1*8ec969ceSTreehugger Robot /* 2*8ec969ceSTreehugger Robot * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische 3*8ec969ceSTreehugger Robot * Universitaet Berlin. See the accompanying file "COPYRIGHT" for 4*8ec969ceSTreehugger Robot * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. 5*8ec969ceSTreehugger Robot */ 6*8ec969ceSTreehugger Robot 7*8ec969ceSTreehugger Robot /* $Header: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/decode.c,v 1.1 1992/10/28 00:15:50 jutta Exp $ */ 8*8ec969ceSTreehugger Robot 9*8ec969ceSTreehugger Robot #include <stdio.h> 10*8ec969ceSTreehugger Robot 11*8ec969ceSTreehugger Robot #include "private.h" 12*8ec969ceSTreehugger Robot #include "gsm.h" 13*8ec969ceSTreehugger Robot #include "proto.h" 14*8ec969ceSTreehugger Robot 15*8ec969ceSTreehugger Robot /* 16*8ec969ceSTreehugger Robot * 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER 17*8ec969ceSTreehugger Robot */ 18*8ec969ceSTreehugger Robot 19*8ec969ceSTreehugger Robot static void Postprocessing P2((S,s), 20*8ec969ceSTreehugger Robot struct gsm_state * S, 21*8ec969ceSTreehugger Robot register word * s) 22*8ec969ceSTreehugger Robot { 23*8ec969ceSTreehugger Robot register int k; 24*8ec969ceSTreehugger Robot register word msr = S->msr; 25*8ec969ceSTreehugger Robot register longword ltmp; /* for GSM_ADD */ 26*8ec969ceSTreehugger Robot register word tmp; 27*8ec969ceSTreehugger Robot 28*8ec969ceSTreehugger Robot for (k = 160; k--; s++) { 29*8ec969ceSTreehugger Robot tmp = GSM_MULT_R( msr, 28180 ); 30*8ec969ceSTreehugger Robot msr = GSM_ADD(*s, tmp); /* Deemphasis */ 31*8ec969ceSTreehugger Robot *s = GSM_ADD(msr, msr) & 0xFFF8; /* Truncation & Upscaling */ 32*8ec969ceSTreehugger Robot } 33*8ec969ceSTreehugger Robot S->msr = msr; 34*8ec969ceSTreehugger Robot } 35*8ec969ceSTreehugger Robot 36*8ec969ceSTreehugger Robot void Gsm_Decoder P8((S,LARcr, Ncr,bcr,Mcr,xmaxcr,xMcr,s), 37*8ec969ceSTreehugger Robot struct gsm_state * S, 38*8ec969ceSTreehugger Robot 39*8ec969ceSTreehugger Robot word * LARcr, /* [0..7] IN */ 40*8ec969ceSTreehugger Robot 41*8ec969ceSTreehugger Robot word * Ncr, /* [0..3] IN */ 42*8ec969ceSTreehugger Robot word * bcr, /* [0..3] IN */ 43*8ec969ceSTreehugger Robot word * Mcr, /* [0..3] IN */ 44*8ec969ceSTreehugger Robot word * xmaxcr, /* [0..3] IN */ 45*8ec969ceSTreehugger Robot word * xMcr, /* [0..13*4] IN */ 46*8ec969ceSTreehugger Robot 47*8ec969ceSTreehugger Robot word * s) /* [0..159] OUT */ 48*8ec969ceSTreehugger Robot { 49*8ec969ceSTreehugger Robot int j, k; 50*8ec969ceSTreehugger Robot word erp[40], wt[160]; 51*8ec969ceSTreehugger Robot word * drp = S->dp0 + 120; 52*8ec969ceSTreehugger Robot 53*8ec969ceSTreehugger Robot for (j=0; j <= 3; j++, xmaxcr++, bcr++, Ncr++, Mcr++, xMcr += 13) { 54*8ec969ceSTreehugger Robot 55*8ec969ceSTreehugger Robot Gsm_RPE_Decoding( S, *xmaxcr, *Mcr, xMcr, erp ); 56*8ec969ceSTreehugger Robot Gsm_Long_Term_Synthesis_Filtering( S, *Ncr, *bcr, erp, drp ); 57*8ec969ceSTreehugger Robot 58*8ec969ceSTreehugger Robot for (k = 0; k <= 39; k++) wt[ j * 40 + k ] = drp[ k ]; 59*8ec969ceSTreehugger Robot } 60*8ec969ceSTreehugger Robot 61*8ec969ceSTreehugger Robot Gsm_Short_Term_Synthesis_Filter( S, LARcr, wt, s ); 62*8ec969ceSTreehugger Robot Postprocessing(S, s); 63*8ec969ceSTreehugger Robot } 64