/*

 * SpanDSP - a series of DSP components for telephony

 *

 * g722_encode.c - The ITU G.722 codec, encode part.

 *

 * Written by Steve Underwood <steveu@coppice.org>

 *

 * Copyright (C) 2005 Steve Underwood

 *

 * All rights reserved.

 *

 *  Despite my general liking of the GPL, I place my own contributions 

 *  to this code in the public domain for the benefit of all mankind -

 *  even the slimy ones who might try to proprietize my work and use it

 *  to my detriment.

 *

 * Based on a single channel 64kbps only G.722 codec which is:

 *

 *****    Copyright (c) CMU    1993      *****

 * Computer Science, Speech Group

 * Chengxiang Lu and Alex Hauptmann

 *

 * $Id: g722_encode.c 48661 2006-12-21 00:08:21Z mattf $

 */

/*! \file */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdio.h>

//#include <inttypes.h>

#include <memory.h>

#include <stdlib.h>

#if 0

#include <tgmath.h>

#endif

#include "g722.h"

#if !defined(FALSE)

#define FALSE 0

#endif

#if !defined(TRUE)

#define TRUE (!FALSE)

#endif

static int16_t saturate(int32_t amp)

{

    int16_t amp16;

    /* Hopefully this is optimised for the common case - not clipping */

    amp16 = (int16_t) amp;

    if (amp == amp16)

        return amp16;

    if (amp > INT16_MAX)

        return  INT16_MAX;

    return  INT16_MIN;

}

/*- End of function --------------------------------------------------------*/

static void block4(g722_encode_state_t *s, int band, int d)

{

    int wd1;

    int wd2;

    int wd3;

    int i;

    /* Block 4, RECONS */

    s->band[band].d[0] = d;

    s->band[band].r[0] = saturate(s->band[band].s + d);

    /* Block 4, PARREC */

    s->band[band].p[0] = saturate(s->band[band].sz + d);

    /* Block 4, UPPOL2 */

    for (i = 0;  i < 3;  i++)

        s->band[band].sg[i] = s->band[band].p[i] >> 15;

    wd1 = saturate(s->band[band].a[1] << 2);

    wd2 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  -wd1  :  wd1;

    if (wd2 > 32767)

        wd2 = 32767;

    wd3 = (wd2 >> 7) + ((s->band[band].sg[0] == s->band[band].sg[2])  ?  128  :  -128);

    wd3 += (s->band[band].a[2]*32512) >> 15;

    if (wd3 > 12288)

        wd3 = 12288;

    else if (wd3 < -12288)

        wd3 = -12288;

    s->band[band].ap[2] = wd3;

    /* Block 4, UPPOL1 */

    s->band[band].sg[0] = s->band[band].p[0] >> 15;

    s->band[band].sg[1] = s->band[band].p[1] >> 15;

    wd1 = (s->band[band].sg[0] == s->band[band].sg[1])  ?  192  :  -192;

    wd2 = (s->band[band].a[1]*32640) >> 15;

    s->band[band].ap[1] = saturate(wd1 + wd2);

    wd3 = saturate(15360 - s->band[band].ap[2]);

    if (s->band[band].ap[1] > wd3)

        s->band[band].ap[1] = wd3;

    else if (s->band[band].ap[1] < -wd3)

        s->band[band].ap[1] = -wd3;

    /* Block 4, UPZERO */

    wd1 = (d == 0)  ?  0  :  128;

    s->band[band].sg[0] = d >> 15;

    for (i = 1;  i < 7;  i++)

    {

        s->band[band].sg[i] = s->band[band].d[i] >> 15;

        wd2 = (s->band[band].sg[i] == s->band[band].sg[0])  ?  wd1  :  -wd1;

        wd3 = (s->band[band].b[i]*32640) >> 15;

        s->band[band].bp[i] = saturate(wd2 + wd3);

    }

    /* Block 4, DELAYA */

    for (i = 6;  i > 0;  i--)

    {

        s->band[band].d[i] = s->band[band].d[i - 1];

        s->band[band].b[i] = s->band[band].bp[i];

    }

    for (i = 2;  i > 0;  i--)

    {

        s->band[band].r[i] = s->band[band].r[i - 1];

        s->band[band].p[i] = s->band[band].p[i - 1];

        s->band[band].a[i] = s->band[band].ap[i];

