Отправлено SM 31 марта 2004 г. 20:50 В ответ на: Ответ: отправлено st256 31 марта 2004 г. 20:36

квантователь квантователю рознь... Я беру конкретный пример G.723.1 а например в простом GSM'e - так там вообще принцип возбуждения не такой, и сложный векторный квантователь не используется...

Вот он - этот МОНСТР. Причем далеко не весь, а кусочек :)))))

    /*-------------------------------------------------------------------
     * Search the optimum positions of the four  pulses which maximize
     *     square(correlation) / energy
     * The search is performed in four  nested loops. At each loop, one
     * pulse contribution is added to the correlation and energy.
     *
     * The fourth loop is entered only if the correlation due to the
     *  contribution of the first three pulses exceeds the preset
     *  threshold.
     */
    /*  Default values  */
    ip0    = 0;
    ip1    = 2;
    ip2    = 4;
    ip3    = 6;
    shif   = 0;
    psc    = (FLOAT)0.0;
    alpha  = (FLOAT)1.0;
    time   = max_time + extra;
    /*  Four loops to search innovation code. */
    /*  Init. pointers that depend on first loop  */
    ptr_ri0i0 = rri0i0;
    ptr_ri0i1 = rri0i1;
    ptr_ri0i2 = rri0i2;
    ptr_ri0i3 = rri0i3;
    /*  first pulse loop   */
    for (i0=0; i0 < SubFrLen; i0 +=STEP)
    {
        ps0  = Dn[i0];
        ps0a = Dn[i0+1];
        alp0 = *ptr_ri0i0++;
        /*  Init. pointers that depend on second loop */
        ptr_ri1i1 = rri1i1;
        ptr_ri1i2 = rri1i2;
        ptr_ri1i3 = rri1i3;
        /*  second pulse loop */
        for (i1=2; i1 < SubFrLen; i1 +=STEP)
        {
            ps1  = ps0 + Dn[i1];
            ps1a = ps0a + Dn[i1+1];
            alp1 = alp0 + *ptr_ri1i1++ + *ptr_ri0i1++;
            /*  Init. pointers that depend on third loop */
            ptr_ri2i2 = rri2i2;
            ptr_ri2i3 = rri2i3;
            /*  third pulse loop */
            for (i2 = 4; i2 < SubFrLen2; i2 +=STEP)
            {
                ps2  = ps1 + Dn[i2];
                ps2a = ps1a + Dn[i2+1];
                alp2 = alp1 + *ptr_ri2i2++ + *ptr_ri0i2++ + *ptr_ri1i2++;
                /*  Decide the shift */
                shift = 0;
                if (ps2a > ps2)
                {
                    shift = 1;
                    ps2   = ps2a;
                }
                /*  Test threshold  */
                if (ps2 > thres)
                {
                    /*  Init. pointers that depend on 4th loop */
                    ptr_ri3i3 = rri3i3;
                    /*  4th pulse loop */
                    for (i3 = 6; i3 < SubFrLen2; i3 +=STEP)
                    {
                        ps3 = ps2 + Dn[i3+shift];
                        alp3 = alp2 + *ptr_ri3i3++ +
                        *ptr_ri0i3++ + *ptr_ri1i3++ + *ptr_ri2i3++;
                        ps3c = ps3 * ps3;
                        if ((ps3c * alpha) > (psc * alp3))
                        {
                            psc = ps3c;
                            alpha = alp3;
                            ip0 = i0;
                            ip1 = i1;
                            ip2 = i2;
                            ip3 = i3;
                            shif = shift;
                        }
                    }
                    time--;
                    /*  Maximum time finish  */
                    if (time <= 0)
                        goto end_search;
                    ptr_ri0i3 -= NB_POS;
                    ptr_ri1i3 -= NB_POS;
                }
                else
                    ptr_ri2i3 += NB_POS;
            }
            ptr_ri0i2 -= NB_POS;
            ptr_ri1i3 += NB_POS;
        }
        ptr_ri0i2 += NB_POS;
        ptr_ri0i3 += NB_POS;
    }
end_search:
    extra = time;

• Ни хрена себе на ночь глядя... — st256   (31.03.2004 21:03, пустое)