summaryrefslogtreecommitdiffstats
path: root/libavcodec/aacsbr.c
blob: 1d2a8d472d841763a83e391da5ae7dfb51e51d6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
/*
 * AAC Spectral Band Replication decoding functions
 * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
 * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * AAC Spectral Band Replication decoding functions
 * @author Robert Swain ( rob opendot cl )
 */
#define USE_FIXED 0

#include "aac.h"
#include "sbr.h"
#include "aacsbr.h"
#include "aacsbrdata.h"
#include "aacsbr_tablegen.h"
#include "fft.h"
#include "internal.h"
#include "aacps.h"
#include "sbrdsp.h"
#include "libavutil/internal.h"
#include "libavutil/libm.h"
#include "libavutil/avassert.h"

#include <stdint.h>
#include <float.h>
#include <math.h>

#if ARCH_MIPS
#include "mips/aacsbr_mips.h"
#endif /* ARCH_MIPS */

static VLC vlc_sbr[10];
static void aacsbr_func_ptr_init(AACSBRContext *c);

static void make_bands(int16_t* bands, int start, int stop, int num_bands)
{
    int k, previous, present;
    float base, prod;

    base = powf((float)stop / start, 1.0f / num_bands);
    prod = start;
    previous = start;

    for (k = 0; k < num_bands-1; k++) {
        prod *= base;
        present  = lrintf(prod);
        bands[k] = present - previous;
        previous = present;
    }
    bands[num_bands-1] = stop - previous;
}

/// Dequantization and stereo decoding (14496-3 sp04 p203)
static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
{
    int k, e;
    int ch;
    static const double exp2_tab[2] = {1, M_SQRT2};
    if (id_aac == TYPE_CPE && sbr->bs_coupling) {
        int pan_offset = sbr->data[0].bs_amp_res ? 12 : 24;
        for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
            for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
                float temp1, temp2, fac;
                if (sbr->data[0].bs_amp_res) {
                    temp1 = ff_exp2fi(sbr->data[0].env_facs_q[e][k] + 7);
                    temp2 = ff_exp2fi(pan_offset - sbr->data[1].env_facs_q[e][k]);
                }
                else {
                    temp1 = ff_exp2fi((sbr->data[0].env_facs_q[e][k]>>1) + 7) *
                            exp2_tab[sbr->data[0].env_facs_q[e][k] & 1];
                    temp2 = ff_exp2fi((pan_offset - sbr->data[1].env_facs_q[e][k])>>1) *
                            exp2_tab[(pan_offset - sbr->data[1].env_facs_q[e][k]) & 1];
                }
                if (temp1 > 1E20) {
                    av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
                    temp1 = 1;
                }
                fac   = temp1 / (1.0f + temp2);
                sbr->data[0].env_facs[e][k] = fac;
                sbr->data[1].env_facs[e][k] = fac * temp2;
            }
        }
        for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
            for (k = 0; k < sbr->n_q; k++) {
                float temp1 = ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs_q[e][k] + 1);
                float temp2 = ff_exp2fi(12 - sbr->data[1].noise_facs_q[e][k]);
                float fac;
                av_assert0(temp1 <= 1E20);
                fac = temp1 / (1.0f + temp2);
                sbr->data[0].noise_facs[e][k] = fac;
                sbr->data[1].noise_facs[e][k] = fac * temp2;
            }
        }
    } else { // SCE or one non-coupled CPE
        for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
            for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
                for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){
                    if (sbr->data[ch].bs_amp_res)
                        sbr->data[ch].env_facs[e][k] = ff_exp2fi(sbr->data[ch].env_facs_q[e][k] + 6);
                    else
                        sbr->data[ch].env_facs[e][k] = ff_exp2fi((sbr->data[ch].env_facs_q[e][k]>>1) + 6)
                                                       * exp2_tab[sbr->data[ch].env_facs_q[e][k] & 1];
                    if (sbr->data[ch].env_facs[e][k] > 1E20) {
                        av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
                        sbr->data[ch].env_facs[e][k] = 1;
                    }
                }

            for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
                for (k = 0; k < sbr->n_q; k++)
                    sbr->data[ch].noise_facs[e][k] =
                        ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs_q[e][k]);
        }
    }
}

/** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering
 * (14496-3 sp04 p214)
 * Warning: This routine does not seem numerically stable.
 */
static void sbr_hf_inverse_filter(SBRDSPContext *dsp,
                                  float (*alpha0)[2], float (*alpha1)[2],
                                  const float X_low[32][40][2], int k0)
{
    int k;
    for (k = 0; k < k0; k++) {
        LOCAL_ALIGNED_16(float, phi, [3], [2][2]);
        float dk;

        dsp->autocorrelate(X_low[k], phi);

        dk =  phi[2][1][0] * phi[1][0][0] -
             (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

        if (!dk) {
            alpha1[k][0] = 0;
            alpha1[k][1] = 0;
        } else {
            float temp_real, temp_im;
            temp_real = phi[0][0][0] * phi[1][1][0] -
                        phi[0][0][1] * phi[1][1][1] -
                        phi[0][1][0] * phi[1][0][0];
            temp_im   = phi[0][0][0] * phi[1][1][1] +
                        phi[0][0][1] * phi[1][1][0] -
                        phi[0][1][1] * phi[1][0][0];

            alpha1[k][0] = temp_real / dk;
            alpha1[k][1] = temp_im   / dk;
        }

        if (!phi[1][0][0]) {
            alpha0[k][0] = 0;
            alpha0[k][1] = 0;
        } else {
            float temp_real, temp_im;
            temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
                                       alpha1[k][1] * phi[1][1][1];
            temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
                                       alpha1[k][0] * phi[1][1][1];

            alpha0[k][0] = -temp_real / phi[1][0][0];
            alpha0[k][1] = -temp_im   / phi[1][0][0];
        }

        if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
           alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
            alpha1[k][0] = 0;
            alpha1[k][1] = 0;
            alpha0[k][0] = 0;
            alpha0[k][1] = 0;
        }
    }
}

