/
SdpUtils.java
1829 lines (1604 loc) · 66.2 KB
/
SdpUtils.java
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/*
* Jitsi, the OpenSource Java VoIP and Instant Messaging client.
*
* Copyright @ 2015 Atlassian Pty Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.java.sip.communicator.impl.protocol.sip.sdp;
import java.io.*;
import java.net.*;
import java.net.URI;
import java.util.*;
import javax.sdp.*;
import javax.sip.header.*;
import net.java.sip.communicator.impl.protocol.sip.*;
import net.java.sip.communicator.service.protocol.*;
import net.java.sip.communicator.service.protocol.media.*;
import net.java.sip.communicator.util.*;
import net.java.sip.communicator.util.Logger;
import org.ice4j.ice.sdp.*;
import org.jitsi.service.neomedia.*;
import org.jitsi.service.neomedia.MediaType;
import org.jitsi.service.neomedia.format.*;
import org.jitsi.util.*;
import org.opentelecoms.javax.sdp.*;
/**
* The class contains a number of utility methods that are meant to facilitate
* creating and parsing SDP descriptions.
*
* @author Emil Ivov
* @author Lyubomir Marinov
*/
public class SdpUtils
{
/**
* The name of the SDP attribute that defines RTP extension mappings.
*/
private static final String EXTMAP_ATTR = "extmap";
/**
* Our class logger.
*/
private static final Logger logger = Logger.getLogger(SdpUtils.class);
/**
* The name of the SDP attribute that contains RTCP address and port.
*/
private static final String RTCP_ATTR = "rtcp";
/**
* A reference to the currently valid SDP factory instance.
*/
private static final SdpFactory sdpFactory = new NistSdpFactory();
/**
* The name of the SDP attribute that defines zrtp hello hash.
*/
public static final String ZRTP_HASH_ATTR = "zrtp-hash";
/**
* Returns whether <tt>description</tt> contains the specified
* <tt>attributeName</tt>.
*
* @param description the <tt>MediaDescription</tt>
* @param attributeName name of the attribute to check
* @return the media type (e.g. audio or video) for the specified media
* <tt>description</tt>.
* @throws IllegalArgumentException if <tt>description</tt> does not contain
* a known media type.
*/
@SuppressWarnings("unchecked") // legacy jain-sdp code
public static boolean containsAttribute(MediaDescription description,
String attributeName)
throws IllegalArgumentException
{
try
{
Vector<Attribute> atts = description.getAttributes(false);
for(Attribute a : atts)
{
if(a.getName().equals(attributeName))
return true;
}
return false;
}
catch (SdpException e)
{
// impossible to happen for reasons mentioned many times here :)
String message = "Invalid media type in a= line: " + description;
if (logger.isDebugEnabled())
logger.debug(message, e);
throw new IllegalArgumentException(message, e);
}
}
/**
* Creates an <tt>Attribute</tt> object with the specified values.
*
* @param name the name of the <tt>Attribute</tt>
* @param value the value of the <tt>Attribute</tt>
* @return Attribute
*/
public static Attribute createAttribute(String name, String value)
{
return sdpFactory.createAttribute(name, value);
}
/**
* Creates an <tt>Attribute</tt> instance reflecting the value of the
* <tt>direction</tt> parameter (e.g. a=sendrecv, a=recvonly, etc.).
*
* @param direction the direction that we'd like to convert to an SDP
* <tt>Attribute</tt>.
* @return an SDP <tt>Attribute</tt> field translating the value of the
* <tt>direction</tt> parameter.
*/
private static Attribute createDirectionAttribute(MediaDirection direction)
{
String dirStr;
switch (direction)
{
case RECVONLY: dirStr = "recvonly"; break;
case SENDONLY: dirStr = "sendonly"; break;
case SENDRECV: dirStr = "sendrecv"; break;
default: dirStr = "inactive"; break;
}
return sdpFactory.createAttribute(dirStr, null);
}
/**
* Creates and returns a <tt>MediaDescription</tt> in answer of the
* specified <tt>offer</tt> that disables the corresponding stream by
* setting a <tt>0</tt> port and keeping the original list of formats and
* eliminating all attributes.
