1 files changed, 72 insertions, 0 deletions
diff --git a/xtract/xtract_helper.h b/xtract/xtract_helper.h
new file mode 100644
index 0000000..31a2183
--- /dev/null
+++ b/xtract/xtract_helper.h
@@ -0,0 +1,72 @@
+/* libxtract feature extraction library
+ *  
+ * Copyright (C) 2006 Jamie Bullock
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
+ * USA.
+ */
+
+/** \file xtract_helper.h: helper functions for making life with libxtract a bit more bearable */
+
+#ifndef XTRACT_HELPER_H
+#define XTRACT_HELPER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+  * \defgroup helper helper functions
+  *
+  * Declares helper functions, and their parameters. 
+  *
+  * \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)
+  *
+  * @{
+  */
+
+/** \brief Apply a window function to an array of length N
+ *
+ * \param *data a pointer to an array of floats
+ * \param N the number of elements in the array pointed to by *data
+ * \param *argv a pointer to a window function as returned by xtract_make_window()
+ * \param *result a pointer to the first element an array containing the windowed data
+ *
+ * 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
+ *
+ */
+int xtract_windowed(const float *data, const int N, const void *argv, float *result);
+
+/** \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
+ *
+ * \param *data an array of floats
+ * \param N the number of elements in the array pointed by *data
+ * \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)
+ * \param *argv a pointer to the argument vector to be passed to the feature extraction function as determined by feature
+ * \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.
+ *
+ */
+int xtract_features_from_subframes(const float *data, const int N, const int feature, const void *argv, float *result);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+
+