| 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 |