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#include "config.h"
24#include "libavutil/attributes.h"
25#include "libavutil/intfloat.h"
26#include "sbrdsp.h"
27
28static void sbr_sum64x5_c(float *z)
29{
30    int k;
31    for (k = 0; k < 64; k++) {
32        float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
33        z[k] = f;
34    }
35}
36
37static float sbr_sum_square_c(float (*x)[2], int n)
38{
39    float sum0 = 0.0f, sum1 = 0.0f;
40    int i;
41
42    for (i = 0; i < n; i += 2)
43    {
44        sum0 += x[i + 0][0] * x[i + 0][0];
45        sum1 += x[i + 0][1] * x[i + 0][1];
46        sum0 += x[i + 1][0] * x[i + 1][0];
47        sum1 += x[i + 1][1] * x[i + 1][1];
48    }
49
50    return sum0 + sum1;
51}
52
53static void sbr_neg_odd_64_c(float *x)
54{
55    union av_intfloat32 *xi = (union av_intfloat32*) x;
56    int i;
57    for (i = 1; i < 64; i += 4) {
58        xi[i + 0].i ^= 1U << 31;
59        xi[i + 2].i ^= 1U << 31;
60    }
61}
62
63static void sbr_qmf_pre_shuffle_c(float *z)
64{
65    union av_intfloat32 *zi = (union av_intfloat32*) z;
66    int k;
67    zi[64].i = zi[0].i;
68    zi[65].i = zi[1].i;
69    for (k = 1; k < 31; k += 2) {
70        zi[64 + 2 * k + 0].i = zi[64 - k].i ^ (1U << 31);
71        zi[64 + 2 * k + 1].i = zi[ k + 1].i;
72        zi[64 + 2 * k + 2].i = zi[63 - k].i ^ (1U << 31);
73        zi[64 + 2 * k + 3].i = zi[ k + 2].i;
74    }
75
76    zi[64 + 2 * 31 + 0].i = zi[64 - 31].i ^ (1U << 31);
77    zi[64 + 2 * 31 + 1].i = zi[31 +  1].i;
78}
79
80static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
81{
82    const union av_intfloat32 *zi = (const union av_intfloat32*) z;
83    union av_intfloat32 *Wi       = (union av_intfloat32*) W;
84    int k;
85    for (k = 0; k < 32; k += 2) {
86        Wi[2 * k + 0].i = zi[63 - k].i ^ (1U << 31);
87        Wi[2 * k + 1].i = zi[ k + 0].i;
88        Wi[2 * k + 2].i = zi[62 - k].i ^ (1U << 31);
89        Wi[2 * k + 3].i = zi[ k + 1].i;
90    }
91}
92
93static void sbr_qmf_deint_neg_c(float *v, const float *src)
94{
95    const union av_intfloat32 *si = (const union av_intfloat32*)src;
96    union av_intfloat32 *vi = (union av_intfloat32*)v;
97    int i;
98    for (i = 0; i < 32; i++) {
99        vi[     i].i = si[63 - 2 * i    ].i;
100        vi[63 - i].i = si[63 - 2 * i - 1].i ^ (1U << 31);
101    }
102}
103
104static void sbr_qmf_deint_bfly_c(float *v, const float *src0, const float *src1)
105{
106    int i;
107    for (i = 0; i < 64; i++) {
108        v[      i] = src0[i] - src1[63 - i];
109        v[127 - i] = src0[i] + src1[63 - i];
110    }
111}
112
113
114#if 0
115    /* This code is slower because it multiplies memory accesses.
116     * It is left for educational purposes and because it may offer
117     * a better reference for writing arch-specific DSP functions. */
118static av_always_inline void autocorrelate(const float x[40][2],
119                                           float phi[3][2][2], int lag)
120{
121    int i;
122    float real_sum = 0.0f;
123    float imag_sum = 0.0f;
124    if (lag) {
125        for (i = 1; i < 38; i++) {
126            real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
127            imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
128        }
129        phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
130        phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
131        if (lag == 1) {
132            phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
133            phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
134        }
135    } else {
136        for (i = 1; i < 38; i++) {
137            real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
138        }
139        phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
140        phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
141    }
142}
143
144static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
145{
146    autocorrelate(x, phi, 0);
147    autocorrelate(x, phi, 1);
148    autocorrelate(x, phi, 2);
149}
150#else
151static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
152{
153    float real_sum2 = x[0][0] * x[2][0] + x[0][1] * x[2][1];
154    float imag_sum2 = x[0][0] * x[2][1] - x[0][1] * x[2][0];
155    float real_sum1 = 0.0f, imag_sum1 = 0.0f, real_sum0 = 0.0f;
156    int   i;
157    for (i = 1; i < 38; i++) {
158        real_sum0 += x[i][0] * x[i    ][0] + x[i][1] * x[i    ][1];
159        real_sum1 += x[i][0] * x[i + 1][0] + x[i][1] * x[i + 1][1];
160        imag_sum1 += x[i][0] * x[i + 1][1] - x[i][1] * x[i + 1][0];
161        real_sum2 += x[i][0] * x[i + 2][0] + x[i][1] * x[i + 2][1];
162        imag_sum2 += x[i][0] * x[i + 2][1] - x[i][1] * x[i + 2][0];
163    }
164    phi[2 - 2][1][0] = real_sum2;
165    phi[2 - 2][1][1] = imag_sum2;
