--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/lsp.h	Mon May 06 06:43:22 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.h
+*      Purpose          : Conversion from A(z) to LSP. Quantization and
+*                         interpolation of LSPs.
+*
+********************************************************************************
+*/
+#ifndef lsp_h
+#define lsp_h "$Id $"
+ 
+/*
+********************************************************************************
+*                         INCLUDE FILES
+********************************************************************************
+*/
+#include "tw_amr.h"
+#include "typedef.h"
+#include "q_plsf.h"
+
+/*
+********************************************************************************
+*                         LOCAL VARIABLES AND TABLES
+********************************************************************************
+*/
+
+/*
+********************************************************************************
+*                         DEFINITION OF DATA TYPES
+********************************************************************************
+*/
+typedef struct {
+   /* Past LSPs */
+   Word16 lsp_old[M];
+   Word16 lsp_old_q[M];
+
+   /* Quantization state */
+   Q_plsfState qSt;
+} lspState;
+
+/*
+********************************************************************************
+*                         DECLARATION OF PROTOTYPES
+********************************************************************************
+*/
+ 
+/*
+**************************************************************************
+*
+*  Function    : lsp_reset
+*  Purpose     : Resets state memory
+*  Returns     : 0 on success
+*
+**************************************************************************
+*/
+void lsp_reset (lspState *st);
+
+/*
+**************************************************************************
+*
+*  Function    : lsp
+*  Purpose     : Conversion from LP coefficients to LSPs.
+*                Quantization of LSPs.
+*  Description : Generates 2 sets of LSPs from 2 sets of
+*                LP coefficients for mode 12.2. For the other
+*                modes 1 set of LSPs is generated from 1 set of
+*                LP coefficients. These LSPs are quantized with
+*                Matrix/Vector quantization (depending on the mode)
+*                and interpolated for the subframes not yet having
+*                their own LSPs.
+*                
+**************************************************************************
+*/
+int lsp(lspState *st,        /* i/o : State struct                            */
+        enum Mode req_mode,  /* i   : requested coder mode                    */
+        enum Mode used_mode, /* i   : used coder mode                         */        
+        Word16 az[],         /* i/o : interpolated LP parameters Q12          */
+        Word16 azQ[],        /* o   : quantization interpol. LP parameters Q12*/
+        Word16 lsp_new[],    /* o   : new lsp vector                          */ 
+        Word16 **anap        /* o   : analysis parameters                     */
+        );
+
+#endif