/* * 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"