/*

 * AAC Spectral Band Replication decoding functions

 * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )

 * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 *

 * Note: Rounding-to-nearest used unless otherwise stated

 *

 */

#define USE_FIXED 1

#include "aac.h"

#include "libavutil/attributes.h"

#include "libavutil/intfloat.h"

#include "sbrdsp.h"

static SoftFloat sbr_sum_square_c(int (*x)[2], int n)

{

    SoftFloat ret;

    uint64_t accu = 0, round;

    uint64_t accu0 = 0, accu1 = 0, accu2 = 0, accu3 = 0;

    int i, nz, nz0;

    unsigned u;

    nz = 0;

    for (i = 0; i < n; i += 2) {

        accu0 += (int64_t)x[i + 0][0] * x[i + 0][0];

        accu1 += (int64_t)x[i + 0][1] * x[i + 0][1];

        accu2 += (int64_t)x[i + 1][0] * x[i + 1][0];

        accu3 += (int64_t)x[i + 1][1] * x[i + 1][1];

        if ((accu0|accu1|accu2|accu3) > UINT64_MAX - INT32_MIN*(int64_t)INT32_MIN || i+2>=n) {

            accu0 >>= nz;

            accu1 >>= nz;

            accu2 >>= nz;

            accu3 >>= nz;

            while ((accu0|accu1|accu2|accu3) > (UINT64_MAX - accu) >> 2) {

                accu0 >>= 1;

                accu1 >>= 1;

                accu2 >>= 1;

                accu3 >>= 1;

                accu  >>= 1;

                nz ++;

            }

            accu += accu0 + accu1 + accu2 + accu3;

            accu0 = accu1 = accu2 = accu3 = 0;

        }

    }

    nz0 = 15 - nz;

    u = accu >> 32;

    if (u) {

        nz = 33;

        while (u < 0x80000000U) {

            u <<= 1;

            nz--;

        }

    } else

        nz = 1;

    round = 1ULL << (nz-1);

    u = ((accu + round) >> nz);

    u >>= 1;

    ret = av_int2sf(u, nz0 - nz);

    return ret;

}

static void sbr_neg_odd_64_c(int *x)

{

    int i;

    for (i = 1; i < 64; i += 2)

        x[i] = -(unsigned)x[i];

}

static void sbr_qmf_pre_shuffle_c(int *z)

{

    int k;

    z[64] = z[0];

    z[65] = z[1];

    for (k = 1; k < 32; k++) {

        z[64+2*k  ] = -z[64 - k];

        z[64+2*k+1] =  z[ k + 1];

    }

}

static void sbr_qmf_post_shuffle_c(int W[32][2], const int *z)

{

    int k;

    for (k = 0; k < 32; k++) {

        W[k][0] = -z[63-k];

        W[k][1] = z[k];

    }

}

static void sbr_qmf_deint_neg_c(int *v, const int *src)

{

    int i;

    for (i = 0; i < 32; i++) {

        v[     i] = (int)(0x10U + src[63 - 2*i    ]) >> 5;

        v[63 - i] = (int)(0x10U - src[63 - 2*i - 1]) >> 5;

    }

}

static av_always_inline SoftFloat autocorr_calc(int64_t accu)

{

        int nz, mant, expo;

        unsigned round;

        int i = (int)(accu >> 32);

        if (i == 0) {

            nz = 1;

        } else {

            nz = 0;

            while (FFABS(i) < 0x40000000) {

                i *= 2;

                nz++;

            }

            nz = 32-nz;

        }

        round = 1U << (nz-1);

        mant = (int)((accu + round) >> nz);

        mant = (mant + 0x40LL)>>7;

        mant *= 64;

        expo = nz + 15;

        return av_int2sf(mant, 30 - expo);

}

static av_always_inline void autocorrelate(const int x[40][2], SoftFloat phi[3][2][2], int lag)

{

    int i;

    int64_t real_sum, imag_sum;

    int64_t accu_re = 0, accu_im = 0;

    if (lag) {

        for (i = 1; i < 38; i++) {

            accu_re += (uint64_t)x[i][0] * x[i+lag][0];

            accu_re += (uint64_t)x[i][1] * x[i+lag][1];

            accu_im += (uint64_t)x[i][0] * x[i+lag][1];

            accu_im -= (uint64_t)x[i][1] * x[i+lag][0];

        }

        real_sum = accu_re;

        imag_sum = accu_im;

        accu_re += (uint64_t)x[ 0][0] * x[lag][0];

        accu_re += (uint64_t)x[ 0][1] * x[lag][1];

        accu_im += (uint64_t)x[ 0][0] * x[lag][1];

        accu_im -= (uint64_t)x[ 0][1] * x[lag][0];

        phi[2-lag][1][0] = autocorr_calc(accu_re);

        phi[2-lag][1][1] = autocorr_calc(accu_im);

        if (lag == 1) {

            accu_re = real_sum;

            accu_im = imag_sum;

            accu_re += (uint64_t)x[38][0] * x[39][0];

            accu_re += (uint64_t)x[38][1] * x[39][1];

            accu_im += (uint64_t)x[38][0] * x[39][1];

            accu_im -= (uint64_t)x[38][1] * x[39][0];

            phi[0][0][0] = autocorr_calc(accu_re);

            phi[0][0][1] = autocorr_calc(accu_im);

