FreeCalypso > hg > gsm-codec-lib
view libtwamr/enc_main.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 | 4c9222d95647 |
| children |
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/* * This C module is the top level entity for our stateful encoder engine. */ #include <stdint.h> #include <stdlib.h> #include "tw_amr.h" #include "namespace.h" #include "typedef.h" #include "cnst.h" #include "cod_amr.h" #include "pre_proc.h" #include "sid_sync.h" #include "e_homing.h" struct amr_encoder_state { cod_amrState cod; Pre_ProcessState pre; sid_syncState sid; }; struct amr_encoder_state *amr_encoder_create(int dtx, int use_vad2) { struct amr_encoder_state *st; st = malloc(sizeof(struct amr_encoder_state)); if (st) amr_encoder_reset(st, dtx, use_vad2); return st; } void amr_encoder_reset(struct amr_encoder_state *st, int dtx, int use_vad2) { cod_amr_reset(&st->cod, dtx, use_vad2); Pre_Process_reset(&st->pre); sid_sync_reset(&st->sid); } void amr_encode_frame(struct amr_encoder_state *st, enum Mode mode, const int16_t *pcm, struct amr_param_frame *frame) { Word16 new_speech[L_FRAME], syn[L_FRAME]; enum Mode used_mode; enum TXFrameType tx_type; Word16 i; /* input */ for (i = 0; i < L_FRAME; i++) new_speech[i] = pcm[i] & 0xFFF8; Pre_Process(&st->pre, new_speech, L_FRAME); /* main process */ cod_amr(&st->cod, mode, new_speech, frame->param, &used_mode, syn); sid_sync(&st->sid, used_mode, &tx_type); frame->type = tx_type; frame->mode = mode; /* encoder homing */ if (encoder_homing_frame_test(pcm)) amr_encoder_reset(st, st->cod.dtx, st->cod.vadSt.use_vad2); }
