Я должен создать собственный медиаплеер в приложении с поддержкой файлов mp3 и wav. Я прочитал в документации, что не могу найти или получить продолжительность медиафайла без настраиваемого источника данных.
Я проверил демонстрацию в JDE 4.6, но у меня все еще проблемы ... Я не могу определить продолжительность, она возвращает намного больше, чем ожидалось, поэтому я уверен, что я что-то напортачил, пока я модифицировал код для чтения mp3-файла локально из файловой системы.
Может кто-нибудь сказать мне, что я сделал не так? (Я слышу мп3, поэтому плеер проигрывает его правильно от начала до конца)
Я должен поддерживать ОС> = 4.6.
Вот мой измененный источник данных:
/* LimitedRateStreaminSource.java
*
* Copyright © 1998-2009 Research In Motion Ltd.
*
* Note: For the sake of simplicity, this sample application may not leverage
* resource bundles and resource strings. However, it is STRONGLY recommended
* that application developers make use of the localization features available
* within the BlackBerry development platform to ensure a seamless application
* experience across a variety of languages and geographies.
* For more information on localizing your application, please refer to the
* BlackBerry Java Development Environment Development Guide associated with
* this release.
*/
package com.halcyon.tawkwidget.model;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.media.Control;
import javax.microedition.media.protocol.ContentDescriptor;
import javax.microedition.media.protocol.DataSource;
import javax.microedition.media.protocol.SourceStream;
import net.rim.device.api.io.SharedInputStream;
/**
* The data source used by the BufferedPlayback's media player.
*/
public final class LimitedRateStreamingSource extends DataSource
{
/** The max size to be read from the stream at one time. */
private static final int READ_CHUNK = 512; // bytes
/** A reference to the field which displays the load status. */
//private TextField _loadStatusField;
/** A reference to the field which displays the player status. */
//private TextField _playStatusField;
/**
* The minimum number of bytes that must be buffered before the media file
* will begin playing.
*/
private int _startBuffer = 200000;
/** The maximum size (in bytes) of a single read. */
private int _readLimit = 32000;
/**
* The minimum forward byte buffer which must be maintained in order for
* the video to keep playing. If the forward buffer falls below this
* number, the playback will pause until the buffer increases.
*/
private int _pauseBytes = 64000;
/**
* The minimum forward byte buffer required to resume
* playback after a pause.
*/
private int _resumeBytes = 128000;
/** The stream connection over which media content is passed. */
//private ContentConnection _contentConnection;
private FileConnection _fileConnection;
/** An input stream shared between several readers. */
private SharedInputStream _readAhead;
/** A stream to the buffered resource. */
private LimitedRateSourceStream _feedToPlayer;
/** The MIME type of the remote media file. */
private String _forcedContentType;
/** A counter for the total number of buffered bytes */
private volatile int _totalRead;
/** A flag used to tell the connection thread to stop */
private volatile boolean _stop;
/**
* A flag used to indicate that the initial buffering is complete. In
* other words, that the current buffer is larger than the defined start
* buffer size.
*/
private volatile boolean _bufferingComplete;
/** A flag used to indicate that the remote file download is complete. */
private volatile boolean _downloadComplete;
/** The thread which retrieves the remote media file. */
private ConnectionThread _loaderThread;
/** The local save file into which the remote file is written. */
private FileConnection _saveFile;
/** A stream for the local save file. */
private OutputStream _saveStream;
/**
* Constructor.
* @param locator The locator that describes the DataSource.
*/
public LimitedRateStreamingSource(String locator)
{
super(locator);
}
/**
* Open a connection to the locator.
* @throws IOException
*/
public void connect() throws IOException
{
//Open the connection to the remote file.
_fileConnection = (FileConnection)Connector.open(getLocator(),
Connector.READ);
//Cache a reference to the locator.
String locator = getLocator();
//Report status.
System.out.println("Loading: " + locator);
//System.out.println("Size: " + _contentConnection.getLength());
System.out.println("Size: " + _fileConnection.totalSize());
//The name of the remote file begins after the last forward slash.
int filenameStart = locator.lastIndexOf('/');
//The file name ends at the first instance of a semicolon.
int paramStart = locator.indexOf(';');
//If there is no semicolon, the file name ends at the end of the line.
if (paramStart < 0)
{
paramStart = locator.length();
}
//Extract the file name.
