Example #1
0
  public void startProcessing() {

    try {
      processor = Manager.createProcessor(getMainCamSource());
    } catch (IOException e) {
      //            JOptionPane.showMessageDialog(parent,
      //               "IO Exception creating processor: " + e.getMessage(), "Error",
      // JOptionPane.WARNING_MESSAGE);
      return;
    } catch (NoProcessorException e) {
      //            JOptionPane.showMessageDialog(parent,
      //               "Exception creating processor: " + e.getMessage(), "Error",
      // JOptionPane.WARNING_MESSAGE);
      return;
    }

    CamStateHelper playhelper = new CamStateHelper(processor);
    if (!playhelper.configure(10000)) {
      JOptionPane.showMessageDialog(
          parent, "cannot configure processor", "Error", JOptionPane.WARNING_MESSAGE);
      return;
    }
    processor.setContentDescriptor(null);
    if (!playhelper.realize(10000)) {
      JOptionPane.showMessageDialog(
          parent, "cannot realize processor", "Error", JOptionPane.WARNING_MESSAGE);
      return;
    }
    // In order for or your clones to start, you must start the original source
    processor.start();
    setProcessing(true);
  }
    public synchronized boolean waitForState(int state) {
      switch (state) {
        case Processor.Configured:
          p.configure();
          break;
        case Controller.Realized:
          p.realize();
          break;
        case Controller.Prefetched:
          p.prefetch();
          break;
        case Controller.Started:
          p.start();
          break;
      }

      while (p.getState() < state && !error) {
        try {
          wait(1000);
        } catch (Exception e) {
        }
      }
      // p.removeControllerListener(this);
      return !(error);
    }
Example #3
0
  private synchronized boolean waitForState(Processor p, int state) {
    p.addControllerListener(new StateListener());
    failed = false;

    // Call the required method on the processor
    if (state == Processor.Configured) {
      p.configure();
    } else if (state == Processor.Realized) {
      p.realize();
    }

    // Wait until we get an event that confirms the
    // success of the method, or a failure event.
    // See StateListener inner class
    while (p.getState() < state && !failed) {
      synchronized (getStateLock()) {
        try {
          getStateLock().wait();
        } catch (InterruptedException ie) {
          return false;
        }
      }
    }

    if (failed) return false;
    else return true;
  }
Example #4
0
 /** Stops the transmission if already started */
 public void stop() {
   synchronized (this) {
     if (processor != null) {
       processor.stop();
       processor.close();
       processor = null;
       rtptransmitter.close();
       rtptransmitter = null;
     }
   }
 }
  private InputStream getInputStream(
      String urlStr, Format outputFormat, ContentDescriptor outputContentDescriptor)
      throws Exception {
    final ProcessorModel processorModel =
        new ProcessorModel(
            new MediaLocator(urlStr),
            outputFormat == null ? null : new Format[] {outputFormat},
            outputContentDescriptor);

    final Processor processor = Manager.createRealizedProcessor(processorModel);

    final DataSource ds = processor.getDataOutput();

    final DataSink[] streamDataSinkHolder = new DataSink[] {null};
    // connect the data output of the processor to a StreamDataSink, which
    // will make the data available to PipedInputStream, which we return.
    final PipedInputStream in =
        new PipedInputStream() {
          // override close to clean up everything when the media has been
          // served.
          @Override
          public void close() throws IOException {
            super.close();
            logger.fine("Closed input stream");
            logger.fine("Stopping processor");
            processor.stop();
            logger.fine("Closing processor");
            processor.close();
            logger.fine("Deallocating processor");
            processor.deallocate();
            if (streamDataSinkHolder[0] != null) {
              logger.fine("Closing StreamDataSink");
              streamDataSinkHolder[0].close();
            }
          }
        };
    final PipedOutputStream out = new PipedOutputStream(in);
    final DataSink streamDataSink = new StreamDataSink(out);
    streamDataSinkHolder[0] = streamDataSink;

    streamDataSink.setSource(ds);
    streamDataSink.open();
    streamDataSink.start();

    logger.info("Starting processor");
    processor.start();

