float.h

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/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2004-2009 Josh Coalson
 * Copyright (C) 2011-2016 Xiph.Org Foundation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FLAC__PRIVATE__FLOAT_H
#define FLAC__PRIVATE__FLOAT_H

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "../FLAC/ordinals.h"

/*
 * All the code in libFLAC that uses float and double
 * should be protected by checks of the macro
 * FLAC__INTEGER_ONLY_LIBRARY.
 *
 */
#ifndef FLAC__INTEGER_ONLY_LIBRARY
/*
 * FLAC__real is the basic floating point type used in LPC analysis.
 *
 * WATCHOUT: changing FLAC__real will change the signatures of many
 * functions that have assembly language equivalents and break them.
 */
typedef float FLAC__real;
#else
/*
 * The convention for FLAC__fixedpoint is to use the upper 16 bits
 * for the integer part and lower 16 bits for the fractional part.
 */
typedef FLAC__int32 FLAC__fixedpoint;
extern const FLAC__fixedpoint FLAC__FP_ZERO;
extern const FLAC__fixedpoint FLAC__FP_ONE_HALF;
extern const FLAC__fixedpoint FLAC__FP_ONE;
extern const FLAC__fixedpoint FLAC__FP_LN2;
extern const FLAC__fixedpoint FLAC__FP_E;

#define FLAC__fixedpoint_trunc(x) ((x)>>16)

#define FLAC__fixedpoint_mul(x, y) ( (FLAC__fixedpoint) ( ((FLAC__int64)(x)*(FLAC__int64)(y)) >> 16 ) )

#define FLAC__fixedpoint_div(x, y) ( (FLAC__fixedpoint) ( ( ((FLAC__int64)(x)<<32) / (FLAC__int64)(y) ) >> 16 ) )

/*
 * FLAC__fixedpoint_log2()
 * --------------------------------------------------------------------
 * Returns the base-2 logarithm of the fixed-point number 'x' using an
 * algorithm by Knuth for x >= 1.0
 *
 * 'fracbits' is the number of fractional bits of 'x'. 'fracbits' must
 * be < 32 and evenly divisible by 4 (0 is OK but not very precise).
 *
 * 'precision' roughly limits the number of iterations that are done;
 * use (unsigned)(-1) for maximum precision.
 *
 * If 'x' is less than one -- that is, x < (1<<fracbits) -- then this
 * function will punt and return 0.
 *
 * The return value will also have 'fracbits' fractional bits.
 */
FLAC__uint32 FLAC__fixedpoint_log2(FLAC__uint32 x, unsigned fracbits, unsigned precision);

#endif

#endif