diff options
Diffstat (limited to 'lib/fixedpoint')
-rw-r--r-- | lib/fixedpoint/fixedpoint.c | 457 | ||||
-rw-r--r-- | lib/fixedpoint/fixedpoint.h | 125 | ||||
-rw-r--r-- | lib/fixedpoint/fixedpoint.make | 36 |
3 files changed, 618 insertions, 0 deletions
diff --git a/lib/fixedpoint/fixedpoint.c b/lib/fixedpoint/fixedpoint.c new file mode 100644 index 0000000000..b5bbe68a95 --- /dev/null +++ b/lib/fixedpoint/fixedpoint.c | |||
@@ -0,0 +1,457 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006 Jens Arnold | ||
11 | * | ||
12 | * Fixed point library for plugins | ||
13 | * | ||
14 | * This program is free software; you can redistribute it and/or | ||
15 | * modify it under the terms of the GNU General Public License | ||
16 | * as published by the Free Software Foundation; either version 2 | ||
17 | * of the License, or (at your option) any later version. | ||
18 | * | ||
19 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
20 | * KIND, either express or implied. | ||
21 | * | ||
22 | ****************************************************************************/ | ||
23 | #include "fixedpoint.h" | ||
24 | #include <stdlib.h> | ||
25 | #include <stdbool.h> | ||
26 | #include <inttypes.h> | ||
27 | |||
28 | #ifndef BIT_N | ||
29 | #define BIT_N(n) (1U << (n)) | ||
30 | #endif | ||
31 | |||
32 | /** TAKEN FROM ORIGINAL fixedpoint.h */ | ||
33 | /* Inverse gain of circular cordic rotation in s0.31 format. */ | ||
34 | static const long cordic_circular_gain = 0xb2458939; /* 0.607252929 */ | ||
35 | |||
36 | /* Table of values of atan(2^-i) in 0.32 format fractions of pi where pi = 0xffffffff / 2 */ | ||
37 | static const unsigned long atan_table[] = { | ||
38 | 0x1fffffff, /* +0.785398163 (or pi/4) */ | ||
39 | 0x12e4051d, /* +0.463647609 */ | ||
40 | 0x09fb385b, /* +0.244978663 */ | ||
41 | 0x051111d4, /* +0.124354995 */ | ||
42 | 0x028b0d43, /* +0.062418810 */ | ||
43 | 0x0145d7e1, /* +0.031239833 */ | ||
44 | 0x00a2f61e, /* +0.015623729 */ | ||
45 | 0x00517c55, /* +0.007812341 */ | ||
46 | 0x0028be53, /* +0.003906230 */ | ||
47 | 0x00145f2e, /* +0.001953123 */ | ||
48 | 0x000a2f98, /* +0.000976562 */ | ||
49 | 0x000517cc, /* +0.000488281 */ | ||
50 | 0x00028be6, /* +0.000244141 */ | ||
51 | 0x000145f3, /* +0.000122070 */ | ||
52 | 0x0000a2f9, /* +0.000061035 */ | ||
53 | 0x0000517c, /* +0.000030518 */ | ||
54 | 0x000028be, /* +0.000015259 */ | ||
55 | 0x0000145f, /* +0.000007629 */ | ||
56 | 0x00000a2f, /* +0.000003815 */ | ||
57 | 0x00000517, /* +0.000001907 */ | ||
58 | 0x0000028b, /* +0.000000954 */ | ||
59 | 0x00000145, /* +0.000000477 */ | ||
60 | 0x000000a2, /* +0.000000238 */ | ||
61 | 0x00000051, /* +0.000000119 */ | ||
62 | 0x00000028, /* +0.000000060 */ | ||
63 | 0x00000014, /* +0.000000030 */ | ||
64 | 0x0000000a, /* +0.000000015 */ | ||
65 | 0x00000005, /* +0.000000007 */ | ||
66 | 0x00000002, /* +0.000000004 */ | ||
67 | 0x00000001, /* +0.000000002 */ | ||
