1/* 2 * LSP routines for ACELP-based codecs 3 * 4 * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet (QCELP decoder) 5 * Copyright (c) 2008 Vladimir Voroshilov 6 * 7 * This file is part of FFmpeg. 8 * 9 * FFmpeg is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2.1 of the License, or (at your option) any later version. 13 * 14 * FFmpeg is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with FFmpeg; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 22 */ 23 24#include <inttypes.h> 25 26#include "avcodec.h" 27#define FRAC_BITS 14 28#include "mathops.h" 29#include "lsp.h" 30#include "libavcodec/mips/lsp_mips.h" 31#include "libavutil/avassert.h" 32 33void ff_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsfq_min, int lsfq_max, int lp_order) 34{ 35 int i, j; 36 37 /* sort lsfq in ascending order. float bubble agorithm, 38 O(n) if data already sorted, O(n^2) - otherwise */ 39 for(i=0; i<lp_order-1; i++) 40 for(j=i; j>=0 && lsfq[j] > lsfq[j+1]; j--) 41 FFSWAP(int16_t, lsfq[j], lsfq[j+1]); 42 43 for(i=0; i<lp_order; i++) 44 { 45 lsfq[i] = FFMAX(lsfq[i], lsfq_min); 46 lsfq_min = lsfq[i] + lsfq_min_distance; 47 } 48 lsfq[lp_order-1] = FFMIN(lsfq[lp_order-1], lsfq_max);//Is warning required ? 49} 50 51void ff_set_min_dist_lsf(float *lsf, double min_spacing, int size) 52{ 53 int i; 54 float prev = 0.0; 55 for (i = 0; i < size; i++) 56 prev = lsf[i] = FFMAX(lsf[i], prev + min_spacing); 57} 58 59 60/* Cosine table: base_cos[i] = (1 << 15) * cos(i * PI / 64) */ 61static const int16_t tab_cos[65] = 62{ 63 32767, 32738, 32617, 32421, 32145, 31793, 31364, 30860, 64 30280, 29629, 28905, 28113, 27252, 26326, 25336, 24285, 65 23176, 22011, 20793, 19525, 18210, 16851, 15451, 14014, 66 12543, 11043, 9515, 7965, 6395, 4810, 3214, 1609, 67 1, -1607, -3211, -4808, -6393, -7962, -9513, -11040, 68 -12541, -14012, -15449, -16848, -18207, -19523, -20791, -22009, 69 -23174, -24283, -25334, -26324, -27250, -28111, -28904, -29627, 70 -30279, -30858, -31363, -31792, -32144, -32419, -32616, -32736, -32768, 71}; 72 73static int16_t ff_cos(uint16_t arg) 74{ 75 uint8_t offset= arg; 76 uint8_t ind = arg >> 8; 77 78 av_assert2(arg <= 0x3fff); 79 80 return tab_cos[ind] + (offset * (tab_cos[ind+1] - tab_cos[ind]) >> 8); 81} 82 83void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf, int lp_order) 84{ 85 int i; 86 87 /* Convert LSF to LSP, lsp=cos(lsf) */ 88 for(i=0; i<lp_order; i++) 89 // 20861 = 2.0 / PI in (0.15) 90 lsp[i] = ff_cos(lsf[i] * 20861 >> 15); // divide by PI and (0,13) -> (0,14) 91} 92 93void ff_acelp_lsf2lspd(double *lsp, const float *lsf, int lp_order) 94{ 95 int i; 96 97 for(i = 0; i < lp_order; i++) 98 lsp[i] = cos(2.0 * M_PI * lsf[i]); 99} 100 101/** 102 * @brief decodes polynomial coefficients from LSP 103 * @param[out] f decoded polynomial coefficients (-0x20000000 <= (3.22) <= 0x1fffffff) 104 * @param lsp LSP coefficients (-0x8000 <= (0.15) <= 0x7fff) 105 */ 106static void lsp2poly(int* f, const int16_t* lsp, int lp_half_order) 107{ 108 int i, j; 109 110 f[0] = 0x400000; // 1.0 in (3.22) 111 f[1] = -lsp[0] << 8; // *2 and (0.15) -> (3.22) 112 113 for(i=2; i<=lp_half_order; i++) 114 { 115 f[i] = f[i-2]; 116 for(j=i; j>1; j--) 117 f[j] -= MULL(f[j-1], lsp[2*i-2], FRAC_BITS) - f[j-2]; 118 119 