FreeCalypso > hg > gsm-codec-lib

view libtwamr/sid_sync.h @ 604:54f0f1b74c25

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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 a8b73b1c5b19
children
line wrap: on
line source

/*
*****************************************************************************
*
*      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             : sid_sync.h
*      Purpose          : To ensure that the mode only switches to a
*                         neighbouring mode
*
*****************************************************************************
*/
#ifndef sid_sync_h
#define sid_sync_h "$Id $"
 
/*
*****************************************************************************
*                         INCLUDE FILES
*****************************************************************************
*/
#include "tw_amr.h"
#include "typedef.h"
 
/*
******************************************************************************
*                         CONSTANTS
******************************************************************************
*/

/*
******************************************************************************
*                         DEFINITION OF DATA TYPES
******************************************************************************
*/
typedef struct {
    Word16 sid_update_rate;  /* Send SID Update every sid_update_rate frame */
    Word16 sid_update_counter; /* Number of frames since last SID          */
    Word16 sid_handover_debt;  /* Number of extra SID_UPD frames to schedule*/
    enum TXFrameType prev_ft;
} sid_syncState;
 
/*
*****************************************************************************
*                         LOCAL VARIABLES AND TABLES
*****************************************************************************
*/
 
/*
*****************************************************************************
*                         DECLARATION OF PROTOTYPES
*****************************************************************************
*/
 
void sid_sync_reset (sid_syncState *st);
/* reset of sid_sync module (i.e. set state memory to zero)
   returns 0 on success
 */

int sid_sync_set_handover_debt (sid_syncState *st, /* i/o: sid_sync state  */
                                Word16 debtFrames);
/*  update handover debt 
    debtFrames extra SID_UPD are scheduled .
    to update remote decoder CNI states, right after an handover.
    (primarily for use on MS UL side )  
*/ 

void sid_sync(sid_syncState *st , /* i/o: sid_sync state      */
              enum Mode mode,
              enum TXFrameType *tx_frame_type); 

#endif