68 | 0x00000000, /* +0.000000001 */ | ||
69 | 0x00000000, /* +0.000000000 */ | ||
70 | }; | ||
71 | |||
72 | /* Precalculated sine and cosine * 16384 (2^14) (fixed point 18.14) */ | ||
73 | static const short sin_table[91] = | ||
74 | { | ||
75 | 0, 285, 571, 857, 1142, 1427, 1712, 1996, 2280, 2563, | ||
76 | 2845, 3126, 3406, 3685, 3963, 4240, 4516, 4790, 5062, 5334, | ||
77 | 5603, 5871, 6137, 6401, 6663, 6924, 7182, 7438, 7691, 7943, | ||
78 | 8191, 8438, 8682, 8923, 9161, 9397, 9630, 9860, 10086, 10310, | ||
79 | 10531, 10748, 10963, 11173, 11381, 11585, 11785, 11982, 12175, 12365, | ||
80 | 12550, 12732, 12910, 13084, 13254, 13420, 13582, 13740, 13894, 14043, | ||
81 | 14188, 14329, 14466, 14598, 14725, 14848, 14967, 15081, 15190, 15295, | ||
82 | 15395, 15491, 15582, 15668, 15749, 15825, 15897, 15964, 16025, 16082, | ||
83 | 16135, 16182, 16224, 16261, 16294, 16321, 16344, 16361, 16374, 16381, | ||
84 | 16384 | ||
85 | }; | ||
86 | |||
87 | /** | ||
88 | * Implements sin and cos using CORDIC rotation. | ||
89 | * | ||
90 | * @param phase has range from 0 to 0xffffffff, representing 0 and | ||
91 | * 2*pi respectively. | ||
92 | * @param cos return address for cos | ||
93 | * @return sin of phase, value is a signed value from LONG_MIN to LONG_MAX, | ||
94 | * representing -1 and 1 respectively. | ||
95 | */ | ||
96 | long fp_sincos(unsigned long phase, long *cos) | ||
97 | { | ||
98 | int32_t x, x1, y, y1; | ||
99 | unsigned long z, z1; | ||
100 | int i; | ||
101 | |||
102 | /* Setup initial vector */ | ||
103 | x = cordic_circular_gain; | ||
104 | y = 0; | ||
105 | z = phase; | ||
106 | |||
107 | /* The phase has to be somewhere between 0..pi for this to work right */ | ||
108 | if (z < 0xffffffff / 4) { | ||
109 | /* z in first quadrant, z += pi/2 to correct */ | ||
110 | x = -x; | ||
111 | z += 0xffffffff / 4; | ||
112 | } else if (z < 3 * (0xffffffff / 4)) { | ||
113 | /* z in third quadrant, z -= pi/2 to correct */ | ||
114 | z -= 0xffffffff / 4; | ||
115 | } else { | ||
116 | /* z in fourth quadrant, z -= 3pi/2 to correct */ | ||
117 | x = -x; | ||
118 | z -= 3 * (0xffffffff / 4); | ||
119 | } | ||
120 | |||
121 | /* Each iteration adds roughly 1-bit of extra precision */ | ||
122 | for (i = 0; i < 31; i++) { | ||
123 | x1 = x >> i; | ||
124 | y1 = y >> i; | ||
125 | z1 = atan_table[i]; | ||
126 | |||
127 | /* Decided which direction to rotate vector. Pivot point is pi/2 */ | ||
128 | if (z >= 0xffffffff / 4) { | ||
129 | x -= y1; | ||
130 | y += x1; | ||
131 | z -= z1; | ||
132 | } else { | ||
133 | x += y1; | ||
134 | y -= x1; | ||
135 | z += z1; | ||
136 | } | ||
137 | } | ||
138 | |||
139 | if (cos) | ||
140 | *cos = x; | ||
141 | |||
142 | return y; | ||
143 | } | ||
144 | |||
145 | /** | ||
146 | * Fixed point square root via Newton-Raphson. | ||
147 | * @param x square root argument. | ||
148 | * @param fracbits specifies number of fractional bits in argument. | ||
