FreeCalypso > hg > gsm-codec-lib
view libgsmfr2/pp_state.c @ 605:63f774192906
gsmhr_decoder_twts002_in(): set BFI=1 SID=1 for invalid SID
When a received TW-TS-002 RTP payload indicates invalid SID,
which of the 3 possible BFI/SID combinations should we pass to
our internal ETSI-based speech decoder or TFO engine?
Our original code passed BFI=0 SID=1, but upon further reflection,
BFI=1 SID=1 is a better choice. In the corner case where received
invalid SID is fed to a full decoder in homed state, setting BFI=1
allows that decoder to emit zeros on PCM and stay homed, instead of
launching into full decoding.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Thu, 04 Dec 2025 21:01:46 +0000 |
| parents | 3a617e4e9b27 |
| children |
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/* * In this module we implement allocation and initialization * of state structures for our GSM FR preprocessor. */ #include <stdint.h> #include <stdlib.h> #include <string.h> #include "tw_gsmfr.h" #include "pp_state.h" const unsigned gsmfr_preproc_state_size = sizeof(struct gsmfr_preproc_state); struct gsmfr_preproc_state *gsmfr_preproc_create(void) { struct gsmfr_preproc_state *st; st = malloc(sizeof(struct gsmfr_preproc_state)); if (st) gsmfr_preproc_reset(st); return st; } void gsmfr_preproc_reset(struct gsmfr_preproc_state *st) { memset(st, 0, sizeof(struct gsmfr_preproc_state)); st->cn_random_lfsr = PN_INITIAL_SEED; }
