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.

/**************************************************************************
 *
 *   File Name:  e_homing.h
 *
 *   Purpose:   Contains the prototypes for all the functions of
 *              encoder homing.
 *
 **************************************************************************/

#define EHF_MASK 0x0008 /* Encoder Homing Frame pattern */

/* Function Prototypes */

Word16 encoder_homing_frame_test (const Word16 input_frame[]);

void encoder_reset (struct EFR_encoder_state *st);