--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/lsp_avg.c	Mon May 06 06:49:54 2024 +0000
@@ -0,0 +1,90 @@
+/*
+*****************************************************************************
+*
+*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
+*                                R99   Version 3.3.0                
+*                                REL-4 Version 4.1.0                
+*
+*****************************************************************************
+*
+*      File             : lsp_avg.c
+*      Purpose:         : LSP averaging and history
+*
+*****************************************************************************
+*/
+
+/*
+*****************************************************************************
+*                         MODULE INCLUDE FILE AND VERSION ID
+*****************************************************************************
+*/
+#include "namespace.h"
+#include "lsp_avg.h"
+ 
+/*
+*****************************************************************************
+*                         INCLUDE FILES
+*****************************************************************************
+*/
+#include "basic_op.h"
+#include "oper_32b.h"
+#include "no_count.h"
+#include "q_plsf5_tab.h"
+#include "memops.h"
+
+/*
+*****************************************************************************
+*                         LOCAL VARIABLES AND TABLES
+*****************************************************************************
+*/
+/*
+*****************************************************************************
+*                         PUBLIC PROGRAM CODE
+*****************************************************************************
+*/
+ 
+/*
+**************************************************************************
+*
+*  Function    : lsp_avg_reset
+*  Purpose     : Resets state memory
+*
+**************************************************************************
+*/
+void lsp_avg_reset (lsp_avgState *st)
+{ 
+  Copy(mean_lsf, &st->lsp_meanSave[0], M);
+}
+ 
+/*
+**************************************************************************
+*
+*  Function    : lsp_avg
+*  Purpose     : Calculate the LSP averages
+*
+**************************************************************************
+*/
+
+void lsp_avg (
+    lsp_avgState *st,         /* i/o : State struct                 Q15 */
+    Word16 *lsp               /* i   : state of the state machine   Q15 */
+)
+{
+    Word16 i;
+    Word32 L_tmp;            /* Q31 */
+
+    for (i = 0; i < M; i++) {
+
+       /* mean = 0.84*mean */
+       L_tmp = L_deposit_h(st->lsp_meanSave[i]);
+       L_tmp = L_msu(L_tmp, EXPCONST, st->lsp_meanSave[i]);
+
+       /* Add 0.16 of newest LSPs to mean */
+       L_tmp = L_mac(L_tmp, EXPCONST, lsp[i]);
+
+       /* Save means */
+       st->lsp_meanSave[i] = round(L_tmp);          move16();   /* Q15 */
+    }
+
+    return;
+}