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view libtwamr/pre_big.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 38ee82480462
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             : pre_big.h
*      Purpose          : Big subframe (2 subframes) preprocessing
*
********************************************************************************
*/
#ifndef pre_big_h
#define pre_big_h "$Id $"

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

/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/

int pre_big(
    enum Mode mode,            /* i  : coder mode                             */
    const Word16 gamma1[],     /* i  : spectral exp. factor 1                 */
    const Word16 gamma1_12k2[],/* i  : spectral exp. factor 1 for EFR         */
    const Word16 gamma2[],     /* i  : spectral exp. factor 2                 */
    Word16 A_t[],              /* i  : A(z) unquantized, for 4 subframes, Q12 */
    Word16 frameOffset,        /* i  : Start position in speech vector,   Q0  */
    Word16 speech[],           /* i  : speech,                            Q0  */
    Word16 mem_w[],            /* i/o: synthesis filter memory state,     Q0  */
    Word16 wsp[]               /* o  : weighted speech                    Q0  */
);

#endif