/*
* 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.
*/
package android.media.audiofx;
import android.media.AudioTrack;
import android.media.MediaPlayer;
import android.media.audiofx.AudioEffect;
import android.util.Log;
import java.util.StringTokenizer;
/**
* LoudnessEnhancer is an audio effect for increasing audio loudness.
* The processing is parametrized by a target gain value, which determines the maximum amount
* by which an audio signal will be amplified; signals amplified outside of the sample
* range supported by the platform are compressed.
* An application creates a LoudnessEnhancer object to instantiate and control a
* this audio effect in the audio framework.
* To attach the LoudnessEnhancer to a particular AudioTrack or MediaPlayer,
* specify the audio session ID of this AudioTrack or MediaPlayer when constructing the effect
* (see {@link AudioTrack#getAudioSessionId()} and {@link MediaPlayer#getAudioSessionId()}).
*/
public class LoudnessEnhancer extends AudioEffect {
private final static String TAG = "LoudnessEnhancer";
// These parameter constants must be synchronized with those in
// /system/media/audio_effects/include/audio_effects/effect_loudnessenhancer.h
/**
* The maximum gain applied applied to the signal to process.
* It is expressed in millibels (100mB = 1dB) where 0mB corresponds to no amplification.
*/
public static final int PARAM_TARGET_GAIN_MB = 0;
/**
* Registered listener for parameter changes.
*/
private OnParameterChangeListener mParamListener = null;
/**
* Listener used internally to to receive raw parameter change events
* from AudioEffect super class
*/
private BaseParameterListener mBaseParamListener = null;
/**
* Lock for access to mParamListener
*/
private final Object mParamListenerLock = new Object();
/**
* Class constructor.
* @param audioSession system-wide unique audio session identifier. The LoudnessEnhancer
* will be attached to the MediaPlayer or AudioTrack in the same audio session.
*
* @throws java.lang.IllegalStateException
* @throws java.lang.IllegalArgumentException
* @throws java.lang.UnsupportedOperationException
* @throws java.lang.RuntimeException
*/
public LoudnessEnhancer(int audioSession)
throws IllegalStateException, IllegalArgumentException,
UnsupportedOperationException, RuntimeException {
super(EFFECT_TYPE_LOUDNESS_ENHANCER, EFFECT_TYPE_NULL, 0, audioSession);
if (audioSession == 0) {
Log.w(TAG, "WARNING: attaching a LoudnessEnhancer to global output mix is deprecated!");
}
}
/**
* @hide
* Class constructor for the LoudnessEnhancer audio effect.
* @param priority the priority level requested by the application for controlling the
* LoudnessEnhancer engine. As the same engine can be shared by several applications,
* this parameter indicates how much the requesting application needs control of effect
* parameters. The normal priority is 0, above normal is a positive number, below normal a
* negative number.
* @param audioSession system-wide unique audio session identifier. The LoudnessEnhancer
* will be attached to the MediaPlayer or AudioTrack in the same audio session.
*
* @throws java.lang.IllegalStateException
* @throws java.lang.IllegalArgumentException
* @throws java.lang.UnsupportedOperationException
* @throws java.lang.RuntimeException
*/
public LoudnessEnhancer(int priority, int audioSession)
throws IllegalStateException, IllegalArgumentException,
UnsupportedOperationException, RuntimeException {
super(EFFECT_TYPE_LOUDNESS_ENHANCER, EFFECT_TYPE_NULL, priority, audioSession);
if (audioSession == 0) {
Log.w(TAG, "WARNING: attaching a LoudnessEnhancer to global output mix is deprecated!");
}
}
/**
* Set the target gain for the audio effect.
* The target gain is the maximum value by which a sample value will be amplified when the
* effect is enabled.
* @param gainmB the effect target gain expressed in mB. 0mB corresponds to no amplification.
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public void setTargetGain(int gainmB)
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
checkStatus(setParameter(PARAM_TARGET_GAIN_MB, gainmB));
}
/**
* Return the target gain.
* @return the effect target gain expressed in mB.
