view libtwamr/lsp.h @ 477:4c9222d95647

libtwamr encoder: always emit frame->mode = mode; In the original implementation of amr_encode_frame(), the 'mode' member of the output struct was set to 0xFF if the output frame type is TX_NO_DATA. This design was made to mimic the mode field (16-bit word) being set to 0xFFFF (or -1) in 3GPP test sequence format - but nothing actually depends on this struct member being set in any way, and amr_frame_to_tseq() generates the needed 0xFFFF on its own, based on frame->type being equal to TX_NO_DATA. It is simpler and more efficient to always set frame->mode to the actual encoding mode in amr_encode_frame(), and this new behavior has already been documented in doc/AMR-library-API description in anticipation of the present change.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 18 May 2024 22:30:42 +0000
parents 550d3594c878
children
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/*
********************************************************************************
*
*      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