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 /**
24 * @file
25 * AAC Spectral Band Replication decoding functions
26 * @author Robert Swain ( rob opendot cl )
27 */
28 #define USE_FIXED 0
29
30 #include "aac.h"
31 #include "sbr.h"
32 #include "aacsbr.h"
33 #include "aacsbrdata.h"
34 #include "fft.h"
35 #include "internal.h"
36 #include "aacps.h"
37 #include "sbrdsp.h"
38 #include "libavutil/internal.h"
39 #include "libavutil/libm.h"
40 #include "libavutil/avassert.h"
41 #include "libavutil/mem_internal.h"
42
43 #include <stdint.h>
44 #include <float.h>
45 #include <math.h>
46
47 #if ARCH_MIPS
48 #include "mips/aacsbr_mips.h"
49 #endif /* ARCH_MIPS */
50
51 static VLC vlc_sbr[10];
52 static void aacsbr_func_ptr_init(AACSBRContext *c);
53
make_bands(int16_t * bands,int start,int stop,int num_bands)54 static void make_bands(int16_t* bands, int start, int stop, int num_bands)
55 {
56 int k, previous, present;
57 float base, prod;
58
59 base = powf((float)stop / start, 1.0f / num_bands);
60 prod = start;
61 previous = start;
62
63 for (k = 0; k < num_bands-1; k++) {
64 prod *= base;
65 present = lrintf(prod);
66 bands[k] = present - previous;
67 previous = present;
68 }
69 bands[num_bands-1] = stop - previous;
70 }
71
72 /// Dequantization and stereo decoding (14496-3 sp04 p203)
sbr_dequant(SpectralBandReplication * sbr,int id_aac)73 static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
74 {
75 int k, e;
76 int ch;
77 static const double exp2_tab[2] = {1, M_SQRT2};
78 if (id_aac == TYPE_CPE && sbr->bs_coupling) {
79 int pan_offset = sbr->data[0].bs_amp_res ? 12 : 24;
80 for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
81 for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
82 float temp1, temp2, fac;
83 if (sbr->data[0].bs_amp_res) {
84 temp1 = ff_exp2fi(sbr->data[0].env_facs_q[e][k] + 7);
85 temp2 = ff_exp2fi(pan_offset - sbr->data[1].env_facs_q[e][k]);
86 }
87 else {
88 temp1 = ff_exp2fi((sbr->data[0].env_facs_q[e][k]>>1) + 7) *
89 exp2_tab[sbr->data[0].env_facs_q[e][k] & 1];
90 temp2 = ff_exp2fi((pan_offset - sbr->data[1].env_facs_q[e][k])>>1) *
91 exp2_tab[(pan_offset - sbr->data[1].env_facs_q[e][k]) & 1];
92 }
93 if (temp1 > 1E20) {
94 av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
95 temp1 = 1;
96 }
97 fac = temp1 / (1.0f + temp2);
98 sbr->data[0].env_facs[e][k] = fac;
99 sbr->data[1].env_facs[e][k] = fac * temp2;
100 }
101 }
102 for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
103 for (k = 0; k < sbr->n_q; k++) {
104 float temp1 = ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs_q[e][k] + 1);
105 float temp2 = ff_exp2fi(12 - sbr->data[1].noise_facs_q[e][k]);
106 float fac;
107 av_assert0(temp1 <= 1E20);
108 fac = temp1 / (1.0f + temp2);
109 sbr->data[0].noise_facs[e][k] = fac;
110 sbr->data[1].noise_facs[e][k] = fac * temp2;
111 }
112 }
113 } else { // SCE or one non-coupled CPE
114 for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
115 for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
116 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){
117 if (sbr->data[ch].bs_amp_res)
118 sbr->data[ch].env_facs[e][k] = ff_exp2fi(sbr->data[ch].env_facs_q[e][k] + 6);
119 else
120 sbr->data[ch].env_facs[e][k] = ff_exp2fi((sbr->data[ch].env_facs_q[e][k]>>1) + 6)
121 * exp2_tab[sbr->data[ch].env_facs_q[e][k] & 1];
122 if (sbr->data[ch].env_facs[e][k] > 1E20) {
123 av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
124 sbr->data[ch].env_facs[e][k] = 1;
125 }
126 }
127
128 for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
129 for (k = 0; k < sbr->n_q; k++)
130 sbr->data[ch].noise_facs[e][k] =
131 ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs_q[e][k]);
132 }
133 }
134 }
135
136 /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering
137 * (14496-3 sp04 p214)
138 * Warning: This routine does not seem numerically stable.
