1 files changed, 76 insertions, 0 deletions
diff --git a/trunk/codecs/ilbc/StateConstructW.c b/trunk/codecs/ilbc/StateConstructW.c
new file mode 100644
index 000000000..e48fe035d
--- /dev/null
+++ b/trunk/codecs/ilbc/StateConstructW.c
@@ -0,0 +1,76 @@
+
+/******************************************************************
+
+
+
+    iLBC Speech Coder ANSI-C Source Code
+
+    StateConstructW.c 
+
+    Copyright (C) The Internet Society (2004). 
+    All Rights Reserved.
+
+******************************************************************/
+
+#include <math.h> 
+#include <string.h>
+
+#include "iLBC_define.h"
+#include "StateConstructW.h"
+#include "constants.h"
+#include "filter.h"
+
+/*----------------------------------------------------------------*
+ *  decoding of the start state
+ *---------------------------------------------------------------*/
+
+void StateConstructW( 
+    int idxForMax,      /* (i) 6-bit index for the quantization of 
+                               max amplitude */
+    int *idxVec,    /* (i) vector of quantization indexes */
+    float *syntDenum,   /* (i) synthesis filter denumerator */
+    float *out,         /* (o) the decoded state vector */
+    int len             /* (i) length of a state vector */
+){
+    float maxVal, tmpbuf[LPC_FILTERORDER+2*STATE_LEN], *tmp, 
+        numerator[LPC_FILTERORDER+1];
+    float foutbuf[LPC_FILTERORDER+2*STATE_LEN], *fout;
+    int k,tmpi;
+    
+    /* decoding of the maximum value */
+
+    maxVal = state_frgqTbl[idxForMax];
+    maxVal = (float)pow(10,maxVal)/(float)4.5;
+        
+    /* initialization of buffers and coefficients */
+    
+    memset(tmpbuf, 0, LPC_FILTERORDER*sizeof(float));
+    memset(foutbuf, 0, LPC_FILTERORDER*sizeof(float));
+    for (k=0; k<LPC_FILTERORDER; k++) {
+        numerator[k]=syntDenum[LPC_FILTERORDER-k];
+    }
+    numerator[LPC_FILTERORDER]=syntDenum[0];
+    tmp = &tmpbuf[LPC_FILTERORDER];
+    fout = &foutbuf[LPC_FILTERORDER];
+
+    /* decoding of the sample values */
+    
+    for (k=0; k<len; k++) {
+        tmpi = len-1-k;
+        /* maxVal = 1/scal */
+
+
+        tmp[k] = maxVal*state_sq3Tbl[idxVec[tmpi]];
+    }
+
+    /* circular convolution with all-pass filter */
+
+    memset(tmp+len, 0, len*sizeof(float));
+    ZeroPoleFilter(tmp, numerator, syntDenum, 2*len, 
+        LPC_FILTERORDER, fout);
+    for (k=0;k<len;k++) {
+        out[k] = fout[len-1-k]+fout[2*len-1-k];
+    }
+}
+
+