jamie@254: /* jamie@254: * Copyright (C) 2012 Jamie Bullock jamie@254: * jamie@254: * Permission is hereby granted, free of charge, to any person obtaining a copy jamie@254: * of this software and associated documentation files (the "Software"), to jamie@254: * deal in the Software without restriction, including without limitation the jamie@254: * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or jamie@254: * sell copies of the Software, and to permit persons to whom the Software is jamie@254: * furnished to do so, subject to the following conditions: jamie@254: * jamie@254: * The above copyright notice and this permission notice shall be included in jamie@254: * all copies or substantial portions of the Software. jamie@254: * jamie@254: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR jamie@254: * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, jamie@254: * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE jamie@254: * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER jamie@254: * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING jamie@254: * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS jamie@254: * IN THE SOFTWARE. jamie@254: * jamie@254: */ jamie@254: jamie@254: /** \file xtract_helper.h: helper functions for making life with libxtract a bit more bearable */ jamie@254: jamie@254: #ifndef XTRACT_HELPER_H jamie@254: #define XTRACT_HELPER_H jamie@254: jamie@254: #ifdef __cplusplus jamie@254: extern "C" { jamie@254: #endif jamie@254: jamie@254: #ifdef _MSC_VER jamie@254: #ifndef __cplusplus jamie@254: typedef int bool; jamie@254: #define false 0 jamie@254: #define true 1 jamie@254: #endif jamie@254: #else jamie@254: #include jamie@254: #endif jamie@254: jamie@254: jamie@254: /** jamie@254: * \defgroup helper helper functions jamie@254: * jamie@254: * Declares helper functions, and their parameters. jamie@254: * jamie@254: * \note These functions don't necessarily conform to the prototype used in xtract_scalar.h and xtract_vector.h etc, and as such are intended to be called 'directly' rather than via the xtract[] function pointer array (libxtract.h) jamie@254: * jamie@254: * @{ jamie@254: */ jamie@254: jamie@254: /** \brief Apply a window function to an array of length N jamie@254: * jamie@254: * \param *data a pointer to an array of doubles jamie@254: * \param N the number of elements in the array pointed to by *data jamie@254: * \param *argv a pointer to a window function as returned by xtract_make_window() jamie@254: * \param *result a pointer to the first element an array containing the windowed data jamie@254: * jamie@254: * It is up to the caller to generate and free the array containing the window, and to allocate and free memory of size N to hold the data pointed to by *result jamie@254: * jamie@254: */ jamie@254: int xtract_windowed(const double *data, const int N, const void *argv, double *result); jamie@254: jamie@254: /** \brief Divides the array pointed to by *data into two subframes, and applies a given feature to each subframe, returning them in a single array pointed to by result jamie@254: * jamie@254: * \param *data an array of doubles jamie@254: * \param N the number of elements in the array pointed by *data jamie@254: * \param feature an integer representing the feature to be applied to each subframe in data. This will be a value as given in the enumeration xtract_features_ (libxtract.h) jamie@254: * \param *argv a pointer to the argument vector to be passed to the feature extraction function as determined by feature jamie@254: * \param *result a pointer to the 'packed' results of the feature calculation. This may be passed in as *data to xtract_features_from_subframes() to calculate further features on the subframes, or xtract_difference_vector(), to get the difference between the subframes. jamie@254: * jamie@254: * jamie@254: * It is important to ensure that any _init_*() functions that are called in preparation for functions that are called on subframes are given the subframe size as 'N', and not the frame size. i.e. if xtract_features_from_subframes() is called with N=64, and feature=XTRACT_SPECTRUM, then xtract_init_fft() should be called with N=32. jamie@254: * jamie@254: */ jamie@254: int xtract_features_from_subframes(const double *data, const int N, const int feature, const void *argv, double *result); jamie@254: jamie@254: /** \brief Test whether a number is denormal */ jamie@254: int xtract_is_denormal(double const d); jamie@254: jamie@254: /** \brief Test whether a number is a power of two */ jamie@254: bool xtract_is_poweroftwo(unsigned int x); jamie@254: jamie@254: jamie@254: /** \brief Smooth a vector jamie@254: * jamie@254: * \param *data a pointer to an array of doubles jamie@254: * \param N the number of elements in the array pointed to by *data to be smoothed jamie@254: * \param *argv a pointer to a double giving the smoothing gain jamie@254: * \param *result a pointer to the first element an array containing the smoothed data jamie@254: * jamie@254: * \note if passing in a spectrum e.g. *result from xtract_spectrum(), then N for xtract_smoothed() should be N / 2 with respect to the N for xtract_spectrum() so only amplitude components are smoothed, not frequencies! jamie@254: * jamie@254: */ jamie@254: int xtract_smoothed(const double *data, const int N, const void *argv, double *result); jamie@254: jamie@254: jamie@254: /** @} */ jamie@254: jamie@254: #ifdef __cplusplus jamie@254: } jamie@254: #endif jamie@254: jamie@254: #endif jamie@254: jamie@254: jamie@254: