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 FFmpeg.
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.
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.
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
22 * Note: Rounding-to-nearest used unless otherwise stated
30 #include "libavutil/attributes.h"
31 #include "libavutil/intfloat.h"
34 static SoftFloat sbr_sum_square_c(int (*x)[2], int n)
40 for (i = 0; i < n; i += 2) {
41 // Larger values are inavlid and could cause overflows of accu.
42 av_assert2(FFABS(x[i + 0][0]) >> 29 == 0);
43 accu += (int64_t)x[i + 0][0] * x[i + 0][0];
44 av_assert2(FFABS(x[i + 0][1]) >> 29 == 0);
45 accu += (int64_t)x[i + 0][1] * x[i + 0][1];
46 av_assert2(FFABS(x[i + 1][0]) >> 29 == 0);
47 accu += (int64_t)x[i + 1][0] * x[i + 1][0];
48 av_assert2(FFABS(x[i + 1][1]) >> 29 == 0);
49 accu += (int64_t)x[i + 1][1] * x[i + 1][1];
52 i = (int)(accu >> 32);
57 while (FFABS(i) < 0x40000000) {
65 i = (int)((accu + round) >> nz);
67 ret = av_int2sf(i, 15 - nz);
72 static void sbr_neg_odd_64_c(int *x)
75 for (i = 1; i < 64; i += 2)
79 static void sbr_qmf_pre_shuffle_c(int *z)
84 for (k = 1; k < 32; k++) {
85 z[64+2*k ] = -z[64 - k];
86 z[64+2*k+1] = z[ k + 1];
90 static void sbr_qmf_post_shuffle_c(int W[32][2], const int *z)
93 for (k = 0; k < 32; k++) {
99 static void sbr_qmf_deint_neg_c(int *v, const int *src)
102 for (i = 0; i < 32; i++) {
103 v[ i] = ( src[63 - 2*i ] + 0x10) >> 5;
104 v[63 - i] = (-src[63 - 2*i - 1] + 0x10) >> 5;
108 static av_always_inline SoftFloat autocorr_calc(int64_t accu)
110 int nz, mant, expo, round;
111 int i = (int)(accu >> 32);
116 while (FFABS(i) < 0x40000000) {
124 mant = (int)((accu + round) >> nz);
125 mant = (mant + 0x40)>>7;
128 return av_int2sf(mant, 30 - expo);
131 static av_always_inline void autocorrelate(const int x[40][2], SoftFloat phi[3][2][2], int lag)
134 int64_t real_sum, imag_sum;
135 int64_t accu_re = 0, accu_im = 0;
138 for (i = 1; i < 38; i++) {
139 accu_re += (int64_t)x[i][0] * x[i+lag][0];
140 accu_re += (int64_t)x[i][1] * x[i+lag][1];
141 accu_im += (int64_t)x[i][0] * x[i+lag][1];
142 accu_im -= (int64_t)x[i][1] * x[i+lag][0];
148 accu_re += (int64_t)x[ 0][0] * x[lag][0];
149 accu_re += (int64_t)x[ 0][1] * x[lag][1];
150 accu_im += (int64_t)x[ 0][0] * x[lag][1];
151 accu_im -= (int64_t)x[ 0][1] * x[lag][0];
153 phi[2-lag][1][0] = autocorr_calc(accu_re);
154 phi[2-lag][1][1] = autocorr_calc(accu_im);
159 accu_re += (int64_t)x[38][0] * x[39][0];
160 accu_re += (int64_t)x[38][1] * x[39][1];
161 accu_im += (int64_t)x[38][0] * x[39][1];
162 accu_im -= (int64_t)x[38][1] * x[39][0];
164 phi[0][0][0] = autocorr_calc(accu_re);
165 phi[0][0][1] = autocorr_calc(accu_im);
168 for (i = 1; i < 38; i++) {
169 accu_re += (int64_t)x[i][0] * x[i][0];
170 accu_re += (int64_t)x[i][1] * x[i][1];