*
* @param offer the <tt>MediaDescription</tt> of the stream that we'd like
* to disable.
* @return a <tt>MediaDescription</tt> meant to disable the media stream
* specified by the <tt>offer</tt> description.
* @throws IllegalArgumentException if the <tt>offer</tt> argument is so
* in-parsable that there was no way we could create a meaningful answer.
*
*/
@SuppressWarnings("unchecked") // legacy jain-sdp code
public static MediaDescription createDisablingAnswer(
MediaDescription offer)
throws IllegalArgumentException
{
try
{
String mediaType = offer.getMedia().getMediaType();
Vector<String> formatsVec = offer.getMedia().getMediaFormats(true);
if(formatsVec == null)
{
formatsVec = new Vector<String>();
//add at least one format so that we could generate a valid
//offer.
formatsVec.add(Integer.toString(0));
}
String[] formatsArray = new String[formatsVec.size()];
return sdpFactory.createMediaDescription(mediaType, 0, 1,
offer.getMedia().getProtocol(),
formatsVec.toArray(formatsArray));
}
catch (Exception e)
{
throw new IllegalArgumentException(
"Could not create a disabling answer",
e);
}
}
/**
* Creates and returns <tt>MediaFormat</tt> instance corresponding to the
* specified <tt>payloadType</tt> and the parameters in the <tt>rtpmap</tt>
* and <tt>fmtp</tt> <tt>Attribute</tt>s. The method would only return
* <tt>MediaFormat</tt> instances for formats known to our media service
* implementation and returns <tt>null</tt> otherwise.
*
* @param payloadType a static or dynamic payload type number that
* determines the encoding of the format we'd like to create.
* @param rtpmap an SDP <tt>Attribute</tt> mapping the <tt>payloadType</tt>
* to an encoding name.
* @param fmtp a list of format specific parameters
* @param advp list of advanced parameters
* @param ptRegistry the {@link DynamicPayloadTypeRegistry} that we are to
* use in case <tt>payloadType</tt> is dynamic and <tt>rtpmap</tt> is
* <tt>null</tt> (in which case we can hope its in the registry).
* @return a <tt>MediaForamt</tt> instance corresponding to the specified
* <tt>payloadType</tt> and <tt>rtpmap</tt>, and <tt>fmtp</tt> attributes or
* <tt>null</tt> if such a format is not currently supported by our
* <tt>MediaService</tt> implementation.
* @throws SdpException never, the exception is only there because the
* jain-sdp API declares exceptions in case of impls using lazy parsing but
* the one in the jain-sip-ri isn't doing it.
*/
private static MediaFormat createFormat(
byte payloadType,
Attribute rtpmap,
Attribute fmtp,
float frameRate,
List<Attribute> advp,
DynamicPayloadTypeRegistry ptRegistry)
throws SdpException
{
//default values in case rtpmap is null.
String encoding = null;
double clockRate = -1;
int numChannels = 1;
if (rtpmap != null)
{
String rtpmapValue = rtpmap.getValue();
//rtpmapValue looks sth like this: "98 H264/90000" or
//"97 speex/16000/2" we need to extract the encoding name, the clock
// rate and the number of channels if any
// if at any point we determine there's something wrong with the
// rtpmap we bail out and try to create a format based on the
// payloadType only.