    // TODO: if there is an error, make sure we clean up.
    // for example, if the client breaks the connection.
    // we need a controller listener to listen for errors.

    return in;
  }
Example #6
0
  /**
   * Restarts the recording for a specific SSRC.
   *
   * @param ssrc the SSRC for which to restart recording. RTP packet of the new recording).
   */
  private void resetRecording(long ssrc, long timestamp) {
    ReceiveStreamDesc receiveStream = findReceiveStream(ssrc);

    // we only restart audio recordings
    if (receiveStream != null && receiveStream.format instanceof AudioFormat) {
      String newFilename = getNextFilename(path + "/" + ssrc, AUDIO_FILENAME_SUFFIX);

      // flush the buffer contained in the MP3 encoder
      String s = "trying to flush ssrc=" + ssrc;
      Processor p = receiveStream.processor;
      if (p != null) {
        s += " p!=null";
        for (TrackControl tc : p.getTrackControls()) {
          Object o = tc.getControl(FlushableControl.class.getName());
          if (o != null) ((FlushableControl) o).flush();
        }
      }

      if (logger.isInfoEnabled()) {
        logger.info("Restarting recording for SSRC=" + ssrc + ". New filename: " + newFilename);
      }

      receiveStream.dataSink.close();
      receiveStream.dataSink = null;

      // flush the FMJ jitter buffer
      // DataSource ds = receiveStream.receiveStream.getDataSource();
      // if (ds instanceof net.sf.fmj.media.protocol.rtp.DataSource)
      //    ((net.sf.fmj.media.protocol.rtp.DataSource)ds).flush();

      receiveStream.filename = newFilename;
      try {
        receiveStream.dataSink =
            Manager.createDataSink(
                receiveStream.dataSource, new MediaLocator("file:" + newFilename));
      } catch (NoDataSinkException ndse) {
        logger.warn("Could not reset recording for SSRC=" + ssrc + ": " + ndse);
        removeReceiveStream(receiveStream, false);
      }

      try {
        receiveStream.dataSink.open();
        receiveStream.dataSink.start();
      } catch (IOException ioe) {
        logger.warn("Could not reset recording for SSRC=" + ssrc + ": " + ioe);
        removeReceiveStream(receiveStream, false);
      }

      audioRecordingStarted(ssrc, timestamp);
    }
  }
Example #7
0
  /**
   * Finds the <tt>ReceiveStreamDesc</tt> with a particular <tt>Processor</tt>
   *
   * @param processor The <tt>Processor</tt> to match.
   * @return the <tt>ReceiveStreamDesc</tt> with a particular <tt>Processor</tt>, or <tt>null</tt>.
   */
  private ReceiveStreamDesc findReceiveStream(Processor processor) {
    if (processor == null) return null;

    synchronized (receiveStreams) {
      for (ReceiveStreamDesc r : receiveStreams) if (processor.equals(r.processor)) return r;
    }

    return null;
  }
  /** With the given processor info generated from matchTracks, build each of the processors. */
  public boolean buildTracks(ProcInfo pInfo[]) {
    ContentDescriptor cd = new ContentDescriptor(ContentDescriptor.RAW);
    Processor p;

    for (int i = 0; i < pInfo.length; i++) {
      p = pInfo[i].p;
      p.setContentDescriptor(cd);

      // We are done with programming the processor. Let's just
      // realize the it.
      if (!waitForState(p, Controller.Realized)) {
        System.err.println("- Failed to realize the processor.");
        return false;
      }

      // Set the JPEG quality to .5.
      setJPEGQuality(p, 0.5f);

      PushBufferStream pbs[];
      TrackInfo tInfo;
      int trackID;

      // Cheating. I should have checked the type of DataSource
      // returned.
      pInfo[i].ds = (PushBufferDataSource) p.getDataOutput();
      pbs = pInfo[i].ds.getStreams();

      // Find the matching data stream for the given track for audio.

