/* * Copyright (C) 2010 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.AudioDevice; import android.media.AudioFormat; import android.media.audiofx.AudioEffect; import android.util.Log; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.util.StringTokenizer; /** * An audio virtualizer is a general name for an effect to spatialize audio channels. The exact * behavior of this effect is dependent on the number of audio input channels and the types and * number of audio output channels of the device. For example, in the case of a stereo input and * stereo headphone output, a stereo widening effect is used when this effect is turned on. *
An application creates a Virtualizer object to instantiate and control a virtualizer engine * in the audio framework. *
The methods, parameter types and units exposed by the Virtualizer implementation are directly * mapping those defined by the OpenSL ES 1.0.1 Specification (http://www.khronos.org/opensles/) * for the SLVirtualizerItf interface. Please refer to this specification for more details. *
To attach the Virtualizer to a particular AudioTrack or MediaPlayer, specify the audio session * ID of this AudioTrack or MediaPlayer when constructing the Virtualizer. *
NOTE: attaching a Virtualizer to the global audio output mix by use of session 0 is * deprecated. *
See {@link android.media.MediaPlayer#getAudioSessionId()} for details on audio sessions. *
See {@link android.media.audiofx.AudioEffect} class for more details on controlling
* audio effects.
*/
public class Virtualizer extends AudioEffect {
private final static String TAG = "Virtualizer";
private final static boolean DEBUG = false;
// These constants must be synchronized with those in
// system/media/audio_effects/include/audio_effects/effect_virtualizer.h
/**
* Is strength parameter supported by virtualizer engine. Parameter ID for getParameter().
*/
public static final int PARAM_STRENGTH_SUPPORTED = 0;
/**
* Virtualizer effect strength. Parameter ID for
* {@link android.media.audiofx.Virtualizer.OnParameterChangeListener}
*/
public static final int PARAM_STRENGTH = 1;
/**
* @hide
* Parameter ID to query the virtual speaker angles for a channel mask / device configuration.
*/
public static final int PARAM_VIRTUAL_SPEAKER_ANGLES = 2;
/**
* @hide
* Parameter ID to force the virtualization mode to be that of a specific device
*/
public static final int PARAM_FORCE_VIRTUALIZATION_MODE = 3;
/**
* @hide
* Parameter ID to query the current virtualization mode.
*/
public static final int PARAM_VIRTUALIZATION_MODE = 4;
/**
* Indicates if strength parameter is supported by the virtualizer engine
*/
private boolean mStrengthSupported = false;
/**
* Registered listener for parameter changes.
*/
private OnParameterChangeListener mParamListener = null;
/**
* Listener used internally to to receive raw parameter change event from AudioEffect super class
*/
private BaseParameterListener mBaseParamListener = null;
/**
* Lock for access to mParamListener
*/
private final Object mParamListenerLock = new Object();
/**
* Class constructor.
* @param priority the priority level requested by the application for controlling the Virtualizer
* 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 Virtualizer 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 Virtualizer(int priority, int audioSession)
throws IllegalStateException, IllegalArgumentException,
UnsupportedOperationException, RuntimeException {
super(EFFECT_TYPE_VIRTUALIZER, EFFECT_TYPE_NULL, priority, audioSession);
if (audioSession == 0) {
Log.w(TAG, "WARNING: attaching a Virtualizer to global output mix is deprecated!");
}
int[] value = new int[1];
checkStatus(getParameter(PARAM_STRENGTH_SUPPORTED, value));
mStrengthSupported = (value[0] != 0);
}
/**
* Indicates whether setting strength is supported. If this method returns false, only one
* strength is supported and the setStrength() method always rounds to that value.
* @return true is strength parameter is supported, false otherwise
*/
public boolean getStrengthSupported() {
return mStrengthSupported;
}
/**
* Sets the strength of the virtualizer effect. If the implementation does not support per mille
* accuracy for setting the strength, it is allowed to round the given strength to the nearest
* supported value. You can use the {@link #getRoundedStrength()} method to query the
* (possibly rounded) value that was actually set.
* @param strength strength of the effect. The valid range for strength strength is [0, 1000],
* where 0 per mille designates the mildest effect and 1000 per mille designates the strongest.
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public void setStrength(short strength)
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
checkStatus(setParameter(PARAM_STRENGTH, strength));
}
/**
* Gets the current strength of the effect.
* @return the strength of the effect. The valid range for strength is [0, 1000], where 0 per
* mille designates the mildest effect and 1000 per mille the strongest
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public short getRoundedStrength()
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
short[] value = new short[1];
checkStatus(getParameter(PARAM_STRENGTH, value));
return value[0];
}
/**
* Checks if a configuration is supported, and query the virtual speaker angles.
* @param inputChannelMask
* @param deviceType
* @param angles if non-null: array in which the angles will be written. If null, no angles
* are returned
* @return true if the combination of channel mask and output device type is supported, false
* otherwise
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
private boolean getAnglesInt(int inputChannelMask, int deviceType, int[] angles)
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
// parameter check
if (inputChannelMask == AudioFormat.CHANNEL_INVALID) {
throw (new IllegalArgumentException(
"Virtualizer: illegal CHANNEL_INVALID channel mask"));
}
int channelMask = inputChannelMask == AudioFormat.CHANNEL_OUT_DEFAULT ?
