156 lines
3.6 KiB
C++
156 lines
3.6 KiB
C++
/*
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* Chromaprint -- Audio fingerprinting toolkit
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* Copyright (C) 2010 Lukas Lalinsky <lalinsky@gmail.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
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* USA
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*/
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#ifndef CHROMAPRINT_UTILS_H_
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#define CHROMAPRINT_UTILS_H_
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#if defined(HAVE_CONFIG_H)
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#include <config.h>
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#endif
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#include <math.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <algorithm>
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#include <limits>
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#include <iterator>
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#ifndef HAVE_ROUND
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static inline double round(double x)
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{
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if (x >= 0.0)
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return floor(x + 0.5);
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else
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return ceil(x - 0.5);
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}
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#endif
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#define CHROMAPRINT_DISABLE_COPY(ClassName) \
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ClassName(const ClassName &); \
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void operator=(const ClassName &);
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//#include <iostream>
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namespace Chromaprint
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{
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template<class RandomAccessIterator>
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void PrepareHammingWindow(RandomAccessIterator first, RandomAccessIterator last)
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{
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size_t i = 0, max_i = last - first - 1;
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double scale = 2. * M_PI / max_i;
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while (first != last) {
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*first++ = 0.54 - 0.46 * cos(scale * i++);
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}
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}
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template<class InputIterator1, class InputIterator2, class OutputIterator>
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void ApplyWindow(InputIterator1 input, InputIterator2 window, OutputIterator output, int size, double scale)
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{
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while (size--) {
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*output = *input * *window * scale;
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++input;
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++window;
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++output;
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}
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}
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template<class Iterator>
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typename std::iterator_traits<Iterator>::value_type Sum(Iterator first, Iterator last)
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{
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typename std::iterator_traits<Iterator>::value_type sum = 0;
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while (first != last) {
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sum += *first;
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++first;
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}
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return sum;
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}
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template<class Iterator>
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typename std::iterator_traits<Iterator>::value_type EuclideanNorm(Iterator first, Iterator last)
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{
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typename std::iterator_traits<Iterator>::value_type squares = 0;
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while (first != last) {
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squares += *first * *first;
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++first;
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}
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return (squares > 0) ? sqrt(squares) : 0;
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}
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template<class Iterator, class Func>
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void NormalizeVector(Iterator first, Iterator last, Func func, double threshold = 0.01)
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{
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double norm = func(first, last);
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if (norm < threshold) {
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std::fill(first, last, 0.0);
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}
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else {
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while (first != last) {
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*first /= norm;
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++first;
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}
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}
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}
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inline int GrayCode(int i)
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{
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static const unsigned char CODES[] = { 0, 1, 3, 2 };
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return CODES[i];
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}
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inline double IndexToFreq(int i, int frame_size, int sample_rate)
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{
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return double(i) * sample_rate / frame_size;
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}
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inline int FreqToIndex(double freq, int frame_size, int sample_rate)
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{
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return (int)round(frame_size * freq / sample_rate);
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}
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inline int32_t UnsignedToSigned(uint32_t x)
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{
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return *((int32_t *)&x);
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//return x & 0x80000000 ? x & 0x7FFFFFFF - 0x80000000 : x;
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}
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template<class T>
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inline bool IsNaN(T value)
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{
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return value != value;
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}
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inline double FreqToBark(double f)
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{
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double z = (26.81 * f) / (1960.0 + f) - 0.53;
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if (z < 2.0) {
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z = z + 0.15 * (2.0 - z);
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} else if (z > 20.1) {
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z = z + 0.22 * (z - 20.1);
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}
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return z;
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}
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};
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#endif
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