//first strip the payload type
StringTokenizer tokenizer
= new StringTokenizer(rtpmapValue, " /", false);
//skip payload type number (mandatory)
if(tokenizer.hasMoreTokens())
{
tokenizer.nextToken();
}
//encoding name (mandatory)
if(tokenizer.hasMoreTokens())
{
encoding = tokenizer.nextToken();
}
//clock rate (mandatory)
if(tokenizer.hasMoreTokens())
{
clockRate = Double.parseDouble(tokenizer.nextToken());
}
//number of channels (optional)
if(tokenizer.hasMoreTokens())
{
String nChansStr = tokenizer.nextToken();
try
{
numChannels = Integer.parseInt(nChansStr);
}
catch(NumberFormatException exc)
{
if (logger.isDebugEnabled())
logger.debug(
nChansStr + " is not a valid number of channels.",
exc);
}
}
}
else
{
//if rtpmap was null, check whether we have previously registered
//the type in our dynamic payload type registry. and if that's
//the case return it.
MediaFormat fmt = ptRegistry.findFormat(payloadType);
if (fmt != null)
return fmt;
}
//Format parameters
Map<String, String> fmtParamsMap = null;
Map<String, String> advancedAttrMap = null;
if (fmtp != null)
fmtParamsMap = parseFmtpAttribute(fmtp);
if (advp != null)
advancedAttrMap = parseAdvancedAttributes(advp);
// Many implementations use opus as "opus/48000", while the specification
// mandates "opus/48000/2". Our upper layers only support 2 channels, so
// we patch it here.
if ("opus".equals(encoding))
numChannels = 2;
//now create the format.
MediaFormat format
= SipActivator.getMediaService().getFormatFactory()
.createMediaFormat(
payloadType,
encoding, clockRate, numChannels, frameRate,
fmtParamsMap,
advancedAttrMap);
/*
* We've just created a MediaFormat for the specified payloadType so we
* have to remember the mapping between the two so that we don't, for
* example, map the same payloadType to a different MediaFormat at a
* later time when we do automatic generation of payloadType in
* DynamicPayloadTypeRegistry. If the remote peer tries to remap a
* payloadType in its answer to a different MediaFormat than the one
* we've specified in our offer, then the dynamic paylaod type registry
* will keep the original value for receiving and also add an overriding
* value for the new one. The overriding value will be streamed to our
* peer.
*/
if ((payloadType >= MediaFormat.MIN_DYNAMIC_PAYLOAD_TYPE)
&& (payloadType
<= MediaFormat.MAX_DYNAMIC_PAYLOAD_TYPE)
&& (format != null))
//some systems will violate 3264 by reusing previously defined
//payload types for new formats. we try and salvage that
//situation by creating an overriding mapping in such cases
//we therefore don't do the following check.
//&& (ptRegistry.findFormat(payloadType) == null))
{
ptRegistry.addMapping(format, payloadType);
}
return format;
}
/**
* Creates a new <tt>MediaDescription</tt> instance according to the
* specified <tt>formats</tt>, <tt>connector</tt> and <tt>direction</tt>,
* and using the <tt>dynamicPayloadTypes</tt> registry to handle dynamic
* payload type registrations. The type (e.g. audio/video) of the media
* description is determined via from the type of the first
* <tt>MediaFormat</tt> in the <tt>formats</tt> list.
*
* @param transport the profile name (RTP/SAVP or RTP/AVP)
* @param formats the list of formats that should be advertised in the newly
* created <tt>MediaDescription</tt>.
* @param connector the socket couple that will be used for the media stream
* which we are advertising with the media description created here.
* @param direction the direction of the media stream that we are describing
* here.
* @param rtpExtensions a list of <tt>RTPExtension</tt>s supported by the
* <tt>MediaDevice</tt> that we will be advertising.
* @param dynamicPayloadTypes a reference to the
* <tt>DynamicPayloadTypeRegistry</tt> that we should be using to lookup
* and register dynamic RTP mappings.
* @param rtpExtensionsRegistry a reference to the
* <tt>DynamicRTPExtensionRegistry</tt> that we should be using to lookup
* and register URN to ID mappings.
* @return the newly create SDP <tt>MediaDescription</tt>.
* @throws OperationFailedException in case we fail to get payload type
* numbers for dynamic payload types or in case our SDP generation fails for
* some other reason.
