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>
6 * This file is part of Libav.
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.
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.
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
24 #include "libavutil/attributes.h"
27 static void sbr_sum64x5_c(float *z)
30 for (k = 0; k < 64; k++) {
31 float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
36 static float sbr_sum_square_c(float (*x)[2], int n)
41 for (i = 0; i < n; i++)
42 sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
47 static void sbr_neg_odd_64_c(float *x)
50 for (i = 1; i < 64; i += 2)
54 static void sbr_qmf_pre_shuffle_c(float *z)
59 for (k = 1; k < 32; k++) {
60 z[64+2*k ] = -z[64 - k];
61 z[64+2*k+1] = z[ k + 1];
65 static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
68 for (k = 0; k < 32; k++) {
74 static void sbr_qmf_deint_neg_c(float *v, const float *src)
77 for (i = 0; i < 32; i++) {
78 v[ i] = src[63 - 2*i ];
79 v[63 - i] = -src[63 - 2*i - 1];
83 static void sbr_qmf_deint_bfly_c(float *v, const float *src0, const float *src1)
86 for (i = 0; i < 64; i++) {
87 v[ i] = src0[i] - src1[63 - i];
88 v[127 - i] = src0[i] + src1[63 - i];
92 static av_always_inline void autocorrelate(const float x[40][2],
93 float phi[3][2][2], int lag)
96 float real_sum = 0.0f;
97 float imag_sum = 0.0f;
99 for (i = 1; i < 38; i++) {
100 real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
101 imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
103 phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
104 phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
106 phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
107 phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
110 for (i = 1; i < 38; i++) {
111 real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
113 phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
114 phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
118 static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
120 autocorrelate(x, phi, 0);
121 autocorrelate(x, phi, 1);
122 autocorrelate(x, phi, 2);
125 static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
126 const float alpha0[2], const float alpha1[2],
127 float bw, int start, int end)
132 alpha[0] = alpha1[0] * bw * bw;
133 alpha[1] = alpha1[1] * bw * bw;
134 alpha[2] = alpha0[0] * bw;
135 alpha[3] = alpha0[1] * bw;
137 for (i = start; i < end; i++) {
139 X_low[i - 2][0] * alpha[0] -
140 X_low[i - 2][1] * alpha[1] +
141 X_low[i - 1][0] * alpha[2] -
142 X_low[i - 1][1] * alpha[3] +
145 X_low[i - 2][1] * alpha[0] +
146 X_low[i - 2][0] * alpha[1] +
147 X_low[i - 1][1] * alpha[2] +
148 X_low[i - 1][0] * alpha[3] +
153 static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],
154 const float *g_filt, int m_max, int ixh)
158 for (m = 0; m < m_max; m++) {
159 Y[m][0] = X_high[m][ixh][0] * g_filt[m];
160 Y[m][1] = X_high[m][ixh][1] * g_filt[m];
164 static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
174 for (m = 0; m < m_max; m++) {
177 noise = (noise + 1) & 0x1ff;
179 y0 += s_m[m] * phi_sign0;
180 y1 += s_m[m] * phi_sign1;
182 y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
183 y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
187 phi_sign1 = -phi_sign1;
191 static void sbr_hf_apply_noise_0(float (*Y)[2], const float *s_m,
192 const float *q_filt, int noise,
195 sbr_hf_apply_noise(Y, s_m, q_filt, noise, 1.0, 0.0, m_max);
198 static void sbr_hf_apply_noise_1(float (*Y)[2], const float *s_m,
199 const float *q_filt, int noise,
202 float phi_sign = 1 - 2 * (kx & 1);
203 sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, phi_sign, m_max);
206 static void sbr_hf_apply_noise_2(float (*Y)[2], const float *s_m,
207 const float *q_filt, int noise,
210 sbr_hf_apply_noise(Y, s_m, q_filt, noise, -1.0, 0.0, m_max);
213 static void sbr_hf_apply_noise_3(float (*Y)[2], const float *s_m,
214 const float *q_filt, int noise,
217 float phi_sign = 1 - 2 * (kx & 1);
218 sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, -phi_sign, m_max);
221 av_cold void ff_sbrdsp_init(SBRDSPContext *s)
223 s->sum64x5 = sbr_sum64x5_c;
224 s->sum_square = sbr_sum_square_c;
225 s->neg_odd_64 = sbr_neg_odd_64_c;
226 s->qmf_pre_shuffle = sbr_qmf_pre_shuffle_c;
227 s->qmf_post_shuffle = sbr_qmf_post_shuffle_c;
228 s->qmf_deint_neg = sbr_qmf_deint_neg_c;
229 s->qmf_deint_bfly = sbr_qmf_deint_bfly_c;
230 s->autocorrelate = sbr_autocorrelate_c;
231 s->hf_gen = sbr_hf_gen_c;
232 s->hf_g_filt = sbr_hf_g_filt_c;
234 s->hf_apply_noise[0] = sbr_hf_apply_noise_0;
235 s->hf_apply_noise[1] = sbr_hf_apply_noise_1;
236 s->hf_apply_noise[2] = sbr_hf_apply_noise_2;
237 s->hf_apply_noise[3] = sbr_hf_apply_noise_3;
240 ff_sbrdsp_init_arm(s);