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 FFmpeg.
   7  *
   8  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define USE_FIXED 0
  24
  25 #include "aac.h"
  26 #include "config.h"
  27 #include "libavutil/attributes.h"
  28 #include "libavutil/intfloat.h"
  29 #include "sbrdsp.h"
  30
  31 static float sbr_sum_square_c(float (*x)[2], int n)
  32 {
  33     float sum0 = 0.0f, sum1 = 0.0f;
  34     int i;
  35
  36     for (i = 0; i < n; i += 2)
  37     {
  38         sum0 += x[i + 0][0] * x[i + 0][0];
  39         sum1 += x[i + 0][1] * x[i + 0][1];
  40         sum0 += x[i + 1][0] * x[i + 1][0];
  41         sum1 += x[i + 1][1] * x[i + 1][1];
  42     }
  43
  44     return sum0 + sum1;
  45 }
  46
  47 static void sbr_neg_odd_64_c(float *x)
  48 {
  49     union av_intfloat32 *xi = (union av_intfloat32*) x;
  50     int i;
  51     for (i = 1; i < 64; i += 4) {
  52         xi[i + 0].i ^= 1U << 31;
  53         xi[i + 2].i ^= 1U << 31;
  54     }
  55 }
  56
  57 static void sbr_qmf_pre_shuffle_c(float *z)
  58 {
  59     union av_intfloat32 *zi = (union av_intfloat32*) z;
  60     int k;
  61     zi[64].i = zi[0].i;
  62     zi[65].i = zi[1].i;
  63     for (k = 1; k < 31; k += 2) {
  64         zi[64 + 2 * k + 0].i = zi[64 - k].i ^ (1U << 31);
  65         zi[64 + 2 * k + 1].i = zi[ k + 1].i;
  66         zi[64 + 2 * k + 2].i = zi[63 - k].i ^ (1U << 31);
  67         zi[64 + 2 * k + 3].i = zi[ k + 2].i;
  68     }
  69
  70     zi[64 + 2 * 31 + 0].i = zi[64 - 31].i ^ (1U << 31);
  71     zi[64 + 2 * 31 + 1].i = zi[31 +  1].i;
  72 }
  73
  74 static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
  75 {
  76     const union av_intfloat32 *zi = (const union av_intfloat32*) z;
  77     union av_intfloat32 *Wi       = (union av_intfloat32*) W;
  78     int k;
  79     for (k = 0; k < 32; k += 2) {
  80         Wi[2 * k + 0].i = zi[63 - k].i ^ (1U << 31);
  81         Wi[2 * k + 1].i = zi[ k + 0].i;
  82         Wi[2 * k + 2].i = zi[62 - k].i ^ (1U << 31);
  83         Wi[2 * k + 3].i = zi[ k + 1].i;
  84     }
  85 }
  86
  87 static void sbr_qmf_deint_neg_c(float *v, const float *src)
  88 {
  89     const union av_intfloat32 *si = (const union av_intfloat32*)src;
  90     union av_intfloat32 *vi = (union av_intfloat32*)v;
  91     int i;
  92     for (i = 0; i < 32; i++) {
  93         vi[     i].i = si[63 - 2 * i    ].i;
  94         vi[63 - i].i = si[63 - 2 * i - 1].i ^ (1U << 31);
  95     }
  96 }
  97
  98 #if 0
  99     /* This code is slower because it multiplies memory accesses.
