| /* |
| * LSP routines for ACELP-based codecs |
| * |
| * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet (QCELP decoder) |
| * Copyright (c) 2008 Vladimir Voroshilov |
| * |
| * 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 |
| */ |
| |
| #include <inttypes.h> |
| |
| #include "avcodec.h" |
| #define FRAC_BITS 14 |
| #include "mathops.h" |
| #include "lsp.h" |
| #include "celp_math.h" |
| |
| void ff_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsfq_min, int lsfq_max, int lp_order) |
| { |
| int i, j; |
| |
| /* sort lsfq in ascending order. float bubble agorithm, |
| O(n) if data already sorted, O(n^2) - otherwise */ |
| for(i=0; i<lp_order-1; i++) |
| for(j=i; j>=0 && lsfq[j] > lsfq[j+1]; j--) |
| FFSWAP(int16_t, lsfq[j], lsfq[j+1]); |
| |
| for(i=0; i<lp_order; i++) |
| { |
| lsfq[i] = FFMAX(lsfq[i], lsfq_min); |
| lsfq_min = lsfq[i] + lsfq_min_distance; |
| } |
| lsfq[lp_order-1] = FFMIN(lsfq[lp_order-1], lsfq_max);//Is warning required ? |
| } |
| |
| void ff_set_min_dist_lsf(float *lsf, double min_spacing, int size) |
| { |
| int i; |
| float prev = 0.0; |
| for (i = 0; i < size; i++) |
| prev = lsf[i] = FFMAX(lsf[i], prev + min_spacing); |
| } |
| |
| void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf, int lp_order) |
| { |
| int i; |
| |
| /* Convert LSF to LSP, lsp=cos(lsf) */ |
| for(i=0; i<lp_order; i++) |
| // 20861 = 2.0 / PI in (0.15) |
| lsp[i] = ff_cos(lsf[i] * 20861 >> 15); // divide by PI and (0,13) -> (0,14) |
| } |
| |
| void ff_acelp_lsf2lspd(double *lsp, const float *lsf, int lp_order) |
| { |
| int i; |
| |
| for(i = 0; i < lp_order; i++) |
| lsp[i] = cos(2.0 * M_PI * lsf[i]); |
| } |
| |
| /** |
| * \brief decodes polynomial coefficients from LSP |
| * \param f [out] decoded polynomial coefficients (-0x20000000 <= (3.22) <= 0x1fffffff) |
| * \param lsp LSP coefficients (-0x8000 <= (0.15) <= 0x7fff) |
| */ |
| static void lsp2poly(int* f, const int16_t* lsp, int lp_half_order) |
| { |
| int i, j; |
| |
| f[0] = 0x400000; // 1.0 in (3.22) |
| f[1] = -lsp[0] << 8; // *2 and (0.15) -> (3.22) |
| |
| for(i=2; i<=lp_half_order; i++) |
| { |
| f[i] = f[i-2]; |
| for(j=i; j>1; j--) |
| f[j] -= MULL(f[j-1], lsp[2*i-2], FRAC_BITS) - f[j-2]; |
| |
| f[1] -= lsp[2*i-2] << 8; |
| } |
| } |
| |
| void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order) |
| { |
| int i; |
| int f1[MAX_LP_HALF_ORDER+1]; // (3.22) |
| int f2[MAX_LP_HALF_ORDER+1]; // (3.22) |
| |
| lsp2poly(f1, lsp , lp_half_order); |
| lsp2poly(f2, lsp+1, lp_half_order); |
| |
| /* 3.2.6 of G.729, Equations 25 and 26*/ |
| lp[0] = 4096; |
| for(i=1; i<lp_half_order+1; i++) |
| { |
| int ff1 = f1[i] + f1[i-1]; // (3.22) |
| int ff2 = f2[i] - f2[i-1]; // (3.22) |