      for (int type = AUDIO; type < MEDIA_TYPES; type++) {
        for (trackID = 0; trackID < pInfo[i].numTracksByType[type]; trackID++) {
          tInfo = pInfo[i].tracksByType[type][trackID];
          tInfo.pbs = pbs[tInfo.idx];
        }
      }
    }

    return true;
  }
Example #9
0
  /**
   * Starts the transmission. Returns null if transmission started ok. Otherwise it returns a string
   * with the reason why the setup failed.
   */
  public synchronized String start() {
    String result;

    // Create a processor for the specified media locator
    // and program it to output JPEG/RTP
    result = createProcessor();
    if (result != null) return result;

    // Create an RTP session to transmit the output of the
    // processor to the specified IP address and port no.
    result = createTransmitter();
    if (result != null) {
      processor.close();
      processor = null;
      return result;
    }

    // Start the transmission
    processor.start();

    return null;
  }
  /** Create the DataSink. */
  DataSink createDataSink(Processor p, MediaLocator outML) {
    DataSource ds;

    if ((ds = p.getDataOutput()) == null) {
      System.err.println(
          "Something is really wrong: the processor does not have an output DataSource");
      return null;
    }

    DataSink dsink;

    try {
      System.err.println("- Create DataSink for: " + outML);
      dsink = Manager.createDataSink(ds, outML);
      dsink.open();
    } catch (Exception e) {
      System.err.println("Cannot create the DataSink: " + e);
      return null;
    }

    return dsink;
  }
Example #11
0
  /**
   * Implements {@link ControllerListener#controllerUpdate(ControllerEvent)}. Handles events from
   * the <tt>Processor</tt>s that this instance uses to transcode media.
   *
   * @param ev the event to handle.
   */
  public void controllerUpdate(ControllerEvent ev) {
    if (ev == null || ev.getSourceController() == null) {
      return;
    }

    Processor processor = (Processor) ev.getSourceController();
    ReceiveStreamDesc desc = findReceiveStream(processor);

    if (desc == null) {
      logger.warn("Event from an orphaned processor, ignoring: " + ev);
      return;
    }

    if (ev instanceof ConfigureCompleteEvent) {
      if (logger.isInfoEnabled()) {
        logger.info(
            "Configured processor for ReceiveStream ssrc="
                + desc.ssrc
                + " ("
                + desc.format
                + ")"
                + " "
                + System.currentTimeMillis());
      }

      boolean audio = desc.format instanceof AudioFormat;

      if (audio) {
        ContentDescriptor cd = processor.setContentDescriptor(AUDIO_CONTENT_DESCRIPTOR);
        if (!AUDIO_CONTENT_DESCRIPTOR.equals(cd)) {
          logger.error(
              "Failed to set the Processor content "
                  + "descriptor to "
                  + AUDIO_CONTENT_DESCRIPTOR
                  + ". Actual result: "
                  + cd);
          removeReceiveStream(desc, false);
          return;
        }
      }

      for (TrackControl track : processor.getTrackControls()) {
        Format trackFormat = track.getFormat();

        if (audio) {
          final long ssrc = desc.ssrc;
          SilenceEffect silenceEffect;
          if (Constants.OPUS_RTP.equals(desc.format.getEncoding())) {
            silenceEffect = new SilenceEffect(48000);
          } else {
            // We haven't tested that the RTP timestamps survive
            // the journey through the chain when codecs other than
            // opus are in use, so for the moment we rely on FMJ's
            // timestamps for non-opus formats.
            silenceEffect = new SilenceEffect();
          }

          silenceEffect.setListener(
              new SilenceEffect.Listener() {
                boolean first = true;

