FreeCalypso > hg > gsm-codec-lib
view libgsmfr2/dec_main.c @ 282:9ee8ad3d4d30
frtest: rm gsmfr-hand-test and gsmfr-max-out utils
These hack programs were never properly documented and were written
only as part of a debug chase, in pursuit of a bug that ultimately
turned out to be in our then-hacky patch to osmo-bts-sysmo,
before beginning of proper patches in Osmocom. These hack programs
need to be dropped from the present sw package because they depend
on old libgsm, and we are eliminating that dependency.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sun, 14 Apr 2024 05:44:47 +0000 |
parents | 8821ffaa93a5 |
children |
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/* * This C source file has been adapted from TU-Berlin libgsm source * (src/decode.c), 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. */ #include <stdint.h> #include "tw_gsmfr.h" #include "typedef.h" #include "ed_state.h" #include "ed_internal.h" /* * 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER */ static void Postprocessing ( struct gsmfr_0610_state * S, register word * s) { register int k; register word msr = S->msr; register longword ltmp; /* for GSM_ADD */ register word tmp; for (k = 160; k--; s++) { tmp = GSM_MULT_R( msr, 28180 ); msr = GSM_ADD(*s, tmp); /* Deemphasis */ *s = GSM_ADD(msr, msr) & 0xFFF8; /* Truncation & Upscaling */ } S->msr = msr; } void gsmfr_0610_decode_params(struct gsmfr_0610_state *S, const struct gsmfr_param_frame *inp, int16_t *s) { int j, k; word erp[40], wt[160]; word * drp = S->dp0 + 120; for (j=0; j <= 3; j++) { Gsm_RPE_Decoding(S, inp->xmaxc[j], inp->Mc[j], inp->xMc[j], erp); Gsm_Long_Term_Synthesis_Filtering(S, inp->Nc[j], inp->bc[j], erp, drp); for (k = 0; k <= 39; k++) wt[ j * 40 + k ] = drp[ k ]; } Gsm_Short_Term_Synthesis_Filter(S, inp->LARc, wt, s); Postprocessing(S, s); }