Steve's patch to removed unused variables in LPC routines

git-svn-id: https://svn.code.sf.net/p/freetel/code@1712 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/src/lpc.c b/codec2-dev/src/lpc.c
index 66da9a9d8f77b2b17fcfebf9d1add881face3f38..4622dc375b472309016cc03e61fcf3c1cfd1056d 100644 (file)
--- a/codec2-dev/src/lpc.c
+++ b/codec2-dev/src/lpc.c
@@ -156,28 +156,26 @@ void levinson_durbin(
   int order            /* order of the LPC analysis */
 )
 {
-  float E[order+1];
-  float k[order+1];
   float a[order+1][order+1];
-  float sum;
+  float sum, e, k;
   int i,j;                             /* loop variables */
 
-  E[0] = R[0];                         /* Equation 38a, Makhoul */
+  e = R[0];                            /* Equation 38a, Makhoul */
 
   for(i=1; i<=order; i++) {
     sum = 0.0;
     for(j=1; j<=i-1; j++)
       sum += a[i-1][j]*R[i-j];
-    k[i] = -1.0*(R[i] + sum)/E[i-1];   /* Equation 38b, Makhoul */
-    if (fabsf(k[i]) > 1.0)
-      k[i] = 0.0;
+    k = -1.0*(R[i] + sum)/e;           /* Equation 38b, Makhoul */
+    if (fabsf(k) > 1.0)
+      k = 0.0;
 
-    a[i][i] = k[i];
+    a[i][i] = k;
 
     for(j=1; j<=i-1; j++)
-      a[i][j] = a[i-1][j] + k[i]*a[i-1][i-j];  /* Equation 38c, Makhoul */
+      a[i][j] = a[i-1][j] + k*a[i-1][i-j];     /* Equation 38c, Makhoul */
 
-    E[i] = (1-k[i]*k[i])*E[i-1];               /* Equation 38d, Makhoul */
+    e *= (1-k*k);                              /* Equation 38d, Makhoul */
   }
 
   for(i=1; i<=order; i++)