libavcodec/sbrdsp.c

   1 /*
   2  * AAC Spectral Band Replication decoding functions
   3  * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
   4  * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "config.h"
  24 #include "libavutil/attributes.h"
  25 #include "sbrdsp.h"
  26
  27 static void sbr_sum64x5_c(float *z)
  28 {
  29     int k;
  30     for (k = 0; k < 64; k++) {
  31         float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
  32         z[k] = f;
  33     }
  34 }
  35
  36 static float sbr_sum_square_c(float (*x)[2], int n)
  37 {
  38     float sum0 = 0.0f, sum1 = 0.0f;
  39     int i;
  40
  41     for (i = 0; i < n; i += 2)
  42     {
  43         sum0 += x[i + 0][0] * x[i + 0][0];
  44         sum1 += x[i + 0][1] * x[i + 0][1];
  45         sum0 += x[i + 1][0] * x[i + 1][0];
  46         sum1 += x[i + 1][1] * x[i + 1][1];
  47     }
  48
  49     return sum0 + sum1;
  50 }
  51
  52 static void sbr_neg_odd_64_c(float *x)
  53 {
  54     int i;
  55     for (i = 1; i < 64; i += 2)
  56         x[i] = -x[i];
  57 }
  58
  59 static void sbr_qmf_pre_shuffle_c(float *z)
  60 {
  61     int k;
  62     z[64] = z[0];
  63     z[65] = z[1];
  64     for (k = 1; k < 32; k++) {
  65         z[64+2*k  ] = -z[64 - k];
  66         z[64+2*k+1] =  z[ k + 1];
  67     }
  68 }
  69
  70 static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
  71 {
  72     int k;
  73     for (k = 0; k < 32; k++) {
  74         W[k][0] = -z[63-k];
  75         W[k][1] = z[k];
  76     }
  77 }
  78
  79 static void sbr_qmf_deint_neg_c(float *v, const float *src)
  80 {
  81     int i;
  82     for (i = 0; i < 32; i++) {
  83         v[     i] =  src[63 - 2*i    ];
  84         v[63 - i] = -src[63 - 2*i - 1];
  85     }
  86 }
  87
  88 static void sbr_qmf_deint_bfly_c(float *v, const float *src0, const float *src1)
  89 {
  90     int i;
  91     for (i = 0; i < 64; i++) {
  92         v[      i] = src0[i] - src1[63 - i];
  93         v[127 - i] = src0[i] + src1[63 - i];
  94     }
  95 }
  96
  97 static av_always_inline void autocorrelate(const float x[40][2],
  98                                            float phi[3][2][2], int lag)
  99 {
 100     int i;
 101     float real_sum = 0.0f;
 102     float imag_sum = 0.0f;
 103     if (lag) {
 104         for (i = 1; i < 38; i++) {
 105             real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
 106             imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
 107         }
 108         phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
 109         phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
 110         if (lag == 1) {
 111             phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
 112             phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
 113         }
 114     } else {
 115         for (i = 1; i < 38; i++) {
 116             real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
 117         }
 118         phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
 119         phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
 120     }
 121 }
 122
 123 static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
 124 {
 125     autocorrelate(x, phi, 0);
 126     autocorrelate(x, phi, 1);
 127     autocorrelate(x, phi, 2);
 128 }
 129
 130 static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
 131                          const float alpha0[2], const float alpha1[2],
 132                          float bw, int start, int end)
 133 {
 134     float alpha[4];
 135     int i;
 136
 137     alpha[0] = alpha1[0] * bw * bw;
 138     alpha[1] = alpha1[1] * bw * bw;
 139     alpha[2] = alpha0[0] * bw;
 140     alpha[3] = alpha0[1] * bw;
 141
 142     for (i = start; i < end; i++) {
 143         X_high[i][0] =
 144             X_low[i - 2][0] * alpha[0] -
 145             X_low[i - 2][1] * alpha[1] +