f[1] -= lsp[2*i-2] << 8; 120 } 121} 122 123void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order) 124{ 125 int i; 126 int f1[MAX_LP_HALF_ORDER+1]; // (3.22) 127 int f2[MAX_LP_HALF_ORDER+1]; // (3.22) 128 129 lsp2poly(f1, lsp , lp_half_order); 130 lsp2poly(f2, lsp+1, lp_half_order); 131 132 /* 3.2.6 of G.729, Equations 25 and 26*/ 133 lp[0] = 4096; 134 for(i=1; i<lp_half_order+1; i++) 135 { 136 int ff1 = f1[i] + f1[i-1]; // (3.22) 137 int ff2 = f2[i] - f2[i-1]; // (3.22) 138 139 ff1 += 1 << 10; // for rounding 140 lp[i] = (ff1 + ff2) >> 11; // divide by 2 and (3.22) -> (3.12) 141 lp[(lp_half_order << 1) + 1 - i] = (ff1 - ff2) >> 11; // divide by 2 and (3.22) -> (3.12) 142 } 143} 144 145void ff_amrwb_lsp2lpc(const double *lsp, float *lp, int lp_order) 146{ 147 int lp_half_order = lp_order >> 1; 148 double buf[MAX_LP_HALF_ORDER + 1]; 149 double pa[MAX_LP_HALF_ORDER + 1]; 150 double *qa = buf + 1; 151 int i,j; 152 153 qa[-1] = 0.0; 154 155 ff_lsp2polyf(lsp , pa, lp_half_order ); 156 ff_lsp2polyf(lsp + 1, qa, lp_half_order - 1); 157 158 for (i = 1, j = lp_order - 1; i < lp_half_order; i++, j--) { 159 double paf = pa[i] * (1 + lsp[lp_order - 1]); 160 double qaf = (qa[i] - qa[i-2]) * (1 - lsp[lp_order - 1]); 161 lp[i-1] = (paf + qaf) * 0.5; 162 lp[j-1] = (paf - qaf) * 0.5; 163 } 164 165 lp[lp_half_order - 1] = (1.0 + lsp[lp_order - 1]) * 166 pa[lp_half_order] * 0.5; 167 168 lp[lp_order - 1] = lsp[lp_order - 1]; 169} 170 171void ff_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd, const int16_t* lsp_prev, int lp_order) 172{ 173 int16_t lsp_1st[MAX_LP_ORDER]; // (0.15) 174 int i; 175 176 /* LSP values for first subframe (3.2.5 of G.729, Equation 24)*/ 177 for(i=0; i<lp_order; i++) 178#ifdef G729_BITEXACT 179 lsp_1st[i] = (lsp_2nd[i] >> 1) + (lsp_prev[i] >> 1); 180#else 181 lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) >> 1; 182#endif 183 184 ff_acelp_lsp2lpc(lp_1st, lsp_1st, lp_order >> 1); 185 186 /* LSP values for second subframe (3.2.5 of G.729)*/ 187 ff_acelp_lsp2lpc(lp_2nd, lsp_2nd, lp_order >> 1); 188} 189 190#ifndef ff_lsp2polyf 191void ff_lsp2polyf(const double *lsp, double *f, int lp_half_order) 192{ 193 int i, j; 194 195 f[0] = 1.0; 196 f[1] = -2 * lsp[0]; 197 lsp -= 2; 198 for(i=2; i<=lp_half_order; i++) 199 { 200 double val = -2 * lsp[2*i]; 201 f[i] = val * f[i-1] + 2*f[i-2]; 202 for(j=i-1; j>1; j--) 203 f[j] += f[j-1] * val + f[j-2]; 204 f[1] += val; 205 } 206} 207#endif /* ff_lsp2polyf */ 208 209void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order) 210{ 211 double pa[MAX_LP_HALF_ORDER+1], qa[MAX_LP_HALF_ORDER+1]; 212 float *lpc2 = lpc + (lp_half_order << 1) - 1; 213 214 av_assert2(lp_half_order <= MAX_LP_HALF_ORDER); 215 216 ff_lsp2polyf(lsp, pa, lp_half_order); 217 ff_lsp2polyf(lsp + 1, qa, lp_half_order); 218 219 while (lp_half_order--) { 220 double paf = pa[lp_half_order+1] + pa[lp_half_order]; 221 double qaf = qa[lp_half_order+1] - qa[lp_half_order]; 222 223 lpc [ lp_half_order] = 0.5*(paf+qaf); 224 lpc2[-lp_half_order] = 0.5*(paf-qaf); 225 } 226} 227 228void ff_sort_nearly_sorted_floats(float *vals, int len) 229{ 230 int i,j; 231 232 for (i = 0; i < len - 1; i++) 233 for (j = i; j >= 0 && vals[j] > vals[j+1]; j--) 234 FFSWAP(float, vals[j], vals[j+1]); 235} 236