*/
public static MediaDescription createMediaDescription(
String transport,
List<MediaFormat> formats,
StreamConnector connector,
MediaDirection direction,
List<RTPExtension> rtpExtensions,
DynamicPayloadTypeRegistry dynamicPayloadTypes,
DynamicRTPExtensionsRegistry rtpExtensionsRegistry)
throws OperationFailedException
{
int[] payloadTypesArray = new int[formats.size()];
Vector<Attribute> mediaAttributes
= new Vector<Attribute>(2 * payloadTypesArray.length + 1);
MediaType mediaType = null;
// a=sendonly|sendrecv|recvonly|inactive
if( direction != MediaDirection.SENDRECV)
mediaAttributes.add(createDirectionAttribute(direction));
for (int i = 0; i < payloadTypesArray.length; i++)
{
MediaFormat format = formats.get(i);
MediaType fmtMediaType = format.getMediaType();
// determine whether we are dealing with audio or video.
if (mediaType == null)
mediaType = fmtMediaType;
byte payloadType = format.getRTPPayloadType();
// is this a dynamic payload type.
if (payloadType == MediaFormat.RTP_PAYLOAD_TYPE_UNKNOWN)
{
try
{
payloadType
= dynamicPayloadTypes.obtainPayloadTypeNumber(format);
}
catch (IllegalStateException exception)
{
//means we ran out of dynamic rtp payload types.
throw new OperationFailedException(
"Failed to allocate a new dynamic PT number.",
OperationFailedException.INTERNAL_ERROR,
exception);
}
}
// a=rtpmap:
String numChannelsStr = "";
if (format instanceof AudioMediaFormat)
{
int channels = ((AudioMediaFormat) format).getChannels();
if (channels > 1)
numChannelsStr = "/" + channels;
}
Attribute rtpmap
= sdpFactory.createAttribute(
SdpConstants.RTPMAP,
payloadType + " " + format.getEncoding() + "/"
+ format.getClockRateString() + numChannelsStr);
mediaAttributes.add(rtpmap);
// a=fmtp:
if( format.getFormatParameters().size() > 0)
{
Attribute fmtp
= sdpFactory.createAttribute(
"fmtp",
payloadType + " " + encodeFmtp(format));
mediaAttributes.add(fmtp);
}
/* add extra attributes */
Iterator<Map.Entry<String, String>> iter = format
.getAdvancedAttributes().entrySet().iterator();
while (iter.hasNext())
{
Map.Entry<String, String> ntry = iter.next();
Attribute adv = sdpFactory.createAttribute(ntry.getKey(),
payloadType + " " + ntry.getValue());
mediaAttributes.add(adv);
}
payloadTypesArray[i] = payloadType;
}
// rtcp: (only include it if different from the default (i.e. rtp + 1)
int rtpPort = connector.getDataSocket().getLocalPort();
int rtcpPort = connector.getControlSocket().getLocalPort();
if ((rtpPort + 1) != rtcpPort)
{
Attribute rtcpAttr
= sdpFactory.createAttribute(
RTCP_ATTR,
Integer.toString(rtcpPort));
mediaAttributes.add(rtcpAttr);
}
// extmap: attributes
if (rtpExtensions != null && rtpExtensions.size() > 0)
{
for (RTPExtension extension : rtpExtensions)
{
byte extID
= rtpExtensionsRegistry.obtainExtensionMapping(extension);
String uri = extension.getURI().toString();
MediaDirection extDirection = extension.getDirection();
String attributes = extension.getExtensionAttributes();
//this is what our extmap value should look like:
//extmap:<value>["/"<direction>] <URI> <extensionattributes>
String attrValue
= Byte.toString(extID)
+ ((extDirection == MediaDirection.SENDRECV)
? ""
: ("/" + extDirection.toString()))
+ " "
+ uri
+ (attributes == null? "" : (" " + attributes));
Attribute extMapAttr
= sdpFactory.createAttribute(EXTMAP_ATTR, attrValue);
mediaAttributes.add(extMapAttr);
}
}
MediaDescription mediaDesc = null;
try
{
mediaDesc
= sdpFactory.createMediaDescription(
mediaType.toString(),
connector.getDataSocket().getLocalPort(),
1,
transport,
payloadTypesArray);
// add all the attributes we have created above
mediaDesc.setAttributes(mediaAttributes);
}
catch (Exception cause)
{
// this is very unlikely to happen but we should still re-throw
ProtocolProviderServiceSipImpl.throwOperationFailedException(
"Failed to create a media description",
OperationFailedException.INTERNAL_ERROR, cause,
logger);
}
return mediaDesc;
}
/**
* Creates an empty instance of a <tt>SessionDescription</tt> with
* preinitialized <tt>s</tt>, <tt>v</tt>, <tt>c</tt>, <tt>o</tt> and
* <tt>t</tt> parameters.
