ref: e81132de6cd16b432e6a14bb0c4a1f8e2c01a1ae
dir: /src/libgsm/decode.c/
/* * 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. */ /* $Header: /cvsroot/sox/sox/src/libgsm/Attic/decode.c,v 1.4 2007/01/29 03:09:32 cbagwell Exp $ */ #include <stdio.h> #include "private.h" #include "gsm.h" /* * 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER */ static void Postprocessing ( struct gsm_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 Gsm_Decoder ( struct gsm_state * S, word * LARcr, /* [0..7] IN */ word * Ncr, /* [0..3] IN */ word * bcr, /* [0..3] IN */ word * Mcr, /* [0..3] IN */ word * xmaxcr, /* [0..3] IN */ word * xMcr, /* [0..13*4] IN */ word * s) /* [0..159] OUT */ { int j, k; word erp[40], wt[160]; word * drp = S->dp0 + 120; for (j=0; j <= 3; j++, xmaxcr++, bcr++, Ncr++, Mcr++, xMcr += 13) { Gsm_RPE_Decoding( S, *xmaxcr, *Mcr, xMcr, erp ); Gsm_Long_Term_Synthesis_Filtering( S, *Ncr, *bcr, erp, drp ); for (k = 0; k <= 39; k++) wt[ j * 40 + k ] = drp[ k ]; } Gsm_Short_Term_Synthesis_Filter( S, LARcr, wt, s ); Postprocessing(S, s); }