2 * Copyright (C) 2016 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_AUDIO_LIMITER_H
18 #define ANDROID_AUDIO_LIMITER_H
20 #include <sys/cdefs.h>
30 * This limiter function is the identity for [-sqrt(0.5), sqrt(0.5)]
31 * and then approximates atan or spline.
32 * \param in input in range [-sqrt(2), sqrt(2)]; out of range, inf, and NaN are not permitted
33 * \return the limited output in range no larger than [-1.0, 1.0].
34 * The implementation is permitted to limit the output to a slightly smaller range,
35 * so the minimum and maximum outputs may not be achievable.
37 extern float limiter(float in);
46 #endif /* !ANDROID_AUDIO_LIMITER_H */