Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * 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.
 */

public class Main {
    private static final float MAX_REPORTABLE_DB = 90.3087f;
    private static final float MAX_REPORTABLE_AMP = 32767f;

    public static double getAmplitude(byte[] data, int len) {
        return (MAX_REPORTABLE_DB + (20 * Math.log10(getRawAmplitude(data, len) / MAX_REPORTABLE_AMP)));
    }

    public static double getAmplitude(short[] data, int len) {
        return (MAX_REPORTABLE_DB + 20 * Math.log10(getRawAmplitude(data, len)));
    }

    private static double getRawAmplitude(byte[] data, int len) {
        if (len <= 0 || data == null || data.length <= 0) {
            return 0;
        }

        double sum = 0;
        for (int i = 0; i < len; i++) {
            sum += Math.abs(data[i]);
        }
        return sum / len;
    }

    private static double getRawAmplitude(short[] data, int len) {
        if (len <= 0 || data == null || data.length <= 0) {
            return 0;
        }

        double sum = 0;
        for (int i = 0; i < len; i++) {
            double sample = data[i] / 32768.0;
            sum += sample * sample;
        }
        return Math.sqrt(sum / len);
    }
}