/** {@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;
}
public int write(byte[] buffer, int offset, int length, boolean transform) {
RawPacket pkt = rawPacketArray[0];
if (pkt == null) pkt = new RawPacket();
rawPacketArray[0] = pkt;
byte[] pktBuf = pkt.getBuffer();
if (pktBuf == null || pktBuf.length < length) {
pktBuf = new byte[length];
pkt.setBuffer(pktBuf);
}
System.arraycopy(buffer, offset, pktBuf, 0, length);
pkt.setOffset(0);
pkt.setLength(length);
if (transform) {
PacketTransformer packetTransformer =
isControlStream ? rtcpPacketTransformer : rtpPacketTransformer;
if (packetTransformer != null)
rawPacketArray = packetTransformer.reverseTransform(rawPacketArray);
}
SourceTransferHandler transferHandler;
PushSourceStream pushSourceStream;
try {
if (isControlStream) {
transferHandler = controlTransferHandler;
pushSourceStream = getControlInputStream();
} else {
transferHandler = dataTransferHandler;
pushSourceStream = getDataInputStream();
}
} catch (IOException ioe) {
throw new UndeclaredThrowableException(ioe);
}
for (int i = 0; i < rawPacketArray.length; i++) {
RawPacket packet = rawPacketArray[i];
// keep the first element for reuse
if (i != 0) rawPacketArray[i] = null;
if (packet != null) {
if (isControlStream) pendingControlPacket = packet;
else pendingDataPacket = packet;
if (transferHandler != null) {
transferHandler.transferData(pushSourceStream);
}
}
}
return length;
}
private void emptyPacketBuffer(long ssrc) {
RawPacket[] pkts = rtpConnector.packetBuffer.emptyBuffer(ssrc);
RTPConnectorImpl.OutputDataStreamImpl dataStream;
try {
dataStream = rtpConnector.getDataOutputStream();
} catch (IOException ioe) {
logger.error("Failed to empty packet buffer for SSRC=" + ssrc + ": " + ioe);
return;
}
for (RawPacket pkt : pkts)
dataStream.write(
pkt.getBuffer(), pkt.getOffset(), pkt.getLength(), false /* already transformed */);
}
@Override
public int read(byte[] buffer, int offset, int length) throws IOException {
RawPacket pendingPacket;
if (isControlStream) {
pendingPacket = pendingControlPacket;
} else {
pendingPacket = pendingDataPacket;
}
int bytesToRead = 0;
byte[] pendingPacketBuffer = pendingPacket.getBuffer();
if (pendingPacketBuffer != null) {
int pendingPacketLength = pendingPacket.getLength();
bytesToRead = length > pendingPacketLength ? pendingPacketLength : length;
System.arraycopy(
pendingPacketBuffer, pendingPacket.getOffset(), buffer, offset, bytesToRead);
}
return bytesToRead;
}
/**
* Removes the RTX encapsulation from a packet.
*
* @param pkt the packet to remove the RTX encapsulation from.
* @return the original media packet represented by {@code pkt}, or null if we couldn't
* reconstruct the original packet.
*/
private RawPacket deRtx(RawPacket pkt) {
boolean success = false;
if (pkt.getPayloadLength() - pkt.getPaddingSize() < 2) {
// We need at least 2 bytes to read the OSN field.
if (logger.isDebugEnabled()) {
logger.debug("Dropping an incoming RTX packet with padding only: " + pkt);
}
return null;
}
long mediaSsrc = getPrimarySsrc(pkt);
if (mediaSsrc != -1) {
if (rtxAssociatedPayloadType != -1) {
int osn = pkt.getOriginalSequenceNumber();
// Remove the RTX header by moving the RTP header two bytes
// right.
byte[] buf = pkt.getBuffer();
int off = pkt.getOffset();
System.arraycopy(buf, off, buf, off + 2, pkt.getHeaderLength());
pkt.setOffset(off + 2);
pkt.setLength(pkt.getLength() - 2);
pkt.setSSRC((int) mediaSsrc);
pkt.setSequenceNumber(osn);
pkt.setPayloadType(rtxAssociatedPayloadType);
success = true;
} else {
logger.warn(
"RTX packet received, but no APT is defined. Packet "
+ "SSRC "
+ pkt.getSSRCAsLong()
+ ", associated media"
+ " SSRC "
+ mediaSsrc);
}
}
// If we failed to handle the RTX packet, drop it.
return success ? pkt : null;
}
/**
* Encapsulates {@code pkt} in the RTX format, using {@code rtxSsrc} as its SSRC, and transmits it
* to {@link #channel} by injecting it in the {@code MediaStream}.
*
* @param pkt the packet to transmit.
* @param rtxSsrc the SSRC for the RTX stream.
* @param after the {@code TransformEngine} in the chain of {@code TransformEngine}s of the
* associated {@code MediaStream} after which the injection of {@code pkt} is to begin
* @return {@code true} if the packet was successfully retransmitted, {@code false} otherwise.
*/
private boolean encapsulateInRtxAndTransmit(RawPacket pkt, long rtxSsrc, TransformEngine after) {
byte[] buf = pkt.getBuffer();
int len = pkt.getLength();
int off = pkt.getOffset();
byte[] newBuf = new byte[len + 2];
RawPacket rtxPkt = new RawPacket(newBuf, 0, len + 2);
int osn = pkt.getSequenceNumber();
int headerLength = pkt.getHeaderLength();
int payloadLength = pkt.getPayloadLength();
// Copy the header.
System.arraycopy(buf, off, newBuf, 0, headerLength);
// Set the OSN field.
newBuf[headerLength] = (byte) ((osn >> 8) & 0xff);
newBuf[headerLength + 1] = (byte) (osn & 0xff);
// Copy the payload.
System.arraycopy(buf, off + headerLength, newBuf, headerLength + 2, payloadLength);
MediaStream mediaStream = channel.getStream();
if (mediaStream != null) {
rtxPkt.setSSRC((int) rtxSsrc);
rtxPkt.setPayloadType(rtxPayloadType);
// Only call getNextRtxSequenceNumber() when we're sure we're going
// to transmit a packet, because it consumes a sequence number.
rtxPkt.setSequenceNumber(getNextRtxSequenceNumber(rtxSsrc));
try {
mediaStream.injectPacket(rtxPkt, /* data */ true, after);
} catch (TransmissionFailedException tfe) {
logger.warn("Failed to transmit an RTX packet.");
return false;
}
}
return true;
}