139 */
sbr_hf_inverse_filter(SBRDSPContext * dsp,float (* alpha0)[2],float (* alpha1)[2],const float X_low[32][40][2],int k0)140 static void sbr_hf_inverse_filter(SBRDSPContext *dsp,
141 float (*alpha0)[2], float (*alpha1)[2],
142 const float X_low[32][40][2], int k0)
143 {
144 int k;
145 for (k = 0; k < k0; k++) {
146 LOCAL_ALIGNED_16(float, phi, [3], [2][2]);
147 float dk;
148
149 dsp->autocorrelate(X_low[k], phi);
150
151 dk = phi[2][1][0] * phi[1][0][0] -
152 (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;
153
154 if (!dk) {
155 alpha1[k][0] = 0;
156 alpha1[k][1] = 0;
157 } else {
158 float temp_real, temp_im;
159 temp_real = phi[0][0][0] * phi[1][1][0] -
160 phi[0][0][1] * phi[1][1][1] -
161 phi[0][1][0] * phi[1][0][0];
162 temp_im = phi[0][0][0] * phi[1][1][1] +
163 phi[0][0][1] * phi[1][1][0] -
164 phi[0][1][1] * phi[1][0][0];
165
166 alpha1[k][0] = temp_real / dk;
167 alpha1[k][1] = temp_im / dk;
168 }
169
170 if (!phi[1][0][0]) {
171 alpha0[k][0] = 0;
172 alpha0[k][1] = 0;
173 } else {
174 float temp_real, temp_im;
175 temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
176 alpha1[k][1] * phi[1][1][1];
177 temp_im = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
178 alpha1[k][0] * phi[1][1][1];
179
180 alpha0[k][0] = -temp_real / phi[1][0][0];
181 alpha0[k][1] = -temp_im / phi[1][0][0];
182 }
183
184 if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
185 alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
186 alpha1[k][0] = 0;
187 alpha1[k][1] = 0;
188 alpha0[k][0] = 0;
189 alpha0[k][1] = 0;
190 }
191 }
192 }
193
194 /// Chirp Factors (14496-3 sp04 p214)
sbr_chirp(SpectralBandReplication * sbr,SBRData * ch_data)195 static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
196 {
197 int i;
198 float new_bw;
199 static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };
200
201 for (i = 0; i < sbr->n_q; i++) {
202 if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
203 new_bw = 0.6f;
204 } else
205 new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];
206
207 if (new_bw < ch_data->bw_array[i]) {
208 new_bw = 0.75f * new_bw + 0.25f * ch_data->bw_array[i];
209 } else
210 new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
211 ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
212 }
213 }
214
215 /**
216 * Calculation of levels of additional HF signal components (14496-3 sp04 p219)
217 * and Calculation of gain (14496-3 sp04 p219)
218 */
sbr_gain_calc(AACContext * ac,SpectralBandReplication * sbr,SBRData * ch_data,const int e_a[2])219 static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
220 SBRData *ch_data, const int e_a[2])
221 {
222 int e, k, m;
223 // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
224 static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };
225
226 for (e = 0; e < ch_data->bs_num_env; e++) {
227 int delta = !((e == e_a[1]) || (e == e_a[0]));
228 for (k = 0; k < sbr->n_lim; k++) {
229 float gain_boost, gain_max;
230 float sum[2] = { 0.0f, 0.0f };
231 for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
232 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
233 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
234 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
235 if (!sbr->s_mapped[e][m]) {
236 sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
237 ((1.0f + sbr->e_curr[e][m]) *
238 (1.0f + sbr->q_mapped[e][m] * delta)));
239 } else {
240 sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
241 ((1.0f + sbr->e_curr[e][m]) *
242 (1.0f + sbr->q_mapped[e][m])));
243 }
244 sbr->gain[e][m] += FLT_MIN;
245 }
246 for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
247 sum[0] += sbr->e_origmapped[e][m];
248 sum[1] += sbr->e_curr[e][m];
249 }
250 gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
251 gain_max = FFMIN(100000.f, gain_max);
252 for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
