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view libtwamr/d1035pf.c @ 477:4c9222d95647

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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 2cf33c211544
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             : d1035pf.c
*      Purpose          : Builds the innovative codevector
*
********************************************************************************
*/
 
 
/*
********************************************************************************
*                         MODULE INCLUDE FILE AND VERSION ID
********************************************************************************
*/
#include "namespace.h"
#include "d1035pf.h"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
#include "basic_op.h"
#include "no_count.h"
#include "cnst.h"
#include "graytab.h"

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/
#define NB_PULSE  10            /* number of pulses  */

/*
********************************************************************************
*                         PUBLIC PROGRAM CODE
********************************************************************************
*/
/*************************************************************************
 *
 *  FUNCTION:   dec_10i40_35bits()
 *
 *  PURPOSE:  Builds the innovative codevector from the received
 *            index of algebraic codebook.
 *
 *   See  c1035pf.c  for more details about the algebraic codebook structure.
 *
 *************************************************************************/
void dec_10i40_35bits (
    Word16 index[],    /* (i)     : index of 10 pulses (sign+position)       */
    Word16 cod[]       /* (o)     : algebraic (fixed) codebook excitation    */
)
{
    Word16 i, j, pos1, pos2, sign, tmp;

    for (i = 0; i < L_CODE; i++)
    {
        cod[i] = 0;                                     move16 (); 
    }

    /* decode the positions and signs of pulses and build the codeword */

    for (j = 0; j < NB_TRACK; j++)
    {
        /* compute index i */

        tmp = index[j];                                 move16 ();
        i = tmp & 7;                                    logic16 (); 
        i = dgray[i];                                   move16 (); 

        i = extract_l (L_shr (L_mult (i, 5), 1));
        pos1 = add (i, j); /* position of pulse "j" */

        i = shr (tmp, 3) & 1;                           logic16 (); 
        test (); 
        if (i == 0)
        {
            sign = 4096;                                move16 (); /* +1.0 */
        }
        else
        {
            sign = -4096;                               move16 (); /* -1.0 */
        }

        cod[pos1] = sign;                               move16 (); 

        /* compute index i */

        i = index[add (j, 5)] & 7;                      logic16 (); 
        i = dgray[i];                                   move16 (); 
        i = extract_l (L_shr (L_mult (i, 5), 1));

        pos2 = add (i, j);      /* position of pulse "j+5" */

        test (); 
        if (sub (pos2, pos1) < 0)
        {
            sign = negate (sign);
        }
        cod[pos2] = add (cod[pos2], sign);              move16 (); 
    }

    return;
}