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author | Sean Bartell <wingedtachikoma@gmail.com> | 2011-06-25 21:32:25 -0400 |
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committer | Nils Wallménius <nils@rockbox.org> | 2012-04-25 22:13:20 +0200 |
commit | f40bfc9267b13b54e6379dfe7539447662879d24 (patch) | |
tree | 9b20069d5e62809ff434061ad730096836f916f2 /lib/rbcodec/codecs/libspeex/math_approx.h | |
parent | a0009907de7a0107d49040d8a180f140e2eff299 (diff) | |
download | rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.tar.gz rockbox-f40bfc9267b13b54e6379dfe7539447662879d24.zip |
Add codecs to librbcodec.
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
Diffstat (limited to 'lib/rbcodec/codecs/libspeex/math_approx.h')
-rw-r--r-- | lib/rbcodec/codecs/libspeex/math_approx.h | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libspeex/math_approx.h b/lib/rbcodec/codecs/libspeex/math_approx.h new file mode 100644 index 0000000000..9ca830755d --- /dev/null +++ b/lib/rbcodec/codecs/libspeex/math_approx.h | |||
@@ -0,0 +1,332 @@ | |||
1 | /* Copyright (C) 2002 Jean-Marc Valin */ | ||
2 | /** | ||
3 | @file math_approx.h | ||
4 | @brief Various math approximation functions for Speex | ||
5 | */ | ||
6 | /* | ||
7 | Redistribution and use in source and binary forms, with or without | ||
8 | modification, are permitted provided that the following conditions | ||
9 | are met: | ||
10 | |||
11 | - Redistributions of source code must retain the above copyright | ||
12 | notice, this list of conditions and the following disclaimer. | ||
13 | |||
14 | - Redistributions in binary form must reproduce the above copyright | ||
15 | notice, this list of conditions and the following disclaimer in the | ||
16 | documentation and/or other materials provided with the distribution. | ||
17 | |||
18 | - Neither the name of the Xiph.org Foundation nor the names of its | ||
19 | contributors may be used to endorse or promote products derived from | ||
20 | this software without specific prior written permission. | ||
21 | |||
22 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | ||
23 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | ||
24 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | ||
25 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR | ||
26 | CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | ||
27 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | ||
28 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | ||
29 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | ||
30 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | ||
31 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
32 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
33 | */ | ||
34 | |||
35 | #ifndef MATH_APPROX_H | ||
36 | #define MATH_APPROX_H | ||
37 | |||
38 | #include "arch.h" | ||
39 | |||
40 | #ifndef FIXED_POINT | ||
41 | |||
42 | #define spx_sqrt sqrt | ||
43 | #define spx_acos acos | ||
44 | #define spx_exp exp | ||
45 | #define spx_cos_norm(x) (cos((.5f*M_PI)*(x))) | ||
46 | #define spx_atan atan | ||
47 | |||
48 | /** Generate a pseudo-random number */ | ||
49 | static inline spx_word16_t speex_rand(spx_word16_t std, spx_int32_t *seed) | ||
50 | { | ||
51 | const unsigned int jflone = 0x3f800000; | ||
52 | const unsigned int jflmsk = 0x007fffff; | ||
53 | union {int i; float f;} ran; | ||
54 | *seed = 1664525 * *seed + 1013904223; | ||
55 | ran.i = jflone | (jflmsk & *seed); | ||
56 | ran.f -= 1.5; | ||
57 | return 3.4642*std*ran.f; | ||
58 | } | ||
59 | |||
60 | |||
61 | #endif | ||
62 | |||
63 | |||
64 | static inline spx_int16_t spx_ilog2(spx_uint32_t x) | ||
65 | { | ||
66 | int r=0; | ||
67 | if (x>=(spx_int32_t)65536) | ||
68 | { | ||
