/**
   * Creates a new <tt>RawPacket</tt> from a specific <tt>DatagramPacket</tt> in order to have this
   * instance receive its packet data through its {@link #read(byte[], int, int)} method. Returns an
   * array of <tt>RawPacket</tt> with the created packet as its first element (and <tt>null</tt> for
   * the other elements).
   *
   * <p>Allows extenders to intercept the packet data and possibly filter and/or modify it.
   *
   * @param datagramPacket the <tt>DatagramPacket</tt> containing the packet data
   * @return an array of <tt>RawPacket</tt> containing the <tt>RawPacket</tt> which contains the
   *     packet data of the specified <tt>DatagramPacket</tt> as its first element.
   */
  protected RawPacket[] createRawPacket(DatagramPacket datagramPacket) {
    RawPacket[] pkts = rawPacketArrayPool.poll();
    if (pkts == null) pkts = new RawPacket[1];

    RawPacket pkt = rawPacketPool.poll();
    if (pkt == null) pkt = new RawPacket();

    pkt.setBuffer(datagramPacket.getData());
    pkt.setFlags(0);
    pkt.setLength(datagramPacket.getLength());
    pkt.setOffset(datagramPacket.getOffset());

    pkts[0] = pkt;
    return pkts;
  }
 /**
  * Pools the specified <tt>RawPacket</tt> in order to avoid future allocations and to reduce the
  * effects of garbage collection.
  *
  * @param pkt the <tt>RawPacket</tt> to be offered to {@link #rawPacketPool}
  */
 private void poolRawPacket(RawPacket pkt) {
   pkt.setBuffer(null);
   pkt.setFlags(0);
   pkt.setLength(0);
   pkt.setOffset(0);
   rawPacketPool.offer(pkt);
 }
  /**
   * Listens for incoming datagrams, stores them for reading by the <tt>read</tt> method and
   * notifies the local <tt>transferHandler</tt> that there's data to be read.
   */
  public void run() {
    DatagramPacket p = new DatagramPacket(buffer, 0, PACKET_RECEIVE_BUFFER_LENGTH);

    while (!closed) {
      try {
        // http://code.google.com/p/android/issues/detail?id=24765
        if (OSUtils.IS_ANDROID) p.setLength(PACKET_RECEIVE_BUFFER_LENGTH);

        receivePacket(p);
      } catch (IOException e) {
        ioError = true;
        break;
      }

      /*
       * Do the DatagramPacketFilters accept the received DatagramPacket?
       */
      DatagramPacketFilter[] datagramPacketFilters = getDatagramPacketFilters();
      boolean accept;

      if (!enabled) accept = false;
      else if (datagramPacketFilters == null) accept = true;
      else {
        accept = true;
        for (int i = 0; i < datagramPacketFilters.length; i++) {
          try {
            if (!datagramPacketFilters[i].accept(p)) {
              accept = false;
              break;
            }
          } catch (Throwable t) {
            if (t instanceof ThreadDeath) throw (ThreadDeath) t;
          }
        }
      }

      if (accept) {
        RawPacket pkts[] = createRawPacket(p);

        for (int i = 0; i < pkts.length; i++) {
          RawPacket pkt = pkts[i];

          pkts[i] = null;

          if (pkt != null) {
            if (pkt.isInvalid()) {
              /*
               * Return pkt to the pool because it is invalid and,
               * consequently, will not be made available to
               * reading.
               */
              poolRawPacket(pkt);
            } else {
              RawPacket oldPkt;

              synchronized (pktSyncRoot) {
                oldPkt = this.pkt;
                this.pkt = pkt;
              }
              if (oldPkt != null) {
                /*
                 * Return oldPkt to the pool because it was made
                 * available to reading and it was not read.
                 */
                poolRawPacket(oldPkt);
              }

              if (videoRecorder != null) videoRecorder.recordData(pkt);

              if ((transferHandler != null) && !closed) {
                try {
                  transferHandler.transferData(this);
                } catch (Throwable t) {
                  /*
                   * XXX We cannot allow transferHandler to
                   * kill us.
                   */
                  if (t instanceof ThreadDeath) {
                    throw (ThreadDeath) t;
                  } else {
                    logger.warn("An RTP packet may have not been" + " fully handled.", t);
                  }
                }
              }
            }
          }
        }
        rawPacketArrayPool.offer(pkts);
      }
    }
  }