--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/cl_ltp.h	Mon May 06 23:32:59 2024 +0000
@@ -0,0 +1,77 @@
+/*
+********************************************************************************
+*
+*      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             : cl_ltp.h
+*      Purpose          : Closed-loop fractional pitch search
+*
+********************************************************************************
+*/
+#ifndef cl_ltp_h
+#define cl_ltp_h "$Id $"
+ 
+/*
+********************************************************************************
+*                         INCLUDE FILES
+********************************************************************************
+*/
+#include "tw_amr.h"
+#include "typedef.h"
+#include "pitch_fr.h"
+#include "ton_stab.h"
+
+/*
+********************************************************************************
+*                         LOCAL VARIABLES AND TABLES
+********************************************************************************
+*/
+
+/*
+********************************************************************************
+*                         DEFINITION OF DATA TYPES
+********************************************************************************
+*/
+
+/* state variable */
+typedef struct {
+    Pitch_frState pitchSt;
+} clLtpState;
+
+/*
+********************************************************************************
+*                         DECLARATION OF PROTOTYPES
+********************************************************************************
+*/
+ 
+void cl_ltp_reset (clLtpState *st);
+/* reset of pre processing state (i.e. set state memory to zero)
+   returns 0 on success
+ */
+
+int cl_ltp(
+    clLtpState *clSt,    /* i/o : State struct                              */
+    tonStabState *tonSt, /* i/o : State struct                              */
+    enum Mode mode,      /* i   : coder mode                                */
+    Word16 frameOffset,  /* i   : Offset to subframe                        */
+    Word16 T_op[],       /* i   : Open loop pitch lags                      */
+    Word16 *h1,          /* i   : Impulse response vector               Q12 */
+    Word16 *exc,         /* i/o : Excitation vector                      Q0 */
+    Word16 res2[],       /* i/o : Long term prediction residual          Q0 */
+    Word16 xn[],         /* i   : Target vector for pitch search         Q0 */
+    Word16 lsp_flag,     /* i   : LSP resonance flag                        */
+    Word16 xn2[],        /* o   : Target vector for codebook search      Q0 */
+    Word16 y1[],         /* o   : Filtered adaptive excitation           Q0 */
+    Word16 *T0,          /* o   : Pitch delay (integer part)                */
+    Word16 *T0_frac,     /* o   : Pitch delay (fractional part)             */
+    Word16 *gain_pit,    /* o   : Pitch gain                            Q14 */
+    Word16 g_coeff[],    /* o   : Correlations between xn, y1, & y2         */
+    Word16 **anap,       /* o   : Analysis parameters                       */
+    Word16 *gp_limit     /* o   : pitch gain limit                          */
+);
+
+#endif