\section{feat\+\_\+s Struct Reference}
\label{structfeat__s}\index{feat\+\_\+s@{feat\+\_\+s}}
\subsection*{Data Fields}
\begin{DoxyCompactItemize}
\item 
int \textbf{ refcount}
\begin{DoxyCompactList}\small\item\em Reference count. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_ab58e7419bc24969680baf4289dc756ce}} 
char $\ast$ \textbf{ name}
\begin{DoxyCompactList}\small\item\em Printable name for this feature type. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_aee30d93416c0c392f946dacd58dec984}} 
int32 \textbf{ cepsize}
\begin{DoxyCompactList}\small\item\em Size of input speech vector (typically, a cepstrum vector) \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a5b4ed4ce256ddcc3e97864cbbc8547a2}} 
int32 \textbf{ n\+\_\+stream}
\begin{DoxyCompactList}\small\item\em Number of feature streams; e.\+g., 4 in Sphinx-\/\+II. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a79f153013d8738796976e3de626a6772}} 
uint32 $\ast$ \textbf{ stream\+\_\+len}
\begin{DoxyCompactList}\small\item\em Vector length of each feature stream. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a02cf7454beea5fc6968165cfd17a7f34}} 
int32 \textbf{ window\+\_\+size}
\begin{DoxyCompactList}\small\item\em Number of extra frames around given input frame needed to compute corresponding output feature (so total = window\+\_\+size$\ast$2 + 1) \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_afe74101645e3e9dafe07d78f68ddf694}} 
int32 \textbf{ n\+\_\+sv}
\begin{DoxyCompactList}\small\item\em Number of subvectors. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_acfe00502fb5fb605f99b4b1f9842d650}} 
uint32 $\ast$ \textbf{ sv\+\_\+len}
\begin{DoxyCompactList}\small\item\em Vector length of each subvector. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a0a89f7965e2db52b32519d967d7d13db}} 
int32 $\ast$$\ast$ \textbf{ subvecs}
\begin{DoxyCompactList}\small\item\em Subvector specification (or N\+U\+LL for none) \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_af747bcddb70ea570fc07e8cefc2f8896}} 
mfcc\+\_\+t $\ast$ \textbf{ sv\+\_\+buf}
\begin{DoxyCompactList}\small\item\em Temporary copy buffer for subvector projection. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a32f835789890a70dab6271491f1400e3}} 
int32 \textbf{ sv\+\_\+dim}
\begin{DoxyCompactList}\small\item\em Total dimensionality of subvector (length of sv\+\_\+buf) \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a3e31d666805a9183f3188249bb6ff45f}} 
\textbf{ cmn\+\_\+type\+\_\+t} \textbf{ cmn}
\begin{DoxyCompactList}\small\item\em Type of C\+MN to be performed on each utterance. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a7b222bd84282defdabdba35987e7ae7b}} 
int32 \textbf{ varnorm}
\begin{DoxyCompactList}\small\item\em Whether variance normalization is to be performed on each utt; Irrelevant if no C\+MN is performed. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a4580c133e0bb9b9e2856f66482e91d3d}} 
\textbf{ agc\+\_\+type\+\_\+t} \textbf{ agc}
\begin{DoxyCompactList}\small\item\em Type of A\+GC to be performed on each utterance. \end{DoxyCompactList}\item 
void($\ast$ \textbf{ compute\+\_\+feat} )(struct \textbf{ feat\+\_\+s} $\ast$fcb, mfcc\+\_\+t $\ast$$\ast$input, mfcc\+\_\+t $\ast$$\ast$feat)
\begin{DoxyCompactList}\small\item\em Feature computation function. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_af405f775cc9df57701f93f2056be3c4a}} 
\textbf{ cmn\+\_\+t} $\ast$ \textbf{ cmn\+\_\+struct}
\begin{DoxyCompactList}\small\item\em Structure that stores the temporary variables for cepstral means normalization. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a2cc3e4a25a696379e8843d36cfcf3656}} 
\textbf{ agc\+\_\+t} $\ast$ \textbf{ agc\+\_\+struct}
\begin{DoxyCompactList}\small\item\em Structure that stores the temporary variables for acoustic gain control. \end{DoxyCompactList}\item 
mfcc\+\_\+t $\ast$$\ast$ \textbf{ cepbuf}
\begin{DoxyCompactList}\small\item\em Circular buffer of M\+F\+CC frames for live feature computation. \end{DoxyCompactList}\item 
mfcc\+\_\+t $\ast$$\ast$ \textbf{ tmpcepbuf}
\begin{DoxyCompactList}\small\item\em Array of pointers into cepbuf to handle border cases. \end{DoxyCompactList}\item 
int32 \textbf{ bufpos}
\begin{DoxyCompactList}\small\item\em Write index in cepbuf. \end{DoxyCompactList}\item 
int32 \textbf{ curpos}
\begin{DoxyCompactList}\small\item\em Read index in cepbuf. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_a2c54fea16330caf82c5f516137c2d454}} 
mfcc\+\_\+t $\ast$$\ast$$\ast$ \textbf{ lda}
\begin{DoxyCompactList}\small\item\em Array of linear transformations (for L\+DA, M\+L\+LT, or whatever) \end{DoxyCompactList}\item 
uint32 \textbf{ n\+\_\+lda}
\begin{DoxyCompactList}\small\item\em Number of linear transformations in lda. \end{DoxyCompactList}\item 
\mbox{\label{structfeat__s_acbebc734e2c212aa7078b29531a78bc7}} 
uint32 \textbf{ out\+\_\+dim}
\begin{DoxyCompactList}\small\item\em Output dimensionality. \end{DoxyCompactList}\end{DoxyCompactItemize}


\subsection{Detailed Description}


Definition at line 155 of file feat.\+h.



