/*
* ServeStream: A HTTP stream browser/player for Android
* Copyright 2013 William Seemann
*
* 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 net.sourceforge.servestream.media;
import java.io.FileDescriptor;
import java.io.IOException;
import android.content.Context;
import android.media.AudioManager;
/**
* Provides a unified interface for dealing with audio files and
* other media files.
*/
public abstract class AbstractMediaPlayer {
/**
* Default constructor.
* <p>When done with the MediaPlayer, you should call {@link #release()},
* to free the resources. If not released, too many MediaPlayer instances may
* result in an exception.</p>
*/
protected AbstractMediaPlayer() {
}
/**
* Sets the data source (file-path or http/rtsp URL) to use.
*
* @param context the current context
* @param id the database identifier of the file to play
*
* <p>When <code>path</code> refers to a local file, the file may actually be opened by a
* process other than the calling application. This implies that the pathname
* should be an absolute path (as any other process runs with unspecified current working
* directory), and that the pathname should reference a world-readable file.
* As an alternative, the application could first open the file for reading,
* and then use the file descriptor form {@link #setDataSource(FileDescriptor)}.
*/
public abstract void setDataSource(Context context, long id)
throws IOException, IllegalArgumentException, SecurityException, IllegalStateException;
/**
* Sets the data source (file-path or http/rtsp URL) to use.
*
* @param path the path of the file, or the http/rtsp URL of the stream you want to play
* @throws IllegalStateException if it is called in an invalid state
*
* <p>When <code>path</code> refers to a local file, the file may actually be opened by a
* process other than the calling application. This implies that the pathname
* should be an absolute path (as any other process runs with unspecified current working
* directory), and that the pathname should reference a world-readable file.
* As an alternative, the application could first open the file for reading,
* and then use the file descriptor form {@link #setDataSource(FileDescriptor)}.
*/
public abstract void setDataSource(String path)
throws IOException, IllegalArgumentException, SecurityException, IllegalStateException;
/**
* Prepares the player for playback, synchronously.
*
* After setting the datasource and the display surface, you need to either
* call prepare() or prepareAsync(). For files, it is OK to call prepare(),
* which blocks until MediaPlayer is ready for playback.
*
* @throws IllegalStateException if it is called in an invalid state
*/
public abstract void prepare() throws IOException, IllegalStateException;
/**
* Prepares the player for playback, asynchronously.
*
* After setting the datasource and the display surface, you need to either
* call prepare() or prepareAsync(). For streams, you should call prepareAsync(),
* which returns immediately, rather than blocking until enough data has been
* buffered.
*
* @throws IllegalStateException if it is called in an invalid state
*/
public abstract void prepareAsync() throws IllegalStateException;
/**
* Starts or resumes playback. If playback had previously been paused,
* playback will continue from where it was paused. If playback had
* been stopped, or never started before, playback will start at the
* beginning.
*
* @throws IllegalStateException if it is called in an invalid state
*/
public abstract void start() throws IllegalStateException;
/**
* Stops playback after playback has been stopped or paused.
*
* @throws IllegalStateException if the internal player engine has not been
* initialized.
*/
public abstract void stop() throws IllegalStateException;
/**
* Pauses playback. Call start() to resume.
*
* @throws IllegalStateException if the internal player engine has not been
* initialized.
*/
public abstract void pause() throws IllegalStateException;
/**
* Seeks to specified time position.
*
* @param msec the offset in milliseconds from the start to seek to
* @throws IllegalStateException if the internal player engine has not been
* initialized
*/
public abstract void seekTo(int msec) throws IllegalStateException;
/**
* Gets the current playback position.
*
* @return the current position in milliseconds
*/
public abstract int getCurrentPosition();
/**
* Gets the duration of the file.
*
* @return the duration in milliseconds
*/
public abstract int getDuration();
/**
* Set the MediaPlayer to start when this MediaPlayer finishes playback
* (i.e. reaches the end of the stream).
* The media framework will attempt to transition from this player to
* the next as seamlessly as possible. The next player can be set at
* any time before completion. The next player must be prepared by the
* app, and the application should not call start() on it.
* The next MediaPlayer must be different from 'this'. An exception
* will be thrown if next == this.
* The application may call setNextMediaPlayer(null) to indicate no
* next player should be started at the end of playback.
* If the current player is looping, it will keep looping and the next
* player will not be started.
*
* @param next the player to start after this one completes playback.
*
*/
// TODO add this back
//public abstract void setNextMediaPlayer(AbstractMediaPlayer next);
/**
* Releases resources associated with this MediaPlayer object.
* It is considered good practice to call this method when you're
* done using the MediaPlayer. In particular, whenever an Activity
* of an application is paused (its onPause() method is called),
* or stopped (its onStop() method is called), this method should be
* invoked to release the MediaPlayer object, unless the application
* has a special need to keep the object around. In addition to
* unnecessary resources (such as memory and instances of codecs)
* being held, failure to call this method immediately if a
* MediaPlayer object is no longer needed may also lead to
* continuous battery consumption for mobile devices, and playback
* failure for other applications if no multiple instances of the
* same codec are supported on a device. Even if multiple instances
* of the same codec are supported, some performance degradation
* may be expected when unnecessary multiple instances are used
* at the same time.
*/
public abstract void release();
/**
* Resets the MediaPlayer to its uninitialized state. After calling
* this method, you will have to initialize it again by setting the
* data source and calling prepare().
*/
public abstract void reset();
/**
* Sets the volume on this player.
