ce188d4d |
1 | /* libFLAC - Free Lossless Audio Codec library |
2 | * Copyright (C) 2004-2009 Josh Coalson |
3 | * Copyright (C) 2011-2016 Xiph.Org Foundation |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * |
12 | * - Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * - Neither the name of the Xiph.org Foundation nor the names of its |
17 | * contributors may be used to endorse or promote products derived from |
18 | * this software without specific prior written permission. |
19 | * |
20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR |
24 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
25 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
26 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
27 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
28 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
29 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
30 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
31 | */ |
32 | |
33 | #ifndef FLAC__PRIVATE__FLOAT_H |
34 | #define FLAC__PRIVATE__FLOAT_H |
35 | |
36 | #ifdef HAVE_CONFIG_H |
37 | #include <config.h> |
38 | #endif |
39 | |
40 | #include "FLAC/ordinals.h" |
41 | |
42 | /* |
43 | * All the code in libFLAC that uses float and double |
44 | * should be protected by checks of the macro |
45 | * FLAC__INTEGER_ONLY_LIBRARY. |
46 | * |
47 | */ |
48 | #ifndef FLAC__INTEGER_ONLY_LIBRARY |
49 | /* |
50 | * FLAC__real is the basic floating point type used in LPC analysis. |
51 | * |
52 | * WATCHOUT: changing FLAC__real will change the signatures of many |
53 | * functions that have assembly language equivalents and break them. |
54 | */ |
55 | typedef float FLAC__real; |
56 | #else |
57 | /* |
58 | * The convention for FLAC__fixedpoint is to use the upper 16 bits |
59 | * for the integer part and lower 16 bits for the fractional part. |
60 | */ |
61 | typedef FLAC__int32 FLAC__fixedpoint; |
62 | extern const FLAC__fixedpoint FLAC__FP_ZERO; |
63 | extern const FLAC__fixedpoint FLAC__FP_ONE_HALF; |
64 | extern const FLAC__fixedpoint FLAC__FP_ONE; |
65 | extern const FLAC__fixedpoint FLAC__FP_LN2; |
66 | extern const FLAC__fixedpoint FLAC__FP_E; |
67 | |
68 | #define FLAC__fixedpoint_trunc(x) ((x)>>16) |
69 | |
70 | #define FLAC__fixedpoint_mul(x, y) ( (FLAC__fixedpoint) ( ((FLAC__int64)(x)*(FLAC__int64)(y)) >> 16 ) ) |
71 | |
72 | #define FLAC__fixedpoint_div(x, y) ( (FLAC__fixedpoint) ( ( ((FLAC__int64)(x)<<32) / (FLAC__int64)(y) ) >> 16 ) ) |
73 | |
74 | /* |
75 | * FLAC__fixedpoint_log2() |
76 | * -------------------------------------------------------------------- |
77 | * Returns the base-2 logarithm of the fixed-point number 'x' using an |
78 | * algorithm by Knuth for x >= 1.0 |
79 | * |
80 | * 'fracbits' is the number of fractional bits of 'x'. 'fracbits' must |
81 | * be < 32 and evenly divisible by 4 (0 is OK but not very precise). |
82 | * |
83 | * 'precision' roughly limits the number of iterations that are done; |
84 | * use (unsigned)(-1) for maximum precision. |
85 | * |
86 | * If 'x' is less than one -- that is, x < (1<<fracbits) -- then this |
87 | * function will punt and return 0. |
88 | * |
89 | * The return value will also have 'fracbits' fractional bits. |
90 | */ |
91 | FLAC__uint32 FLAC__fixedpoint_log2(FLAC__uint32 x, unsigned fracbits, unsigned precision); |
92 | |
93 | #endif |
94 | |
95 | #endif |