FreeCalypso > hg > gsm-codec-lib
view libtwamr/s10_8pf.h @ 604:54f0f1b74c25
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 | ebd064c52fe3 |
| 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 : s10_8pf.h * Purpose : Searches a 35/31 bit algebraic codebook containing * : 10/8 pulses in a frame of 40 samples. * ******************************************************************************** */ #ifndef s10_8pf_h #define s10_8pf_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" #include "cnst.h" /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ void search_10and8i40 ( Word16 nbPulse, /* i : nbpulses to find */ Word16 step, /* i : stepsize */ Word16 nbTracks, /* i : nbTracks */ Word16 dn[], /* i : correlation between target and h[] */ Word16 rr[][L_CODE], /* i : matrix of autocorrelation */ Word16 ipos[], /* i : starting position for each pulse */ Word16 pos_max[], /* i : position of maximum of dn[] */ Word16 codvec[] /* o : algebraic codebook vector */ ); #endif
