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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 | ||
33 | void 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 | ||
51 | void 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) */ | |
61 | static 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 | ||
73 | static 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 | ||
83 | void 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 | ||
93 | void 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 | */ | |
106 | static 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 | ||
123 | void 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 | ||
145 | void 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 | ||
171 | 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) | |
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 | |
191 | void 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 | ||
209 | void 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 | ||
228 | void 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 | } |