コード例 #1
0
  /**
   * Determines whether {@code effect} has been paused/stopped by the remote peer. The determination
   * is based on counting frames and is triggered by the receipt of (a piece of) a new (video) frame
   * by {@code cause}.
   *
   * @param cause the {@code SimulcastLayer} which has received (a piece of) a new (video) frame and
   *     has thus triggered a check on {@code effect}
   * @param pkt the {@code RawPacket} which was received by {@code cause} and possibly influenced
   *     the decision to trigger a check on {@code effect}
   * @param effect the {@code SimulcastLayer} which is to be checked whether it looks like it has
   *     been paused/stopped by the remote peer
   * @param endIndexInSimulcastLayerFrameHistory
   */
  private void maybeTimeout(
      SimulcastLayer cause,
      RawPacket pkt,
      SimulcastLayer effect,
      int endIndexInSimulcastLayerFrameHistory) {
    Iterator<SimulcastLayer> it = simulcastLayerFrameHistory.iterator();
    boolean timeout = true;

    for (int ix = 0; it.hasNext() && ix < endIndexInSimulcastLayerFrameHistory; ++ix) {
      if (it.next() == effect) {
        timeout = false;
        break;
      }
    }
    if (timeout) {
      effect.maybeTimeout(pkt);

      if (!effect.isStreaming()) {
        // Since effect has been determined to have been paused/stopped
        // by the remote peer, its possible presence in
        // simulcastLayerFrameHistory is irrelevant now. In other words,
        // remove effect from simulcastLayerFrameHistory.
        while (it.hasNext()) {
          if (it.next() == effect) it.remove();
        }
      }
    }
  }
コード例 #2
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  /**
   * Notifies this {@code SimulcastReceiver} that a specific {@code SimulcastReceiver} has detected
   * the start of a new video frame in the RTP stream that it represents. Determines whether any of
   * {@link #simulcastLayers} other than {@code source} have been paused/stopped by the remote peer.
   * The determination is based on counting (video) frames.
   *
   * @param source the {@code SimulcastLayer} which is the source of the event i.e. which has
   *     detected the start of a new video frame in the RTP stream that it represents
   * @param pkt the {@code RawPacket} which was received by {@code source} and possibly influenced
   *     the decision that a new view frame was started in the RTP stream represented by {@code
   *     source}
   * @param layers the set of {@code SimulcastLayer}s managed by this {@code SimulcastReceiver}.
   *     Explicitly provided to the method in order to avoid invocations of {@link
   *     #getSimulcastLayers()} because the latter makes a copy at the time of this writing.
   */
  private void simulcastLayerFrameStarted(
      SimulcastLayer source, RawPacket pkt, SimulcastLayer[] layers) {
    // Allow the value of the constant TIMEOUT_ON_FRAME_COUNT to disable (at
    // compile time) the frame-based approach to the detection of layer
    // drops.
    if (TIMEOUT_ON_FRAME_COUNT <= 1) return;

    // Timeouts in layers caused by source may occur only based on the span
    // (of time or received frames) during which source has received
    // TIMEOUT_ON_FRAME_COUNT number of frames. The current method
    // invocation signals the receipt of 1 frame by source.
    int indexOfLastSourceOccurrenceInHistory = -1;
    int sourceFrameCount = 0;
    int ix = 0;

    for (Iterator<SimulcastLayer> it = simulcastLayerFrameHistory.iterator(); it.hasNext(); ++ix) {
      if (it.next() == source) {
        if (indexOfLastSourceOccurrenceInHistory != -1) {
          // Prune simulcastLayerFrameHistory so that it does not
          // become unnecessarily long.
          it.remove();
        } else if (++sourceFrameCount >= TIMEOUT_ON_FRAME_COUNT - 1) {
          // The span of TIMEOUT_ON_FRAME_COUNT number of frames
          // received by source only is to be examined for the
          // purposes of timeouts. The current method invocations
          // signals the receipt of 1 frame by source so
          // TIMEOUT_ON_FRAME_COUNT - 1 occurrences of source in
          // simulcastLayerFrameHistory is enough.
          indexOfLastSourceOccurrenceInHistory = ix;
        }
      }
    }

    if (indexOfLastSourceOccurrenceInHistory != -1) {
      // Presumably, if a SimulcastLayer is active, all SimulcastLayers
      // before it (according to SimulcastLayer's order) are active as
      // well. Consequently, timeouts may occur in SimulcastLayers which
      // are after source.
      boolean maybeTimeout = false;

      for (SimulcastLayer layer : layers) {
        if (maybeTimeout) {
          // There's no point in timing layer out if it's timed out
          // already.
          if (layer.isStreaming()) {
            maybeTimeout(source, pkt, layer, indexOfLastSourceOccurrenceInHistory);
          }
        } else if (layer == source) {
          maybeTimeout = true;
        }
      }
    }