\subsection{Field Documentation}
\mbox{\label{structfeat__s_a9bd6277ec5f03e103b9c8a67579a2822}} 
\index{feat\+\_\+s@{feat\+\_\+s}!bufpos@{bufpos}}
\index{bufpos@{bufpos}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{bufpos}
{\footnotesize\ttfamily int32 feat\+\_\+s\+::bufpos}



Write index in cepbuf. 



Definition at line 194 of file feat.\+h.

\mbox{\label{structfeat__s_a9b5c45065c30c9b6b610e54479b3f2c8}} 
\index{feat\+\_\+s@{feat\+\_\+s}!cepbuf@{cepbuf}}
\index{cepbuf@{cepbuf}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{cepbuf}
{\footnotesize\ttfamily mfcc\+\_\+t$\ast$$\ast$ feat\+\_\+s\+::cepbuf}



Circular buffer of M\+F\+CC frames for live feature computation. 



Definition at line 192 of file feat.\+h.

\mbox{\label{structfeat__s_aaa43338c81fbe88f0d60321850bb3361}} 
\index{feat\+\_\+s@{feat\+\_\+s}!compute\+\_\+feat@{compute\+\_\+feat}}
\index{compute\+\_\+feat@{compute\+\_\+feat}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{compute\+\_\+feat}
{\footnotesize\ttfamily void($\ast$ feat\+\_\+s\+::compute\+\_\+feat) (struct \textbf{ feat\+\_\+s} $\ast$fcb, mfcc\+\_\+t $\ast$$\ast$input, mfcc\+\_\+t $\ast$$\ast$feat)}



Feature computation function. 


\begin{DoxyParams}{Parameters}
{\em fcb} & the \doxyref{feat\+\_\+t}{p.}{structfeat__t} describing this feature type \\
\hline
{\em input} & pointer into the input cepstra \\
\hline
{\em feat} & a 2-\/d array of output features (n\+\_\+stream x stream\+\_\+len) \\
\hline
\end{DoxyParams}
\begin{DoxyReturn}{Returns}
0 if successful, -\/ve otherwise.
\end{DoxyReturn}
Function for converting window of input speech vector (input[-\/window\+\_\+size..window\+\_\+size]) to output feature vector (feat[stream][]). If N\+U\+LL, no conversion available, the speech input must be feature vector itself. 

Definition at line 186 of file feat.\+h.

\mbox{\label{structfeat__s_ad27f63c459eb46462e28b2a23d8f8a6f}} 
\index{feat\+\_\+s@{feat\+\_\+s}!curpos@{curpos}}
\index{curpos@{curpos}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{curpos}
{\footnotesize\ttfamily int32 feat\+\_\+s\+::curpos}



Read index in cepbuf. 



Definition at line 195 of file feat.\+h.

\mbox{\label{structfeat__s_a2078107cc1c82d6c0b4f93bfbb75dd7a}} 
\index{feat\+\_\+s@{feat\+\_\+s}!n\+\_\+lda@{n\+\_\+lda}}
\index{n\+\_\+lda@{n\+\_\+lda}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{n\+\_\+lda}
{\footnotesize\ttfamily uint32 feat\+\_\+s\+::n\+\_\+lda}



Number of linear transformations in lda. 



Definition at line 198 of file feat.\+h.

\mbox{\label{structfeat__s_a65eb722aadd471310eff84ac5946d98f}} 
\index{feat\+\_\+s@{feat\+\_\+s}!refcount@{refcount}}
\index{refcount@{refcount}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{refcount}
{\footnotesize\ttfamily int feat\+\_\+s\+::refcount}



Reference count. 



Definition at line 156 of file feat.\+h.

\mbox{\label{structfeat__s_a0ffb1581086d94546b5e91e9ab685cb7}} 
\index{feat\+\_\+s@{feat\+\_\+s}!tmpcepbuf@{tmpcepbuf}}
\index{tmpcepbuf@{tmpcepbuf}!feat\+\_\+s@{feat\+\_\+s}}
\subsubsection{tmpcepbuf}
{\footnotesize\ttfamily mfcc\+\_\+t$\ast$$\ast$ feat\+\_\+s\+::tmpcepbuf}



Array of pointers into cepbuf to handle border cases. 



Definition at line 193 of file feat.\+h.



The documentation for this struct was generated from the following file\+:\begin{DoxyCompactItemize}
\item 
include/sphinxbase/\textbf{ feat.\+h}\end{DoxyCompactItemize}
