git-svn-id: http://webrtc.googlecode.com/svn/trunk@4 4adac7df-926f-26a2-2b94-8c16560cd09d

modules/audio_coding/NetEQ/main/source/min_distortion.c

@@ -0,0 +1,55 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+/*
+ * Calculate best overlap fit according to distortion measure.
+ */
+
+#include "dsp_helpfunctions.h"
+
+#include "signal_processing_library.h"
+
+WebRtc_Word16 WebRtcNetEQ_MinDistortion(const WebRtc_Word16 *pw16_data,
+                                        WebRtc_Word16 w16_minLag, WebRtc_Word16 w16_maxLag,
+                                        WebRtc_Word16 len, WebRtc_Word32 *pw16_dist)
+{
+    int i, j;
+    const WebRtc_Word16 *pw16_data1;
+    const WebRtc_Word16 *pw16_data2;
+    WebRtc_Word32 w32_diff;
+    WebRtc_Word32 w32_sumdiff;
+    WebRtc_Word16 bestIndex = -1;
+    WebRtc_Word32 minDist = WEBRTC_SPL_WORD32_MAX;
+
+    for (i = w16_minLag; i <= w16_maxLag; i++)
+    {
+        w32_sumdiff = 0;
+        pw16_data1 = pw16_data;
+        pw16_data2 = pw16_data - i;
+
+        for (j = 0; j < len; j++)
+        {
+            w32_diff = pw16_data1[j] - pw16_data2[j];
+            w32_sumdiff += WEBRTC_SPL_ABS_W32(w32_diff);
+        }
+
+        /* Compare with previous minimum */
+        if (w32_sumdiff < minDist)
+        {
+            minDist = w32_sumdiff;
+            bestIndex = i;
+        }
+    }
+
+    *pw16_dist = minDist;
+
+    return bestIndex;
+}
+