From 81d1b2797aa3945c529d57f9ddf6179ec2b392a4 Mon Sep 17 00:00:00 2001
From: Benny Prijono <bennylp@teluu.com>
Date: Sat, 7 Apr 2007 12:47:34 +0000
Subject: Moved ilbc to third_party directory

git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/split-3rd-party@1169 74dad513-b988-da41-8d7b-12977e46ad98
---
 third_party/ilbc/filter.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 third_party/ilbc/filter.c

(limited to 'third_party/ilbc/filter.c')

diff --git a/third_party/ilbc/filter.c b/third_party/ilbc/filter.c
new file mode 100644
index 00000000..6565c2be
--- /dev/null
+++ b/third_party/ilbc/filter.c
@@ -0,0 +1,175 @@
+
+   /******************************************************************
+
+       iLBC Speech Coder ANSI-C Source Code
+
+       filter.c
+
+       Copyright (C) The Internet Society (2004).
+       All Rights Reserved.
+
+   ******************************************************************/
+
+   #include "iLBC_define.h"
+
+   /*----------------------------------------------------------------*
+    *  all-pole filter
+    *---------------------------------------------------------------*/
+
+   void AllPoleFilter(
+       float *InOut,   /* (i/o) on entrance InOut[-orderCoef] to
+                              InOut[-1] contain the state of the
+                              filter (delayed samples). InOut[0] to
+                              InOut[lengthInOut-1] contain the filter
+                              input, on en exit InOut[-orderCoef] to
+                              InOut[-1] is unchanged and InOut[0] to
+                              InOut[lengthInOut-1] contain filtered
+                              samples */
+       float *Coef,/* (i) filter coefficients, Coef[0] is assumed
+                              to be 1.0 */
+       int lengthInOut,/* (i) number of input/output samples */
+       int orderCoef   /* (i) number of filter coefficients */
+   ){
+       int n,k;
+
+       for(n=0;n<lengthInOut;n++){
+           for(k=1;k<=orderCoef;k++){
+               *InOut -= Coef[k]*InOut[-k];
+
+
+
+
+
+           }
+           InOut++;
+       }
+   }
+
+   /*----------------------------------------------------------------*
+    *  all-zero filter
+    *---------------------------------------------------------------*/
+
+   void AllZeroFilter(
+       float *In,      /* (i) In[0] to In[lengthInOut-1] contain
+                              filter input samples */
+       float *Coef,/* (i) filter coefficients (Coef[0] is assumed
+                              to be 1.0) */
+       int lengthInOut,/* (i) number of input/output samples */
+       int orderCoef,  /* (i) number of filter coefficients */
+       float *Out      /* (i/o) on entrance Out[-orderCoef] to Out[-1]
+                              contain the filter state, on exit Out[0]
+                              to Out[lengthInOut-1] contain filtered
+                              samples */
+   ){
+       int n,k;
+
+       for(n=0;n<lengthInOut;n++){
+           *Out = Coef[0]*In[0];
+           for(k=1;k<=orderCoef;k++){
+               *Out += Coef[k]*In[-k];
+           }
+           Out++;
+           In++;
+       }
+   }
+
+   /*----------------------------------------------------------------*
+    *  pole-zero filter
+    *---------------------------------------------------------------*/
+
+   void ZeroPoleFilter(
+       float *In,      /* (i) In[0] to In[lengthInOut-1] contain
+                              filter input samples In[-orderCoef] to
+                              In[-1] contain state of all-zero
+                              section */
+       float *ZeroCoef,/* (i) filter coefficients for all-zero
+                              section (ZeroCoef[0] is assumed to
+                              be 1.0) */
+       float *PoleCoef,/* (i) filter coefficients for all-pole section
+                              (ZeroCoef[0] is assumed to be 1.0) */
+       int lengthInOut,/* (i) number of input/output samples */
+
+
+
+
+
+       int orderCoef,  /* (i) number of filter coefficients */
+       float *Out      /* (i/o) on entrance Out[-orderCoef] to Out[-1]
+                              contain state of all-pole section. On
+                              exit Out[0] to Out[lengthInOut-1]
+                              contain filtered samples */
+   ){
+       AllZeroFilter(In,ZeroCoef,lengthInOut,orderCoef,Out);
+       AllPoleFilter(Out,PoleCoef,lengthInOut,orderCoef);
+   }
+
+   /*----------------------------------------------------------------*
+    * downsample (LP filter and decimation)
+    *---------------------------------------------------------------*/
+
+   void DownSample (
+       float  *In,     /* (i) input samples */
+       float  *Coef,   /* (i) filter coefficients */
+       int lengthIn,   /* (i) number of input samples */
+       float  *state,  /* (i) filter state */
+       float  *Out     /* (o) downsampled output */
+   ){
+       float   o;
+       float *Out_ptr = Out;
+       float *Coef_ptr, *In_ptr;
+       float *state_ptr;
+       int i, j, stop;
+
+       /* LP filter and decimate at the same time */
+
+       for (i = DELAY_DS; i < lengthIn; i+=FACTOR_DS)
+       {
+           Coef_ptr = &Coef[0];
+           In_ptr = &In[i];
+           state_ptr = &state[FILTERORDER_DS-2];
+
+           o = (float)0.0;
+
+           stop = (i < FILTERORDER_DS) ? i + 1 : FILTERORDER_DS;
+
+           for (j = 0; j < stop; j++)
+           {
+               o += *Coef_ptr++ * (*In_ptr--);
+           }
+           for (j = i + 1; j < FILTERORDER_DS; j++)
+           {
+               o += *Coef_ptr++ * (*state_ptr--);
+           }
+
+
+
+
+
+
+           *Out_ptr++ = o;
+       }
+
+       /* Get the last part (use zeros as input for the future) */
+
+       for (i=(lengthIn+FACTOR_DS); i<(lengthIn+DELAY_DS);
+               i+=FACTOR_DS) {
+
+           o=(float)0.0;
+
+           if (i<lengthIn) {
+               Coef_ptr = &Coef[0];
+               In_ptr = &In[i];
+               for (j=0; j<FILTERORDER_DS; j++) {
+                       o += *Coef_ptr++ * (*Out_ptr--);
+               }
+           } else {
+               Coef_ptr = &Coef[i-lengthIn];
+               In_ptr = &In[lengthIn-1];
+               for (j=0; j<FILTERORDER_DS-(i-lengthIn); j++) {
+                       o += *Coef_ptr++ * (*In_ptr--);
+               }
+           }
+           *Out_ptr++ = o;
+       }
+   }
+
-- 
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