--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/dec_lag3.h	Sun May 05 22:29:09 2024 +0000
@@ -0,0 +1,69 @@
+/*
+********************************************************************************
+*
+*      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             : dec_lag3.h
+*      Purpose          : Decoding of fractional pitch lag with 1/3 resolution.
+*                         Extract the integer and fraction parts of the pitch lag from
+*                         the received adaptive codebook index.
+*
+********************************************************************************
+*/
+#ifndef dec_lag3_h
+#define dec_lag3_h "$Id $"
+
+/*
+********************************************************************************
+*                         INCLUDE FILES
+********************************************************************************
+*/
+#include "typedef.h"
+
+/*
+********************************************************************************
+*                         LOCAL VARIABLES AND TABLES
+********************************************************************************
+*/
+
+/*
+********************************************************************************
+*                         DEFINITION OF DATA TYPES
+********************************************************************************
+*/
+
+/*
+********************************************************************************
+*                         DECLARATION OF PROTOTYPES
+********************************************************************************
+*/
+/*************************************************************************
+ *   FUNCTION:   Dec_lag3
+ *
+ *   PURPOSE:  Decoding of fractional pitch lag with 1/3 resolution.
+ *             Extract the integer and fraction parts of the pitch lag from
+ *             the received adaptive codebook index.
+ *
+ *    See "Enc_lag3.c" for more details about the encoding procedure.
+ *
+ *    The fractional lag in 1st and 3rd subframes is encoded with 8 bits
+ *    while that in 2nd and 4th subframes is relatively encoded with 4, 5
+ *    and 6 bits depending on the mode.
+ *
+ *************************************************************************/
+void Dec_lag3(Word16 index,     /* i : received pitch index                 */
+              Word16 T0_min,    /* i : minimum of search range              */
+              Word16 T0_max,    /* i : maximum of search range              */
+              Word16 i_subfr,   /* i : subframe flag                        */
+              Word16 T0_prev,   /* i : integer pitch delay of last subframe
+                                       used in 2nd and 4th subframes        */
+              Word16 * T0,      /* o : integer part of pitch lag            */ 
+              Word16 * T0_frac, /* o : fractional part of pitch lag         */
+              Word16 flag4      /* i : flag for encoding with 4 bits        */
+              );
+
+#endif