diff libtwamr/int_lsf.h @ 382:693ea1d5cf1e

libtwamr: integrate int_lsf.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 05:45:31 +0000
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtwamr/int_lsf.h	Mon May 06 05:45:31 2024 +0000
@@ -0,0 +1,63 @@
+/*
+********************************************************************************
+*
+*      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             : int_lsf.h
+*      Purpose          : Interpolates the LSFs
+*
+********************************************************************************
+*/
+#ifndef int_lsf_h
+#define int_lsf_h "$Id $"
+ 
+/*
+********************************************************************************
+*                         INCLUDE FILES
+********************************************************************************
+*/
+#include "typedef.h"
+ 
+/*
+********************************************************************************
+*                         DEFINITION OF DATA TYPES
+********************************************************************************
+*/
+ 
+/*
+********************************************************************************
+*                         DECLARATION OF PROTOTYPES
+********************************************************************************
+*/
+
+/*
+**************************************************************************
+*
+*  Function    : Int_lsf
+*  Purpose     : Interpolates the LSFs for selected subframe
+*  Description : The 20 ms speech frame is divided into 4 subframes.
+*                The LSFs are interpolated at the 1st, 2nd and 3rd
+*                subframe and only forwarded at the 4th subframe.
+*
+*                      |------|------|------|------|
+*                         sf1    sf2    sf3    sf4
+*                   F0                          F1
+*      
+*                 sf1:   3/4 F0 + 1/4 F1         sf3:   1/4 F0 + 3/4 F1
+*                 sf2:   1/2 F0 + 1/2 F1         sf4:       F1
+*  Returns     : void
+*
+**************************************************************************
+*/
+void Int_lsf (
+    Word16 lsf_old[], /* i : LSF vector at the 4th SF of past frame          */
+    Word16 lsf_new[], /* i : LSF vector at the 4th SF of present frame       */
+    Word16 i_subfr,   /* i : Pointer to current sf (equal to 0,40,80 or 120) */
+    Word16 lsf_out[]  /* o : interpolated LSF parameters for current sf      */
+);
+ 
+#endif