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Diffstat (limited to 'lib/fixedpoint/fixedpoint.h')
-rw-r--r-- | lib/fixedpoint/fixedpoint.h | 125 |
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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 | |||
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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 */ | ||