149 | * @return Square root of argument in same fixed point format as input. | ||
150 | * | ||
151 | * This routine has been modified to run longer for greater precision, | ||
152 | * but cuts calculation short if the answer is reached sooner. | ||
153 | */ | ||
154 | long fp_sqrt(long x, unsigned int fracbits) | ||
155 | { | ||
156 | unsigned long xfp, b; | ||
157 | int n = 8; /* iteration limit (should terminate earlier) */ | ||
158 | |||
159 | if (x <= 0) | ||
160 | return 0; /* no sqrt(neg), or just sqrt(0) = 0 */ | ||
161 | |||
162 | /* Increase working precision by one bit */ | ||
163 | xfp = x << 1; | ||
164 | fracbits++; | ||
165 | |||
166 | /* Get the midpoint between fracbits index and the highest bit index */ | ||
167 | b = ((sizeof(xfp)*8-1) - __builtin_clzl(xfp) + fracbits) >> 1; | ||
168 | b = BIT_N(b); | ||
169 | |||
170 | do | ||
171 | { | ||
172 | unsigned long c = b; | ||
173 | b = (fp_div(xfp, b, fracbits) + b) >> 1; | ||
174 | if (c == b) break; | ||
175 | } | ||
176 | while (n-- > 0); | ||
177 | |||
178 | return b >> 1; | ||
179 | } | ||
180 | |||
181 | /* Accurate int sqrt with only elementary operations. | ||
182 | * Snagged from: | ||
183 | * http://www.devmaster.net/articles/fixed-point-optimizations/ */ | ||
184 | unsigned long isqrt(unsigned long x) | ||
185 | { | ||
186 | /* Adding CLZ could optimize this further */ | ||
187 | unsigned long g = 0; | ||
188 | int bshift = 15; | ||
189 | unsigned long b = 1ul << bshift; | ||
190 | |||
191 | do | ||
192 | { | ||
193 | unsigned long temp = (g + g + b) << bshift; | ||
194 | |||
195 | if (x > temp) | ||
196 | { | ||
197 | g += b; | ||
198 | x -= temp; | ||
199 | } | ||
200 | |||
201 | b >>= 1; | ||
202 | } | ||
203 | while (bshift--); | ||
204 | |||
205 | return g; | ||
206 | } | ||
207 | |||
208 | /** | ||
209 | * Fixed point sinus using a lookup table | ||
210 | * don't forget to divide the result by 16384 to get the actual sinus value | ||
211 | * @param val sinus argument in degree | ||
212 | * @return sin(val)*16384 | ||
213 | */ | ||
214 | long fp14_sin(int val) | ||
215 | { | ||
216 | val = (val+360)%360; | ||
217 | if (val < 181) | ||
218 | { | ||
219 | if (val < 91)/* phase 0-90 degree */ | ||
220 | return (long)sin_table[val]; | ||
221 | else/* phase 91-180 degree */ | ||
222 | return (long)sin_table[180-val]; | ||
223 | } | ||
224 | else | ||
225 | { | ||
226 | if (val < 271)/* phase 181-270 degree */ | ||
227 | return -(long)sin_table[val-180]; | ||
228 | else/* phase 270-359 degree */ | ||
229 | return -(long)sin_table[360-val]; | ||
230 | } | ||
231 | return 0; | ||
232 | } | ||
233 | |||
234 | /** | ||
235 | * Fixed point cosinus using a lookup table | ||
236 | * don't forget to divide the result by 16384 to get the actual cosinus value | ||
237 | * @param val sinus argument in degree | ||
238 | * @return cos(val)*16384 | ||
239 | */ | ||
240 | long fp14_cos(int val) | ||
241 | { | ||
242 | val = (val+360)%360; | ||
