mediaLib Library Functions     mlibSignalLPC2CepstralS16(3MLIB)



NAME
     mlibSignalLPC2CepstralS16  -  convert  linear   prediction
     coefficients to cepstral coefficients

SYNOPSIS
     cc [ flag... ] file... -lmlib [ library... ]
     #include 

     mlibstatus mlibSignalLPC2CepstralS16(mlibs16 *cepst,
          mlibs32 cscale, const mlibs16 *lpc, mlibs32 lscale,
          mlibs16 gain, mlibs32 gscale, mlibs32 length,
          mlibs32 order);


DESCRIPTION
     The mlibSignalLPC2CepstralS16() function  converts  linear
     prediction  coefficients  to cepstral coefficients. The user
     supplied scaling factor, cscale, will be used and the output
     will be saturated if necessary.


     The  cepstral  coefficients  are  the  coefficients  of  the
     Fourier  transform representation of the log magnitude spec-
     trum.


     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    actualdata   =   outputdata   *   2**(-



SunOS 5.11           Last change: 2 Mar 2007                    1






mediaLib Library Functions     mlibSignalLPC2CepstralS16(3MLIB)



               scalingfactor).


     lpc       The linear prediction coefficients.


     lscale    The scaling factor of the linear prediction  coef-
               ficients,  where  actualdata = inputdata * 2**(-
               scalingfactor).


     gain      The gain of the LPC model.


     gscale    The scaling factor of the gain of the  LPC  model,
               where    actualdata    =   inputdata   *   2**(-
               scalingfactor).


     length    The length of the cepstral coefficients.


     order     The order of the linear prediction filter.


RETURN VALUES
     The function returns MLIBSUCES if  successful.  Otherwise
     it returns MLIBFAILURE.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     mlibSignalLPC2CepstralS16(3MLIB),
     mlibSignalLPC2CepstralS16Adp(3MLIB),
     mlibSignalLPC2CepstralF32(3MLIB), attributes(5)







SunOS 5.11           Last change: 2 Mar 2007                    2