 100      * It is left for educational purposes and because it may offer
 101      * a better reference for writing arch-specific DSP functions. */
 102 static av_always_inline void autocorrelate(const float x[40][2],
 103                                            float phi[3][2][2], int lag)
 104 {
 105     int i;
 106     float real_sum = 0.0f;
 107     float imag_sum = 0.0f;
 108     if (lag) {
 109         for (i = 1; i < 38; i++) {
 110             real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
 111             imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
 112         }
 113         phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
 114         phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
 115         if (lag == 1) {
 116             phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
 117             phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
 118         }
 119     } else {
 120         for (i = 1; i < 38; i++) {
 121             real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
 122         }
 123         phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
 124         phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
 125     }
 126 }
 127
 128 static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
 129 {
 130     autocorrelate(x, phi, 0);
 131     autocorrelate(x, phi, 1);
 132     autocorrelate(x, phi, 2);
 133 }
 134 #else
 135 static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
 136 {
 137     float real_sum2 = x[0][0] * x[2][0] + x[0][1] * x[2][1];
 138     float imag_sum2 = x[0][0] * x[2][1] - x[0][1] * x[2][0];
 139     float real_sum1 = 0.0f, imag_sum1 = 0.0f, real_sum0 = 0.0f;
 140     int   i;
 141     for (i = 1; i < 38; i++) {
 142         real_sum0 += x[i][0] * x[i    ][0] + x[i][1] * x[i    ][1];
 143         real_sum1 += x[i][0] * x[i + 1][0] + x[i][1] * x[i + 1][1];
 144         imag_sum1 += x[i][0] * x[i + 1][1] - x[i][1] * x[i + 1][0];
 145         real_sum2 += x[i][0] * x[i + 2][0] + x[i][1] * x[i + 2][1];
 146         imag_sum2 += x[i][0] * x[i + 2][1] - x[i][1] * x[i + 2][0];
 147     }
 148     phi[2 - 2][1][0] = real_sum2;
 149     phi[2 - 2][1][1] = imag_sum2;
 150     phi[2    ][1][0] = real_sum0 + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
 151     phi[1    ][0][0] = real_sum0 + x[38][0] * x[38][0] + x[38][1] * x[38][1];
 152     phi[2 - 1][1][0] = real_sum1 + x[ 0][0] * x[ 1][0] + x[ 0][1] * x[ 1][1];
 153     phi[2 - 1][1][1] = imag_sum1 + x[ 0][0] * x[ 1][1] - x[ 0][1] * x[ 1][0];
 154     phi[0    ][0][0] = real_sum1 + x[38][0] * x[39][0] + x[38][1] * x[39][1];
 155     phi[0    ][0][1] = imag_sum1 + x[38][0] * x[39][1] - x[38][1] * x[39][0];
 156 }
 157 #endif
 158
 159 static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
 160                          const float alpha0[2], const float alpha1[2],
 161                          float bw, int start, int end)
 162 {
 163     float alpha[4];
 164     int i;
 165
 166     alpha[0] = alpha1[0] * bw * bw;
 167     alpha[1] = alpha1[1] * bw * bw;
 168     alpha[2] = alpha0[0] * bw;
 169     alpha[3] = alpha0[1] * bw;
 170
 171     for (i = start; i < end; i++) {
 172         X_high[i][0] =
 173             X_low[i - 2][0] * alpha[0] -
 174             X_low[i - 2][1] * alpha[1] +
 175             X_low[i - 1][0] * alpha[2] -
 176             X_low[i - 1][1] * alpha[3] +
 177             X_low[i][0];
 178         X_high[i][1] =
 179             X_low[i - 2][1] * alpha[0] +
 180             X_low[i - 2][0] * alpha[1] +
 181             X_low[i - 1][1] * alpha[2] +
 182             X_low[i - 1][0] * alpha[3] +
 183             X_low[i][1];
 184     }
 185 }
 186
 187 static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],
 188                             const float *g_filt, int m_max, intptr_t ixh)
 189 {
 190     int m;
 191
 192     for (m = 0; m < m_max; m++) {
 193         Y[m][0] = X_high[m][ixh][0] * g_filt[m];
 194         Y[m][1] = X_high[m][ixh][1] * g_filt[m];
 195     }
 196 }
 197
 198 static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
 199                                                 const float *s_m,
 200                                                 const float *q_filt,
 201                                                 int noise,
 202                                                 float phi_sign0,
 203                                                 float phi_sign1,
 204                                                 int m_max)
 205 {
 206     int m;
 207
 208     for (m = 0; m < m_max; m++) {
 209         float y0 = Y[m][0];
 210         float y1 = Y[m][1];
 211         noise = (noise + 1) & 0x1ff;
 212         if (s_m[m]) {
 213             y0 += s_m[m] * phi_sign0;
 214             y1 += s_m[m] * phi_sign1;
 215         } else {
 216             y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
 217             y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
 218         }
 219         Y[m][0] = y0;
 220         Y[m][1] = y1;
 221         phi_sign1 = -phi_sign1;
 222     }
 223 }
 224
 225 #include "sbrdsp_template.c"