1 files changed, 108 insertions, 0 deletions
diff --git a/trunk/codecs/ilbc/iCBConstruct.c b/trunk/codecs/ilbc/iCBConstruct.c
new file mode 100644
index 000000000..dbee586c2
--- /dev/null
+++ b/trunk/codecs/ilbc/iCBConstruct.c
@@ -0,0 +1,108 @@
+
+/******************************************************************
+
+    iLBC Speech Coder ANSI-C Source Code
+
+    iCBConstruct.c 
+
+    Copyright (C) The Internet Society (2004). 
+    All Rights Reserved.
+
+******************************************************************/
+
+#include <math.h>
+
+#include "iLBC_define.h"
+#include "iCBConstruct.h"
+#include "gainquant.h"
+#include "getCBvec.h"
+
+/*----------------------------------------------------------------*
+ *  Convert the codebook indexes to make the search easier
+ *---------------------------------------------------------------*/
+
+
+
+void index_conv_enc(
+    int *index          /* (i/o) Codebook indexes */
+){
+    int k;
+
+    for (k=1; k<CB_NSTAGES; k++) {
+        
+        if ((index[k]>=108)&&(index[k]<172)) {
+            index[k]-=64;
+        } else if (index[k]>=236) {
+            index[k]-=128;
+        } else {
+            /* ERROR */
+        }
+    }
+}
+
+void index_conv_dec(
+    int *index          /* (i/o) Codebook indexes */
+){
+    int k;
+
+    for (k=1; k<CB_NSTAGES; k++) {
+        
+        if ((index[k]>=44)&&(index[k]<108)) {
+            index[k]+=64;
+        } else if ((index[k]>=108)&&(index[k]<128)) {
+            index[k]+=128;
+        } else {
+            /* ERROR */
+        }
+    }
+}
+
+/*----------------------------------------------------------------*
+ *  Construct decoded vector from codebook and gains.
+ *---------------------------------------------------------------*/
+
+void iCBConstruct(
+    float *decvector,   /* (o) Decoded vector */
+    int *index,         /* (i) Codebook indices */
+    int *gain_index,/* (i) Gain quantization indices */
+    float *mem,         /* (i) Buffer for codevector construction */
+    int lMem,           /* (i) Length of buffer */
+    int veclen,         /* (i) Length of vector */
+    int nStages         /* (i) Number of codebook stages */
+){
+    int j,k;
+    float gain[CB_NSTAGES];
+    float cbvec[SUBL];
+
+    /* gain de-quantization */
+
+    gain[0] = gaindequant(gain_index[0], 1.0, 32);
+
+
+    if (nStages > 1) {
+        gain[1] = gaindequant(gain_index[1], 
+            (float)fabs(gain[0]), 16);  
+    }
+    if (nStages > 2) {
+        gain[2] = gaindequant(gain_index[2], 
+            (float)fabs(gain[1]), 8);
+    }
+
+    /* codebook vector construction and construction of 
+    total vector */
+
+    getCBvec(cbvec, mem, index[0], lMem, veclen);
+    for (j=0;j<veclen;j++){
+        decvector[j] = gain[0]*cbvec[j];
+    }
+    if (nStages > 1) {
+        for (k=1; k<nStages; k++) {
+            getCBvec(cbvec, mem, index[k], lMem, veclen);
+            for (j=0;j<veclen;j++) {
+                decvector[j] += gain[k]*cbvec[j];
+            }
+        }
+    }
+}
+
+