FreeCalypso > hg > gsm-codec-lib
view libtwamr/inter_36.tab @ 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 | 838ed426bb76 |
| 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 : inter_36.tab * Purpose : Tables for interpolating the normalized correlation * with 1/3 or 1/6 resolution. * $Id $ * ******************************************************************************** */ #define FIR_SIZE (UP_SAMP_MAX*L_INTER_SRCH+1) /* 1/6 resolution interpolation filter (-3 dB at 3600 Hz) */ /* Note: The IS641 (7.4) 1/3 resolution filter is simply a subsampled version of the 1/6 resolution filter, i.e. it uses every second coefficient: inter_3[k] = inter_6[2*k], 0 <= k <= 3*L_INTER_SRCH */ static const Word16 inter_6[FIR_SIZE] = { 29519, 28316, 24906, 19838, 13896, 7945, 2755, -1127, -3459, -4304, -3969, -2899, -1561, -336, 534, 970, 1023, 823, 516, 220, 0, -131, -194, -215, 0 };