blob: 9aba020ebbbab717732b727d7e321be229b8b344
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 algorithm, |
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 | } |
236 |