    }

    /* Block 4, FILTEP */

    wd1 = saturate(s->band[band].r[1] + s->band[band].r[1]);

    wd1 = (s->band[band].a[1]*wd1) >> 15;

    wd2 = saturate(s->band[band].r[2] + s->band[band].r[2]);

    wd2 = (s->band[band].a[2]*wd2) >> 15;

    s->band[band].sp = saturate(wd1 + wd2);

    /* Block 4, FILTEZ */

    s->band[band].sz = 0;

    for (i = 6;  i > 0;  i--)

    {

        wd1 = saturate(s->band[band].d[i] + s->band[band].d[i]);

        s->band[band].sz += (s->band[band].b[i]*wd1) >> 15;

    }

    s->band[band].sz = saturate(s->band[band].sz);

    /* Block 4, PREDIC */

    s->band[band].s = saturate(s->band[band].sp + s->band[band].sz);

}

/*- End of function --------------------------------------------------------*/

g722_encode_state_t *g722_encode_init(g722_encode_state_t *s, int rate, int options)

{

    if (s == NULL)

    {

        if ((s = (g722_encode_state_t *) malloc(sizeof(*s))) == NULL)

            return NULL;

    }

    memset(s, 0, sizeof(*s));

    if (rate == 48000)

        s->bits_per_sample = 6;

    else if (rate == 56000)

        s->bits_per_sample = 7;

    else

        s->bits_per_sample = 8;

    if ((options & G722_SAMPLE_RATE_8000))

        s->eight_k = TRUE;

    if ((options & G722_PACKED)  &&  s->bits_per_sample != 8)

        s->packed = TRUE;

    else

        s->packed = FALSE;

    s->band[0].det = 32;

    s->band[1].det = 8;

    return s;

}

/*- End of function --------------------------------------------------------*/

int g722_encode_release(g722_encode_state_t *s)

{

    free(s);

    return 0;

}

/*- End of function --------------------------------------------------------*/

int g722_encode(g722_encode_state_t *s, uint8_t g722_data[], const int16_t amp[], int len)

{

    static const int q6[32] =

    {

           0,   35,   72,  110,  150,  190,  233,  276,

         323,  370,  422,  473,  530,  587,  650,  714,

         786,  858,  940, 1023, 1121, 1219, 1339, 1458,

        1612, 1765, 1980, 2195, 2557, 2919,    0,    0

    };

    static const int iln[32] =

    {

         0, 63, 62, 31, 30, 29, 28, 27,

        26, 25, 24, 23, 22, 21, 20, 19,

        18, 17, 16, 15, 14, 13, 12, 11,

        10,  9,  8,  7,  6,  5,  4,  0

    };

    static const int ilp[32] =

    {

         0, 61, 60, 59, 58, 57, 56, 55,

        54, 53, 52, 51, 50, 49, 48, 47,

        46, 45, 44, 43, 42, 41, 40, 39,

        38, 37, 36, 35, 34, 33, 32,  0

    };

    static const int wl[8] =

    {

        -60, -30, 58, 172, 334, 538, 1198, 3042

    };

    static const int rl42[16] =

    {

        0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 0

    };

    static const int ilb[32] =

    {

        2048, 2093, 2139, 2186, 2233, 2282, 2332,

        2383, 2435, 2489, 2543, 2599, 2656, 2714,

        2774, 2834, 2896, 2960, 3025, 3091, 3158,

        3228, 3298, 3371, 3444, 3520, 3597, 3676,

        3756, 3838, 3922, 4008

    };

    static const int qm4[16] =

    {

             0, -20456, -12896, -8968,

         -6288,  -4240,  -2584, -1200,

         20456,  12896,   8968,  6288,

          4240,   2584,   1200,     0

    };

    static const int qm2[4] =

    {

        -7408,  -1616,   7408,   1616

    };

    static const int qmf_coeffs[12] =

    {

           3,  -11,   12,   32, -210,  951, 3876, -805,  362, -156,   53,  -11,

    };

    static const int ihn[3] = {0, 1, 0};

    static const int ihp[3] = {0, 3, 2};

    static const int wh[3] = {0, -214, 798};

    static const int rh2[4] = {2, 1, 2, 1};

    int dlow;

    int dhigh;

    int el;

    int wd;

    int wd1;

    int ril;

    int wd2;

    int il4;

    int ih2;

    int wd3;

    int eh;

    int mih;

    int i;

    int j;

    /* Low and high band PCM from the QMF */

    int xlow;

    int xhigh;

    int g722_bytes;

