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view libtwamr/d2_9pf.h @ 604:54f0f1b74c25

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libgsmhr1 TFO: require BFI=0 and SID=0 for homing In order for a received frame to be recognized as DHF, we need not only the correct bit pattern, but also BFI=0 and SID=0. The BFI=0 requirement should be obvious, while the SID=0 requirement is needed only for HR codec. With FR and EFR, SID classification comes from the payload bits and no separate check is needed - but in HR we get an out-of-band SID ternary flag. When SID=1, no payload bits are used at all; when SID=2, we use only the first 33 bits of the payload. Therefore, it is proper to conditionalize DHF acceptance on SID=0. We already implemented this logic in the just finished full decoder; now bring TFO code into agreement.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 04 Dec 2025 19:40:35 +0000
parents 2303ba1490dd
children
line wrap: on
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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             : d2_9pf.h
*      Purpose          : Algebraic codebook decoder
*
*****************************************************************************
*/
#ifndef d2_9pf_h
#define d2_9pf_h "$Id $"

/*
*****************************************************************************
*                         INCLUDE FILES
*****************************************************************************
*/
#include "typedef.h"

/*
*****************************************************************************
*                         LOCAL VARIABLES AND TABLES
*****************************************************************************
*/
 
/*
*****************************************************************************
*                         DEFINITION OF DATA TYPES
*****************************************************************************
*/

/*
*****************************************************************************
*                         DECLARATION OF PROTOTYPES
*****************************************************************************
*/
/*************************************************************************
 *
 *  FUNCTION:  decode_2i40_9bits (decod_ACELP())
 *
 *  PURPOSE:   Algebraic codebook decoder for 2 pulses coded with 9 bits
 *
 *************************************************************************/

void decode_2i40_9bits(
    Word16 subNr,  /* i : subframe number                          */
    Word16 sign,   /* i : signs of 2 pulses.                       */
    Word16 index,  /* i : Positions of the 2 pulses.               */
    Word16 cod[]   /* o : algebraic (fixed) codebook excitation    */
);

#endif