String filename = locator.substring(filenameStart, paramStart);
System.out.println("Filename: " + filename);
//Open a local save file with the same name as the remote file.
_saveFile = (FileConnection) Connector.open("file:///SDCard"+
"/blackberry/music" + filename, Connector.READ_WRITE);
//If the file doesn't already exist, create it.
if (!_saveFile.exists())
{
_saveFile.create();
}
System.out.println("---------- 1");
//Open the file for writing.
_saveFile.setReadable(true);
//Open a shared input stream to the local save file to
//allow many simultaneous readers.
SharedInputStream fileStream = SharedInputStream.getSharedInputStream(
_saveFile.openInputStream());
//Begin reading at the beginning of the file.
fileStream.setCurrentPosition(0);
System.out.println("---------- 2");
//If the local file is smaller than the remote file...
if (_saveFile.fileSize() < _fileConnection.totalSize())
{
System.out.println("---------- 3");
//Did not get the entire file, set the system to try again.
_saveFile.setWritable(true);
System.out.println("---------- 4");
//A non-null save stream is used as a flag later to indicate that
//the file download was incomplete.
_saveStream = _saveFile.openOutputStream();
System.out.println("---------- 5");
//Use a new shared input stream for buffered reading.
_readAhead = SharedInputStream.getSharedInputStream(
_fileConnection.openInputStream());
System.out.println("---------- 6");
}
else
{
//The download is complete.
System.out.println("---------- 7");
_downloadComplete = true;
//We can use the initial input stream to read the buffered media.
_readAhead = fileStream;
System.out.println("---------- 8");
//We can close the remote connection.
_fileConnection.close();
System.out.println("---------- 9");
}
if (_forcedContentType != null)
{
//Use the user-defined content type if it is set.
System.out.println("---------- 10");
_feedToPlayer = new LimitedRateSourceStream(_readAhead,
_forcedContentType);
System.out.println("---------- 11");
}
else
{
System.out.println("---------- 12");
//Otherwise, use the MIME types of the remote file.
// _feedToPlayer = new LimitedRateSourceStream(_readAhead,
_fileConnection));
}
System.out.println("---------- 13");
}
/**
* Destroy and close all existing connections.
*/
public void disconnect() {
try
{
if (_saveStream != null)
{
//Destroy the stream to the local save file.
_saveStream.close();
_saveStream = null;
}
//Close the local save file.
_saveFile.close();
if (_readAhead != null)
{
//Close the reader stream.
_readAhead.close();
_readAhead = null;
}
//Close the remote file connection.
_fileConnection.close();
//Close the stream to the player.
_feedToPlayer.close();
}
catch (Exception e)
{
System.err.println(e.getMessage());
}
}
/**
* Returns the content type of the remote file.
* @return The content type of the remote file.
*/
public String getContentType()
{
return _feedToPlayer.getContentDescriptor().getContentType();
}
/**
* Returns a stream to the buffered resource.
* @return A stream to the buffered resource.
*/
public SourceStream[] getStreams()
{
return new SourceStream[] { _feedToPlayer };
}
/**
* Starts the connection thread used to download the remote file.
*/
public void start() throws IOException
{
//If the save stream is null, we have already completely downloaded
//the file.
if (_saveStream != null)
{
//Open the connection thread to finish downloading the file.
_loaderThread = new ConnectionThread();
_loaderThread.start();
}
}
/**
* Stop the connection thread.
*/
public void stop() throws IOException
{
//Set the boolean flag to stop the thread.
_stop = true;
}
/**
* @see javax.microedition.media.Controllable#getControl(String)
*/
public Control getControl(String controlType)
{
// No implemented Controls.
return null;
}
/**
* @see javax.microedition.media.Controllable#getControls()
*/
public Control[] getControls()
{
// No implemented Controls.
return null;
}
/**
* Force the lower level stream to a given content type. Must be called
* before the connect function in order to work.
* @param contentType The content type to use.
*/
public void setContentType(String contentType)
{
_forcedContentType = contentType;
}
/**
* A stream to the buffered media resource.
