FreeCalypso > hg > gsm-codec-lib
view libgsmfr2/ed_internal.h @ 581:e2d5cad04cbf
libgsmhr1 RxFE: store CN R0+LPC separately from speech
In the original GSM 06.06 code the ECU for speech mode is entirely
separate from the CN generator, maintaining separate state. (The
main intertie between them is the speech vs CN state variable,
distinguishing between speech and CN BFIs, in addition to the
CN-specific function of distinguishing between initial and update
SIDs.)
In the present RxFE implementation I initially thought that we could
use the same saved_frame buffer for both ECU and CN, overwriting
just the first 4 params (R0 and LPC) when a valid SID comes in.
However, I now realize it was a bad idea: the original code has a
corner case (long sequence of speech-mode BFIs to put the ECU in
state 6, then SID and CN-mode BFIs, then a good speech frame) that
would be broken by that buffer reuse approach. We could eliminate
this corner case by resetting the ECU state when passing through
a CN insertion period, but doing so would needlessly increase
the behavioral diffs between GSM 06.06 and our version.
Solution: use a separate CN-specific buffer for CN R0+LPC parameters,
and match the behavior of GSM 06.06 code in this regard.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Thu, 13 Feb 2025 10:02:45 +0000 |
parents | 8b21a6b7a3bf |
children |
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/* * This header file has been adapted from inc/private.h * in TU-Berlin libgsm source, original notice follows: * * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische * Universitaet Berlin. See the accompanying file "COPYRIGHT" for * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. */ #define SASR(x, by) ((x) >> (by)) /* * Prototypes from add.c */ extern word gsm_mult (word a, word b); extern longword gsm_L_mult (word a, word b); extern word gsm_mult_r (word a, word b); extern word gsm_div (word num, word denum); extern word gsm_add ( word a, word b ); extern longword gsm_L_add ( longword a, longword b ); extern word gsm_sub (word a, word b); extern longword gsm_L_sub (longword a, longword b); extern word gsm_abs (word a); extern word gsm_norm ( longword a ); extern longword gsm_L_asl (longword a, int n); extern word gsm_asl (word a, int n); extern longword gsm_L_asr (longword a, int n); extern word gsm_asr (word a, int n); /* * Inlined functions from add.h */ /* * #define GSM_MULT_R(a, b) (* word a, word b, !(a == b == MIN_WORD) *) \ * (0x0FFFF & SASR(((longword)(a) * (longword)(b) + 16384), 15)) */ #define GSM_MULT_R(a, b) /* word a, word b, !(a == b == MIN_WORD) */ \ (SASR( ((longword)(a) * (longword)(b) + 16384), 15 )) # define GSM_MULT(a,b) /* word a, word b, !(a == b == MIN_WORD) */ \ (SASR( ((longword)(a) * (longword)(b)), 15 )) # define GSM_L_MULT(a, b) /* word a, word b */ \ (((longword)(a) * (longword)(b)) << 1) # define GSM_L_ADD(a, b) \ ( (a) < 0 ? ( (b) >= 0 ? (a) + (b) \ : (utmp = (ulongword)-((a) + 1) + (ulongword)-((b) + 1)) \ >= MAX_LONGWORD ? MIN_LONGWORD : -(longword)utmp-2 ) \ : ((b) <= 0 ? (a) + (b) \ : (utmp = (ulongword)(a) + (ulongword)(b)) >= MAX_LONGWORD \ ? MAX_LONGWORD : utmp)) /* * # define GSM_ADD(a, b) \ * ((ltmp = (longword)(a) + (longword)(b)) >= MAX_WORD \ * ? MAX_WORD : ltmp <= MIN_WORD ? MIN_WORD : ltmp) */ /* Nonportable, but faster: */ #define GSM_ADD(a, b) \ ((ulongword)((ltmp = (longword)(a) + (longword)(b)) - MIN_WORD) > \ MAX_WORD - MIN_WORD ? (ltmp > 0 ? MAX_WORD : MIN_WORD) : ltmp) # define GSM_SUB(a, b) \ ((ltmp = (longword)(a) - (longword)(b)) >= MAX_WORD \ ? MAX_WORD : ltmp <= MIN_WORD ? MIN_WORD : ltmp) # define GSM_ABS(a) ((a) < 0 ? ((a) == MIN_WORD ? MAX_WORD : -(a)) : (a)) /* Use these if necessary: # define GSM_MULT_R(a, b) gsm_mult_r(a, b) # define GSM_MULT(a, b) gsm_mult(a, b) # define GSM_L_MULT(a, b) gsm_L_mult(a, b) # define GSM_L_ADD(a, b) gsm_L_add(a, b) # define GSM_ADD(a, b) gsm_add(a, b) # define GSM_SUB(a, b) gsm_sub(a, b) # define GSM_ABS(a) gsm_abs(a) */ /* * More prototypes from implementations.. */ void Gsm_Long_Term_Predictor ( /* 4x for 160 samples */ struct gsmfr_0610_state * S, word * d, /* [0..39] residual signal IN */ word * dp, /* [-120..-1] d' IN */ word * e, /* [0..40] OUT */ word * dpp, /* [0..40] OUT */ word * Nc, /* correlation lag OUT */ word * bc /* gain factor OUT */); void Gsm_LPC_Analysis ( struct gsmfr_0610_state * S, word * s, /* 0..159 signals IN/OUT */ word * LARc); /* 0..7 LARc's OUT */ void Gsm_Preprocess ( struct gsmfr_0610_state * S, const word * s, word * so); void Gsm_Encoding ( struct gsmfr_0610_state * S, word * e, word * ep, word * xmaxc, word * Mc, word * xMc); void Gsm_Short_Term_Analysis_Filter ( struct gsmfr_0610_state * S, const word * LARc, /* coded log area ratio [0..7] IN */ word * d /* st res. signal [0..159] IN/OUT */); void Gsm_Decoding ( struct gsmfr_0610_state * S, word xmaxcr, word Mcr, const word * xMcr, /* [0..12] IN */ word * erp); /* [0..39] OUT */ void Gsm_Long_Term_Synthesis_Filtering ( struct gsmfr_0610_state* S, word Ncr, word bcr, word * erp, /* [0..39] IN */ word * drp); /* [-120..-1] IN, [0..40] OUT */ void Gsm_RPE_Decoding ( struct gsmfr_0610_state *S, word xmaxcr, word Mcr, const word * xMcr, /* [0..12], 3 bits IN */ word * erp); /* [0..39] OUT */ void Gsm_RPE_Encoding ( struct gsmfr_0610_state * S, word * e, /* -5..-1][0..39][40..44 IN/OUT */ word * xmaxc, /* OUT */ word * Mc, /* OUT */ word * xMc); /* [0..12] OUT */ void Gsm_Short_Term_Synthesis_Filter ( struct gsmfr_0610_state * S, const word * LARcr, /* log area ratios [0..7] IN */ word * drp, /* received d [0...39] IN */ word * s); /* signal s [0..159] OUT */ void Gsm_Update_of_reconstructed_short_time_residual_signal ( word * dpp, /* [0...39] IN */ word * ep, /* [0...39] IN */ word * dp); /* [-120...-1] IN/OUT */ /* * Tables from table.c */ extern word gsm_A[8], gsm_B[8], gsm_MIC[8], gsm_MAC[8]; extern word gsm_INVA[8]; extern word gsm_DLB[4], gsm_QLB[4]; extern word gsm_H[11]; extern word gsm_NRFAC[8]; extern word gsm_FAC[8];