* This API is recommended for balancing the output of audio streams
* within an application. Unless you are writing an application to
* control user settings, this API should be used in preference to
* {@link AudioManager#setStreamVolume(int, int, int)} which sets the volume of ALL streams of
* a particular type. Note that the passed volume values are raw scalars.
* UI controls should be scaled logarithmically.
*
* @param leftVolume left volume scalar
* @param rightVolume right volume scalar
*/
public abstract void setVolume(float leftVolume, float rightVolume);
/**
* Sets the audio session ID.
*
* @param sessionId the audio session ID.
* The audio session ID is a system wide unique identifier for the audio stream played by
* this MediaPlayer instance.
* The primary use of the audio session ID is to associate audio effects to a particular
* instance of MediaPlayer: if an audio session ID is provided when creating an audio effect,
* this effect will be applied only to the audio content of media players within the same
* audio session and not to the output mix.
* When created, a MediaPlayer instance automatically generates its own audio session ID.
* However, it is possible to force this player to be part of an already existing audio session
* by calling this method.
* This method must be called before one of the overloaded <code> setDataSource </code> methods.
* @throws IllegalStateException if it is called in an invalid state
*/
public abstract void setAudioSessionId(int sessionId) throws IllegalArgumentException, IllegalStateException;
/**
* Returns the audio session ID.
*
* @return the audio session ID. {@see #setAudioSessionId(int)}
* Note that the audio session ID is 0 only if a problem occured when the MediaPlayer was contructed.
*/
public abstract int getAudioSessionId();
/**
* Interface definition for a callback to be invoked when the media
* source is ready for playback.
*/
public interface OnPreparedListener
{
/**
* Called when the media file is ready for playback.
*
* @param mp the MediaPlayer that is ready for playback
*/
void onPrepared(AbstractMediaPlayer mp);
}
/**
* Register a callback to be invoked when the media source is ready
* for playback.
*
* @param listener the callback that will be run
*/
public void setOnPreparedListener(OnPreparedListener listener)
{
mOnPreparedListener = listener;
}
protected OnPreparedListener mOnPreparedListener;
/**
* Interface definition for a callback to be invoked when playback of
* a media source has completed.
*/
public interface OnCompletionListener
{
/**
* Called when the end of a media source is reached during playback.
*
* @param mp the MediaPlayer that reached the end of the file
*/
void onCompletion(AbstractMediaPlayer mp);
}
/**
* Register a callback to be invoked when the end of a media source
* has been reached during playback.
*
* @param listener the callback that will be run
*/
public void setOnCompletionListener(OnCompletionListener listener)
{
mOnCompletionListener = listener;
}
protected OnCompletionListener mOnCompletionListener;
/**
* Interface definition of a callback to be invoked when there
* has been an error during an asynchronous operation (other errors
* will throw exceptions at method call time).
*/
public interface OnErrorListener
{
/**
* Called to indicate an error.
*
* @param mp the MediaPlayer the error pertains to
* @param what the type of error that has occurred:
* <ul>
* <li>{@link #MEDIA_ERROR_UNKNOWN}
* <li>{@link #MEDIA_ERROR_SERVER_DIED}
* </ul>
* @param extra an extra code, specific to the error. Typically
* implementation dependent.
* <ul>
* <li>{@link #MEDIA_ERROR_IO}
* <li>{@link #MEDIA_ERROR_MALFORMED}
* <li>{@link #MEDIA_ERROR_UNSUPPORTED}
* <li>{@link #MEDIA_ERROR_TIMED_OUT}
* </ul>
* @return True if the method handled the error, false if it didn't.
* Returning false, or not having an OnErrorListener at all, will
* cause the OnCompletionListener to be called.
*/
boolean onError(AbstractMediaPlayer mp, int what, int extra);
}
/**
* Register a callback to be invoked when an error has happened
* during an asynchronous operation.
*
* @param listener the callback that will be run
*/
public void setOnErrorListener(OnErrorListener listener)
{
mOnErrorListener = listener;
}
protected OnErrorListener mOnErrorListener;
/**
* Interface definition of a callback to be invoked to communicate some
* info and/or warning about the media or its playback.
*/
public interface OnInfoListener
{
/**
* Called to indicate an info or a warning.
*
* @param mp the MediaPlayer the info pertains to.
* @param what the type of info or warning.
* <ul>
* <li>{@link #MEDIA_INFO_UNKNOWN}
* <li>{@link #MEDIA_INFO_VIDEO_TRACK_LAGGING}
* <li>{@link #MEDIA_INFO_BUFFERING_START}
* <li>{@link #MEDIA_INFO_BUFFERING_END}
* <li>{@link #MEDIA_INFO_BAD_INTERLEAVING}
* <li>{@link #MEDIA_INFO_NOT_SEEKABLE}
* <li>{@link #MEDIA_INFO_METADATA_UPDATE}
* </ul>
* @param extra an extra code, specific to the info. Typically
* implementation dependant.
* @return True if the method handled the info, false if it didn't.
* Returning false, or not having an OnErrorListener at all, will
* cause the info to be discarded.
*/
boolean onInfo(AbstractMediaPlayer mp, int what, int extra);
}
/** A new set of metadata is available.
* @see android.media.MediaPlayer.OnInfoListener
*/
public static final int MEDIA_INFO_METADATA_UPDATE = 802;
/**
* Register a callback to be invoked when an info/warning is available.
*
* @param listener the callback that will be run
*/
public void setOnInfoListener(OnInfoListener listener)
{
mOnInfoListener = listener;
}
protected OnInfoListener mOnInfoListener;
}