Revert of Reland "Move smoothing filter to common audio".

webrtc/base/exp_filter_unittest.cc

Index: webrtc/base/exp_filter_unittest.cc
diff --git a/webrtc/base/exp_filter_unittest.cc b/webrtc/base/exp_filter_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f0278081138edd9005275c313065a20ef4e94bbe
--- /dev/null
+++ b/webrtc/base/exp_filter_unittest.cc
@@ -0,0 +1,71 @@
+/*
+ *  Copyright 2014 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.
+ */
+
+#include <math.h>
+
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/exp_filter.h"
+
+namespace rtc {
+
+TEST(ExpFilterTest, FirstTimeOutputEqualInput) {
+  // No max value defined.
+  ExpFilter filter = ExpFilter(0.9f);
+  filter.Apply(100.0f, 10.0f);
+
+  // First time, first argument no effect.
+  double value = 10.0f;
+  EXPECT_FLOAT_EQ(value, filter.filtered());
+}
+
+TEST(ExpFilterTest, SecondTime) {
+  double value;
+
+  ExpFilter filter = ExpFilter(0.9f);
+  filter.Apply(100.0f, 10.0f);
+
+  // First time, first argument no effect.
+  value = 10.0f;
+
+  filter.Apply(10.0f, 20.0f);
+  double alpha = pow(0.9f, 10.0f);
+  value = alpha * value + (1.0f - alpha) * 20.0f;
+  EXPECT_FLOAT_EQ(value, filter.filtered());
+}
+
+TEST(ExpFilterTest, Reset) {
+  ExpFilter filter = ExpFilter(0.9f);
+  filter.Apply(100.0f, 10.0f);
+
+  filter.Reset(0.8f);
+  filter.Apply(100.0f, 1.0f);
+
+  // Become first time after a reset.
+  double value = 1.0f;
+  EXPECT_FLOAT_EQ(value, filter.filtered());
+}
+
+TEST(ExpfilterTest, OutputLimitedByMax) {
+  double value;
+
+  // Max value defined.
+  ExpFilter filter = ExpFilter(0.9f, 1.0f);
+  filter.Apply(100.0f, 10.0f);
+
+  // Limited to max value.
+  value = 1.0f;
+  EXPECT_EQ(value, filter.filtered());
+
+  filter.Apply(1.0f, 0.0f);
+  value = 0.9f * value;
+  EXPECT_FLOAT_EQ(value, filter.filtered());
+}
+
+}  // namespace rtc