        }

    } else {

        for (i = 1; i < 38; i++) {

            accu_re += (uint64_t)x[i][0] * x[i][0];

            accu_re += (uint64_t)x[i][1] * x[i][1];

        }

        real_sum = accu_re;

        accu_re += (uint64_t)x[ 0][0] * x[ 0][0];

        accu_re += (uint64_t)x[ 0][1] * x[ 0][1];

        phi[2][1][0] = autocorr_calc(accu_re);

        accu_re = real_sum;

        accu_re += (uint64_t)x[38][0] * x[38][0];

        accu_re += (uint64_t)x[38][1] * x[38][1];

        phi[1][0][0] = autocorr_calc(accu_re);

    }

}

static void sbr_autocorrelate_c(const int x[40][2], SoftFloat phi[3][2][2])

{

    autocorrelate(x, phi, 0);

    autocorrelate(x, phi, 1);

    autocorrelate(x, phi, 2);

}

static void sbr_hf_gen_c(int (*X_high)[2], const int (*X_low)[2],

                       const int alpha0[2], const int alpha1[2],

                       int bw, int start, int end)

{

    int alpha[4];

    int i;

    int64_t accu;

    accu = (int64_t)alpha0[0] * bw;

    alpha[2] = (int)((accu + 0x40000000) >> 31);

    accu = (int64_t)alpha0[1] * bw;

    alpha[3] = (int)((accu + 0x40000000) >> 31);

    accu = (int64_t)bw * bw;

    bw = (int)((accu + 0x40000000) >> 31);

    accu = (int64_t)alpha1[0] * bw;

    alpha[0] = (int)((accu + 0x40000000) >> 31);

    accu = (int64_t)alpha1[1] * bw;

    alpha[1] = (int)((accu + 0x40000000) >> 31);

    for (i = start; i < end; i++) {

        accu  = (int64_t)X_low[i][0] * 0x20000000;

        accu += (int64_t)X_low[i - 2][0] * alpha[0];

        accu -= (int64_t)X_low[i - 2][1] * alpha[1];

        accu += (int64_t)X_low[i - 1][0] * alpha[2];

        accu -= (int64_t)X_low[i - 1][1] * alpha[3];

        X_high[i][0] = (int)((accu + 0x10000000) >> 29);

        accu  = (int64_t)X_low[i][1] * 0x20000000;

        accu += (int64_t)X_low[i - 2][1] * alpha[0];

        accu += (int64_t)X_low[i - 2][0] * alpha[1];

        accu += (int64_t)X_low[i - 1][1] * alpha[2];

        accu += (int64_t)X_low[i - 1][0] * alpha[3];

        X_high[i][1] = (int)((accu + 0x10000000) >> 29);

    }

}

static void sbr_hf_g_filt_c(int (*Y)[2], const int (*X_high)[40][2],

                          const SoftFloat *g_filt, int m_max, intptr_t ixh)

{

    int m;

    int64_t accu;

    for (m = 0; m < m_max; m++) {

        if (22 - g_filt[m].exp < 61) {

            int64_t r = 1LL << (22-g_filt[m].exp);

            accu = (int64_t)X_high[m][ixh][0] * ((g_filt[m].mant + 0x40)>>7);

            Y[m][0] = (int)((accu + r) >> (23-g_filt[m].exp));

            accu = (int64_t)X_high[m][ixh][1] * ((g_filt[m].mant + 0x40)>>7);

            Y[m][1] = (int)((accu + r) >> (23-g_filt[m].exp));

        }

    }

}

static av_always_inline int sbr_hf_apply_noise(int (*Y)[2],

                                                const SoftFloat *s_m,

                                                const SoftFloat *q_filt,

                                                int noise,

                                                int phi_sign0,

                                                int phi_sign1,

                                                int m_max)

{

    int m;

    for (m = 0; m < m_max; m++) {

        unsigned y0 = Y[m][0];

        unsigned y1 = Y[m][1];

        noise = (noise + 1) & 0x1ff;

        if (s_m[m].mant) {

            int shift, round;

            shift = 22 - s_m[m].exp;

            if (shift < 1) {

                av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_apply_noise, shift=%d\n", shift);

                return AVERROR(ERANGE);

            } else if (shift < 30) {

                round = 1 << (shift-1);

                y0 += (s_m[m].mant * phi_sign0 + round) >> shift;

                y1 += (s_m[m].mant * phi_sign1 + round) >> shift;

            }

        } else {

            int shift, round, tmp;

            int64_t accu;

            shift = 22 - q_filt[m].exp;

            if (shift < 1) {

                av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_apply_noise, shift=%d\n", shift);

                return AVERROR(ERANGE);

            } else if (shift < 30) {

                round = 1 << (shift-1);

                accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][0];

                tmp = (int)((accu + 0x40000000) >> 31);

                y0 += (tmp + round) >> shift;

                accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][1];

                tmp = (int)((accu + 0x40000000) >> 31);

                y1 += (tmp + round) >> shift;

            }

        }

        Y[m][0] = y0;

        Y[m][1] = y1;

        phi_sign1 = -phi_sign1;

    }

    return 0;

}

#include "sbrdsp_template.c"