/*
* Copyright (C) 2012 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;
The MediaSyncEvent class defines events that can be used to synchronize playback or capture
actions between different players and recorders.
For instance, AudioRecord.startRecording(MediaSyncEvent) is used to start capture only when the playback on a particular audio session is complete. The audio session ID is retrieved from a player (e.g MediaPlayer, AudioTrack or ToneGenerator) by use of the getAudioSessionId() method.
/**
* The MediaSyncEvent class defines events that can be used to synchronize playback or capture
* actions between different players and recorders.
* <p>For instance, {@link AudioRecord#startRecording(MediaSyncEvent)} is used to start capture
* only when the playback on a particular audio session is complete.
* The audio session ID is retrieved from a player (e.g {@link MediaPlayer}, {@link AudioTrack} or
* {@link ToneGenerator}) by use of the getAudioSessionId() method.
*/
public class MediaSyncEvent {
No sync event specified. When used with a synchronized playback or capture method, the
behavior is equivalent to calling the corresponding non synchronized method.
/**
* No sync event specified. When used with a synchronized playback or capture method, the
* behavior is equivalent to calling the corresponding non synchronized method.
*/
public static final int SYNC_EVENT_NONE = AudioSystem.SYNC_EVENT_NONE;
The corresponding action is triggered only when the presentation is completed (meaning the media has been presented to the user) on the specified session. A synchronization of this type requires a source audio session ID to be set via setAudioSessionId(int) method. /**
* The corresponding action is triggered only when the presentation is completed
* (meaning the media has been presented to the user) on the specified session.
* A synchronization of this type requires a source audio session ID to be set via
* {@link #setAudioSessionId(int)} method.
*/
public static final int SYNC_EVENT_PRESENTATION_COMPLETE =
AudioSystem.SYNC_EVENT_PRESENTATION_COMPLETE;
Creates a synchronization event of the sepcified type.
The type specifies which kind of event is monitored. For instance, event SYNC_EVENT_PRESENTATION_COMPLETE corresponds to the audio being presented to the user on a particular audio session.
Params: - eventType – the synchronization event type.
Throws: Returns: the MediaSyncEvent created.
/**
* Creates a synchronization event of the sepcified type.
*
* <p>The type specifies which kind of event is monitored.
* For instance, event {@link #SYNC_EVENT_PRESENTATION_COMPLETE} corresponds to the audio being
* presented to the user on a particular audio session.
* @param eventType the synchronization event type.
* @return the MediaSyncEvent created.
* @throws java.lang.IllegalArgumentException
*/
public static MediaSyncEvent createEvent(int eventType)
throws IllegalArgumentException {
if (!isValidType(eventType)) {
throw (new IllegalArgumentException(eventType
+ "is not a valid MediaSyncEvent type."));
} else {
return new MediaSyncEvent(eventType);
}
}
private final int mType;
private int mAudioSession = 0;
private MediaSyncEvent(int eventType) {
mType = eventType;
}
Sets the event source audio session ID.
The audio session ID specifies on which audio session the synchronization event should be monitored. It is mandatory for certain event types (e.g. SYNC_EVENT_PRESENTATION_COMPLETE). For instance, the audio session ID can be retrieved via MediaPlayer.getAudioSessionId() when monitoring an event on a particular MediaPlayer.
Params: - audioSessionId – the audio session ID of the event source being monitored.
Throws: Returns: the MediaSyncEvent the method is called on.
/**
* Sets the event source audio session ID.
*
* <p>The audio session ID specifies on which audio session the synchronization event should be
* monitored.
* It is mandatory for certain event types (e.g. {@link #SYNC_EVENT_PRESENTATION_COMPLETE}).
* For instance, the audio session ID can be retrieved via
* {@link MediaPlayer#getAudioSessionId()} when monitoring an event on a particular MediaPlayer.
* @param audioSessionId the audio session ID of the event source being monitored.
* @return the MediaSyncEvent the method is called on.
* @throws java.lang.IllegalArgumentException
*/
public MediaSyncEvent setAudioSessionId(int audioSessionId)
throws IllegalArgumentException {
if (audioSessionId > 0) {
mAudioSession = audioSessionId;
} else {
throw (new IllegalArgumentException(audioSessionId + " is not a valid session ID."));
}
return this;
}
Gets the synchronization event type.
Returns: the synchronization event type.
/**
* Gets the synchronization event type.
*
* @return the synchronization event type.
*/
public int getType() {
return mType;
}
Gets the synchronization event audio session ID.
Returns: the synchronization audio session ID. The returned audio session ID is 0 if it has
not been set.
/**
* Gets the synchronization event audio session ID.
*
* @return the synchronization audio session ID. The returned audio session ID is 0 if it has
* not been set.
*/
public int getAudioSessionId() {
return mAudioSession;
}
private static boolean isValidType(int type) {
switch (type) {
case SYNC_EVENT_NONE:
case SYNC_EVENT_PRESENTATION_COMPLETE:
return true;
default:
return false;
}
}
}