lsp.h

这是一个平台无关的标准C的AMR解码库

/*
********************************************************************************
*
*      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
********************************************************************************
*/
#ifdef __PRINT_TEST
#include <stdio.h>
#include <stdlib.h>
#endif //#ifdef __PRINT_TEST
#include "typedef.h"
#include "q_plsf.h"
#include "mode.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_init
*  Purpose     : Allocates memory and initializes state variables
*  Description : Stores pointer to filter status struct in *st. This
*                pointer has to be passed to lsp in each call.
*  Returns     : 0 on success
*
**************************************************************************
*/ 
int lsp_init (lspState **st);
 
/*
**************************************************************************
*
*  Function    : lsp_reset
*  Purpose     : Resets state memory
*  Returns     : 0 on success
*
**************************************************************************
*/
int lsp_reset (lspState *st);

/*
**************************************************************************
*
*  Function    : lsp_exit
*  Purpose     : The memory used for state memory is freed
*  Description : Stores NULL in *st
*
**************************************************************************
*/
void lsp_exit (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