    /* Even and odd tap accumulators */

    int sumeven;

    int sumodd;

    int ihigh;

    int ilow;

    int code;

    g722_bytes = 0;

    xhigh = 0;

    for (j = 0;  j < len;  )

    {

        if (s->itu_test_mode)

        {

            xlow =

            xhigh = amp[j++] >> 1;

        }

        else

        {

            if (s->eight_k)

            {

                xlow = amp[j++];

            }

            else

            {

                /* Apply the transmit QMF */

                /* Shuffle the buffer down */

                for (i = 0;  i < 22;  i++)

                    s->x[i] = s->x[i + 2];

                s->x[22] = amp[j++];

                s->x[23] = amp[j++];

                /* Discard every other QMF output */

                sumeven = 0;

                sumodd = 0;

                for (i = 0;  i < 12;  i++)

                {

                    sumodd += s->x[2*i]*qmf_coeffs[i];

                    sumeven += s->x[2*i + 1]*qmf_coeffs[11 - i];

                }

                xlow = (sumeven + sumodd) >> 13;

                xhigh = (sumeven - sumodd) >> 13;

            }

        }

        /* Block 1L, SUBTRA */

        el = saturate(xlow - s->band[0].s);

        /* Block 1L, QUANTL */

        wd = (el >= 0)  ?  el  :  -(el + 1);

        for (i = 1;  i < 30;  i++)

        {

            wd1 = (q6[i]*s->band[0].det) >> 12;

            if (wd < wd1)

                break;

        }

        ilow = (el < 0)  ?  iln[i]  :  ilp[i];

        /* Block 2L, INVQAL */

        ril = ilow >> 2;

        wd2 = qm4[ril];

        dlow = (s->band[0].det*wd2) >> 15;

        /* Block 3L, LOGSCL */

        il4 = rl42[ril];

        wd = (s->band[0].nb*127) >> 7;

        s->band[0].nb = wd + wl[il4];

        if (s->band[0].nb < 0)

            s->band[0].nb = 0;

        else if (s->band[0].nb > 18432)

            s->band[0].nb = 18432;

        /* Block 3L, SCALEL */

        wd1 = (s->band[0].nb >> 6) & 31;

        wd2 = 8 - (s->band[0].nb >> 11);

        wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);

        s->band[0].det = wd3 << 2;

        block4(s, 0, dlow);

        if (s->eight_k)

        {

            /* Just leave the high bits as zero */

            code = (0xC0 | ilow) >> (8 - s->bits_per_sample);

        }

        else

        {

            /* Block 1H, SUBTRA */

            eh = saturate(xhigh - s->band[1].s);

            /* Block 1H, QUANTH */

            wd = (eh >= 0)  ?  eh  :  -(eh + 1);

            wd1 = (564*s->band[1].det) >> 12;

            mih = (wd >= wd1)  ?  2  :  1;

            ihigh = (eh < 0)  ?  ihn[mih]  :  ihp[mih];

            /* Block 2H, INVQAH */

            wd2 = qm2[ihigh];

            dhigh = (s->band[1].det*wd2) >> 15;

            /* Block 3H, LOGSCH */

            ih2 = rh2[ihigh];

            wd = (s->band[1].nb*127) >> 7;

            s->band[1].nb = wd + wh[ih2];

            if (s->band[1].nb < 0)

                s->band[1].nb = 0;

            else if (s->band[1].nb > 22528)

                s->band[1].nb = 22528;

            /* Block 3H, SCALEH */

            wd1 = (s->band[1].nb >> 6) & 31;

            wd2 = 10 - (s->band[1].nb >> 11);

            wd3 = (wd2 < 0)  ?  (ilb[wd1] << -wd2)  :  (ilb[wd1] >> wd2);

            s->band[1].det = wd3 << 2;

            block4(s, 1, dhigh);

            code = ((ihigh << 6) | ilow) >> (8 - s->bits_per_sample);

        }

        if (s->packed)

        {

            /* Pack the code bits */

            s->out_buffer |= (code << s->out_bits);

            s->out_bits += s->bits_per_sample;

            if (s->out_bits >= 8)

            {

                g722_data[g722_bytes++] = (uint8_t) (s->out_buffer & 0xFF);

                s->out_bits -= 8;

                s->out_buffer >>= 8;

            }

        }

        else

        {

            g722_data[g722_bytes++] = (uint8_t) code;

        }

    }

    return g722_bytes;

}

/*- End of function --------------------------------------------------------*/

/*- End of file ------------------------------------------------------------*/