diff src/helper.c @ 107:3e648eec95cb

- Added new helper functions: xtract_windowed() and xtract_features_from_subframes()
- Added windowing functions (window.c)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/helper.c	Fri Dec 28 19:34:51 2007 +0000
@@ -0,0 +1,65 @@
+/* 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.
+ */
+
+
+/* helper.c: helper functions. */
+
+#include "xtract/libxtract.h"
+
+int xtract_windowed(const float *data, const int N, const void *argv, float *result){
+
+    int n;
+    const float *window;
+
+    n = N;
+    window = (const float *)argv;
+
+    while(n--)
+        result[n] = data[n] * window[n];
+
+    return XTRACT_SUCCESS;
+
+}
+
+int xtract_features_from_subframes(const float *data, const int N, const int feature, const void *argv, float *result){
+
+    const float *frame1,
+          *frame2;
+    float *result1,
+          *result2;
+
+    int n,
+        rv;
+
+    n = N >> 1;
+
+    frame1 = data;
+    frame2 = data + n;
+    result1 = result;
+    result2 = result + n;
+
+    rv = xtract[feature](frame1, n, argv, result1);
+
+    if(rv == XTRACT_SUCCESS)
+        rv = xtract[feature](frame2, n, argv, result2);
+
+    return rv;
+
+}