/* * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package com.sun.media.sound; /** * A simple look-ahead volume limiter with very fast attack and fast release. * This filter is used for preventing clipping. * * @author Karl Helgason */public class SoftLimiter implements SoftAudioProcessor {     float lastmax = 0;    float gain = 1;    float[] temp_bufferL;    float[] temp_bufferR;    boolean mix = false;    SoftAudioBuffer bufferL;    SoftAudioBuffer bufferR;    SoftAudioBuffer bufferLout;    SoftAudioBuffer bufferRout;    float controlrate;     public void init(float samplerate, float controlrate) {        this.controlrate = controlrate;    }     public void setInput(int pin, SoftAudioBuffer input) {        if (pin == 0)            bufferL = input;        if (pin == 1)            bufferR = input;    }     public void setOutput(int pin, SoftAudioBuffer output) {        if (pin == 0)            bufferLout = output;        if (pin == 1)            bufferRout = output;    }     public void setMixMode(boolean mix) {        this.mix = mix;    }     public void globalParameterControlChange(int[] slothpath, long param,            long value) {    }     double silentcounter = 0;     public void processAudio() {        if (this.bufferL.isSilent()                && (this.bufferR == null || this.bufferR.isSilent())) {            silentcounter += 1 / controlrate;             if (silentcounter > 60) {                if (!mix) {                    bufferLout.clear();                    if (bufferRout != null) bufferRout.clear();                }                return;            }        } else            silentcounter = 0;         float[] bufferL = this.bufferL.array();        float[] bufferR = this.bufferR == null ? null : this.bufferR.array();        float[] bufferLout = this.bufferLout.array();        float[] bufferRout = this.bufferRout == null                                ? null : this.bufferRout.array();         if (temp_bufferL == null || temp_bufferL.length < bufferL.length)            temp_bufferL = new float[bufferL.length];        if (bufferR != null)            if (temp_bufferR == null || temp_bufferR.length < bufferR.length)                temp_bufferR = new float[bufferR.length];         float max = 0;        int len = bufferL.length;         if (bufferR == null) {            for (int i = 0; i < len; i++) {                if (bufferL[i] > max)                    max = bufferL[i];                if (-bufferL[i] > max)                    max = -bufferL[i];            }        } else {            for (int i = 0; i < len; i++) {                if (bufferL[i] > max)                    max = bufferL[i];                if (bufferR[i] > max)                    max = bufferR[i];                if (-bufferL[i] > max)                    max = -bufferL[i];                if (-bufferR[i] > max)                    max = -bufferR[i];            }        }         float lmax = lastmax;        lastmax = max;        if (lmax > max)            max = lmax;         float newgain = 1;        if (max > 0.99f)            newgain = 0.99f / max;        else            newgain = 1;         if (newgain > gain)            newgain = (newgain + gain * 9) / 10f;         float gaindelta = (newgain - gain) / len;        if (mix) {            if (bufferR == null) {                for (int i = 0; i < len; i++) {                    gain += gaindelta;                    float bL = bufferL[i];                    float tL = temp_bufferL[i];                    temp_bufferL[i] = bL;                    bufferLout[i] += tL * gain;                }            } else {                for (int i = 0; i < len; i++) {                    gain += gaindelta;                    float bL = bufferL[i];                    float bR = bufferR[i];                    float tL = temp_bufferL[i];                    float tR = temp_bufferR[i];                    temp_bufferL[i] = bL;                    temp_bufferR[i] = bR;                    bufferLout[i] += tL * gain;                    bufferRout[i] += tR * gain;                }            }         } else {            if (bufferR == null) {                for (int i = 0; i < len; i++) {                    gain += gaindelta;                    float bL = bufferL[i];                    float tL = temp_bufferL[i];                    temp_bufferL[i] = bL;                    bufferLout[i] = tL * gain;                }            } else {                for (int i = 0; i < len; i++) {                    gain += gaindelta;                    float bL = bufferL[i];                    float bR = bufferR[i];                    float tL = temp_bufferL[i];                    float tR = temp_bufferR[i];                    temp_bufferL[i] = bL;                    temp_bufferR[i] = bR;                    bufferLout[i] = tL * gain;                    bufferRout[i] = tR * gain;                }            }         }        gain = newgain;    }     public void processControlLogic() {    }}