                @Override
                public void onSilenceNotInserted(long timestamp) {
                  if (first) {
                    first = false;
                    // send event only
                    audioRecordingStarted(ssrc, timestamp);
                  } else {
                    // change file and send event
                    resetRecording(ssrc, timestamp);
                  }
                }
              });
          desc.silenceEffect = silenceEffect;
          AudioLevelEffect audioLevelEffect = new AudioLevelEffect();
          audioLevelEffect.setAudioLevelListener(
              new SimpleAudioLevelListener() {
                @Override
                public void audioLevelChanged(int level) {
                  activeSpeakerDetector.levelChanged(ssrc, level);
                }
              });

          try {
            // We add an effect, which will insert "silence" in
            // place of lost packets.
            track.setCodecChain(new Codec[] {silenceEffect, audioLevelEffect});
          } catch (UnsupportedPlugInException upie) {
            logger.warn("Failed to insert silence effect: " + upie);
            // But do go on, a recording without extra silence is
            // better than nothing ;)
          }
        } else {
          // transcode vp8/rtp to vp8 (i.e. depacketize vp8)
          if (trackFormat.matches(vp8RtpFormat)) track.setFormat(vp8Format);
          else {
            logger.error("Unsupported track format: " + trackFormat + " for ssrc=" + desc.ssrc);
            // we currently only support vp8
            removeReceiveStream(desc, false);
            return;
          }
        }
      }

      processor.realize();
    } else if (ev instanceof RealizeCompleteEvent) {
      desc.dataSource = processor.getDataOutput();

      long ssrc = desc.ssrc;
      boolean audio = desc.format instanceof AudioFormat;
      String suffix = audio ? AUDIO_FILENAME_SUFFIX : VIDEO_FILENAME_SUFFIX;

      // XXX '\' on windows?
      String filename = getNextFilename(path + "/" + ssrc, suffix);
      desc.filename = filename;

      DataSink dataSink;
      if (audio) {
        try {
          dataSink = Manager.createDataSink(desc.dataSource, new MediaLocator("file:" + filename));
        } catch (NoDataSinkException ndse) {
          logger.error("Could not create DataSink: " + ndse);
          removeReceiveStream(desc, false);
          return;
        }

      } else {
        dataSink = new WebmDataSink(filename, desc.dataSource);
      }

      if (logger.isInfoEnabled())
        logger.info(
            "Created DataSink ("
                + dataSink
                + ") for SSRC="
                + ssrc
                + ". Output filename: "
                + filename);
      try {
        dataSink.open();
      } catch (IOException e) {
        logger.error("Failed to open DataSink (" + dataSink + ") for" + " SSRC=" + ssrc + ": " + e);
        removeReceiveStream(desc, false);
        return;
      }

      if (!audio) {
        final WebmDataSink webmDataSink = (WebmDataSink) dataSink;
        webmDataSink.setSsrc(ssrc);
        webmDataSink.setEventHandler(eventHandler);
        webmDataSink.setKeyFrameControl(
            new KeyFrameControlAdapter() {
              @Override
              public boolean requestKeyFrame(boolean urgent) {
                return requestFIR(webmDataSink);
              }
            });
      }

      try {
        dataSink.start();
      } catch (IOException e) {
        logger.error(
            "Failed to start DataSink (" + dataSink + ") for" + " SSRC=" + ssrc + ". " + e);
        removeReceiveStream(desc, false);
        return;
      }

      if (logger.isInfoEnabled()) logger.info("Started DataSink for SSRC=" + ssrc);

      desc.dataSink = dataSink;

      processor.start();
    } else if (logger.isDebugEnabled()) {
      logger.debug(
          "Unhandled ControllerEvent from the Processor for ssrc=" + desc.ssrc + ": " + ev);
    }
  }
Example #12
0
  /**
   * Implements {@link ReceiveStreamListener#update(ReceiveStreamEvent)}.
   *
   * <p>{@link #rtpManager} will use this to notify us of <tt>ReceiveStreamEvent</tt>s.
   */
  @Override
  public void update(ReceiveStreamEvent event) {
    if (event == null) return;
    ReceiveStream receiveStream = event.getReceiveStream();

    if (event instanceof NewReceiveStreamEvent) {
      if (receiveStream == null) {
        logger.warn("NewReceiveStreamEvent: null");
        return;
      }

      final long ssrc = getReceiveStreamSSRC(receiveStream);

