cepst,
mlib_s32 *cscale, const mlib_s16 *lpc, mlib_s32 lscale,
mlib_s16 gain, mlib_s32 gscale, mlib_s32 length,
mlib_s32 order);
DESCRIPTION
The mlib_SignalLPC2Cepstral_S16_Adp() function converts linear predic‐
tion coefficients to cepstral coefficients. The scaling factor of the
output data, cscale, will be calculated based on the actual data.
The cepstral coefficients are the coefficients of the Fourier transform
representation of the log magnitude spectrum.
The LPC cepstral coefficients can be derived recursively from the LPC
coefficients as following.
c(0) = log(G)
m-1 k
c(m) = a(m) + SUM --- * c(k) * a(m-k), 1 ≤ m ≤ M
k=1 m
m-1 k
c(m) = SUM --- * c(k) * a(m-k), m > M
k=1 m
See Fundamentals of Speech Recognition by Lawrence Rabiner and Biing-
Hwang Juang, Prentice Hall, 1993.
PARAMETERS
The function takes the following arguments:
cepst The cepstral coefficients.
cscale The scaling factor of the cepstral coefficients, where
actual_data = output_data * 2**(-scaling_factor).
lpc The linear prediction coefficients.
lscale The scaling factor of the linear prediction coefficients,
where actual_data = input_data * 2**(-scaling_factor).
gain The gain of the LPC model.
gscale The scaling factor of the gain of the LPC model, where
actual_data = input_data * 2**(-scaling_factor).
length The length of the cepstral coefficients.
order The order of the linear prediction filter.
RETURN VALUES
The function returns MLIB_SUCCESS if successful. Otherwise it returns
MLIB_FAILURE.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOmlib_SignalLPC2Cepstral_S16(3MLIB), mlib_SignalLPC2Cep‐
stral_S16_Adp(3MLIB), mlib_SignalLPC2Cepstral_F32(3MLIB), attributes(5)SunOS 5.10 2 Mar mlib_SignalLPC2Cepstral_S16_Adp(3MLIB)
