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.

/*
 * We implement a couple of helper functions on top of the WAV reader
 * which we've lifted out of opencore-amrnb test code; this header file
 * provides prototype declarations for these functions.
 */

extern int wavrd_check_header(void *wav, const char *filename);
extern int wavrd_get_pcm_block(void *wav, int16_t *pcmbuf);