      ReceiveStreamDesc receiveStreamDesc = findReceiveStream(ssrc);

      if (receiveStreamDesc != null) {
        String s = "NewReceiveStreamEvent for an existing SSRC. ";
        if (receiveStream != receiveStreamDesc.receiveStream)
          s += "(but different ReceiveStream object)";
        logger.warn(s);
        return;
      } else receiveStreamDesc = new ReceiveStreamDesc(receiveStream);

      if (logger.isInfoEnabled()) logger.info("New ReceiveStream, ssrc=" + ssrc);

      // Find the format of the ReceiveStream
      DataSource dataSource = receiveStream.getDataSource();
      if (dataSource instanceof PushBufferDataSource) {
        Format format = null;
        PushBufferDataSource pbds = (PushBufferDataSource) dataSource;
        for (PushBufferStream pbs : pbds.getStreams()) {
          if ((format = pbs.getFormat()) != null) break;
        }

        if (format == null) {
          logger.error("Failed to handle new ReceiveStream: " + "Failed to determine format");
          return;
        }

        receiveStreamDesc.format = format;
      } else {
        logger.error("Failed to handle new ReceiveStream: " + "Unsupported DataSource");
        return;
      }

      int rtpClockRate = -1;
      if (receiveStreamDesc.format instanceof AudioFormat)
        rtpClockRate = (int) ((AudioFormat) receiveStreamDesc.format).getSampleRate();
      else if (receiveStreamDesc.format instanceof VideoFormat) rtpClockRate = 90000;
      getSynchronizer().setRtpClockRate(ssrc, rtpClockRate);

      // create a Processor and configure it
      Processor processor = null;
      try {
        processor = Manager.createProcessor(receiveStream.getDataSource());
      } catch (NoProcessorException npe) {
        logger.error("Failed to create Processor: ", npe);
        return;
      } catch (IOException ioe) {
        logger.error("Failed to create Processor: ", ioe);
        return;
      }

      if (logger.isInfoEnabled()) logger.info("Created processor for SSRC=" + ssrc);

      processor.addControllerListener(this);
      receiveStreamDesc.processor = processor;

      final int streamCount;
      synchronized (receiveStreams) {
        receiveStreams.add(receiveStreamDesc);
        streamCount = receiveStreams.size();
      }

      /*
       * XXX TODO IRBABOON
       * This is a terrible hack which works around a failure to realize()
       * some of the Processor-s for audio streams, when multiple streams
       * start nearly simultaneously. The cause of the problem is currently
       * unknown (and synchronizing all FMJ calls in RecorderRtpImpl
       * does not help).
       * XXX TODO NOOBABRI
       */
      if (receiveStreamDesc.format instanceof AudioFormat) {
        final Processor p = processor;
        new Thread() {
          @Override
          public void run() {
            // delay configuring the processors for the different
            // audio streams to decrease the probability that they
            // run together.
            try {
              int ms = 450 * (streamCount - 1);
              logger.warn(
                  "Sleeping for "
                      + ms
                      + "ms before"
                      + " configuring processor for SSRC="
                      + ssrc
                      + " "
                      + System.currentTimeMillis());
              Thread.sleep(ms);
            } catch (Exception e) {
            }

            p.configure();
          }
        }.run();
      } else {
        processor.configure();
      }
    } else if (event instanceof TimeoutEvent) {
      if (receiveStream == null) {
        // TODO: we might want to get the list of ReceiveStream-s from
        // rtpManager and compare it to our list, to see if we should
        // remove a stream.
        logger.warn("TimeoutEvent: null.");
        return;
      }

      // FMJ silently creates new ReceiveStream instances, so we have to
      // recognize them by the SSRC.
      ReceiveStreamDesc receiveStreamDesc = findReceiveStream(getReceiveStreamSSRC(receiveStream));
      if (receiveStreamDesc != null) {
        if (logger.isInfoEnabled()) {
          logger.info("ReceiveStream timeout, ssrc=" + receiveStreamDesc.ssrc);
        }

        removeReceiveStream(receiveStreamDesc, true);
      }
    } else if (event != null && logger.isInfoEnabled()) {
      logger.info("Unhandled ReceiveStreamEvent (" + event.getClass().getName() + "): " + event);
    }
  }
Example #13
0
  public static void main(String[] args) {

