sl@0: // Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: //
sl@0: 
sl@0: #include "rpeltp.h"
sl@0: #include "codec.h"
sl@0: #include "gsm610fr.h"
sl@0: 
sl@0: /*
sl@0: ** LPC analysis part of the RPE-LTP-coder
sl@0: **
sl@0: ** Input:
sl@0: **      sop[0..159]
sl@0: **              unprocessed sample frame 
sl@0: ** Output:
sl@0: **      d[0..159]
sl@0: **              residual 
sl@0: **      LARc[0..7]
sl@0: **              coded reflection coefficients 
sl@0: **      *SP_flag:
sl@0: **              decision of tx DTX (boolean)
sl@0: **      *VAD_flag:
sl@0: **              decision of VAD (boolean)
sl@0: **
sl@0: ** Return value:
sl@0: **      None
sl@0: */
sl@0: void LPC_analysis(CGSM610FR_Encoder* aEncoder, int2 ibuf[], struct codes *ecodes)
sl@0: {
sl@0: 
sl@0:   int4 L_ACF[9];
sl@0:   int2 LAR[8]; /* used for r[], LAR[], LARpp */
sl@0:   int2 rp[8]; /* used for LARp[], rp[] */
sl@0: //  int2 scalauto; /* returned from autoc to be used by vad */
sl@0: 
sl@0: 
sl@0:   prepr( aEncoder, ibuf, ibuf ); /* sof <- so */
sl@0:   preemp( aEncoder, ibuf, ibuf ); /* s <- sof */
sl@0: //  scalauto = autoc( L_ACF, ibuf ); /* L_ACF <- , s <- s */
sl@0:   autoc( L_ACF, ibuf ); /* L_ACF <- , s <- s */
sl@0: 
sl@0:   /*
sl@0:   ** VAD decision could be computed here when L_ACF and scalauto are available.
sl@0:   ** In current version vad is executed after LAR computation
sl@0:   */
sl@0: 
sl@0:   schur( LAR, L_ACF ); /* r <- L_ACF */
sl@0: 
sl@0:   larcomp( LAR, LAR ); /* LAR <- r */
sl@0: 
sl@0:   codlar( ecodes->LARc, LAR ); /* LARc <- LAR */
sl@0:   declar( LAR, ecodes->LARc ); /* LARpp <- LARc */
sl@0: 
sl@0:   cparc1( rp, aEncoder->LARpp_prev, LAR ); /* LARp <- LARpp_prev, LARpp */
sl@0:   crp( rp, rp ); /* rp <- LARp */
sl@0:   invfil( aEncoder, ibuf, ibuf, rp, 0, 12 ); /* d <- s */
sl@0: 
sl@0:   cparc2( rp, aEncoder->LARpp_prev, LAR ); /* LARp <- LARpp_prev, LARpp */
sl@0:   crp( rp, rp ); /* rp <- LARp */
sl@0:   invfil( aEncoder, ibuf, ibuf, rp, 13, 26 ); /* d <- s */
sl@0: 
sl@0:   cparc3( rp, aEncoder->LARpp_prev, LAR ); /* LARp <- LARpp_prev, LARpp */
sl@0:   crp( rp, rp ); /* rp <- LARp */
sl@0:   invfil( aEncoder, ibuf, ibuf, rp, 27, 39 ); /* d <- s*/
sl@0: 
sl@0:   cparc4( rp, aEncoder->LARpp_prev, LAR ); /* LARp <- LARpp_prev, LARpp */
sl@0:   crp( rp, rp ); /* rp <- LARp */
sl@0:   invfil( aEncoder, ibuf, ibuf, rp, 40, 159 ); /* d <- s */
sl@0:   return;
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** Encoding of the residual signal of the LPC analysis filter
sl@0: ** Input:
sl@0: **
sl@0: ** d[k_start..k_start+39]
sl@0: **      LPC residual (output of LPC analysis filter)
sl@0: **
sl@0: ** Output:
sl@0: **
sl@0: ** bc, Nc
sl@0: **      encoded LTP parameters (gain and lag)
sl@0: ** xmaxc
sl@0: **      block maximum of the encoded subframe.