243 | if (val < 181) | ||
244 | { | ||
245 | if (val < 91)/* phase 0-90 degree */ | ||
246 | return (long)sin_table[90-val]; | ||
247 | else/* phase 91-180 degree */ | ||
248 | return -(long)sin_table[val-90]; | ||
249 | } | ||
250 | else | ||
251 | { | ||
252 | if (val < 271)/* phase 181-270 degree */ | ||
253 | return -(long)sin_table[270-val]; | ||
254 | else/* phase 270-359 degree */ | ||
255 | return (long)sin_table[val-270]; | ||
256 | } | ||
257 | return 0; | ||
258 | } | ||
259 | |||
260 | /** | ||
261 | * Fixed-point natural log | ||
262 | * taken from http://www.quinapalus.com/efunc.html | ||
263 | * "The code assumes integers are at least 32 bits long. The (positive) | ||
264 | * argument and the result of the function are both expressed as fixed-point | ||
265 | * values with 16 fractional bits, although intermediates are kept with 28 | ||
266 | * bits of precision to avoid loss of accuracy during shifts." | ||
267 | */ | ||
268 | long fp16_log(int x) | ||
269 | { | ||
270 | int t; | ||
271 | int y = 0xa65af; | ||
272 | |||
273 | if (x < 0x00008000) x <<=16, y -= 0xb1721; | ||
274 | if (x < 0x00800000) x <<= 8, y -= 0x58b91; | ||
275 | if (x < 0x08000000) x <<= 4, y -= 0x2c5c8; | ||
276 | if (x < 0x20000000) x <<= 2, y -= 0x162e4; | ||
277 | if (x < 0x40000000) x <<= 1, y -= 0x0b172; | ||
278 | t = x + (x >> 1); if ((t & 0x80000000) == 0) x = t, y -= 0x067cd; | ||
279 | t = x + (x >> 2); if ((t & 0x80000000) == 0) x = t, y -= 0x03920; | ||
280 | t = x + (x >> 3); if ((t & 0x80000000) == 0) x = t, y -= 0x01e27; | ||
281 | t = x + (x >> 4); if ((t & 0x80000000) == 0) x = t, y -= 0x00f85; | ||
282 | t = x + (x >> 5); if ((t & 0x80000000) == 0) x = t, y -= 0x007e1; | ||
283 | t = x + (x >> 6); if ((t & 0x80000000) == 0) x = t, y -= 0x003f8; | ||
284 | t = x + (x >> 7); if ((t & 0x80000000) == 0) x = t, y -= 0x001fe; | ||
285 | x = 0x80000000 - x; | ||
286 | y -= x >> 15; | ||
287 | |||
288 | return y; | ||
289 | } | ||
290 | |||
291 | /** | ||
292 | * Fixed-point exponential | ||
293 | * taken from http://www.quinapalus.com/efunc.html | ||
294 | * "The code assumes integers are at least 32 bits long. The (non-negative) | ||
295 | * argument and the result of the function are both expressed as fixed-point | ||
296 | * values with 16 fractional bits. Notice that after 11 steps of the | ||
297 | * algorithm the constants involved become such that the code is simply | ||
298 | * doing a multiplication: this is explained in the note below. | ||
299 | * The extension to negative arguments is left as an exercise." | ||
300 | */ | ||
301 | long fp16_exp(int x) | ||
302 | { | ||
303 | int t; | ||
304 | int y = 0x00010000; | ||
305 | |||
306 | if (x < 0) x += 0xb1721, y >>= 16; | ||
307 | t = x - 0x58b91; if (t >= 0) x = t, y <<= 8; | ||
308 | t = x - 0x2c5c8; if (t >= 0) x = t, y <<= 4; | ||
309 | t = x - 0x162e4; if (t >= 0) x = t, y <<= 2; | ||
310 | t = x - 0x0b172; if (t >= 0) x = t, y <<= 1; | ||
