swap to new ilbc library

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@12095 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/ilbc/src/FrameClassify.c

@@ -0,0 +1,131 @@
+/*
+ * iLBC - a library for the iLBC codec
+ *
+ * FrameClassify.c - The iLBC low bit rate speech codec.
+ *
+ * Adapted by Steve Underwood <steveu@coppice.org> from the reference
+ * iLBC code supplied in RFC3951.
+ *
+ * Original code Copyright (C) The Internet Society (2004).
+ * All changes to produce this version Copyright (C) 2008 by Steve Underwood
+ * All Rights Reserved.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * $Id: FrameClassify.c,v 1.2 2008/03/06 12:27:37 steveu Exp $
+ */
+
+/*! \file */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <inttypes.h>
+#include <string.h>
+
+#include "ilbc.h"
+#include "FrameClassify.h"
+
+/*---------------------------------------------------------------*
+ *  Classification of subframes to localize start state
+ *--------------------------------------------------------------*/
+
+int FrameClassify(                                      /* index to the max-energy sub-frame */
+                  ilbc_encode_state_t *iLBCenc_inst,    /* (i/o) the encoder state structure */
+                  float *residual)                      /* (i) lpc residual signal */
+{
+    float max_ssqEn;
+    float fssqEn[ILBC_NUM_SUB_MAX];
+    float bssqEn[ILBC_NUM_SUB_MAX];
+    float *pp;
+    int n;
+    int l;
+    int max_ssqEn_n;
+    static const float ssqEn_win[ILBC_NUM_SUB_MAX - 1] =
+    {
+        0.8f, 0.9f,
+        1.0f, 0.9f, 0.8f
+    };
+    static const float sampEn_win[5]=
+    {
+        1.0f/6.0f,
+        2.0f/6.0f, 3.0f/6.0f,
+        4.0f/6.0f, 5.0f/6.0f
+    };
+
+    /* init the front and back energies to zero */
+    memset(fssqEn, 0, ILBC_NUM_SUB_MAX*sizeof(float));
+    memset(bssqEn, 0, ILBC_NUM_SUB_MAX*sizeof(float));
+
+    /* Calculate front of first sequence */
+    n = 0;
+    pp = residual;
+    for (l = 0;  l < 5;  l++)
+    {
+        fssqEn[n] += sampEn_win[l]*(*pp)*(*pp);
+        pp++;
+    }
+    for (l = 5;  l < SUBL;  l++)
+    {
+        fssqEn[n] += (*pp)*(*pp);
+        pp++;
+    }
+
+    /* Calculate front and back of all middle sequences */
+    for (n = 1;  n < iLBCenc_inst->nsub - 1;  n++)
+    {
+        pp = residual + n*SUBL;
+        for (l = 0;  l < 5;  l++)
+        {
+            fssqEn[n] += sampEn_win[l]*(*pp)*(*pp);
+            bssqEn[n] += (*pp)*(*pp);
+            pp++;
+        }
+        for (l = 5;  l < SUBL - 5;  l++)
+        {
+            fssqEn[n] += (*pp)*(*pp);
+            bssqEn[n] += (*pp)*(*pp);
+            pp++;
+        }
+        for (l = SUBL - 5; l < SUBL;  l++)
+        {
+            fssqEn[n] += (*pp)*(*pp);
+            bssqEn[n] += sampEn_win[SUBL - l - 1]*(*pp)*(*pp);
+            pp++;
+        }
+    }
+
+    /* Calculate back of last sequence */
+    n = iLBCenc_inst->nsub - 1;
+    pp = residual + n*SUBL;
+    for (l = 0;  l < SUBL - 5;  l++)
+    {
+        bssqEn[n] += (*pp)*(*pp);
+        pp++;
+    }
+    for (l = SUBL - 5;  l < SUBL;  l++)
+    {
+        bssqEn[n] += sampEn_win[SUBL - l - 1]*(*pp)*(*pp);
+        pp++;
+    }
+
+    /* find the index to the weighted 80 sample with
+       most energy */
+    l = (iLBCenc_inst->mode == 20)  ?  1  :  0;
+    max_ssqEn = (fssqEn[0] + bssqEn[1])*ssqEn_win[l];
+    max_ssqEn_n = 1;
+    for (n = 2;  n < iLBCenc_inst->nsub;  n++)
+    {
+        l++;
+        if ((fssqEn[n - 1] + bssqEn[n])*ssqEn_win[l] > max_ssqEn)
+        {
+            max_ssqEn = (fssqEn[n - 1] + bssqEn[n])*ssqEn_win[l];
+            max_ssqEn_n = n;
+        }
+    }
+
+    return max_ssqEn_n;
+}