/** {@inheritDoc} */
        @Override
        public RawPacket transform(RawPacket pkt) {
          if (pkt == null) {
            return pkt;
          }

          RTCPCompoundPacket inPacket;
          try {
            inPacket =
                (RTCPCompoundPacket)
                    parser.parse(pkt.getBuffer(), pkt.getOffset(), pkt.getLength());
          } catch (BadFormatException e) {
            logger.warn("Failed to terminate an RTCP packet. " + "Dropping packet.");
            return null;
          }

          // Update our RTCP stats map (timestamps). This operation is
          // read-only.
          remoteClockEstimator.apply(inPacket);

          cnameRegistry.update(inPacket);

          // Remove SRs and RRs from the RTCP packet.
          pkt = feedbackGateway.gateway(inPacket);

          return pkt;
        }
    /**
     * Updates this <tt>RTPStatsMap</tt> with information it gets from the <tt>RawPacket</tt>.
     *
     * @param pkt the <tt>RawPacket</tt> that is being transmitted.
     */
    public void apply(RawPacket pkt) {
      int ssrc = pkt.getSSRC();
      if (this.containsKey(ssrc)) {
        RTPStatsEntry oldRtpStatsEntry = this.get(ssrc);

        // Replace whatever was in there before. A feature of the two's
        // complement encoding (which is used by Java integers) is that
        // the bitwise results for add, subtract, and multiply are the
        // same if both inputs are interpreted as signed values or both
        // inputs are interpreted as unsigned values. (Other encodings
        // like one's complement and signed magnitude don't have this
        // properly.)
        this.put(
            ssrc,
            new RTPStatsEntry(
                ssrc,
                oldRtpStatsEntry.getBytesSent()
                    + pkt.getLength()
                    - pkt.getHeaderLength()
                    - pkt.getPaddingSize(),
                oldRtpStatsEntry.getPacketsSent() + 1));
      } else {
        // Add a new <tt>RTPStatsEntry</tt> in this map.
        this.put(
            ssrc,
            new RTPStatsEntry(
                ssrc, pkt.getLength() - pkt.getHeaderLength() - pkt.getPaddingSize(), 1));
      }
    }
    @Override
    public RawPacket transform(RawPacket p) {
      // Update octets and packets sent in SRs.
      RTCPCompoundPacket compound;

      try {
        compound = (RTCPCompoundPacket) parser.parse(p.getBuffer(), p.getOffset(), p.getLength());
      } catch (BadFormatException e) {
        logger.warn("Failed to terminate an RTCP packet. Dropping it.");
        return null;
      }

      if (srGateway.gateway(compound)) {
        return generator.apply(compound);
      } else {
        // If the RTCP packet hasn't been modified, send the input
        // without regenerating it (i.e. optimize).
        return p;
      }
    }