LoudnessEnhancer audio effect implementation

Implementation based on DRC effect, controlled by a
 target gain.
 The target gain is used to amplify the signal at
 the input of the DRC, and to compute the knee
 of the DRC.

Bug 8413913

Change-Id: I386d64793a9fa3f7218e053d6f0a99f6836c02bd

1 files changed, 48 insertions, 0 deletions

diff --git a/media/libeffects/loudness/dsp/core/basic.h b/media/libeffects/loudness/dsp/core/basic.h
new file mode 100644
index 0000000..27e0a8d
--- /dev/null
+++ b/media/libeffects/loudness/dsp/core/basic.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LE_FX_ENGINE_DSP_CORE_BASIC_H_
+#define LE_FX_ENGINE_DSP_CORE_BASIC_H_
+
+#include <limits.h>
+#include "common/core/math.h"
+#include "common/core/types.h"
+
+namespace le_fx {
+
+namespace sigmod {
+
+// Searchs for the interval that contains <x> using a divide-and-conquer
+// algorithm.
+// X[]: a vector of sorted values (X[i+1] > X[i])
+// x:   a value
+// StartIndex: the minimum searched index
+// EndIndex: the maximum searched index
+// returns: the index <i> that satisfies: X[i] <= x <= X[i+1] &&
+//          StartIndex <= i <= (EndIndex-1)
+template <typename T>
+int SearchIndex(const T x_data[],
+                T x,
+                int start_index,
+                int end_index);
+
+}  // namespace sigmod
+
+}  // namespace le_fx
+
+#include "dsp/core/basic-inl.h"
+
+#endif  // LE_FX_ENGINE_DSP_CORE_BASIC_H_