AudioFormat.CHANNEL_OUT_STEREO : inputChannelMask;
int nbChannels = AudioFormat.channelCountFromOutChannelMask(channelMask);
if ((angles != null) && (angles.length < (nbChannels * 3))) {
Log.e(TAG, "Size of array for angles cannot accomodate number of channels in mask ("
+ nbChannels + ")");
throw (new IllegalArgumentException(
"Virtualizer: array for channel / angle pairs is too small: is " + angles.length
+ ", should be " + (nbChannels * 3)));
}
ByteBuffer paramsConverter = ByteBuffer.allocate(3 /* param + mask + device*/ * 4);
paramsConverter.order(ByteOrder.nativeOrder());
paramsConverter.putInt(PARAM_VIRTUAL_SPEAKER_ANGLES);
// convert channel mask to internal native representation
paramsConverter.putInt(AudioFormat.convertChannelOutMaskToNativeMask(channelMask));
// convert Java device type to internal representation
paramsConverter.putInt(AudioDevice.convertDeviceTypeToInternalDevice(deviceType));
// allocate an array to store the results
byte[] result = new byte[nbChannels * 4/*int to byte*/ * 3/*for mask, azimuth, elevation*/];
// call into the effect framework
int status = getParameter(paramsConverter.array(), result);
if (DEBUG) {
Log.v(TAG, "getAngles(0x" + Integer.toHexString(inputChannelMask) + ", 0x"
+ Integer.toHexString(deviceType) + ") returns " + status);
}
if (status >= 0) {
if (angles != null) {
// convert and copy the results
ByteBuffer resultConverter = ByteBuffer.wrap(result);
resultConverter.order(ByteOrder.nativeOrder());
for (int i = 0 ; i < nbChannels ; i++) {
// write the channel mask
angles[3 * i] = AudioFormat.convertNativeChannelMaskToOutMask(
resultConverter.getInt((i * 4 * 3)));
// write the azimuth
angles[3 * i + 1] = resultConverter.getInt(i * 4 * 3 + 4);
// write the elevation
angles[3 * i + 2] = resultConverter.getInt(i * 4 * 3 + 8);
if (DEBUG) {
Log.v(TAG, "channel 0x" + Integer.toHexString(angles[3*i]).toUpperCase()
+ " at az=" + angles[3*i+1] + "deg"
+ " elev=" + angles[3*i+2] + "deg");
}
}
}
return true;
} else if (status == AudioEffect.ERROR_BAD_VALUE) {
// a BAD_VALUE return from getParameter indicates the configuration is not supported
// don't throw an exception, just return false
return false;
} else {
// something wrong may have happened
checkStatus(status);
}
// unexpected virtualizer behavior
Log.e(TAG, "unexpected status code " + status
+ " after getParameter(PARAM_VIRTUAL_SPEAKER_ANGLES)");
return false;
}
/**
* @hide
* CANDIDATE FOR PUBLIC API
* Checks if the combination of a channel mask and device type is supported by this virtualizer.
* Some virtualizer implementations may only support binaural processing (i.e. only support
* headphone output), some may support transaural processing (i.e. for speaker output) for the
* built-in speakers. Use this method to query the virtualizer implementation capabilities.
* @param inputChannelMask the channel mask of the content to virtualize.
* @param deviceType the device type for which virtualization processing is to be performed.
* Valid values are the device types defined in {@link AudioDevice}.
* @return true if the combination of channel mask and output device type is supported, false
* otherwise.
*
An indication that a certain channel mask is not supported doesn't necessarily mean
* you cannot play content with that channel mask, it more likely implies the content will
* be downmixed before being virtualized. For instance a virtualizer that only supports a
* mask such as {@link AudioFormat#CHANNEL_OUT_STEREO}
* will still be able to process content with a mask of
* {@link AudioFormat#CHANNEL_OUT_5POINT1}, but will downmix the content to stereo first, and
* then will virtualize, as opposed to virtualizing each channel individually.
* @throws IllegalStateException
* @throws IllegalArgumentException
* @throws UnsupportedOperationException
*/
public boolean canVirtualize(int inputChannelMask, int deviceType)
throws IllegalStateException, IllegalArgumentException, UnsupportedOperationException {
return getAnglesInt(inputChannelMask, deviceType, null);
}
/**
* @hide
* CANDIDATE FOR PUBLIC API
* Queries the virtual speaker angles (azimuth and elevation) for a combination of a channel
* mask and device type.
* If the virtualization configuration (mask and device) is supported (see
* {@link #canVirtualize(int, int)}, the array angles will contain upon return the
* definition of each virtual speaker and its azimuth and elevation angles relative to the
* listener.
*
Note that in some virtualizer implementations, the angles may be strength-dependent.
* @param inputChannelMask the channel mask of the content to virtualize.
* @param deviceType the device type for which virtualization processing is to be performed.
* Valid values are the device types defined in {@link AudioDevice}.
* @param angles a non-null array whose length is 3 times the number of channels in the channel
* mask.
* If the method indicates the configuration is supported, the array will contain upon return
* triplets of values: for each channel i
among the channels of the mask:
*
3*i
in the array contains the speaker
* identification (e.g. {@link AudioFormat#CHANNEL_OUT_FRONT_LEFT}),3*i+1
contains its corresponding azimuth angle
* expressed in degrees, where 0 is the direction the listener faces, 180 is behind
* the listener, and -90 is to her/his left,3*i+2
contains its corresponding elevation angle
* where +90 is directly above the listener, 0 is the horizontal plane, and -90 is
* directly below the listener.