/// Chirp Factors (14496-3 sp04 p214)
static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
{
    int i;
    float new_bw;
    static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

    for (i = 0; i < sbr->n_q; i++) {
        if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
            new_bw = 0.6f;
        } else
            new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

        if (new_bw < ch_data->bw_array[i]) {
            new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];
        } else
            new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
        ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
    }
}

/**
 * Calculation of levels of additional HF signal components (14496-3 sp04 p219)
 * and Calculation of gain (14496-3 sp04 p219)
 */
static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
                          SBRData *ch_data, const int e_a[2])
{
    int e, k, m;
    // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
    static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

    for (e = 0; e < ch_data->bs_num_env; e++) {
        int delta = !((e == e_a[1]) || (e == e_a[0]));
        for (k = 0; k < sbr->n_lim; k++) {
            float gain_boost, gain_max;
            float sum[2] = { 0.0f, 0.0f };
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
                sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
                sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
                if (!sbr->s_mapped[e][m]) {
                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
                                            ((1.0f + sbr->e_curr[e][m]) *
                                             (1.0f + sbr->q_mapped[e][m] * delta)));
                } else {
                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
                                            ((1.0f + sbr->e_curr[e][m]) *
                                             (1.0f + sbr->q_mapped[e][m])));
                }
                sbr->gain[e][m] += FLT_MIN;
            }
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sum[0] += sbr->e_origmapped[e][m];
                sum[1] += sbr->e_curr[e][m];
            }
            gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
            gain_max = FFMIN(100000.f, gain_max);
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
                sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);
                sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
            }
            sum[0] = sum[1] = 0.0f;
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sum[0] += sbr->e_origmapped[e][m];
                sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
                          + sbr->s_m[e][m] * sbr->s_m[e][m]
                          + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
            }
            gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
            gain_boost = FFMIN(1.584893192f, gain_boost);
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sbr->gain[e][m] *= gain_boost;
                sbr->q_m[e][m]  *= gain_boost;
                sbr->s_m[e][m]  *= gain_boost;
            }
        }
    }
}

/// Assembling HF Signals (14496-3 sp04 p220)
static void 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])
{
    int e, i, j, m;
    const int h_SL = 4 * !sbr->bs_smoothing_mode;
    const int kx = sbr->kx[1];
    const int m_max = sbr->m[1];
    static const float h_smooth[5] = {
        0.33333333333333,
        0.30150283239582,
        0.21816949906249,
        0.11516383427084,
        0.03183050093751,
    };
    float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
    int indexnoise = ch_data->f_indexnoise;
    int indexsine  = ch_data->f_indexsine;

    if (sbr->reset) {
        for (i = 0; i < h_SL; i++) {
            memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
            memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));
        }
    } else if (h_SL) {
        for (i = 0; i < 4; i++) {
            memcpy(g_temp[i + 2 * ch_data->t_env[0]],
                   g_temp[i + 2 * ch_data->t_env_num_env_old],
                   sizeof(g_temp[0]));
            memcpy(q_temp[i + 2 * ch_data->t_env[0]],
                   q_temp[i + 2 * ch_data->t_env_num_env_old],
                   sizeof(q_temp[0]));
        }
    }

    for (e = 0; e < ch_data->bs_num_env; e++) {
        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
            memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
            memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));
        }
    }

    for (e = 0; e < ch_data->bs_num_env; e++) {
        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
            LOCAL_ALIGNED_16(float, g_filt_tab, [48]);
            LOCAL_ALIGNED_16(float, q_filt_tab, [48]);
            float *g_filt, *q_filt;

            if (h_SL && e != e_a[0] && e != e_a[1]) {
                g_filt = g_filt_tab;
                q_filt = q_filt_tab;
                for (m = 0; m < m_max; m++) {
                    const int idx1 = i + h_SL;
                    g_filt[m] = 0.0f;
                    q_filt[m] = 0.0f;
                    for (j = 0; j <= h_SL; j++) {
                        g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];
                        q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];
                    }
                }
            } else {
                g_filt = g_temp[i + h_SL];
                q_filt = q_temp[i];
            }

            sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,
                               i + ENVELOPE_ADJUSTMENT_OFFSET);

            if (e != e_a[0] && e != e_a[1]) {
                sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],
                                                   q_filt, indexnoise,
                                                   kx, m_max);
            } else {
                int idx = indexsine&1;
                int A = (1-((indexsine+(kx & 1))&2));
                int B = (A^(-idx)) + idx;
                float *out = &Y1[i][kx][idx];
                float *in  = sbr->s_m[e];
                for (m = 0; m+1 < m_max; m+=2) {
                    out[2*m  ] += in[m  ] * A;
                    out[2*m+2] += in[m+1] * B;
                }
                if(m_max&1)
                    out[2*m  ] += in[m  ] * A;
            }
            indexnoise = (indexnoise + m_max) & 0x1ff;
            indexsine = (indexsine + 1) & 3;
        }
    }
    ch_data->f_indexnoise = indexnoise;
    ch_data->f_indexsine  = indexsine;
}

#include "aacsbr_template.c"
OpenPOWER on IntegriCloud