166    phi[2    ][1][0] = real_sum0 + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
167    phi[1    ][0][0] = real_sum0 + x[38][0] * x[38][0] + x[38][1] * x[38][1];
168    phi[2 - 1][1][0] = real_sum1 + x[ 0][0] * x[ 1][0] + x[ 0][1] * x[ 1][1];
169    phi[2 - 1][1][1] = imag_sum1 + x[ 0][0] * x[ 1][1] - x[ 0][1] * x[ 1][0];
170    phi[0    ][0][0] = real_sum1 + x[38][0] * x[39][0] + x[38][1] * x[39][1];
171    phi[0    ][0][1] = imag_sum1 + x[38][0] * x[39][1] - x[38][1] * x[39][0];
172#endif
173}
174
175static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
176                         const float alpha0[2], const float alpha1[2],
177                         float bw, int start, int end)
178{
179    float alpha[4];
180    int i;
181
182    alpha[0] = alpha1[0] * bw * bw;
183    alpha[1] = alpha1[1] * bw * bw;
184    alpha[2] = alpha0[0] * bw;
185    alpha[3] = alpha0[1] * bw;
186
187    for (i = start; i < end; i++) {
188        X_high[i][0] =
189            X_low[i - 2][0] * alpha[0] -
190            X_low[i - 2][1] * alpha[1] +
191            X_low[i - 1][0] * alpha[2] -
192            X_low[i - 1][1] * alpha[3] +
193            X_low[i][0];
194        X_high[i][1] =
195            X_low[i - 2][1] * alpha[0] +
196            X_low[i - 2][0] * alpha[1] +
197            X_low[i - 1][1] * alpha[2] +
198            X_low[i - 1][0] * alpha[3] +
199            X_low[i][1];
200    }
201}
202
203static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],
204                            const float *g_filt, int m_max, intptr_t ixh)
205{
206    int m;
207
208    for (m = 0; m < m_max; m++) {
209        Y[m][0] = X_high[m][ixh][0] * g_filt[m];
210        Y[m][1] = X_high[m][ixh][1] * g_filt[m];
211    }
212}
213
214static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
215                                                const float *s_m,
216                                                const float *q_filt,
217                                                int noise,
218                                                float phi_sign0,
219                                                float phi_sign1,
220                                                int m_max)
221{
222    int m;
223
224    for (m = 0; m < m_max; m++) {
225        float y0 = Y[m][0];
226        float y1 = Y[m][1];
227        noise = (noise + 1) & 0x1ff;
228        if (s_m[m]) {
229            y0 += s_m[m] * phi_sign0;
230            y1 += s_m[m] * phi_sign1;
231        } else {
232            y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
233            y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
234        }
235        Y[m][0] = y0;
236        Y[m][1] = y1;
237        phi_sign1 = -phi_sign1;
238    }
239}
240
241static void sbr_hf_apply_noise_0(float (*Y)[2], const float *s_m,
242                                 const float *q_filt, int noise,
243                                 int kx, int m_max)
244{
245    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 1.0, 0.0, m_max);
246}
247
248static void sbr_hf_apply_noise_1(float (*Y)[2], const float *s_m,
249                                 const float *q_filt, int noise,
250                                 int kx, int m_max)
251{
252    float phi_sign = 1 - 2 * (kx & 1);
253    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, phi_sign, m_max);
254}
255
256static void sbr_hf_apply_noise_2(float (*Y)[2], const float *s_m,
257                                 const float *q_filt, int noise,
258                                 int kx, int m_max)
259{
260    sbr_hf_apply_noise(Y, s_m, q_filt, noise, -1.0, 0.0, m_max);
261}
262
263static void sbr_hf_apply_noise_3(float (*Y)[2], const float *s_m,
264                                 const float *q_filt, int noise,
265                                 int kx, int m_max)
266{
267    float phi_sign = 1 - 2 * (kx & 1);
268    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, -phi_sign, m_max);
269}
270
271av_cold void ff_sbrdsp_init(SBRDSPContext *s)
272{
273    s->sum64x5 = sbr_sum64x5_c;
274    s->sum_square = sbr_sum_square_c;
275    s->neg_odd_64 = sbr_neg_odd_64_c;
276    s->qmf_pre_shuffle = sbr_qmf_pre_shuffle_c;
277    s->qmf_post_shuffle = sbr_qmf_post_shuffle_c;
278    s->qmf_deint_neg = sbr_qmf_deint_neg_c;
279    s->qmf_deint_bfly = sbr_qmf_deint_bfly_c;
280    s->autocorrelate = sbr_autocorrelate_c;
281    s->hf_gen = sbr_hf_gen_c;
282    s->hf_g_filt = sbr_hf_g_filt_c;
283
284    s->hf_apply_noise[0] = sbr_hf_apply_noise_0;
285    s->hf_apply_noise[1] = sbr_hf_apply_noise_1;
286    s->hf_apply_noise[2] = sbr_hf_apply_noise_2;
287    s->hf_apply_noise[3] = sbr_hf_apply_noise_3;
288
289    if (ARCH_ARM)
290        ff_sbrdsp_init_arm(s);
291    if (ARCH_X86)
292        ff_sbrdsp_init_x86(s);
293    if (ARCH_MIPS)
294        ff_sbrdsp_init_mips(s);
295}
296