69 | x >>= 16; | ||
70 | r += 16; | ||
71 | } | ||
72 | if (x>=256) | ||
73 | { | ||
74 | x >>= 8; | ||
75 | r += 8; | ||
76 | } | ||
77 | if (x>=16) | ||
78 | { | ||
79 | x >>= 4; | ||
80 | r += 4; | ||
81 | } | ||
82 | if (x>=4) | ||
83 | { | ||
84 | x >>= 2; | ||
85 | r += 2; | ||
86 | } | ||
87 | if (x>=2) | ||
88 | { | ||
89 | r += 1; | ||
90 | } | ||
91 | return r; | ||
92 | } | ||
93 | |||
94 | static inline spx_int16_t spx_ilog4(spx_uint32_t x) | ||
95 | { | ||
96 | int r=0; | ||
97 | if (x>=(spx_int32_t)65536) | ||
98 | { | ||
99 | x >>= 16; | ||
100 | r += 8; | ||
101 | } | ||
102 | if (x>=256) | ||
103 | { | ||
104 | x >>= 8; | ||
105 | r += 4; | ||
106 | } | ||
107 | if (x>=16) | ||
108 | { | ||
109 | x >>= 4; | ||
110 | r += 2; | ||
111 | } | ||
112 | if (x>=4) | ||
113 | { | ||
114 | r += 1; | ||
115 | } | ||
116 | return r; | ||
117 | } | ||
118 | |||
119 | #ifdef FIXED_POINT | ||
120 | |||
121 | /** Generate a pseudo-random number */ | ||
122 | static inline spx_word16_t speex_rand(spx_word16_t std, spx_int32_t *seed) | ||
123 | { | ||
124 | spx_word32_t res; | ||
125 | *seed = 1664525 * *seed + 1013904223; | ||
126 | res = MULT16_16(EXTRACT16(SHR32(*seed,16)),std); | ||
127 | return EXTRACT16(PSHR32(SUB32(res, SHR32(res, 3)),14)); | ||
128 | } | ||
129 | |||
130 | /* sqrt(x) ~= 0.22178 + 1.29227*x - 0.77070*x^2 + 0.25723*x^3 (for .25 < x < 1) */ | ||
131 | /*#define C0 3634 | ||
132 | #define C1 21173 | ||
133 | #define C2 -12627 | ||
134 | #define C3 4215*/ | ||
135 | |||
136 | /* sqrt(x) ~= 0.22178 + 1.29227*x - 0.77070*x^2 + 0.25659*x^3 (for .25 < x < 1) */ | ||
137 | #define C0 3634 | ||
138 | #define C1 21173 | ||
139 | #define C2 -12627 | ||
140 | #define C3 4204 | ||
141 | |||
142 | static inline spx_word16_t spx_sqrt(spx_word32_t x) | ||
143 | { | ||
144 | int k; | ||
145 | spx_word32_t rt; | ||
146 | k = spx_ilog4(x)-6; | ||
147 | x = VSHR32(x, (k<<1)); | ||
148 | rt = ADD16(C0, MULT16_16_Q14(x, ADD16(C1, MULT16_16_Q14(x, ADD16(C2, MULT16_16_Q14(x, (C3))))))); | ||
149 | rt = VSHR32(rt,7-k); | ||
150 | return rt; | ||
151 | } | ||
152 | |||
153 | /* log(x) ~= -2.18151 + 4.20592*x - 2.88938*x^2 + 0.86535*x^3 (for .5 < x < 1) */ | ||
154 | |||
155 | |||
156 | #define A1 16469 | ||
157 | #define A2 2242 | ||
158 | #define A3 1486 | ||
159 | |||
160 | static inline spx_word16_t spx_acos(spx_word16_t x) | ||
161 | { | ||
162 | int s=0; | ||
163 | spx_word16_t ret; | ||
164 | spx_word16_t sq; | ||
165 | if (x<0) | ||
166 | { | ||
167 | s=1; | ||
168 | x = NEG16(x); | ||
169 | } | ||
170 | x = SUB16(16384,x); | ||
171 | |||
172 | x = x >> 1; | ||
173 | sq = MULT16_16_Q13(x, ADD16(A1, MULT16_16_Q13(x, ADD16(A2, MULT16_16_Q13(x, (A3)))))); | ||
174 | ret = spx_sqrt(SHL32(EXTEND32(sq),13)); | ||
175 | |||
176 | /*ret = spx_sqrt(67108864*(-1.6129e-04 + 2.0104e+00*f + 2.7373e-01*f*f + 1.8136e-01*f*f*f));*/ | ||
177 | if (s) | ||
178 | ret = SUB16(25736,ret); | ||
179 | return ret; | ||
180 | } | ||
181 | |||
182 | |||
183 | #define K1 8192 | ||
184 | #define K2 -4096 | ||
185 | #define K3 340 | ||
186 | #define K4 -10 | ||
187 | |||
188 | static inline spx_word16_t spx_cos(spx_word16_t x) | ||
189 | { | ||
190 | spx_word16_t x2; | ||
191 | |||
192 | if (x<12868) | ||
193 | { | ||
194 | x2 = MULT16_16_P13(x,x); | ||
195 | return ADD32(K1, MULT16_16_P13(x2, ADD32(K2, MULT16_16_P13(x2, ADD32(K3, MULT16_16_P13(K4, x2)))))); | ||
196 | } else { | ||
197 | x = SUB16(25736,x); | ||
198 | x2 = MULT16_16_P13(x,x); | ||
199 | return SUB32(-K1, MULT16_16_P13(x2, ADD32(K2, MULT16_16_P13(x2, ADD32(K3, MULT16_16_P13(K4, x2)))))); | ||
200 | } | ||
201 | } | ||
202 | |||
203 | #define L1 32767 | ||
204 | #define L2 -7651 | ||
205 | #define L3 8277 | ||
206 | #define L4 -626 | ||