    // As previously stated, the current method invocation signals the
    // receipt of 1 frame by source.
    simulcastLayerFrameHistory.add(0, source);
    // TODO Prune simulcastLayerFrameHistory by forgetting so that it does
    // not become too long.
  }
コード例 #3
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  /**
   * Sets the simulcast layers for this receiver and fires an event about it.
   *
   * @param simulcastLayers the simulcast layers for this receiver.
   */
  public void setSimulcastLayers(SimulcastLayer[] simulcastLayers) {
    this.simulcastLayers = simulcastLayers;

    if (logger.isInfoEnabled()) {
      if (simulcastLayers == null) {
        logInfo("Simulcast disabled.");
      } else {
        for (SimulcastLayer l : simulcastLayers) {
          logInfo(l.getOrder() + ": " + l.getPrimarySSRC());
        }
      }
    }

    executorService.execute(
        new Runnable() {
          public void run() {
            firePropertyChange(SIMULCAST_LAYERS_PNAME, null, null);
          }
        });

    // TODO If simulcastLayers has changed, then simulcastLayerFrameHistory
    // has very likely become irrelevant. In other words, clear
    // simulcastLayerFrameHistory.
  }
コード例 #4
0
  /**
   * Notifies this instance that a <tt>DatagramPacket</tt> packet received on the data
   * <tt>DatagramSocket</tt> of this <tt>Channel</tt> has been accepted for further processing
   * within Jitsi Videobridge.
   *
   * @param pkt the accepted <tt>RawPacket</tt>.
   */
  public void accepted(RawPacket pkt) {
    // With native simulcast we don't have a notification when a stream
    // has started/stopped. The simulcast manager implements a timeout
    // for the high quality stream and it needs to be notified when
    // the channel has accepted a datagram packet for the timeout to
    // function correctly.

    if (!hasLayers() || pkt == null) {
      return;
    }

    // Find the layer that corresponds to this packet.
    int acceptedSSRC = pkt.getSSRC();
    SimulcastLayer[] layers = getSimulcastLayers();
    SimulcastLayer acceptedLayer = null;
    for (SimulcastLayer layer : layers) {
      // We only care about the primary SSRC and not the RTX ssrc (or
      // future FEC ssrc).
      if ((int) layer.getPrimarySSRC() == acceptedSSRC) {
        acceptedLayer = layer;
        break;
      }
    }

    // If this is not an RTP packet or if we can't find an accepted
    // layer, log and return as it makes no sense to continue in this
    // situation.
    if (acceptedLayer == null) {
      return;
    }

    // There are sequences of packets with increasing timestamps but without
    // the marker bit set. Supposedly, they are probes to detect whether the
    // bandwidth may increase. We think that they should cause neither the
    // start nor the stop of any SimulcastLayer.

    // XXX There's RawPacket#getPayloadLength() but the implementation
    // includes pkt.paddingSize at the time of this writing and we do not
    // know whether that's going to stay that way.
    int pktPayloadLength = pkt.getLength() - pkt.getHeaderLength();
    int pktPaddingSize = pkt.getPaddingSize();

    if (pktPayloadLength <= pktPaddingSize) {
      if (logger.isTraceEnabled()) {
        logger.trace(
            "pkt.payloadLength= "
                + pktPayloadLength
                + " <= pkt.paddingSize= "
                + pktPaddingSize
                + "("
                + pkt.getSequenceNumber()
                + ")");
      }
      return;
    }

    // NOTE(gp) we expect the base layer to be always on, so we never touch
    // it or starve it.

    // XXX Refer to the implementation of
    // SimulcastLayer#touch(boolean, RawPacket) for an explanation of why we
    // chose to use a return value.
    boolean frameStarted = acceptedLayer.touch(pkt);
    if (frameStarted) simulcastLayerFrameStarted(acceptedLayer, pkt, layers);
  }