| /* |
| * Copyright (C) 2016 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. |
| */ |
| |
| package org.drrickorang.loopback; |
| |
| /** |
| * Creates a tone that can be injected (and then looped back) in the Latency test. |
| * The generated tone is a sine wave whose amplitude linearly increases than decreases linearly, |
| * that is it has a triangular window. |
| */ |
| public class RampedSineTone extends SineWaveTone { |
| |
| public RampedSineTone(int samplingRate, double frequency) { |
| super(samplingRate, frequency); |
| mAmplitude = Constant.LOOPBACK_AMPLITUDE; |
| } |
| |
| /** |
| * Modifies SineWaveTone by creating an ramp up in amplitude followed by an immediate ramp down |
| */ |
| @Override |
| public void generateTone(short[] tone, int size) { |
| super.generateTone(tone, size); |
| |
| for (int i = 0; i < size; i++) { |
| double factor; // applied to the amplitude of the sine wave |
| |
| //for first half of sample amplitude is increasing hence i < size / 2 |
| if (i < size / 2) { |
| factor = (i / (float) size) * 2; |
| } else { |
| factor = ((size - i) / (float) size) * 2; |
| } |
| tone[i] *= factor; |
| } |
| } |
| |
| /** |
| * Modifies SineWaveTone by creating an ramp up in amplitude followed by an immediate ramp down |
| */ |
| @Override |
| public void generateTone(double[] tone, int size) { |
| super.generateTone(tone, size); |
| |
| for (int i = 0; i < size; i++) { |
| double factor; // applied to the amplitude of the sine wave |
| |
| //for first half of sample amplitude is increasing hence i < size / 2 |
| if (i < size / 2) { |
| factor = Constant.LOOPBACK_AMPLITUDE * i / size; |
| } else { |
| factor = Constant.LOOPBACK_AMPLITUDE * (size - i) / size; |
| } |
| tone[i] *= factor; |
| } |
| } |
| |
| } |