decld8cp.c

ITU-T G.729 Annex C+ - Reference C code for floating point implementation of G.729 at 6.4/8/11.8

        for(i=MP1; i<M_BWDP1; i++) prev_filter[i] = (F)0.;
    }

    /***************************/
    /* Processing active frame */
    /***************************/
    else {
        seed = INIT_SEED;
        
        /* ---------------------------- */
        /* LPC decoding in forward mode */
        /* ---------------------------- */
        if (lp_mode == 0) {

            /* Decode the LSPs */
            d_lspe(parm, lsp_new, bfi, freq_prev, prev_lsp, &prev_ma);
            parm += 2;
            if( prev_lp_mode == 0) { /* Interpolation of LPC for the 2 subframes */
                int_qlpc(lsp_old, lsp_new, A_t_fwd);
            }
            else {
                /* no interpolation */
                lsp_az(lsp_new, A_t_fwd);           /* Subframe 1*/
                copy(A_t_fwd, &A_t_fwd[MP1], MP1); /* Subframe 2 */
            }

            /* update the LSFs for the next frame */
            copy(lsp_new, lsp_old, M);

            c_int = (F)1.1;
            pA_t = A_t_fwd;
            m_aq = M;
            /* update the previous filter for the next frame */
            copy(&A_t_fwd[MP1], prev_filter, MP1);
            for(i=MP1; i<M_BWDP1; i++) prev_filter[i] = (F)0.;
        }
        else {
            int_bwd(A_t_bwd, prev_filter, &c_int);
            pA_t = A_t_bwd;
            m_aq = M_BWD;
            /* update the previous filter for the next frame */
            copy(&A_t_bwd[M_BWDP1], prev_filter, M_BWDP1);
        }

        /*------------------------------------------------------------------------*
        *          Loop for every subframe in the analysis frame                 *
        *------------------------------------------------------------------------*
        * The subframe size is L_SUBFR and the loop is repeated L_FRAME/L_SUBFR  *
        *  times                                                                 *
        *     - decode the pitch delay                                           *
        *     - decode algebraic code                                            *
        *     - decode pitch and codebook gains                                  *
        *     - find the excitation and compute synthesis speech                 *
        *------------------------------------------------------------------------*/

        for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR) {

            index = *parm++;            /* pitch index */

            if(i_subfr == 0) {

                if (rate == G729D)
                    i = 0;      /* no pitch parity at 6.4 kb/s */
                else
                    i = *parm++;             /* get parity check result */
                bad_pitch = bfi + i;     
                if( bad_pitch == 0) {
                    dec_lag3cp(index, PIT_MIN, PIT_MAX, i_subfr, &t0, &t0_frac, rate);
                    prev_t0 = t0;
                    prev_t0_frac = t0_frac;
                }
                else {                     /* Bad frame, or parity error */
                    if (bfi == 0) printf(" ! Wrong Pitch 1st subfr. !   ");
                    t0  =  prev_t0;
                    if (rate == G729E) {
                        t0_frac = prev_t0_frac;
                    }
                    else {
                        t0_frac = 0;
                        prev_t0++;
                        if(prev_t0 > PIT_MAX) {
                            prev_t0 = PIT_MAX;
                        }
                    }
                }
                *t0_first = t0;         /* If first frame */
            }
            else {                       /* second subframe */
                
                if( bfi == 0) {
                    dec_lag3cp(index, PIT_MIN, PIT_MAX, i_subfr, &t0, &t0_frac, rate);
                    prev_t0 = t0;
                    prev_t0_frac = t0_frac;
                }
                else {
                    t0  =  prev_t0;
                    if (rate == G729E) {
                        t0_frac = prev_t0_frac;
                    }
                    else {
                        t0_frac = 0;
                        prev_t0++;
                        if(prev_t0 > PIT_MAX) prev_t0 = PIT_MAX;
                    }
                }
            }
            /*-------------------------------------------------*
            * - Find the adaptive codebook vector.            *
            *-------------------------------------------------*/
            pred_lt_3(&exc[i_subfr], t0, t0_frac, L_SUBFR);
            
            /* --------------------------------- */
            /* pitch tracking for frame erasures */
            /* --------------------------------- */
            if( rate == G729E) {
                track_pit(&prev_t0, &prev_t0_frac, &prev_pitch, &stat_pitch,
                    &pitch_sta, &frac_sta);
            }
            else {
                i = prev_t0;
                j = prev_t0_frac;
                track_pit(&i, &j, &prev_pitch, &stat_pitch,
                    &pitch_sta, &frac_sta);
            }

            /*-------------------------------------------------------*
            * - Decode innovative codebook.                         *
            *-------------------------------------------------------*/
            if(bfi != 0) {        /* Bad frame */
                
                parm[0] = (int)random_g729c(&seed_fer);
                parm[1] = (int)random_g729c(&seed_fer);
                if (rate == G729E) {
                    parm[2] = (int)random_g729c(&seed_fer);
                    parm[3] = (int)random_g729c(&seed_fer);
                    parm[4] = (int)random_g729c(&seed_fer);
                }
                