311 | t = x - 0x067cd; if (t >= 0) x = t, y += y >> 1; | ||
312 | t = x - 0x03920; if (t >= 0) x = t, y += y >> 2; | ||
313 | t = x - 0x01e27; if (t >= 0) x = t, y += y >> 3; | ||
314 | t = x - 0x00f85; if (t >= 0) x = t, y += y >> 4; | ||
315 | t = x - 0x007e1; if (t >= 0) x = t, y += y >> 5; | ||
316 | t = x - 0x003f8; if (t >= 0) x = t, y += y >> 6; | ||
317 | t = x - 0x001fe; if (t >= 0) x = t, y += y >> 7; | ||
318 | y += ((y >> 8) * x) >> 8; | ||
319 | |||
320 | return y; | ||
321 | } | ||
322 | |||
323 | /** MODIFIED FROM replaygain.c */ | ||
324 | |||
325 | #define FP_MUL_FRAC(x, y) fp_mul(x, y, fracbits) | ||
326 | #define FP_DIV_FRAC(x, y) fp_div(x, y, fracbits) | ||
327 | |||
328 | /* constants in fixed point format, 28 fractional bits */ | ||
329 | #define FP28_LN2 (186065279L) /* ln(2) */ | ||
330 | #define FP28_LN2_INV (387270501L) /* 1/ln(2) */ | ||
331 | #define FP28_EXP_ZERO (44739243L) /* 1/6 */ | ||
332 | #define FP28_EXP_ONE (-745654L) /* -1/360 */ | ||
333 | #define FP28_EXP_TWO (12428L) /* 1/21600 */ | ||
334 | #define FP28_LN10 (618095479L) /* ln(10) */ | ||
335 | #define FP28_LOG10OF2 (80807124L) /* log10(2) */ | ||
336 | |||
337 | #define TOL_BITS 2 /* log calculation tolerance */ | ||
338 | |||
339 | |||
340 | /* The fpexp10 fixed point math routine is based | ||
341 | * on oMathFP by Dan Carter (http://orbisstudios.com). | ||
342 | */ | ||
343 | |||
344 | /** FIXED POINT EXP10 | ||
345 | * Return 10^x as FP integer. Argument is FP integer. | ||
346 | */ | ||
347 | long fp_exp10(long x, unsigned int fracbits) | ||
348 | { | ||
349 | long k; | ||
350 | long z; | ||
351 | long R; | ||
352 | long xp; | ||
353 | |||
354 | /* scale constants */ | ||
355 | const long fp_one = (1 << fracbits); | ||
356 | const long fp_half = (1 << (fracbits - 1)); | ||
357 | const long fp_two = (2 << fracbits); | ||
358 | const long fp_mask = (fp_one - 1); | ||
359 | const long fp_ln2_inv = (FP28_LN2_INV >> (28 - fracbits)); | ||
360 | const long fp_ln2 = (FP28_LN2 >> (28 - fracbits)); | ||
361 | const long fp_ln10 = (FP28_LN10 >> (28 - fracbits)); | ||
362 | const long fp_exp_zero = (FP28_EXP_ZERO >> (28 - fracbits)); | ||
363 | const long fp_exp_one = (FP28_EXP_ONE >> (28 - fracbits)); | ||
364 | const long fp_exp_two = (FP28_EXP_TWO >> (28 - fracbits)); | ||
365 | |||
366 | /* exp(0) = 1 */ | ||
367 | if (x == 0) | ||
368 | { | ||
369 | return fp_one; | ||
370 | } | ||
371 | |||
372 | /* convert from base 10 to base e */ | ||
373 | x = FP_MUL_FRAC(x, fp_ln10); | ||
374 | |||
375 | /* calculate exp(x) */ | ||
376 | k = (FP_MUL_FRAC(abs(x), fp_ln2_inv) + fp_half) & ~fp_mask; | ||
377 | |||
378 | if (x < 0) | ||
379 | { | ||
380 | k = -k; | ||
381 | } | ||
382 | |||
383 | x -= FP_MUL_FRAC(k, fp_ln2); | ||
384 | z = FP_MUL_FRAC(x, x); | ||
385 | R = fp_two + FP_MUL_FRAC(z, fp_exp_zero + FP_MUL_FRAC(z, fp_exp_one | ||
386 | + FP_MUL_FRAC(z, fp_exp_two))); | ||