    // ---------------- CUT HERE START ----------------- //

    Format formats[] = new Format[2];
    formats[0] = new AudioFormat(AudioFormat.IMA4);
    formats[1] = new VideoFormat(VideoFormat.CINEPAK);
    FileTypeDescriptor outputType = new FileTypeDescriptor(FileTypeDescriptor.QUICKTIME);
    Processor p = null;

    try {
      p = Manager.createRealizedProcessor(new ProcessorModel(formats, outputType));
    } catch (IOException e) {
      System.exit(-1);
    } catch (NoProcessorException e) {
      System.exit(-1);
    } catch (CannotRealizeException e) {
      System.exit(-1);
    }
    // get the output of the processor
    DataSource source = p.getDataOutput();
    // create a File protocol MediaLocator with the location of the file to
    // which bits are to be written
    MediaLocator dest = new MediaLocator("file://foo.mov");
    // create a datasink to do the file writing & open the sink to make sure
    // we can write to it.
    DataSink filewriter = null;
    try {
      filewriter = Manager.createDataSink(source, dest);
      filewriter.open();
    } catch (NoDataSinkException e) {
      System.exit(-1);
    } catch (IOException e) {
      System.exit(-1);
    } catch (SecurityException e) {
      System.exit(-1);
    }
    // now start the filewriter and processor
    try {
      filewriter.start();
    } catch (IOException e) {
      System.exit(-1);
    }
    p.start();
    // stop and close the processor when done capturing...
    // close the datasink when EndOfStream event is received...

    // ----------------- CUT HERE END ---------------- //
    try {
      Thread.currentThread().sleep(4000);
    } catch (InterruptedException ie) {
    }
    p.stop();
    p.close();
    try {
      Thread.currentThread().sleep(1000);
    } catch (InterruptedException ie) {
    }
    filewriter.close();
    try {
      Thread.currentThread().sleep(4000);
    } catch (InterruptedException ie) {
    }

    System.exit(0);
  }
 StateWaiter(Processor p) {
   this.p = p;
   p.addControllerListener(this);
 }
  /**
   * Given an array of input media locators and an output locator, this method will concatenate the
   * input media files to generate a single concatentated output.
   */
  public boolean doIt(MediaLocator inML[], MediaLocator outML) {
    // Guess the output content descriptor from the file extension.
    ContentDescriptor cd;

    if ((cd = fileExtToCD(outML.getRemainder())) == null) {
      System.err.println("Couldn't figure out from the file extension the type of output needed!");
      return false;
    }

    // Build the ProcInfo data structure for each processor.
    ProcInfo pInfo[] = new ProcInfo[inML.length];

    for (int i = 0; i < inML.length; i++) {
      pInfo[i] = new ProcInfo();
      pInfo[i].ml = inML[i];

      try {
        System.err.println("- Create processor for: " + inML[i]);
        pInfo[i].p = Manager.createProcessor(inML[i]);
      } catch (Exception e) {
        System.err.println("Yikes!  Cannot create a processor from the given url: " + e);
        return false;
      }
    }

    // Try to match the tracks from different processors.
    if (!matchTracks(pInfo, cd)) {
      System.err.println("Failed to match the tracks.");
      return false;
    }

    // Program each processors to perform the necessary transcoding
    // to concatenate the tracks.
    if (!buildTracks(pInfo)) {
      System.err.println("Failed to build processors for the inputs.");
      return false;
    }

    // Generate a super glue data source from the processors.
    SuperGlueDataSource ds = new SuperGlueDataSource(pInfo);

    // Create the processor to generate the final output.
    Processor p;
    try {
      p = Manager.createProcessor(ds);
    } catch (Exception e) {
      System.err.println("Failed to create a processor to concatenate the inputs.");
      return false;
    }

    p.addControllerListener(this);

