From 5f9f6629fa88356e5735f83b09b9fa6623de9640 Mon Sep 17 00:00:00 2001 From: Mohamed Tarek Date: Sat, 7 Aug 2010 11:42:00 +0000 Subject: Initial commit for a WMA Voice decoder; Import a minimal set of files for libwmavoice from ffmpeg r24734 dated 2010-Aug-07. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27740 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libwmavoice/lsp.c | 174 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 apps/codecs/libwmavoice/lsp.c (limited to 'apps/codecs/libwmavoice/lsp.c') diff --git a/apps/codecs/libwmavoice/lsp.c b/apps/codecs/libwmavoice/lsp.c new file mode 100644 index 0000000000..7112492001 --- /dev/null +++ b/apps/codecs/libwmavoice/lsp.c @@ -0,0 +1,174 @@ +/* + * 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 + +#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=0 && lsfq[j] > lsfq[j+1]; j--) + FFSWAP(int16_t, lsfq[j], lsfq[j+1]); + + for(i=0; i> 15); // divide by PI and (0,13) -> (0,14) +} + +/** + * \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> 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_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> 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]); +} -- cgit v1.2.3