207 | |||
208 | static inline spx_word16_t _spx_cos_pi_2(spx_word16_t x) | ||
209 | { | ||
210 | spx_word16_t x2; | ||
211 | |||
212 | x2 = MULT16_16_P15(x,x); | ||
213 | return ADD16(1,MIN16(32766,ADD32(SUB16(L1,x2), MULT16_16_P15(x2, ADD32(L2, MULT16_16_P15(x2, ADD32(L3, MULT16_16_P15(L4, x2)))))))); | ||
214 | } | ||
215 | |||
216 | static inline spx_word16_t spx_cos_norm(spx_word32_t x) | ||
217 | { | ||
218 | x = x&0x0001ffff; | ||
219 | if (x>SHL32(EXTEND32(1), 16)) | ||
220 | x = SUB32(SHL32(EXTEND32(1), 17),x); | ||
221 | if (x&0x00007fff) | ||
222 | { | ||
223 | if (x<SHL32(EXTEND32(1), 15)) | ||
224 | { | ||
225 | return _spx_cos_pi_2(EXTRACT16(x)); | ||
226 | } else { | ||
227 | return NEG32(_spx_cos_pi_2(EXTRACT16(65536-x))); | ||
228 | } | ||
229 | } else { | ||
230 | if (x&0x0000ffff) | ||
231 | return 0; | ||
232 | else if (x&0x0001ffff) | ||
233 | return -32767; | ||
234 | else | ||
235 | return 32767; | ||
236 | } | ||
237 | } | ||
238 | |||
239 | /* | ||
240 | K0 = 1 | ||
241 | K1 = log(2) | ||
242 | K2 = 3-4*log(2) | ||
243 | K3 = 3*log(2) - 2 | ||
244 | */ | ||
245 | #define D0 16384 | ||
246 | #define D1 11356 | ||
247 | #define D2 3726 | ||
248 | #define D3 1301 | ||
249 | /* Input in Q11 format, output in Q16 */ | ||
250 | static inline spx_word32_t spx_exp2(spx_word16_t x) | ||
251 | { | ||
252 | int integer; | ||
253 | spx_word16_t frac; | ||
254 | integer = SHR16(x,11); | ||
255 | if (integer>14) | ||
256 | return 0x7fffffff; | ||
257 | else if (integer < -15) | ||
258 | return 0; | ||
259 | frac = SHL16(x-SHL16(integer,11),3); | ||
260 | frac = ADD16(D0, MULT16_16_Q14(frac, ADD16(D1, MULT16_16_Q14(frac, ADD16(D2 , MULT16_16_Q14(D3,frac)))))); | ||
261 | return VSHR32(EXTEND32(frac), -integer-2); | ||
262 | } | ||
263 | |||
264 | /* Input in Q11 format, output in Q16 */ | ||
265 | static inline spx_word32_t spx_exp(spx_word16_t x) | ||
266 | { | ||
267 | if (x>21290) | ||
268 | return 0x7fffffff; | ||
269 | else if (x<-21290) | ||
270 | return 0; | ||
271 | else | ||
272 | return spx_exp2(MULT16_16_P14(23637,x)); | ||
273 | } | ||
274 | #define M1 32767 | ||
275 | #define M2 -21 | ||
276 | #define M3 -11943 | ||
277 | #define M4 4936 | ||
278 | |||
279 | static inline spx_word16_t spx_atan01(spx_word16_t x) | ||
280 | { | ||
281 | return MULT16_16_P15(x, ADD32(M1, MULT16_16_P15(x, ADD32(M2, MULT16_16_P15(x, ADD32(M3, MULT16_16_P15(M4, x))))))); | ||
282 | } | ||
283 | |||
284 | #undef M1 | ||
285 | #undef M2 | ||
286 | #undef M3 | ||
287 | #undef M4 | ||
288 | |||
289 | /* Input in Q15, output in Q14 */ | ||
290 | static inline spx_word16_t spx_atan(spx_word32_t x) | ||
291 | { | ||
292 | if (x <= 32767) | ||
293 | { | ||
294 | return SHR16(spx_atan01(x),1); | ||
295 | } else { | ||
296 | int e = spx_ilog2(x); | ||
297 | if (e>=29) | ||
298 | return 25736; | ||
299 | x = DIV32_16(SHL32(EXTEND32(32767),29-e), EXTRACT16(SHR32(x, e-14))); | ||
300 | return SUB16(25736, SHR16(spx_atan01(x),1)); | ||
301 | } | ||
302 | } | ||
303 | #else | ||
304 | |||
305 | #ifndef M_PI | ||
306 | #define M_PI 3.14159265358979323846 /* pi */ | ||
307 | #endif | ||
308 | |||
309 | #define C1 0.9999932946f | ||
310 | #define C2 -0.4999124376f | ||
311 | #define C3 0.0414877472f | ||
312 | #define C4 -0.0012712095f | ||
313 | |||
314 | |||
315 | #define SPX_PI_2 1.5707963268 | ||
316 | static inline spx_word16_t spx_cos(spx_word16_t x) | ||
317 | { | ||
318 | if (x<SPX_PI_2) | ||
319 | { | ||
320 | x *= x; | ||
321 | return C1 + x*(C2+x*(C3+C4*x)); | ||
322 | } else { | ||
323 | x = M_PI-x; | ||
324 | x *= x; | ||
325 | return NEG16(C1 + x*(C2+x*(C3+C4*x))); | ||
326 | } | ||
327 | } | ||
328 | |||
329 | #endif | ||
330 | |||
331 | |||
332 | #endif | ||