 146             X_low[i - 1][0] * alpha[2] -
 147             X_low[i - 1][1] * alpha[3] +
 148             X_low[i][0];
 149         X_high[i][1] =
 150             X_low[i - 2][1] * alpha[0] +
 151             X_low[i - 2][0] * alpha[1] +
 152             X_low[i - 1][1] * alpha[2] +
 153             X_low[i - 1][0] * alpha[3] +
 154             X_low[i][1];
 155     }
 156 }
 157
 158 static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],
 159                             const float *g_filt, int m_max, intptr_t ixh)
 160 {
 161     int m;
 162
 163     for (m = 0; m < m_max; m++) {
 164         Y[m][0] = X_high[m][ixh][0] * g_filt[m];
 165         Y[m][1] = X_high[m][ixh][1] * g_filt[m];
 166     }
 167 }
 168
 169 static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
 170                                                 const float *s_m,
 171                                                 const float *q_filt,
 172                                                 int noise,
 173                                                 float phi_sign0,
 174                                                 float phi_sign1,
 175                                                 int m_max)
 176 {
 177     int m;
 178
 179     for (m = 0; m < m_max; m++) {
 180         float y0 = Y[m][0];
 181         float y1 = Y[m][1];
 182         noise = (noise + 1) & 0x1ff;
 183         if (s_m[m]) {
 184             y0 += s_m[m] * phi_sign0;
 185             y1 += s_m[m] * phi_sign1;
 186         } else {
 187             y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
 188             y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
 189         }
 190         Y[m][0] = y0;
 191         Y[m][1] = y1;
 192         phi_sign1 = -phi_sign1;
 193     }
 194 }
 195
 196 static void sbr_hf_apply_noise_0(float (*Y)[2], const float *s_m,
 197                                  const float *q_filt, int noise,
 198                                  int kx, int m_max)
 199 {
 200     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 1.0, 0.0, m_max);
 201 }
 202
 203 static void sbr_hf_apply_noise_1(float (*Y)[2], const float *s_m,
 204                                  const float *q_filt, int noise,
 205                                  int kx, int m_max)
 206 {
 207     float phi_sign = 1 - 2 * (kx & 1);
 208     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, phi_sign, m_max);
 209 }
 210
 211 static void sbr_hf_apply_noise_2(float (*Y)[2], const float *s_m,
 212                                  const float *q_filt, int noise,
 213                                  int kx, int m_max)
 214 {
 215     sbr_hf_apply_noise(Y, s_m, q_filt, noise, -1.0, 0.0, m_max);
 216 }
 217
 218 static void sbr_hf_apply_noise_3(float (*Y)[2], const float *s_m,
 219                                  const float *q_filt, int noise,
 220                                  int kx, int m_max)
 221 {
 222     float phi_sign = 1 - 2 * (kx & 1);
 223     sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, -phi_sign, m_max);
 224 }
 225
 226 av_cold void ff_sbrdsp_init(SBRDSPContext *s)
 227 {
 228     s->sum64x5 = sbr_sum64x5_c;
 229     s->sum_square = sbr_sum_square_c;
 230     s->neg_odd_64 = sbr_neg_odd_64_c;
 231     s->qmf_pre_shuffle = sbr_qmf_pre_shuffle_c;
 232     s->qmf_post_shuffle = sbr_qmf_post_shuffle_c;
 233     s->qmf_deint_neg = sbr_qmf_deint_neg_c;
 234     s->qmf_deint_bfly = sbr_qmf_deint_bfly_c;
 235     s->autocorrelate = sbr_autocorrelate_c;
 236     s->hf_gen = sbr_hf_gen_c;
 237     s->hf_g_filt = sbr_hf_g_filt_c;
 238
 239     s->hf_apply_noise[0] = sbr_hf_apply_noise_0;
 240     s->hf_apply_noise[1] = sbr_hf_apply_noise_1;
 241     s->hf_apply_noise[2] = sbr_hf_apply_noise_2;
 242     s->hf_apply_noise[3] = sbr_hf_apply_noise_3;
 243
 244     if (ARCH_ARM)
 245         ff_sbrdsp_init_arm(s);
 246     if (ARCH_X86)
 247         ff_sbrdsp_init_x86(s);
 248 }