/*
  * 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
  */
 

 #include "config.h"

 #include "libavutil/attributes.h"

 #include "libavutil/intfloat.h"

 #include "sbrdsp.h"
 
 static void sbr_sum64x5_c(float *z)
 {
     int k;
     for (k = 0; k < 64; k++) {
         float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
         z[k] = f;
     }
 }
 
 static float sbr_sum_square_c(float (*x)[2], int n)
 {

     float sum0 = 0.0f, sum1 = 0.0f;

     int i;
 

     for (i = 0; i < n; i += 2)
     {
         sum0 += x[i + 0][0] * x[i + 0][0];
         sum1 += x[i + 0][1] * x[i + 0][1];
         sum0 += x[i + 1][0] * x[i + 1][0];
         sum1 += x[i + 1][1] * x[i + 1][1];
     }

     return sum0 + sum1;

 }
 
 static void sbr_neg_odd_64_c(float *x)
 {

     union av_intfloat32 *xi = (union av_intfloat32*) x;

     int i;

     for (i = 1; i < 64; i += 4) {
         xi[i + 0].i ^= 1U << 31;
         xi[i + 2].i ^= 1U << 31;

     }

 }
 
 static void sbr_qmf_pre_shuffle_c(float *z)
 {

     union av_intfloat32 *zi = (union av_intfloat32*) z;

     int k;

     zi[64].i = zi[0].i;
     zi[65].i = zi[1].i;

     for (k = 1; k < 31; k += 2) {
         zi[64 + 2 * k + 0].i = zi[64 - k].i ^ (1U << 31);
         zi[64 + 2 * k + 1].i = zi[ k + 1].i;
         zi[64 + 2 * k + 2].i = zi[63 - k].i ^ (1U << 31);
         zi[64 + 2 * k + 3].i = zi[ k + 2].i;

     }

     zi[64 + 2 * 31 + 0].i = zi[64 - 31].i ^ (1U << 31);
     zi[64 + 2 * 31 + 1].i = zi[31 +  1].i;

 }
 
 static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
 {

     const union av_intfloat32 *zi = (const union av_intfloat32*) z;
     union av_intfloat32 *Wi       = (union av_intfloat32*) W;

     int k;

     for (k = 0; k < 32; k += 2) {
         Wi[2 * k + 0].i = zi[63 - k].i ^ (1U << 31);
         Wi[2 * k + 1].i = zi[ k + 0].i;
         Wi[2 * k + 2].i = zi[62 - k].i ^ (1U << 31);
         Wi[2 * k + 3].i = zi[ k + 1].i;

     }
 }
 
 static void sbr_qmf_deint_neg_c(float *v, const float *src)
 {

     const union av_intfloat32 *si = (const union av_intfloat32*)src;
     union av_intfloat32 *vi = (union av_intfloat32*)v;

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

         vi[     i].i = si[63 - 2 * i    ].i;
         vi[63 - i].i = si[63 - 2 * i - 1].i ^ (1U << 31);

     }
 }
 
 static void sbr_qmf_deint_bfly_c(float *v, const float *src0, const float *src1)
 {
     int i;
     for (i = 0; i < 64; i++) {
         v[      i] = src0[i] - src1[63 - i];
         v[127 - i] = src0[i] + src1[63 - i];
     }
 }
 
 static av_always_inline void autocorrelate(const float x[40][2],
                                            float phi[3][2][2], int lag)
 {
     int i;
     float real_sum = 0.0f;
     float imag_sum = 0.0f;
     if (lag) {
         for (i = 1; i < 38; i++) {
             real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
             imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
         }
         phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
         phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
         if (lag == 1) {
             phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
             phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
         }
     } else {
         for (i = 1; i < 38; i++) {
             real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
         }
         phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
         phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
     }
 }
 
 static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
 {

 #if 0

     /* This code is slower because it multiplies memory accesses.
      * It is left for educational purposes and because it may offer
      * a better reference for writing arch-specific DSP functions. */

     autocorrelate(x, phi, 0);
     autocorrelate(x, phi, 1);
     autocorrelate(x, phi, 2);

 #else

     float real_sum2 = x[0][0] * x[2][0] + x[0][1] * x[2][1];
     float imag_sum2 = x[0][0] * x[2][1] - x[0][1] * x[2][0];
     float real_sum1 = 0.0f, imag_sum1 = 0.0f, real_sum0 = 0.0f;

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

         real_sum0 += x[i][0] * x[i    ][0] + x[i][1] * x[i    ][1];
         real_sum1 += x[i][0] * x[i + 1][0] + x[i][1] * x[i + 1][1];
         imag_sum1 += x[i][0] * x[i + 1][1] - x[i][1] * x[i + 1][0];
         real_sum2 += x[i][0] * x[i + 2][0] + x[i][1] * x[i + 2][1];
         imag_sum2 += x[i][0] * x[i + 2][1] - x[i][1] * x[i + 2][0];