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public float getTargetGain()
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
int[] value = new int[1];
checkStatus(getParameter(PARAM_TARGET_GAIN_MB, value));
return value[0];
}
/**
* @hide
* The OnParameterChangeListener interface defines a method called by the LoudnessEnhancer
* when a parameter value has changed.
*/
public interface OnParameterChangeListener {
/**
* Method called when a parameter value has changed. The method is called only if the
* parameter was changed by another application having the control of the same
* LoudnessEnhancer engine.
* @param effect the LoudnessEnhancer on which the interface is registered.
* @param param ID of the modified parameter. See {@link #PARAM_GENERIC_PARAM1} ...
* @param value the new parameter value.
*/
void onParameterChange(LoudnessEnhancer effect, int param, int value);
}
/**
* Listener used internally to receive unformatted parameter change events from AudioEffect
* super class.
*/
private class BaseParameterListener implements AudioEffect.OnParameterChangeListener {
private BaseParameterListener() {
}
public void onParameterChange(AudioEffect effect, int status, byte[] param, byte[] value) {
// only notify when the parameter was successfully change
if (status != AudioEffect.SUCCESS) {
return;
}
OnParameterChangeListener l = null;
synchronized (mParamListenerLock) {
if (mParamListener != null) {
l = mParamListener;
}
}
if (l != null) {
int p = -1;
int v = Integer.MIN_VALUE;
if (param.length == 4) {
p = byteArrayToInt(param, 0);
}
if (value.length == 4) {
v = byteArrayToInt(value, 0);
}
if (p != -1 && v != Integer.MIN_VALUE) {
l.onParameterChange(LoudnessEnhancer.this, p, v);
}
}
}
}
/**
* @hide
* Registers an OnParameterChangeListener interface.
* @param listener OnParameterChangeListener interface registered
*/
public void setParameterListener(OnParameterChangeListener listener) {
synchronized (mParamListenerLock) {
if (mParamListener == null) {
mBaseParamListener = new BaseParameterListener();
super.setParameterListener(mBaseParamListener);
}
mParamListener = listener;
}
}
/**
* @hide
* The Settings class regroups the LoudnessEnhancer parameters. It is used in
* conjunction with the getProperties() and setProperties() methods to backup and restore
* all parameters in a single call.
*/
public static class Settings {
public int targetGainmB;
public Settings() {
}
/**
* Settings class constructor from a key=value; pairs formatted string. The string is
* typically returned by Settings.toString() method.
* @throws IllegalArgumentException if the string is not correctly formatted.
*/
public Settings(String settings) {
StringTokenizer st = new StringTokenizer(settings, "=;");
//int tokens = st.countTokens();
if (st.countTokens() != 3) {
throw new IllegalArgumentException("settings: " + settings);
}
String key = st.nextToken();
if (!key.equals("LoudnessEnhancer")) {
throw new IllegalArgumentException(
"invalid settings for LoudnessEnhancer: " + key);
}
try {
key = st.nextToken();
if (!key.equals("targetGainmB")) {
throw new IllegalArgumentException("invalid key name: " + key);
}
targetGainmB = Integer.parseInt(st.nextToken());
} catch (NumberFormatException nfe) {
throw new IllegalArgumentException("invalid value for key: " + key);
}
}
@Override
public String toString() {
String str = new String (
"LoudnessEnhancer"+
";targetGainmB="+Integer.toString(targetGainmB)
);
return str;
}
};
/**
* @hide
* Gets the LoudnessEnhancer properties. This method is useful when a snapshot of current
* effect settings must be saved by the application.
* @return a LoudnessEnhancer.Settings object containing all current parameters values
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public LoudnessEnhancer.Settings getProperties()
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
Settings settings = new Settings();
int[] value = new int[1];
checkStatus(getParameter(PARAM_TARGET_GAIN_MB, value));
settings.targetGainmB = value[0];
return settings;
}
/**
* @hide
* Sets the LoudnessEnhancer properties. This method is useful when bass boost settings
* have to be applied from a previous backup.
* @param settings a LoudnessEnhancer.Settings object containing the properties to apply
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public void setProperties(LoudnessEnhancer.Settings settings)
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
checkStatus(setParameter(PARAM_TARGET_GAIN_MB, settings.targetGainmB));
}
}
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