sl@0: ** xMc[0..12]
sl@0: **              coded normalized RPE pulses
sl@0: **
sl@0: ** return xmax for SID computation
sl@0: */
sl@0: int2 residual_encoder( CGSM610FR_Encoder* aEncoder, int sf_nro, int2 d[], struct sfcodes *sfc )
sl@0: {
sl@0:   int k_start;
sl@0:   int2 xmax; /* return value */
sl@0: 
sl@0:   /* Note: d[] is used also for for x[] and e[] */
sl@0: 
sl@0:   int2 xM[13]; /* used for xM[], xMp[] */
sl@0:   /* xM[] is required simultaneously with xMc because LTP
sl@0:    * also decodes xMc
sl@0:    */
sl@0:   int2 dpp[40]; /* required simultaneously with ep[] that is
sl@0: 		 * stored into d[]
sl@0: 		 */
sl@0:   int2 Exp;
sl@0:   int2 mant;
sl@0: 
sl@0:   k_start = sf_nro * 40;
sl@0: 
sl@0:   ltpcomp( aEncoder, &(sfc->Nc), &(sfc->bc), d, k_start );
sl@0:   ltpfil( aEncoder, &d[k_start], dpp, d, sfc->bc, sfc->Nc, k_start ); /* e, dpp <- d */
sl@0:   weight( &d[k_start], &d[k_start] ); /* x <- e */
sl@0:   sfc->Mc = gridsel( xM, &d[k_start] ); /* xM <- x */
sl@0: 
sl@0:   /*
sl@0:   ** quatize residual and store unquantized xmax for SID
sl@0:   ** computation
sl@0:   */
sl@0:   xmax = apcm( &(sfc->xmaxc), xM, sfc->xMc, &Exp, &mant);
sl@0:   /* EXP, mant computed int APCM */
sl@0: 
sl@0:   iapcm( xM, sfc->xMc, Exp, mant ); /* xMp <- xMc */
sl@0:   gridpos( &d[k_start], xM, sfc->Mc ); /* ep <- xMc,Mc */
sl@0:   ltpupd( aEncoder, dpp, &d[k_start] ); /* dp <- dpp, x */
sl@0: 
sl@0:   return( xmax );
sl@0: }
sl@0: 
sl@0: 
sl@0: /*
sl@0: ** Decoding of the coded LPC-residual
sl@0: **
sl@0: ** Input:
sl@0: ** xmaxcr
sl@0: **      coded block maxmimum
sl@0: ** xMcr[0..12]
sl@0: **      coded normalized RPE pulses
sl@0: **
sl@0: ** Output:
sl@0: ** drp[k_start..k_start+39]
sl@0: **      decoded LPC residual (input signal for LPC-synthesis filter)
sl@0: */
sl@0: void residual_decoder(CGSM610FR_Decoder* aDecoder, int sf_nro, struct sfcodes *sfc, int2 wt[])
sl@0: {
sl@0:   int k_start;
sl@0: 
sl@0:   int2 EXP;
sl@0:   int2 mant;
sl@0:   int2 xMrp[13];
sl@0:   int2 erp[40];
sl@0: 
sl@0:   k_start = sf_nro * 40;
sl@0: 
sl@0:   /* in decoder EXP ja mant must be computed from xmaxcr */
sl@0:   expman( &EXP, &mant, sfc->xmaxc ); /* EXP, mant <- xmaxc */
sl@0:   iapcm( xMrp, sfc->xMc, EXP, mant ); /* xMrp <- xMc */
sl@0:   gridpos( erp, xMrp, sfc->Mc ); /* erp <- xMc,Mc */
sl@0: 	
sl@0:   ltpsyn( aDecoder, erp, &wt[k_start], sfc->bc, sfc->Nc );
sl@0: }
sl@0: 
sl@0: /*
sl@0: ** LPC synthesis part of the RPE-LTP-coder
sl@0: **
sl@0: ** Input:
sl@0: **      LARcr[0..7]
sl@0: **              coded reflection coefficients
sl@0: **      wt[0..159]
sl@0: **              decoded residual
sl@0: **
sl@0: ** Output:
sl@0: **      srop[0..159]
sl@0: **              decoded speech
sl@0: */