253 float q_m_max = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
254 sbr->q_m[e][m] = FFMIN(sbr->q_m[e][m], q_m_max);
255 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
256 }
257 sum[0] = sum[1] = 0.0f;
258 for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
259 sum[0] += sbr->e_origmapped[e][m];
260 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
261 + sbr->s_m[e][m] * sbr->s_m[e][m]
262 + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
263 }
264 gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
265 gain_boost = FFMIN(1.584893192f, gain_boost);
266 for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
267 sbr->gain[e][m] *= gain_boost;
268 sbr->q_m[e][m] *= gain_boost;
269 sbr->s_m[e][m] *= gain_boost;
270 }
271 }
272 }
273 }
274
275 /// Assembling HF Signals (14496-3 sp04 p220)
sbr_hf_assemble(float Y1[38][64][2],const float X_high[64][40][2],SpectralBandReplication * sbr,SBRData * ch_data,const int e_a[2])276 static void sbr_hf_assemble(float Y1[38][64][2],
277 const float X_high[64][40][2],
278 SpectralBandReplication *sbr, SBRData *ch_data,
279 const int e_a[2])
280 {
281 int e, i, j, m;
282 const int h_SL = 4 * !sbr->bs_smoothing_mode;
283 const int kx = sbr->kx[1];
284 const int m_max = sbr->m[1];
285 static const float h_smooth[5] = {
286 0.33333333333333,
287 0.30150283239582,
288 0.21816949906249,
289 0.11516383427084,
290 0.03183050093751,
291 };
292 float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
293 int indexnoise = ch_data->f_indexnoise;
294 int indexsine = ch_data->f_indexsine;
295
296 if (sbr->reset) {
297 for (i = 0; i < h_SL; i++) {
298 memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
299 memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0], m_max * sizeof(sbr->q_m[0][0]));
300 }
301 } else if (h_SL) {
302 for (i = 0; i < 4; i++) {
303 memcpy(g_temp[i + 2 * ch_data->t_env[0]],
304 g_temp[i + 2 * ch_data->t_env_num_env_old],
305 sizeof(g_temp[0]));
306 memcpy(q_temp[i + 2 * ch_data->t_env[0]],
307 q_temp[i + 2 * ch_data->t_env_num_env_old],
308 sizeof(q_temp[0]));
309 }
310 }
311
312 for (e = 0; e < ch_data->bs_num_env; e++) {
313 for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
314 memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
315 memcpy(q_temp[h_SL + i], sbr->q_m[e], m_max * sizeof(sbr->q_m[0][0]));
316 }
317 }
318
319 for (e = 0; e < ch_data->bs_num_env; e++) {
320 for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
321 LOCAL_ALIGNED_16(float, g_filt_tab, [48]);
322 LOCAL_ALIGNED_16(float, q_filt_tab, [48]);
323 float *g_filt, *q_filt;
324
325 if (h_SL && e != e_a[0] && e != e_a[1]) {
326 g_filt = g_filt_tab;
327 q_filt = q_filt_tab;
328 for (m = 0; m < m_max; m++) {
329 const int idx1 = i + h_SL;
330 g_filt[m] = 0.0f;
331 q_filt[m] = 0.0f;
332 for (j = 0; j <= h_SL; j++) {
333 g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];
334 q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];
335 }
336 }
337 } else {
338 g_filt = g_temp[i + h_SL];
339 q_filt = q_temp[i];
340 }
341
342 sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,
343 i + ENVELOPE_ADJUSTMENT_OFFSET);
344
345 if (e != e_a[0] && e != e_a[1]) {
346 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],
347 q_filt, indexnoise,
348 kx, m_max);
349 } else {
350 int idx = indexsine&1;
351 int A = (1-((indexsine+(kx & 1))&2));
352 int B = (A^(-idx)) + idx;
353 float *out = &Y1[i][kx][idx];
354 float *in = sbr->s_m[e];
355 for (m = 0; m+1 < m_max; m+=2) {
356 out[2*m ] += in[m ] * A;
357 out[2*m+2] += in[m+1] * B;
358 }
359 if(m_max&1)
360 out[2*m ] += in[m ] * A;
361 }
362 indexnoise = (indexnoise + m_max) & 0x1ff;
363 indexsine = (indexsine + 1) & 3;
364 }
365 }
366 ch_data->f_indexnoise = indexnoise;
367 ch_data->f_indexsine = indexsine;
368 }
369
370 #include "aacsbr_template.c"
371