FreeCalypso > hg > gsm-codec-lib
view libtwamr/lsp_avg.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 | 9cd332a94c97 |
| children |
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/* ***************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ***************************************************************************** * * File : lsp_avg.c * Purpose: : LSP averaging and history * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "lsp_avg.h" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "basic_op.h" #include "oper_32b.h" #include "no_count.h" #include "q_plsf5_tab.h" #include "memops.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /* ************************************************************************** * * Function : lsp_avg_reset * Purpose : Resets state memory * ************************************************************************** */ void lsp_avg_reset (lsp_avgState *st) { Copy(mean_lsf, &st->lsp_meanSave[0], M); } /* ************************************************************************** * * Function : lsp_avg * Purpose : Calculate the LSP averages * ************************************************************************** */ void lsp_avg ( lsp_avgState *st, /* i/o : State struct Q15 */ Word16 *lsp /* i : state of the state machine Q15 */ ) { Word16 i; Word32 L_tmp; /* Q31 */ for (i = 0; i < M; i++) { /* mean = 0.84*mean */ L_tmp = L_deposit_h(st->lsp_meanSave[i]); L_tmp = L_msu(L_tmp, EXPCONST, st->lsp_meanSave[i]); /* Add 0.16 of newest LSPs to mean */ L_tmp = L_mac(L_tmp, EXPCONST, lsp[i]); /* Save means */ st->lsp_meanSave[i] = round(L_tmp); move16(); /* Q15 */ } return; }