*
* @param localAddress the <tt>InetAddress</tt> corresponding to the local
* address that we'd like to use when talking to the remote party.
* @return an empty instance of a <tt>SessionDescription</tt> with
* preinitialized <tt>s</tt>, <tt>v</tt>, and <tt>t</tt> parameters.
* @throws OperationFailedException if the SDP creation failed
*/
public static SessionDescription createSessionDescription(
InetAddress localAddress)
throws OperationFailedException
{
return createSessionDescription(localAddress, null, null);
}
/**
* Creates an empty instance of a <tt>SessionDescription</tt> with
* preinitialized <tt>s</tt>, <tt>v</tt>, <tt>c</tt>, <tt>o</tt> and
* <tt>t</tt> parameters.
*
* @param localAddress the <tt>InetAddress</tt> corresponding to the local
* address that we'd like to use when talking to the remote party.
* @param userName the user name to use in the origin parameter or
* <tt>null</tt> in case we'd like to use a default.
* @param mediaDescriptions a <tt>Vector</tt> containing the list of
* <tt>MediaDescription</tt>s that we'd like to advertise (leave
* <tt>null</tt> if you'd like to add these later).
* @return an empty instance of a <tt>SessionDescription</tt> with
* preinitialized <tt>s</tt>, <tt>v</tt>, and <tt>t</tt> parameters.
* @throws OperationFailedException if the SDP creation failed
*/
public static SessionDescription createSessionDescription(
InetAddress localAddress,
String userName,
Vector<MediaDescription> mediaDescriptions)
throws OperationFailedException
{
SessionDescription sessDescr = null;
try
{
sessDescr = sdpFactory.createSessionDescription();
//"v=0"
Version v = sdpFactory.createVersion(0);
sessDescr.setVersion(v);
//"s=-"
sessDescr.setSessionName(sdpFactory.createSessionName("-"));
//"t=0 0"
TimeDescription t = sdpFactory.createTimeDescription();
Vector<TimeDescription> timeDescs = new Vector<TimeDescription>();
timeDescs.add(t);
sessDescr.setTimeDescriptions(timeDescs);
String addrType = localAddress instanceof Inet6Address
? Connection.IP6
: Connection.IP4;
//o
if (StringUtils.isNullOrEmpty(userName) )
userName = "jitsi.org";
else
userName += "-jitsi.org";
Origin o = sdpFactory.createOrigin(
userName, 0, 0, "IN", addrType, localAddress.getHostAddress());
sessDescr.setOrigin(o);
//c=
Connection c = sdpFactory.createConnection(
"IN", addrType, localAddress.getHostAddress());
sessDescr.setConnection(c);
if ( mediaDescriptions != null)
sessDescr.setMediaDescriptions(mediaDescriptions);
return sessDescr;
}
catch (SdpException exc)
{
//the jain-sip implementations of the above methods do not throw
//exceptions in the cases we are using them so falling here is quite
//unlikely. we are logging out of mere decency :)
//logger.error("Failed to crate an SDP SessionDescription.", exc);
// Failed to create session description for some reason. Must throw
// an exception so we can inform the user. It could be we were
// unable to open device or some problem with hostnames.