*/
private final class LimitedRateSourceStream implements SourceStream
{
/** A stream to the local copy of the remote resource. */
private SharedInputStream _baseSharedStream;
/** Describes the content type of the media file. */
private ContentDescriptor _contentDescriptor;
/**
* Constructor. Creates a LimitedRateSourceStream from
* the given InputStream.
* @param inputStream The input stream used to create a new reader.
* @param contentType The content type of the remote file.
*/
LimitedRateSourceStream(InputStream inputStream, String contentType)
{
System.out.println("[LimitedRateSoruceStream]---------- 1");
_baseSharedStream = SharedInputStream.getSharedInputStream(
inputStream);
System.out.println("[LimitedRateSoruceStream]---------- 2");
_contentDescriptor = new ContentDescriptor(contentType);
System.out.println("[LimitedRateSoruceStream]---------- 3");
}
/**
* Returns the content descriptor for this stream.
* @return The content descriptor for this stream.
*/
public ContentDescriptor getContentDescriptor()
{
return _contentDescriptor;
}
/**
* Returns the length provided by the connection.
* @return long The length provided by the connection.
*/
public long getContentLength()
{
return _fileConnection.totalSize();
}
/**
* Returns the seek type of the stream.
*/
public int getSeekType()
{
return RANDOM_ACCESSIBLE;
//return SEEKABLE_TO_START;
}
/**
* Returns the maximum size (in bytes) of a single read.
*/
public int getTransferSize()
{
return _readLimit;
}
/**
* Writes bytes from the buffer into a byte array for playback.
* @param bytes The buffer into which the data is read.
* @param off The start offset in array b at which the data is written.
* @param len The maximum number of bytes to read.
* @return the total number of bytes read into the buffer, or -1 if
* there is no more data because the end of the stream has been reached.
* @throws IOException
*/
public int read(byte[] bytes, int off, int len) throws IOException
{
System.out.println("[LimitedRateSoruceStream]---------- 5");
System.out.println("Read Request for: " + len + " bytes");
//Limit bytes read to our readLimit.
int readLength = len;
System.out.println("[LimitedRateSoruceStream]---------- 6");
if (readLength > getReadLimit())
{
readLength = getReadLimit();
}
//The number of available byes in the buffer.
int available;
//A boolean flag indicating that the thread should pause
//until the buffer has increased sufficiently.
boolean paused = false;
System.out.println("[LimitedRateSoruceStream]---------- 7");
for (;;)
{
available = _baseSharedStream.available();
System.out.println("[LimitedRateSoruceStream]---------- 8");
if (_downloadComplete)
{
//Ignore all restrictions if downloading is complete.
System.out.println("Complete, Reading: " + len +
" - Available: " + available);
return _baseSharedStream.read(bytes, off, len);
}
else if(_bufferingComplete)
{
if (paused && available > getResumeBytes())
{
//If the video is paused due to buffering, but the
//number of available byes is sufficiently high,
//resume playback of the media.
System.out.println("Resuming - Available: " +
available);
paused = false;
return _baseSharedStream.read(bytes, off, readLength);
}
else if(!paused && (available > getPauseBytes() ||
available > readLength))
{
//We have enough information for this media playback.
if (available < getPauseBytes())
{
//If the buffer is now insufficient, set the
//pause flag.
paused = true;
}
System.out.println("Reading: " + readLength +
" - Available: " + available);
return _baseSharedStream.read(bytes, off, readLength);
}
else if(!paused)
{
//Set pause until loaded enough to resume.
paused = true;
}
}
else
{
//We are not ready to start yet, try sleeping to allow the
//buffer to increase.
try
{
Thread.sleep(500);
}
catch (Exception e)
{
System.err.println(e.getMessage());
}
}
}
}
/**
* @see javax.microedition.media.protocol.SourceStream#seek(long)
*/
public long seek(long where) throws IOException
{
_baseSharedStream.setCurrentPosition((int) where);
return _baseSharedStream.getCurrentPosition();
}
/**
* @see javax.microedition.media.protocol.SourceStream#tell()
*/
public long tell()
{
return _baseSharedStream.getCurrentPosition();
}
/**
* Close the stream.