            }
            
            stationnary = 0; /* to avoid visual warning */
            if (rate == G729) {
                /* case 8 kbps */
                decod_ACELP(parm[1], parm[0], code);
                parm += 2;
                /* for gain decoding in case of frame erasure */
                stat_bwd = 0;
                stationnary = 0;
            }
            else if (rate == G729D) {
                /* case 8 kbps */
                decod_ACELP64(parm[1], parm[0], code);
                parm += 2;
                /* for gain decoding in case of frame erasure */
                stat_bwd = 0;
                stationnary = 0;
            }
            else if (rate == G729E) {
                /* case 11.8 kbps */
                if (lp_mode == 0) {
                    dec_ACELP_10i40_35bits(parm, code);
                    /* for gain decoding in case of frame erasure */
                    stat_bwd = 0;
                    stationnary = 0;
                }
                else {
                    dec_ACELP_12i40_44bits(parm, code);
                    /* for gain decoding in case of frame erasure */
                    stat_bwd++;
                    if (stat_bwd >= 30) {
                        stationnary = 1;
                        stat_bwd = 30;
                    }
                    else stationnary = 0;
                }
                parm += 5;
            }
            
            /*-------------------------------------------------------*
            * - Add the fixed-gain pitch contribution to code[].    *
            *-------------------------------------------------------*/
            for (i = t0; i < L_SUBFR; i++)   code[i] += sharp * code[i-t0];

            /*-------------------------------------------------*
            * - Decode pitch and codebook gains.              *
            *-------------------------------------------------*/
            index = *parm++;      /* index of energy VQ */

            if (rate == G729D)
                dec_gain_6k(index, code, L_SUBFR, bfi, &gain_pitch, &gain_code);
            else
                dec_gaine(index, code, L_SUBFR, bfi, &gain_pitch, &gain_code, rate,
                gain_pit_mem, gain_cod_mem, &c_muting, count_bfi, stationnary);
            
                /*-------------------------------------------------------------*
                * - Update previous gains
            *-------------------------------------------------------------*/
            gain_pit_mem = gain_pitch;
            gain_cod_mem = gain_code;
            /*-------------------------------------------------------------*
            * - Update pitch sharpening "sharp" with quantized gain_pitch *
            *-------------------------------------------------------------*/
            sharp = gain_pitch;
            if (sharp > SHARPMAX) sharp = SHARPMAX;
            if (sharp < SHARPMIN) sharp = SHARPMIN;
            
            /*-------------------------------------------------------*
            * - Find the total excitation.                          *
            * - Find synthesis speech corresponding to exc[].       *
            *-------------------------------------------------------*/
            if(bfi != 0) {       /* Bad frame */
                count_bfi++;
                if (voicing == 0 ) {
                    g_p = (F)0.;
                    g_c = gain_code;
                }
                else {
                    g_p = gain_pitch;
                    g_c = (F)0.;
                }
            }
            else {
                g_p = gain_pitch;
                g_c = gain_code;
            }
        
            for (i = 0; i < L_SUBFR;  i++) {
                exc[i+i_subfr] = g_p * exc[i+i_subfr] + g_c * code[i];
            }
            
            if (rate == G729D) {
                PhDisp(&exc[i_subfr], exc_phdisp, gain_code, gain_pitch, code);
                syn_filte(m_aq, pA_t, exc_phdisp, &synth[i_subfr], L_SUBFR,
                                &mem_syn[M_BWD-m_aq], 0);
            }
            else {
                syn_filte(m_aq, pA_t, &exc[i_subfr], &synth[i_subfr], L_SUBFR,
                                    &mem_syn[M_BWD-m_aq], 0);

                /* Updates state machine for phase dispersion in
                6.4 kbps mode, if running at other rate */
                Update_PhDisp(gain_pitch, gain_code);
            }

            copy(&synth[i_subfr+L_SUBFR-M_BWD], mem_syn, M_BWD);

            pA_t += m_aq+1;    /* interpolated LPC parameters for next subframe */

        }

    }

    /*------------*
     *  For G729b
     *-----------*/
    if(bfi == 0) {
        sid_sav = (FLOAT)0.0;
        for(i=0; i<L_FRAME; i++) {
            sid_sav += exc[i] * exc[i];
        }
    }
    past_ftyp = ftyp;

    /*------------*
     *  For G729E
     *-----------*/
    energy = ener_dB(synth, L_FRAME);
    if (energy >= (F)40.) tst_bwd_dominant(bwd_dominant, lp_mode);

    /*--------------------------------------------------*
    * Update signal for next frame.                    *
    * -> shift to the left by L_FRAME  exc[]           *
    *--------------------------------------------------*/
    copy(&old_exc[L_FRAME], &old_exc[0], PIT_MAX+L_INTERPOL);

    if( lp_mode == 0) {
        copy(A_t_fwd, Az_dec, 2*MP1);
        *m_pst = M;
    }
    else {
        copy(A_t_bwd, Az_dec, 2*M_BWDP1);
        *m_pst = M_BWD;
    }
    
    prev_bfi     = bfi;
    prev_lp_mode    = lp_mode;
    prev_voicing = voicing;
    
    if (bfi != 0) c_fe = (F)1.;
    else {
        if (lp_mode == 0) c_fe = 0;
        else {
            if (*bwd_dominant == 1) c_fe -= (F)0.1;
            else c_fe -= (F)0.5;
            if (c_fe < 0)  c_fe= 0;
        }
    }
    
    return;
}