FreeCalypso > hg > gsm-codec-lib
view libtwamr/memops.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 | 8dfb7cbe6b59 |
| children |
line wrap: on
line source
/* * The original code from ETSI uses its own Copy() and Set_zero() * functions, operating on Word16 elements. Here we implement them * as static inline functions wrapping around memcpy and memset. */ #include <string.h> static inline void Copy ( const Word16 x[], /* (i) : input vector */ Word16 y[], /* (o) : output vector */ Word16 L /* (i) : vector length */ ) { memcpy(y, x, L * 2); } static inline void Set_zero ( Word16 x[], /* (o) : vector to clear */ Word16 L /* (i) : length of vector */ ) { memset(x, 0, L * 2); }