sl@0: void LPC_synthesis(CGSM610FR_Decoder* aDecoder, struct codes *dcodes, int2 wt[], int2 obuf[])
sl@0: {
sl@0:   int2 LARr[8]; /* used for LARr[], LARpp */
sl@0:   int2 rrp[8]; /* used for LARp[], rrp[] */
sl@0: 
sl@0:   declar(LARr, dcodes->LARc); /* LARrpp <- LARc */
sl@0: 
sl@0:   cparc1( rrp, aDecoder->LARrpp_prev, LARr ); /* LARp <- LARrpp_prev, LARr */
sl@0:   crp( rrp, rrp ); /* rrp <- LARp */
sl@0:   synfil( aDecoder, obuf, wt, rrp, 0, 12 ); /* sr <- wt */
sl@0: 
sl@0:   cparc2( rrp, aDecoder->LARrpp_prev, LARr ); /* LARp <- LARrpp_prev, LARr */
sl@0:   crp( rrp, rrp ); /* rrp <- LARp */
sl@0:   synfil( aDecoder, obuf, wt, rrp, 13, 26 ); /* sr <- wt */
sl@0: 
sl@0:   cparc3( rrp, aDecoder->LARrpp_prev, LARr ); /* LARp <- LARrpp_prev, LARr */
sl@0:   crp( rrp, rrp ); /* rrp <- LARp */
sl@0:   synfil( aDecoder, obuf, wt, rrp, 27, 39 ); /* sr <- wt */
sl@0: 
sl@0:   cparc4( rrp, aDecoder->LARrpp_prev, LARr ); /* LARp <- LARrpp_prev, LARr */
sl@0:   crp( rrp, rrp ); /* rrp <- LARp */
sl@0:   synfil( aDecoder, obuf, wt, rrp, 40, 159 ); /* sr <- wt */
sl@0:   postpr( aDecoder, obuf, obuf );
sl@0:   /* combines deemphasis, upscaling and truncation */
sl@0: 
sl@0: }
sl@0: 
sl@0: 
sl@0: /*
sl@0: ** RPE-LTP Encoder
sl@0: **
sl@0: ** void RPELTP_encoder(CGSM610FR_Encoder* aEncoder, int2 ibuf[], struct codes *ecodes)
sl@0: **
sl@0: ** Input:
sl@0: **      ibuf[0..159]
sl@0: **              Original speech to be coded
sl@0: **
sl@0: ** Output:
sl@0: **      ecodes
sl@0: **              encoded speech stored as codewords
sl@0: */
sl@0: void RPELTP_encoder(CGSM610FR_Encoder* aEncoder, int2 ibuf[], struct codes *ecodes)
sl@0: {
sl@0:   int i;
sl@0: //  int2 xmax[4]; /* collect unquantized xmax data for dtx */	
sl@0: 
sl@0:   LPC_analysis( aEncoder, ibuf, ecodes );
sl@0:   for (i = 0; i < 4; i++)
sl@0: //    xmax[i] = residual_encoder( aEncoder, i, ibuf, &(ecodes->sfc[i]) );	
sl@0:     residual_encoder( aEncoder, i, ibuf, &(ecodes->sfc[i]) );
sl@0: }
sl@0: 
sl@0: 
sl@0: /*
sl@0: ** RPE-LTP Decoder
sl@0: **
sl@0: ** void RPELTP_decoder(struct codes *dcodes, int2 obuf[])
sl@0: ** Input:
sl@0: **      dcodes
sl@0: **              encoded speech stored as codewords to be decoded
sl@0: **
sl@0: ** Output:
sl@0: **      obuf[0..159]
sl@0: **              Decoded speech
sl@0: */
sl@0: void RPELTP_decoder(CGSM610FR_Decoder* aDecoder, struct codes *dcodes, int2 obuf[])
sl@0: {
sl@0:   int i;
sl@0: 
sl@0:   dcodes->LARc[0] &= 0x7fff; /* VAD flag in sequences */
sl@0:   dcodes->LARc[1] &= 0x7fff; /* SP flag in sequences */
sl@0: 
sl@0:   for (i = 0; i < 4; i++)
sl@0:     residual_decoder(aDecoder, i, &(dcodes->sfc[i]), obuf); /* -> wt */
sl@0: 
sl@0:   LPC_synthesis(aDecoder, dcodes, obuf, obuf); /* wt -> srop */
sl@0: }
sl@0: