improved sample helper (normalization is now possible)

AudioProcessing/src/main/java/org/wyrez/audio/util/SampleHelper.java

@@ -100,11 +100,31 @@ public class SampleHelper {
 
     /**
      * Creates a SampleBuffer from the data provided by the given decoder.
-     * 
+     *
      * @param deocder The decoder to read from
      * @returns The new SampleBuffer
      */
     public static SampleBuffer createSampleBuffer(Decoder decoder) {
         return new SampleBuffer(readAllSamples(decoder), decoder.getSamplingRate());
     }
+
+    /**
+     * Normalizes a given float array.
+     *
+     * @param data The float array to normalize
+     * @param lowScale The lower bound of the normalized array
+     * @param highScale The higher bound of the normalized array
+     */
+    public static void normalize(float[] data, float lowScale, float highScale) {
+        float minValue = Float.MAX_VALUE;
+        float maxValue = Float.MIN_VALUE;
+        for (float f : data) {
+            minValue = Math.min(minValue, f);
+            maxValue = Math.max(maxValue, f);
+        }
+
+        for (int i = 0; i < data.length; i++) {
+            data[i] = lowScale + (data[i] - minValue) * (highScale - lowScale) / (maxValue - minValue);
+        }
+    }
 }