    // Put the Processor into configured state.
    if (!waitForState(p, Processor.Configured)) {
      System.err.println("Failed to configure the processor.");
      return false;
    }

    // Set the output content descriptor on the final processor.
    System.err.println("- Set output content descriptor to: " + cd);
    if ((p.setContentDescriptor(cd)) == null) {
      System.err.println("Failed to set the output content descriptor on the processor.");
      return false;
    }

    // We are done with programming the processor. Let's just
    // realize it.
    if (!waitForState(p, Controller.Realized)) {
      System.err.println("Failed to realize the processor.");
      return false;
    }

    // Now, we'll need to create a DataSink.
    DataSink dsink;
    if ((dsink = createDataSink(p, outML)) == null) {
      System.err.println("Failed to create a DataSink for the given output MediaLocator: " + outML);
      return false;
    }

    dsink.addDataSinkListener(this);
    fileDone = false;

    System.err.println("- Start concatenation...");

    // OK, we can now start the actual concatenation.
    try {
      p.start();
      dsink.start();
    } catch (IOException e) {
      System.err.println("IO error during concatenation");
      return false;
    }

    // Wait for EndOfStream event.
    waitForFileDone();

    // Cleanup.
    try {
      dsink.close();
    } catch (Exception e) {
    }
    p.removeControllerListener(this);

    System.err.println("  ...done concatenation.");

    return true;
  }
Example #16
0
  private String createProcessor() {
    if (locator == null) return "Locator is null";

    DataSource ds;
    DataSource clone;

    try {
      ds = Manager.createDataSource(locator);
    } catch (Exception e) {
      return "Couldn't create DataSource";
    }

    // Try to create a processor to handle the input media locator
    try {
      processor = Manager.createProcessor(ds);
    } catch (NoProcessorException npe) {
      return "Couldn't create processor";
    } catch (IOException ioe) {
      return "IOException creating processor";
    }

    // Wait for it to configure
    boolean result = waitForState(processor, Processor.Configured);
    if (result == false) return "Couldn't configure processor";

    // Get the tracks from the processor
    TrackControl[] tracks = processor.getTrackControls();

    // Do we have atleast one track?
    if (tracks == null || tracks.length < 1) return "Couldn't find tracks in processor";

    boolean programmed = false;

    // Search through the tracks for a video track
    for (int i = 0; i < tracks.length; i++) {
      Format format = tracks[i].getFormat();
      if (tracks[i].isEnabled() && format instanceof VideoFormat && !programmed) {

        // Found a video track. Try to program it to output JPEG/RTP
        // Make sure the sizes are multiple of 8's.
        Dimension size = ((VideoFormat) format).getSize();
        float frameRate = ((VideoFormat) format).getFrameRate();
        int w = (size.width % 8 == 0 ? size.width : (int) (size.width / 8) * 8);
        int h = (size.height % 8 == 0 ? size.height : (int) (size.height / 8) * 8);
        VideoFormat jpegFormat =
            new VideoFormat(
                VideoFormat.JPEG_RTP,
                new Dimension(w, h),
                Format.NOT_SPECIFIED,
                Format.byteArray,
                frameRate);
        tracks[i].setFormat(jpegFormat);
        System.err.println("Video transmitted as:");
        System.err.println("  " + jpegFormat);
        // Assume succesful
        programmed = true;
      } else tracks[i].setEnabled(false);
    }

    if (!programmed) return "Couldn't find video track";

    // Set the output content descriptor to RAW_RTP
    ContentDescriptor cd = new ContentDescriptor(ContentDescriptor.RAW_RTP);
    processor.setContentDescriptor(cd);

    // Realize the processor. This will internally create a flow
    // graph and attempt to create an output datasource for JPEG/RTP
    // video frames.
    result = waitForState(processor, Controller.Realized);
    if (result == false) return "Couldn't realize processor";

    // Set the JPEG quality to .5.
    setJPEGQuality(processor, 0.5f);

    // Get the output data source of the processor
    dataOutput = processor.getDataOutput();
    return null;
  }