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-rw-r--r--trunk/codecs/ilbc/hpInput.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/trunk/codecs/ilbc/hpInput.c b/trunk/codecs/ilbc/hpInput.c
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+++ b/trunk/codecs/ilbc/hpInput.c
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+
+/******************************************************************
+
+ iLBC Speech Coder ANSI-C Source Code
+
+ hpInput.c
+
+ Copyright (C) The Internet Society (2004).
+ All Rights Reserved.
+
+******************************************************************/
+
+#include "constants.h"
+#include "hpInput.h"
+
+/*----------------------------------------------------------------*
+ * Input high-pass filter
+ *---------------------------------------------------------------*/
+
+void hpInput(
+ float *In, /* (i) vector to filter */
+ int len, /* (i) length of vector to filter */
+ float *Out, /* (o) the resulting filtered vector */
+ float *mem /* (i/o) the filter state */
+){
+ int i;
+ float *pi, *po;
+
+ /* all-zero section*/
+
+ pi = &In[0];
+ po = &Out[0];
+ for (i=0; i<len; i++) {
+ *po = hpi_zero_coefsTbl[0] * (*pi);
+ *po += hpi_zero_coefsTbl[1] * mem[0];
+ *po += hpi_zero_coefsTbl[2] * mem[1];
+
+ mem[1] = mem[0];
+ mem[0] = *pi;
+ po++;
+
+
+ pi++;
+
+ }
+
+ /* all-pole section*/
+
+ po = &Out[0];
+ for (i=0; i<len; i++) {
+ *po -= hpi_pole_coefsTbl[1] * mem[2];
+ *po -= hpi_pole_coefsTbl[2] * mem[3];
+
+ mem[3] = mem[2];
+ mem[2] = *po;
+ po++;
+ }
+}
+
+