--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/intercom/gsm/decode.c	Fri Jun 25 09:57:52 2010 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
+ * Universitaet Berlin.  See the accompanying file "COPYRIGHT" for
+ * details.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
+ */
+
+/* $Header: /home/kbs/jutta/src/gsm/gsm-1.0/src/RCS/decode.c,v 1.1 1992/10/28 00:15:50 jutta Exp $ */
+
+#include <stdio.h>
+
+#include	"private.h"
+#include	"gsm.h"
+#include	"proto.h"
+
+/*
+ *  4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER
+ */
+
+static void Postprocessing P2((S, s),
+  struct gsm_state *S, register word * s)
+{
+  register int k;
+  register word msr = S->msr;
+  register longword ltmp;       /* for GSM_ADD */
+  register word tmp;
+
+  for (k = 160; k--; s++) {
+    tmp = GSM_MULT_R(msr, 28180);
+    msr = GSM_ADD(*s, tmp);     /* Deemphasis             */
+#ifdef USE_ROUNDING_INSTEAD_OF_TRUNCATION
+    *s = GSM_ADD(msr, msr);     /* Upscaling by 2 */
+    *s = GSM_ADD(*s, 4) & 0xFFF8;       /* Truncation */
+#else
+    *s = GSM_ADD(msr, msr) & 0xFFF8;    /* Upscaling & Truncation */
+#endif
+  }
+  S->msr = msr;
+}
+
+void Gsm_Decoder P8((S, LARcr, Ncr, bcr, Mcr, xmaxcr, xMcr, s), struct gsm_state *S, word * LARcr,      /* [0..7]               IN      */
+  word * Ncr,                   /* [0..3]               IN      */
+  word * bcr,                   /* [0..3]               IN      */
+  word * Mcr,                   /* [0..3]               IN      */
+  word * xmaxcr,                /* [0..3]               IN      */
+  word * xMcr,                  /* [0..13*4]            IN      */
+  word * s)
+{                               /* [0..159]               OUT     */
+  int j, k;
+  word erp[40], wt[160];
+  word *drp = S->dp0 + 120;
+
+  for (j = 0; j <= 3; j++, xmaxcr++, bcr++, Ncr++, Mcr++, xMcr += 13) {
+
+    Gsm_RPE_Decoding(S, *xmaxcr, *Mcr, xMcr, erp);
+    Gsm_Long_Term_Synthesis_Filtering(S, *Ncr, *bcr, erp, drp);
+
+    for (k = 0; k <= 39; k++)
+      wt[j * 40 + k] = drp[k];
+  }
+
+  Gsm_Short_Term_Synthesis_Filter(S, LARcr, wt, s);
+  Postprocessing(S, s);
+}