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| author | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:57:22 +0100 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:57:22 +0100 |
| commit | 8992cb1d0d07edc33d274f6d7924ecdf6f83d994 (patch) | |
| tree | 3a2c86846b7eec8137c1507e623fc7018f13d453 /ffmpeg/libavcodec/lsp.c | |
| parent | 741fb4b9e135cfb161a749db88713229038577bb (diff) | |
making act segmenter
Diffstat (limited to 'ffmpeg/libavcodec/lsp.c')
| -rw-r--r-- | ffmpeg/libavcodec/lsp.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/lsp.c b/ffmpeg/libavcodec/lsp.c new file mode 100644 index 0000000..17f59ea --- /dev/null +++ b/ffmpeg/libavcodec/lsp.c @@ -0,0 +1,235 @@ +/* + * 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 "libavcodec/mips/lsp_mips.h" +#include "libavutil/avassert.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); +} + + +/* Cosine table: base_cos[i] = (1 << 15) * cos(i * PI / 64) */ +static const int16_t tab_cos[65] = +{ + 32767, 32738, 32617, 32421, 32145, 31793, 31364, 30860, + 30280, 29629, 28905, 28113, 27252, 26326, 25336, 24285, + 23176, 22011, 20793, 19525, 18210, 16851, 15451, 14014, + 12543, 11043, 9515, 7965, 6395, 4810, 3214, 1609, + 1, -1607, -3211, -4808, -6393, -7962, -9513, -11040, + -12541, -14012, -15449, -16848, -18207, -19523, -20791, -22009, + -23174, -24283, -25334, -26324, -27250, -28111, -28904, -29627, + -30279, -30858, -31363, -31792, -32144, -32419, -32616, -32736, -32768, +}; + +static int16_t ff_cos(uint16_t arg) +{ + uint8_t offset= arg; + uint8_t ind = arg >> 8; + + av_assert2(arg <= 0x3fff); + + return tab_cos[ind] + (offset * (tab_cos[ind+1] - tab_cos[ind]) >> 8); +} + +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[out] f 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[MAX_LP_HALF_ORDER + 1]; + double pa[MAX_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); +} + +#ifndef ff_lsp2polyf +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; + } +} +#endif /* ff_lsp2polyf */ + +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; + + av_assert2(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]); +} |
