Go to most recent revision | Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
4349 | Serge | 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 |
||
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 |
||
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 |
||
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 |
||
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 |
||
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 |
||
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 | }>=>><>=lp_half_order;>>><>><>><>=lp_half_order;>><>=>=>=>=>>=>><>> |