387 | xp = fp_one + FP_DIV_FRAC(FP_MUL_FRAC(fp_two, x), R - x); | ||
388 | |||
389 | if (k < 0) | ||
390 | { | ||
391 | k = fp_one >> (-k >> fracbits); | ||
392 | } | ||
393 | else | ||
394 | { | ||
395 | k = fp_one << (k >> fracbits); | ||
396 | } | ||
397 | |||
398 | return FP_MUL_FRAC(k, xp); | ||
399 | } | ||
400 | |||
401 | /** FIXED POINT LOG10 | ||
402 | * Return log10(x) as FP integer. Argument is FP integer. | ||
403 | */ | ||
404 | long fp_log10(long n, unsigned int fracbits) | ||
405 | { | ||
406 | /* Calculate log2 of argument */ | ||
407 | |||
408 | long log2, frac; | ||
409 | const long fp_one = (1 << fracbits); | ||
410 | const long fp_two = (2 << fracbits); | ||
411 | const long tolerance = (1 << ((fracbits / 2) + 2)); | ||
412 | |||
413 | if (n <=0) return FP_NEGINF; | ||
414 | log2 = 0; | ||
415 | |||
416 | /* integer part */ | ||
417 | while (n < fp_one) | ||
418 | { | ||
419 | log2 -= fp_one; | ||
420 | n <<= 1; | ||
421 | } | ||
422 | while (n >= fp_two) | ||
423 | { | ||
424 | log2 += fp_one; | ||
425 | n >>= 1; | ||
426 | } | ||
427 | |||
428 | /* fractional part */ | ||
429 | frac = fp_one; | ||
430 | while (frac > tolerance) | ||
431 | { | ||
432 | frac >>= 1; | ||
433 | n = FP_MUL_FRAC(n, n); | ||
434 | if (n >= fp_two) | ||
435 | { | ||
436 | n >>= 1; | ||
437 | log2 += frac; | ||
438 | } | ||
439 | } | ||
440 | |||
441 | /* convert log2 to log10 */ | ||
442 | return FP_MUL_FRAC(log2, (FP28_LOG10OF2 >> (28 - fracbits))); | ||
443 | } | ||
444 | |||
445 | /** CONVERT FACTOR TO DECIBELS */ | ||
446 | long fp_decibels(unsigned long factor, unsigned int fracbits) | ||
447 | { | ||
448 | /* decibels = 20 * log10(factor) */ | ||
449 | return FP_MUL_FRAC((20L << fracbits), fp_log10(factor, fracbits)); | ||
450 | } | ||
451 | |||
452 | /** CONVERT DECIBELS TO FACTOR */ | ||
453 | long fp_factor(long decibels, unsigned int fracbits) | ||
454 | { | ||
455 | /* factor = 10 ^ (decibels / 20) */ | ||
456 | return fp_exp10(FP_DIV_FRAC(decibels, (20L << fracbits)), fracbits); | ||
457 | } | ||
diff --git a/lib/fixedpoint/fixedpoint.h b/lib/fixedpoint/fixedpoint.h new file mode 100644 index 0000000000..31d60eca4b --- /dev/null +++ b/lib/fixedpoint/fixedpoint.h | |||
@@ -0,0 +1,125 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006 Jens Arnold | ||
11 | * | ||
12 | * Fixed point library for plugins | ||
13 | * | ||
14 | * This program is free software; you can redistribute it and/or | ||
15 | * modify it under the terms of the GNU General Public License | ||
16 | * as published by the Free Software Foundation; either version 2 | ||
17 | * of the License, or (at your option) any later version. | ||
18 | * | ||
19 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
20 | * KIND, either express or implied. | ||
21 | * | ||
22 | ****************************************************************************/ | ||
23 | |||
24 | /** FIXED POINT MATH ROUTINES - USAGE | ||
25 | * | ||