| |
| ff1 += 1 << 10; // for rounding |
| lp[i] = (ff1 + ff2) >> 11; // divide by 2 and (3.22) -> (3.12) |
| lp[(lp_half_order << 1) + 1 - i] = (ff1 - ff2) >> 11; // divide by 2 and (3.22) -> (3.12) |
| } |
| } |
| |
| void ff_amrwb_lsp2lpc(const double *lsp, float *lp, int lp_order) |
| { |
| int lp_half_order = lp_order >> 1; |
| double buf[lp_half_order + 1]; |
| double pa[lp_half_order + 1]; |
| double *qa = buf + 1; |
| int i,j; |
| |
| qa[-1] = 0.0; |
| |
| ff_lsp2polyf(lsp , pa, lp_half_order ); |
| ff_lsp2polyf(lsp + 1, qa, lp_half_order - 1); |
| |
| for (i = 1, j = lp_order - 1; i < lp_half_order; i++, j--) { |
| double paf = pa[i] * (1 + lsp[lp_order - 1]); |
| double qaf = (qa[i] - qa[i-2]) * (1 - lsp[lp_order - 1]); |
| lp[i-1] = (paf + qaf) * 0.5; |
| lp[j-1] = (paf - qaf) * 0.5; |
| } |
| |
| lp[lp_half_order - 1] = (1.0 + lsp[lp_order - 1]) * |
| pa[lp_half_order] * 0.5; |
| |
| lp[lp_order - 1] = lsp[lp_order - 1]; |
| } |
| |
| void 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) |
| { |
| int16_t lsp_1st[MAX_LP_ORDER]; // (0.15) |
| int i; |
| |
| /* LSP values for first subframe (3.2.5 of G.729, Equation 24)*/ |
| for(i=0; i<lp_order; i++) |
| #ifdef G729_BITEXACT |
| lsp_1st[i] = (lsp_2nd[i] >> 1) + (lsp_prev[i] >> 1); |
| #else |
| lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) >> 1; |
| #endif |
| |
| ff_acelp_lsp2lpc(lp_1st, lsp_1st, lp_order >> 1); |
| |
| /* LSP values for second subframe (3.2.5 of G.729)*/ |
| ff_acelp_lsp2lpc(lp_2nd, lsp_2nd, lp_order >> 1); |
| } |
| |
| void ff_lsp2polyf(const double *lsp, double *f, int lp_half_order) |
| { |
| int i, j; |
| |
| f[0] = 1.0; |
| f[1] = -2 * lsp[0]; |
| lsp -= 2; |
| for(i=2; i<=lp_half_order; i++) |
| { |
| double val = -2 * lsp[2*i]; |
| f[i] = val * f[i-1] + 2*f[i-2]; |
| for(j=i-1; j>1; j--) |
| f[j] += f[j-1] * val + f[j-2]; |
| f[1] += val; |
| } |
| } |
| |
| void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order) |
| { |
| double pa[MAX_LP_HALF_ORDER+1], qa[MAX_LP_HALF_ORDER+1]; |
| float *lpc2 = lpc + (lp_half_order << 1) - 1; |
| |
| assert(lp_half_order <= MAX_LP_HALF_ORDER); |
| |
| ff_lsp2polyf(lsp, pa, lp_half_order); |
| ff_lsp2polyf(lsp + 1, qa, lp_half_order); |
| |
| while (lp_half_order--) { |
| double paf = pa[lp_half_order+1] + pa[lp_half_order]; |
| double qaf = qa[lp_half_order+1] - qa[lp_half_order]; |
| |
| lpc [ lp_half_order] = 0.5*(paf+qaf); |
| lpc2[-lp_half_order] = 0.5*(paf-qaf); |
| } |
| } |
| |
| void ff_sort_nearly_sorted_floats(float *vals, int len) |
| { |
| int i,j; |
| |
| for (i = 0; i < len - 1; i++) |
| for (j = i; j >= 0 && vals[j] > vals[j+1]; j--) |
| FFSWAP(float, vals[j], vals[j+1]); |
| } |