173 accu_re += (int64_t)x[ 0][0] * x[ 0][0];
174 accu_re += (int64_t)x[ 0][1] * x[ 0][1];
176 phi[2][1][0] = autocorr_calc(accu_re);
179 accu_re += (int64_t)x[38][0] * x[38][0];
180 accu_re += (int64_t)x[38][1] * x[38][1];
182 phi[1][0][0] = autocorr_calc(accu_re);
186 static void sbr_autocorrelate_c(const int x[40][2], SoftFloat phi[3][2][2])
188 autocorrelate(x, phi, 0);
189 autocorrelate(x, phi, 1);
190 autocorrelate(x, phi, 2);
193 static void sbr_hf_gen_c(int (*X_high)[2], const int (*X_low)[2],
194 const int alpha0[2], const int alpha1[2],
195 int bw, int start, int end)
201 accu = (int64_t)alpha0[0] * bw;
202 alpha[2] = (int)((accu + 0x40000000) >> 31);
203 accu = (int64_t)alpha0[1] * bw;
204 alpha[3] = (int)((accu + 0x40000000) >> 31);
205 accu = (int64_t)bw * bw;
206 bw = (int)((accu + 0x40000000) >> 31);
207 accu = (int64_t)alpha1[0] * bw;
208 alpha[0] = (int)((accu + 0x40000000) >> 31);
209 accu = (int64_t)alpha1[1] * bw;
210 alpha[1] = (int)((accu + 0x40000000) >> 31);
212 for (i = start; i < end; i++) {
213 accu = (int64_t)X_low[i][0] * 0x20000000;
214 accu += (int64_t)X_low[i - 2][0] * alpha[0];
215 accu -= (int64_t)X_low[i - 2][1] * alpha[1];
216 accu += (int64_t)X_low[i - 1][0] * alpha[2];
217 accu -= (int64_t)X_low[i - 1][1] * alpha[3];
218 X_high[i][0] = (int)((accu + 0x10000000) >> 29);
220 accu = (int64_t)X_low[i][1] * 0x20000000;
221 accu += (int64_t)X_low[i - 2][1] * alpha[0];
222 accu += (int64_t)X_low[i - 2][0] * alpha[1];
223 accu += (int64_t)X_low[i - 1][1] * alpha[2];
224 accu += (int64_t)X_low[i - 1][0] * alpha[3];
225 X_high[i][1] = (int)((accu + 0x10000000) >> 29);
229 static void sbr_hf_g_filt_c(int (*Y)[2], const int (*X_high)[40][2],
230 const SoftFloat *g_filt, int m_max, intptr_t ixh)
235 for (m = 0; m < m_max; m++) {
236 r = 1 << (22-g_filt[m].exp);
237 accu = (int64_t)X_high[m][ixh][0] * ((g_filt[m].mant + 0x40)>>7);
238 Y[m][0] = (int)((accu + r) >> (23-g_filt[m].exp));
240 accu = (int64_t)X_high[m][ixh][1] * ((g_filt[m].mant + 0x40)>>7);
241 Y[m][1] = (int)((accu + r) >> (23-g_filt[m].exp));
245 static av_always_inline void sbr_hf_apply_noise(int (*Y)[2],
246 const SoftFloat *s_m,
247 const SoftFloat *q_filt,
255 for (m = 0; m < m_max; m++) {
258 noise = (noise + 1) & 0x1ff;
262 shift = 22 - s_m[m].exp;
264 round = 1 << (shift-1);
265 y0 += (s_m[m].mant * phi_sign0 + round) >> shift;
266 y1 += (s_m[m].mant * phi_sign1 + round) >> shift;
269 int shift, round, tmp;
272 shift = 22 - q_filt[m].exp;
274 round = 1 << (shift-1);
276 accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][0];
277 tmp = (int)((accu + 0x40000000) >> 31);
278 y0 += (tmp + round) >> shift;
280 accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][1];
281 tmp = (int)((accu + 0x40000000) >> 31);
282 y1 += (tmp + round) >> shift;
287 phi_sign1 = -phi_sign1;
291 #include "sbrdsp_template.c"