26 | * - x and y arguments are fixed point integers | ||
27 | * - fracbits is the number of fractional bits in the argument(s) | ||
28 | * - functions return long fixed point integers with the specified number | ||
29 | * of fractional bits unless otherwise specified | ||
30 | * | ||
31 | * Multiply two fixed point numbers: | ||
32 | * fp_mul(x, y, fracbits) | ||
33 | * | ||
34 | * Divide two fixed point numbers: | ||
35 | * fp_div(x, y, fracbits) | ||
36 | * | ||
37 | * Calculate sin and cos of an angle: | ||
38 | * fp_sincos(phase, *cos) | ||
39 | * where phase is a 32 bit unsigned integer with 0 representing 0 | ||
40 | * and 0xFFFFFFFF representing 2*pi, and *cos is the address to | ||
41 | * a long signed integer. Value returned is a long signed integer | ||
42 | * from -0x80000000 to 0x7fffffff, representing -1 to 1 respectively. | ||
43 | * That is, value is a fixed point integer with 31 fractional bits. | ||
44 | * | ||
45 | * Take square root of a fixed point number: | ||
46 | * fp_sqrt(x, fracbits) | ||
47 | * | ||
48 | * Take the square root of an integer: | ||
49 | * isqrt(x) | ||
50 | * | ||
51 | * Calculate sin or cos of an angle (very fast, from a table): | ||
52 | * fp14_sin(angle) | ||
53 | * fp14_cos(angle) | ||
54 | * where angle is a non-fixed point integer in degrees. Value | ||
55 | * returned is a fixed point integer with 14 fractional bits. | ||
56 | * | ||
57 | * Calculate the exponential of a fixed point integer | ||
58 | * fp16_exp(x) | ||
59 | * where x and the value returned are fixed point integers | ||
60 | * with 16 fractional bits. | ||
61 | * | ||
62 | * Calculate the natural log of a positive fixed point integer | ||
63 | * fp16_log(x) | ||
64 | * where x and the value returned are fixed point integers | ||
65 | * with 16 fractional bits. | ||
66 | * | ||
67 | * Calculate decibel equivalent of a gain factor: | ||
68 | * fp_decibels(factor, fracbits) | ||
69 | * where fracbits is in the range 12 to 22 (higher is better), | ||
70 | * and factor is a positive fixed point integer. | ||
71 | * | ||
72 | * Calculate factor equivalent of a decibel value: | ||
73 | * fp_factor(decibels, fracbits) | ||
74 | * where fracbits is in the range 12 to 22 (lower is better), | ||
75 | * and decibels is a fixed point integer. | ||
76 | */ | ||
77 | |||
78 | #ifndef FIXEDPOINT_H | ||
79 | #define FIXEDPOINT_H | ||
80 | |||
81 | #define fp_mul(x, y, z) (long)((((long long)(x)) * ((long long)(y))) >> (z)) | ||
82 | #define fp_div(x, y, z) (long)((((long long)(x)) << (z)) / ((long long)(y))) | ||
83 | |||
84 | long fp_sincos(unsigned long phase, long *cos); | ||
85 | long fp_sqrt(long a, unsigned int fracbits); | ||
86 | long fp14_cos(int val); | ||
87 | long fp14_sin(int val); | ||
88 | long fp16_log(int x); | ||
89 | long fp16_exp(int x); | ||
90 | |||
91 | unsigned long isqrt(unsigned long x); | ||
92 | |||
93 | /* fast unsigned multiplication (16x16bit->32bit or 32x32bit->32bit, | ||