* @throws IOException
*/
void close() throws IOException
{
_baseSharedStream.close();
}
/**
* @see javax.microedition.media.Controllable#getControl(String)
*/
public Control getControl(String controlType)
{
// No implemented controls.
return null;
}
/**
* @see javax.microedition.media.Controllable#getControls()
*/
public Control[] getControls()
{
// No implemented controls.
return null;
}
}
/**
* A thread which downloads the remote file and writes it to the local file.
*/
private final class ConnectionThread extends Thread
{
/**
* Download the remote media file, then write it to the local
* file.
* @see java.lang.Thread#run()
*/
public void run()
{
try
{
byte[] data = new byte[READ_CHUNK];
int len = 0;
//Until we reach the end of the file.
while (-1 != (len = _readAhead.read(data)))
{
_totalRead += len;
if (!_bufferingComplete && _totalRead > getStartBuffer())
{
//We have enough of a buffer to begin playback.
_bufferingComplete = true;
System.out.println("Initial Buffering Complete");
}
if (_stop)
{
//Stop reading.
return;
}
}
System.out.println("Downloading Complete");
System.out.println("Total Read: " + _totalRead);
//If the downloaded data is not the same size
//as the remote file, something is wrong.
if (_totalRead != _fileConnection.totalSize())
{
System.err.println("* Unable to Download entire file *");
}
_downloadComplete = true;
_readAhead.setCurrentPosition(0);
//Write downloaded data to the local file.
while (-1 != (len = _readAhead.read(data)))
{
_saveStream.write(data);
}
}
catch (Exception e)
{
System.err.println(e.toString());
}
}
}
/**
* Gets the minimum forward byte buffer which must be maintained in
* order for the video to keep playing.
* @return The pause byte buffer.
*/
int getPauseBytes()
{
return _pauseBytes;
}
/**
* Sets the minimum forward buffer which must be maintained in order
* for the video to keep playing.
* @param pauseBytes The new pause byte buffer.
*/
void setPauseBytes(int pauseBytes)
{
_pauseBytes = pauseBytes;
}
/**
* Gets the maximum size (in bytes) of a single read.
* @return The maximum size (in bytes) of a single read.
*/
int getReadLimit()
{
return _readLimit;
}
/**
* Sets the maximum size (in bytes) of a single read.
* @param readLimit The new maximum size (in bytes) of a single read.
*/
void setReadLimit(int readLimit)
{
_readLimit = readLimit;
}
/**
* Gets the minimum forward byte buffer required to resume
* playback after a pause.
* @return The resume byte buffer.
*/
int getResumeBytes()
{
return _resumeBytes;
}
/**
* Sets the minimum forward byte buffer required to resume
* playback after a pause.
* @param resumeBytes The new resume byte buffer.
*/
void setResumeBytes(int resumeBytes)
{
_resumeBytes = resumeBytes;
}
/**
* Gets the minimum number of bytes that must be buffered before the
* media file will begin playing.
* @return The start byte buffer.
*/
int getStartBuffer()
{
return _startBuffer;
}
/**
* Sets the minimum number of bytes that must be buffered before the
* media file will begin playing.
* @param startBuffer The new start byte buffer.
*/
void setStartBuffer(int startBuffer)
{
_startBuffer = startBuffer;
}
}
И вот так я его использую:
LimitedRateStreamingSource source = new
LimitedRateStreamingSource("file:///SDCard/music3.mp3");
source.setContentType("audio/mpeg");
mediaPlayer = javax.microedition.media.Manager.createPlayer(source);
mediaPlayer.addPlayerListener(this);
mediaPlayer.realize();
mediaPlayer.prefetch();
После запуска я использую mediaPlayer.getDuration
, он возвращается, скажем, около 24:22 (встроенный медиаплеер в Blackberry говорит, что длина файла составляет 4:05)
Я попытался получить продолжительность в слушателе, и, к сожалению, оно вернулось около 64 минут, поэтому я уверен, что что-то не так внутри datasoruce ...
код, конвертирующий
String getElapsedTimeMinutesSeconds(long elapsedTime) {
long Seconds=(elapsedTime/1000)%60;
long Minutes=(elapsedTime/(1000*60))%60;
long Hours=(elapsedTime/(1000*60*60))%24;
return ""+Minutes + ":"+Seconds;
}