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Problem Converting Byte Array to Datasource For JMF

3 New Member
basically im having null pointer exception

//read an inputstream
is = new DataInputStream (new FileInputStream ("test.mpg") );

//pass it as a datasource for the player
public void loadBytes(Input Stream is){
DataSource ds=new DataSource(is);
player = Manager.createP layer(ds);

//datasource class
import java.io.*;
import java.nio.ByteBu ffer;
import javax.media.*;
import javax.media.pro tocol.*;

public class DataSource extends PullDataSource {
private InputStream is;
private byte [] bytes;

/** Creates new MediaViewerData Source */
public DataSource(Inpu tStream is) {
this.is = is;
int byteCount = is.available();
bytes = new byte [byteCount];
catch (Exception e){
System.out.prin tln(e);

public PullSourceStrea m [] getStreams() {

PullSourceStrea m [] streams = new PullSourceStrea m [1];
InputSourceStre am iss = new InputSourceStre am(new ByteArrayInputS tream(bytes), new FileTypeDescrip tor(ContentDesc riptor.RAW));
streams[0] = iss;
return streams;


public void connect() {}

public void disconnect() {}

public String getContentType( ) {
return new String(FileType Descriptor.MPEG );

public MediaLocator getLocator() {
return null;

public void initCheck() {}

public void setLocator(Medi aLocator source) {}

public void start() {}

public void stop() {}

public Object getControl(Stri ng s){
return null;

public Object [] getControls(){
return null;

public Time getDuration(){
return null;


//inputsourcestre am class
import java.io.InputSt ream;
import java.io.IOExcep tion;
import java.nio.ByteBu ffer;

import javax.media.pro tocol.ContentDe scriptor;
import javax.media.pro tocol.PullSourc eStream;
import javax.media.pro tocol.Seekable;
import javax.media.pro tocol.SourceStr eam;

* Build a source stream out of an input stream.
* @see DataSource
* @see SourceStream
* @see java.io.InputSt ream
* @version %I%, %E%.
class InputSourceStre am implements PullSourceStrea m, Seekable {

protected InputStream stream;
protected boolean eosReached;
ContentDescript or contentType;
protected ByteBuffer inputBuffer;
* Construct an <CODE>InputSour ceStream</CODE> from an input stream.
* @param s The input stream to build the source stream from.
* @param type The content-type of the source stream.
public InputSourceStre am(InputStream s, ContentDescript or type) {
stream = s;
eosReached = false;
contentType = type;


* Get the content type for this stream.
* @return content descriptor for the stream.
public ContentDescript or getContentDescr iptor() {
return contentType;

* Obtain the content length
* @return content length for this stream.
public long getContentLengt h() {
return SourceStream.LE NGTH_UNKNOWN;

* Query if the next read will block.
* @return true if a read will block.
public boolean willReadBlock() {
if( eosReached == true) {
return true;
} else {
try {
return stream.availabl e() == 0;
} catch (IOException e) {
return true;

* Read a buffer of data.
* @param buffer The buffer to read data into.
* @param offset The offset into the buffer for reading.
* @param length The number of bytes to read.
* @return The number of bytes read or -1 indicating end-of-stream.
//this where the problem lies
//unable to read the stream into the
// inputBuffer thus giving me the error
public int read(byte[] buffer, int offset, int length) throws IOException { int bytesRead = stream.read(buf fer, offset, length); if( bytesRead == -1) { eosReached = true;
inputBuffer.get (buffer,offset, length);
return bytesRead;

* Turn the stream off.
* @exception IOException Thrown if there is a problem closing the stream.
public void close() throws IOException {
* Return if the end of stream has been reached.
* @return true if the end of the stream has been reached.
// $jdr: This is a bug. Need to figure out
// the "correct" way to determine, before a read
// is done, if we're at EOS.
public boolean endOfStream() {
return eosReached;

* Returns an zero length array because no controls
* are supported.
* @return a zero length <code>Object</code> array.
public Object[] getControls() {
return new Object[0];

* Returns <code>null</code> because no controls are implemented.
* @return <code>null</code>.
public Object getControl(Stri ng controlName) {
return null;
public long seek(long where) {
try {
inputBuffer.pos ition((int)(whe re));
return where;
catch (IllegalArgumen tException E) {
return this.tell(); // staying at the current position
public long tell() {
return inputBuffer.pos ition();

public void SeekableStream( ByteBuffer byteBuffer) {
inputBuffer = byteBuffer;
this.seek((long )(0)); // set the ByteBuffer to to beginning
public boolean isRandomAccess( ) {
// TODO Auto-generated method stub
return false;

please take a look and i'll appreciate any assistance
thank you
Feb 21 '08 #1
2 11578
13,262 MVP
1.) Please use code tags when posting code.
2.) Read the exception trace again. Which line in your code is reported for that exception?
Feb 21 '08 #2
3 New Member
im sorry about not using code tags
was my first post

this is error from the program

Expand|Select|Wrap|Line Numbers
  1. LoadInputStream.loadBytes() - Creating DataSource (InputStream)
  2. LoadInputStream.loadBytes() - Creating Player
  3. LoadInputStream.loadBytes() - Adding Controller Listener
  4. LoadInputStream.loadBytes() - realizing player
  5. Exception in thread "JMF thread: com.sun.media.amovie.AMController@1855af5[ com.
  6. sun.media.amovie.AMController@1855af5 ] ( realizeThread)" java.lang.NullPointerException
  7.         at InputSourceStream.tell(InputSourceStream.java:146)
  8.         at com.sun.media.amovie.AMController.seek(AMController.java:361)
  9.         at com.sun.media.amovie.ActiveMovie.seek(ActiveMovie.java:279)
  10.         at com.sun.media.amovie.ActiveMovie.<init>(ActiveMovie.java:66)
  11.         at com.sun.media.amovie.AMController.createActiveMovie(AMController.java:324)
  12.         at com.sun.media.amovie.AMController.doRealize(AMController.java:416)
  13.         at com.sun.media.RealizeWorkThread.process(BasicController.java:1400)
  14.         at com.sun.media.StateTransitionWorkThread.run(BasicController.java:1339
it seem that the read method in InputSourceStre am class does not read the stream
Expand|Select|Wrap|Line Numbers
  1. public int read(byte[] buffer, int offset, int length) throws IOException {    
  2. int bytesRead = stream.read(buffer, offset, length);
  3. if( bytesRead == -1) {
  4. eosReached = true;
  5. }
  6. inputBuffer.get(buffer,offset,length);
  7. return bytesRead;
  8. }
this is the null pointer exception error
Expand|Select|Wrap|Line Numbers
  1. public long tell() {
  2. return inputBuffer.position();
  3. }
Feb 21 '08 #3

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