     }

     phi[2 - 2][1][0] = real_sum2;
     phi[2 - 2][1][1] = imag_sum2;
     phi[2    ][1][0] = real_sum0 + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
     phi[1    ][0][0] = real_sum0 + x[38][0] * x[38][0] + x[38][1] * x[38][1];
     phi[2 - 1][1][0] = real_sum1 + x[ 0][0] * x[ 1][0] + x[ 0][1] * x[ 1][1];
     phi[2 - 1][1][1] = imag_sum1 + x[ 0][0] * x[ 1][1] - x[ 0][1] * x[ 1][0];
     phi[0    ][0][0] = real_sum1 + x[38][0] * x[39][0] + x[38][1] * x[39][1];
     phi[0    ][0][1] = imag_sum1 + x[38][0] * x[39][1] - x[38][1] * x[39][0];

 #endif

 }
 
 static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
                          const float alpha0[2], const float alpha1[2],
                          float bw, int start, int end)
 {
     float alpha[4];
     int i;
 
     alpha[0] = alpha1[0] * bw * bw;
     alpha[1] = alpha1[1] * bw * bw;
     alpha[2] = alpha0[0] * bw;
     alpha[3] = alpha0[1] * bw;
 
     for (i = start; i < end; i++) {
         X_high[i][0] =
             X_low[i - 2][0] * alpha[0] -
             X_low[i - 2][1] * alpha[1] +
             X_low[i - 1][0] * alpha[2] -
             X_low[i - 1][1] * alpha[3] +
             X_low[i][0];
         X_high[i][1] =
             X_low[i - 2][1] * alpha[0] +
             X_low[i - 2][0] * alpha[1] +
             X_low[i - 1][1] * alpha[2] +
             X_low[i - 1][0] * alpha[3] +
             X_low[i][1];
     }
 }
 
 static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],

                             const float *g_filt, int m_max, intptr_t ixh)

 {
     int m;
 
     for (m = 0; m < m_max; m++) {
         Y[m][0] = X_high[m][ixh][0] * g_filt[m];
         Y[m][1] = X_high[m][ixh][1] * g_filt[m];
     }
 }
 
 static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
                                                 const float *s_m,
                                                 const float *q_filt,
                                                 int noise,
                                                 float phi_sign0,
                                                 float phi_sign1,
                                                 int m_max)
 {
     int m;
 
     for (m = 0; m < m_max; m++) {
         float y0 = Y[m][0];
         float y1 = Y[m][1];
         noise = (noise + 1) & 0x1ff;
         if (s_m[m]) {
             y0 += s_m[m] * phi_sign0;
             y1 += s_m[m] * phi_sign1;
         } else {
             y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
             y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
         }
         Y[m][0] = y0;
         Y[m][1] = y1;
         phi_sign1 = -phi_sign1;
     }
 }
 
 static void sbr_hf_apply_noise_0(float (*Y)[2], const float *s_m,
                                  const float *q_filt, int noise,
                                  int kx, int m_max)
 {
     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 1.0, 0.0, m_max);
 }
 
 static void sbr_hf_apply_noise_1(float (*Y)[2], const float *s_m,
                                  const float *q_filt, int noise,
                                  int kx, int m_max)
 {
     float phi_sign = 1 - 2 * (kx & 1);
     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, phi_sign, m_max);
 }
 
 static void sbr_hf_apply_noise_2(float (*Y)[2], const float *s_m,
                                  const float *q_filt, int noise,
                                  int kx, int m_max)
 {
     sbr_hf_apply_noise(Y, s_m, q_filt, noise, -1.0, 0.0, m_max);
 }
 
 static void sbr_hf_apply_noise_3(float (*Y)[2], const float *s_m,
                                  const float *q_filt, int noise,
                                  int kx, int m_max)
 {
     float phi_sign = 1 - 2 * (kx & 1);
     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, -phi_sign, m_max);
 }
 
 av_cold void ff_sbrdsp_init(SBRDSPContext *s)
 {
     s->sum64x5 = sbr_sum64x5_c;
     s->sum_square = sbr_sum_square_c;
     s->neg_odd_64 = sbr_neg_odd_64_c;
     s->qmf_pre_shuffle = sbr_qmf_pre_shuffle_c;
     s->qmf_post_shuffle = sbr_qmf_post_shuffle_c;
     s->qmf_deint_neg = sbr_qmf_deint_neg_c;
     s->qmf_deint_bfly = sbr_qmf_deint_bfly_c;
     s->autocorrelate = sbr_autocorrelate_c;
     s->hf_gen = sbr_hf_gen_c;
     s->hf_g_filt = sbr_hf_g_filt_c;
 
     s->hf_apply_noise[0] = sbr_hf_apply_noise_0;
     s->hf_apply_noise[1] = sbr_hf_apply_noise_1;
     s->hf_apply_noise[2] = sbr_hf_apply_noise_2;
     s->hf_apply_noise[3] = sbr_hf_apply_noise_3;

 
     if (ARCH_ARM)
         ff_sbrdsp_init_arm(s);

     if (ARCH_X86)

         ff_sbrdsp_init_x86(s);

     if (ARCH_MIPS)
         ff_sbrdsp_init_mips(s);

 }