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view libtwamr/bits2prm.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 f931e704adc5
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             : bits2prm.h
*      Purpose          : Retrieves the vector of encoder parameters from 
*                       : the received serial bits in a frame.
*
*****************************************************************************
*/
#ifndef bits2prm_h
#define bits2prm_h "$Id $"
 
/*
*****************************************************************************
*                         INCLUDE FILES
*****************************************************************************
*/
#include "typedef.h"
#include "tw_amr.h"	/* for enum Mode */
/*
*****************************************************************************
*                         DEFINITION OF DATA TYPES
*****************************************************************************
*/
 
/*
*****************************************************************************
*                         DECLARATION OF PROTOTYPES
*****************************************************************************
*/
/*
**************************************************************************
*
*  Function    : Bits2prm
*  Purpose     : Retrieves the vector of encoder parameters from 
*                the received serial bits in a frame.
*  Returns     : void
*
**************************************************************************
*/
void Bits2prm (
    enum Mode mode,
    const Word16 bits[],   /* input : serial bits (max 244)        */
    Word16 prm[]           /* output: analysis parameters (max 57) */
);
 
#endif