98 lines
3.7 KiB
C
98 lines
3.7 KiB
C
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/* libFLAC - Free Lossless Audio Codec library
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* Copyright (C) 2004,2005 Josh Coalson
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* - Neither the name of the Xiph.org Foundation nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef FLAC__PRIVATE__FLOAT_H
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#define FLAC__PRIVATE__FLOAT_H
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "FLAC/ordinals.h"
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/*
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* These typedefs make it easier to ensure that integer versions of
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* the library really only contain integer operations. All the code
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* in libFLAC should use FLAC__float and FLAC__double in place of
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* float and double, and be protected by checks of the macro
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* FLAC__INTEGER_ONLY_LIBRARY.
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*
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* FLAC__real is the basic floating point type used in LPC analysis.
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*/
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#ifndef FLAC__INTEGER_ONLY_LIBRARY
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typedef double FLAC__double;
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typedef float FLAC__float;
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/*
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* WATCHOUT: changing FLAC__real will change the signatures of many
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* functions that have assembly language equivalents and break them.
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*/
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typedef float FLAC__real;
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#else
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/*
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* The convention for FLAC__fixedpoint is to use the upper 16 bits
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* for the integer part and lower 16 bits for the fractional part.
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*/
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typedef FLAC__int32 FLAC__fixedpoint;
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extern const FLAC__fixedpoint FLAC__FP_ZERO;
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extern const FLAC__fixedpoint FLAC__FP_ONE_HALF;
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extern const FLAC__fixedpoint FLAC__FP_ONE;
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extern const FLAC__fixedpoint FLAC__FP_LN2;
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extern const FLAC__fixedpoint FLAC__FP_E;
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#define FLAC__fixedpoint_trunc(x) ((x)>>16)
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#define FLAC__fixedpoint_mul(x, y) ( (FLAC__fixedpoint) ( ((FLAC__int64)(x)*(FLAC__int64)(y)) >> 16 ) )
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#define FLAC__fixedpoint_div(x, y) ( (FLAC__fixedpoint) ( ( ((FLAC__int64)(x)<<32) / (FLAC__int64)(y) ) >> 16 ) )
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/*
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* FLAC__fixedpoint_log2()
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* --------------------------------------------------------------------
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* Returns the base-2 logarithm of the fixed-point number 'x' using an
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* algorithm by Knuth for x >= 1.0
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*
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* 'fracbits' is the number of fractional bits of 'x'. 'fracbits' must
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* be < 32 and evenly divisible by 4 (0 is OK but not very precise).
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*
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* 'precision' roughly limits the number of iterations that are done;
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* use (unsigned)(-1) for maximum precision.
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*
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* If 'x' is less than one -- that is, x < (1<<fracbits) -- then this
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* function will punt and return 0.
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*
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* The return value will also have 'fracbits' fractional bits.
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*/
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FLAC__uint32 FLAC__fixedpoint_log2(FLAC__uint32 x, unsigned fracbits, unsigned precision);
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#endif
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#endif
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