--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/pre_big.c	Mon May 06 18:57:05 2024 +0000
@@ -0,0 +1,92 @@
+/*
+********************************************************************************
+*
+*      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             : pre_big.c
+*      Purpose          : Big subframe (2 subframes) preprocessing
+*
+********************************************************************************
+*/
+
+/*
+********************************************************************************
+*                         MODULE INCLUDE FILE AND VERSION ID
+********************************************************************************
+*/
+#include "namespace.h"
+#include "pre_big.h"
+ 
+/*
+********************************************************************************
+*                         INCLUDE FILES
+********************************************************************************
+*/
+#include "typedef.h"
+#include "basic_op.h"
+#include "oper_32b.h"
+#include "syn_filt.h"
+#include "weight_a.h"
+#include "residu.h"
+#include "no_count.h"
+#include "cnst.h"
+
+/*
+********************************************************************************
+*                         PUBLIC PROGRAM CODE
+********************************************************************************
+*/
+int pre_big(
+    enum Mode mode,            /* i  : coder mode                             */
+    const Word16 gamma1[],     /* i  : spectral exp. factor 1                 */
+    const Word16 gamma1_12k2[],/* i  : spectral exp. factor 1 for EFR         */
+    const Word16 gamma2[],     /* i  : spectral exp. factor 2                 */
+    Word16 A_t[],              /* i  : A(z) unquantized, for 4 subframes, Q12 */
+    Word16 frameOffset,        /* i  : Start position in speech vector,   Q0  */
+    Word16 speech[],           /* i  : speech,                            Q0  */
+    Word16 mem_w[],            /* i/o: synthesis filter memory state,     Q0  */
+    Word16 wsp[]               /* o  : weighted speech                    Q0  */
+)
+{
+   Word16 Ap1[MP1];            /* A(z) with spectral expansion         */
+   Word16 Ap2[MP1];            /* A(z) with spectral expansion         */
+   const Word16 *g1;           /* Pointer to correct gammma1 vector    */
+   Word16 aOffset;
+   Word16 i;
+   
+   test ();
+   if (sub (mode, MR795) <= 0 )
+   {
+       g1 = gamma1;                          move16 ();
+   }
+   else
+   {
+       g1 = gamma1_12k2;                     move16 ();
+   }
+
+   test ();
+   if (frameOffset > 0) {
+      aOffset = 2*MP1;                       move16 ();
+   }
+   else {
+      aOffset = 0;                           move16 ();
+   }
+
+   /* process two subframes (which form the "big" subframe) */
+   for (i = 0; i < 2; i++)
+   {
+       Weight_Ai(&A_t[aOffset], g1, Ap1);
+       Weight_Ai(&A_t[aOffset], gamma2, Ap2);
+       Residu(Ap1, &speech[frameOffset], &wsp[frameOffset], L_SUBFR);
+       
+       Syn_filt(Ap2, &wsp[frameOffset], &wsp[frameOffset], L_SUBFR, mem_w, 1);
+       aOffset = add (aOffset, MP1);
+       frameOffset = add (frameOffset, L_SUBFR);
+   }   
+
+   return 0;
+}