94 | * whichever is faster for the architecture) */ | ||
95 | #ifdef CPU_ARM | ||
96 | #define FMULU(a, b) ((uint32_t) (((uint32_t) (a)) * ((uint32_t) (b)))) | ||
97 | #else /* SH1, coldfire */ | ||
98 | #define FMULU(a, b) ((uint32_t) (((uint16_t) (a)) * ((uint16_t) (b)))) | ||
99 | #endif | ||
100 | |||
101 | /** MODIFIED FROM replaygain.c */ | ||
102 | #define FP_INF (0x7fffffff) | ||
103 | #define FP_NEGINF -(0x7fffffff) | ||
104 | |||
105 | /** FIXED POINT EXP10 | ||
106 | * Return 10^x as FP integer. Argument is FP integer. | ||
107 | */ | ||
108 | long fp_exp10(long x, unsigned int fracbits); | ||
109 | |||
110 | /** FIXED POINT LOG10 | ||
111 | * Return log10(x) as FP integer. Argument is FP integer. | ||
112 | */ | ||
113 | long fp_log10(long n, unsigned int fracbits); | ||
114 | |||
115 | /* fracbits in range 12 - 22 work well. Higher is better for | ||
116 | * calculating dB, lower is better for calculating factor. | ||
117 | */ | ||
118 | |||
119 | /** CONVERT FACTOR TO DECIBELS */ | ||
120 | long fp_decibels(unsigned long factor, unsigned int fracbits); | ||
121 | |||
122 | /** CONVERT DECIBELS TO FACTOR */ | ||
123 | long fp_factor(long decibels, unsigned int fracbits); | ||
124 | |||
125 | #endif /* FIXEDPOINT_H */ | ||
diff --git a/lib/fixedpoint/fixedpoint.make b/lib/fixedpoint/fixedpoint.make new file mode 100644 index 0000000000..9ee0e1f0c7 --- /dev/null +++ b/lib/fixedpoint/fixedpoint.make | |||
@@ -0,0 +1,36 @@ | |||
1 | # __________ __ ___. | ||
2 | # Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
3 | # Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
4 | # Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
5 | # Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
6 | # \/ \/ \/ \/ \/ | ||
7 | |||
8 | FIXEDPOINTLIB := $(BUILDDIR)/lib/libfixedpoint.a | ||
9 | FIXEDPOINTLIB_DIR := $(ROOTDIR)/lib/fixedpoint | ||
10 | FIXEDPOINTLIB_SRC := $(FIXEDPOINTLIB_DIR)/fixedpoint.c | ||
11 | FIXEDPOINTLIB_OBJ := $(call c2obj, $(FIXEDPOINTLIB_SRC)) | ||
12 | |||
13 | INCLUDES += -I$(FIXEDPOINTLIB_DIR) | ||
14 | OTHER_SRC += $(FIXEDPOINTLIB_SRC) | ||
15 | |||
16 | # If not SOFTWARECODECS, then only plugins depend upon us | ||
17 | ifdef SOFTWARECODECS | ||
18 | CORE_LIBS += $(FIXEDPOINTLIB) | ||
19 | CORE_GCSECTIONS := yes | ||
20 | endif | ||
21 | |||
22 | FIXEDPOINTLIB_FLAGS := $(CFLAGS) | ||
23 | |||
24 | # Do not use '-ffunction-sections' and '-fdata-sections' when compiling sdl-sim | ||
25 | ifneq ($(findstring sdl-sim, $(APP_TYPE)), sdl-sim) | ||
26 | FIXEDPOINTLIB_FLAGS += -ffunction-sections -fdata-sections | ||
27 | endif | ||
28 | |||
29 | $(FIXEDPOINTLIB_OBJ): $(FIXEDPOINTLIB_SRC) | ||
30 | $(SILENT)mkdir -p $(dir $@) | ||
31 | $(call PRINTS,CC $(subst $(ROOTDIR)/,,$<))$(CC) \ | ||
32 | $(FIXEDPOINTLIB_FLAGS) -c $< -o $@ | ||
33 | |||
34 | $(FIXEDPOINTLIB): $(FIXEDPOINTLIB_OBJ) | ||
35 | $(SILENT)$(shell rm -f $@) | ||
36 | $(call PRINTS,AR $(@F))$(AR) rcs $@ $^ >/dev/null | ||