1/* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2004,2005,2006,2007  Josh Coalson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * - Neither the name of the Xiph.org Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef FLAC__PRIVATE__FLOAT_H
33#define FLAC__PRIVATE__FLOAT_H
34
35#ifdef HAVE_CONFIG_H
36#include <config.h>
37#endif
38
39#include "FLAC/ordinals.h"
40
41/*
42 * These typedefs make it easier to ensure that integer versions of
43 * the library really only contain integer operations.  All the code
44 * in libFLAC should use FLAC__float and FLAC__double in place of
45 * float and double, and be protected by checks of the macro
46 * FLAC__INTEGER_ONLY_LIBRARY.
47 *
48 * FLAC__real is the basic floating point type used in LPC analysis.
49 */
50#ifndef FLAC__INTEGER_ONLY_LIBRARY
51typedef double FLAC__double;
52typedef float FLAC__float;
53/*
54 * WATCHOUT: changing FLAC__real will change the signatures of many
55 * functions that have assembly language equivalents and break them.
56 */
57typedef float FLAC__real;
58#else
59/*
60 * The convention for FLAC__fixedpoint is to use the upper 16 bits
61 * for the integer part and lower 16 bits for the fractional part.
62 */
63typedef FLAC__int32 FLAC__fixedpoint;
64extern const FLAC__fixedpoint FLAC__FP_ZERO;
65extern const FLAC__fixedpoint FLAC__FP_ONE_HALF;
66extern const FLAC__fixedpoint FLAC__FP_ONE;
67extern const FLAC__fixedpoint FLAC__FP_LN2;
68extern const FLAC__fixedpoint FLAC__FP_E;
69
70#define FLAC__fixedpoint_trunc(x) ((x)>>16)
71
72#define FLAC__fixedpoint_mul(x, y) ( (FLAC__fixedpoint) ( ((FLAC__int64)(x)*(FLAC__int64)(y)) >> 16 ) )
73
74#define FLAC__fixedpoint_div(x, y) ( (FLAC__fixedpoint) ( ( ((FLAC__int64)(x)<<32) / (FLAC__int64)(y) ) >> 16 ) )
75
76/*
77 *	FLAC__fixedpoint_log2()
78 *	--------------------------------------------------------------------
79 *	Returns the base-2 logarithm of the fixed-point number 'x' using an
80 *	algorithm by Knuth for x >= 1.0
81 *
82 *	'fracbits' is the number of fractional bits of 'x'.  'fracbits' must
83 *	be < 32 and evenly divisible by 4 (0 is OK but not very precise).
84 *
85 *	'precision' roughly limits the number of iterations that are done;
86 *	use (unsigned)(-1) for maximum precision.
87 *
88 *	If 'x' is less than one -- that is, x < (1<<fracbits) -- then this
89 *	function will punt and return 0.
90 *
91 *	The return value will also have 'fracbits' fractional bits.
92 */
93FLAC__uint32 FLAC__fixedpoint_log2(FLAC__uint32 x, unsigned fracbits, unsigned precision);
94
95#endif
96
97#endif
98