ProtocolProviderServiceSipImpl.throwOperationFailedException(
"An error occurred while creating session description",
OperationFailedException.INTERNAL_ERROR,
exc,
logger);
}
return sessDescr;
}
/**
* Creates and returns a new <tt>SessionDescription</tt> that is supposed to
* update our previous <tt>descToUpdate</tt> and advertise the brand new
* <tt>newMediaDescriptions</tt>. The method also respects other 3264
* policies like reusing the origin field and augmenting its version number,
* for example.
*
* @param descToUpdate the <tt>SessionDescription</tt> to update.
* @param newConnectionAddress the <tt>InetAddress</tt> to use in the new
* <tt>c=</tt> field.
* @param newMediaDescriptions the descriptions of the new streams to have
* in the updated session.
* @return a new <tt>SessionDescription</tt> that updates
* <tt>descToUpdate</tt>
* @throws OperationFailedException if the SDP creation failed
*/
public static SessionDescription createSessionUpdateDescription(
SessionDescription descToUpdate,
InetAddress newConnectionAddress,
Vector<MediaDescription> newMediaDescriptions)
throws OperationFailedException
{
SessionDescription update = createSessionDescription(
newConnectionAddress, null, newMediaDescriptions);
//extract the previous o= field.
//RFC 3264 says we must use it in the update and only change the ver
try
{
Origin o = (Origin)descToUpdate.getOrigin().clone();
long version = o.getSessionVersion();
o.setSessionVersion(version + 1);
update.setOrigin(o);
}
catch (Exception e)
{
// can't happen, ignore
if (logger.isInfoEnabled())
logger.info("Something very odd just happened.", e);
}
//now, RFC 3264 says all previous m= fields must be present and new ones
//added at the end. We should also disable all m= fields that are not
//present in the new version. We therefore loop through the previous m=s
//update them along the way and then add our new descs (if any).
Vector<MediaDescription> prevMedias
= extractMediaDescriptions(descToUpdate);
Vector<MediaDescription> completeMediaDescList
= new Vector<MediaDescription>();
//we'll be modifying the newMediaDescs list so let's make sure we don't
//cause any trouble and clone it.
newMediaDescriptions
= new Vector<MediaDescription>(newMediaDescriptions);
//this loop determines which streams are discontinued in the new
//description so that we could explicitly disable them with the new
//description. this loop also guarantees we keep the order of streams
for(MediaDescription medToUpdate : prevMedias)
{
MediaDescription desc = null;
try
{
MediaType type = getMediaType(medToUpdate);
desc = removeMediaDesc(newMediaDescriptions, type);
}
catch (IllegalArgumentException e)
{
//remote party offers a stream of a type that we don't support.
//leave desc to null so that we'll disable it and move on.
}
if (desc == null)
{
//a stream that was in the old description seems to be no longer
//there in the new one. We need to create the SDP necessary to
//explicitly disable it then.
desc = createDisablingAnswer(medToUpdate);
}
completeMediaDescList.add(desc);
}
//now add whatever's left;
for(MediaDescription medToAdd : newMediaDescriptions)
{
completeMediaDescList.add(medToAdd);
}
try
{
update.setMediaDescriptions(completeMediaDescList);
}
catch (SdpException e)
{
// never thrown, unless completeMediaDescList is null and that
// can't be since we just created it.
if (logger.isInfoEnabled())
logger.info("A crazy thing just happened.", e);
}
return update;
}
/**
* Determines the address and port where our interlocutor would like to
* receive RTCP. The method uses the port, and possibly address, indicated
* in the <tt>rtcpAttribute</tt> or returns the default
* <tt>defaultAddr:defaultPort</tt> in case <tt>rtcpAttribute</tt> is null.
* We also use <tt>defaultAddr</tt> in case <tt>rtcpAttribute</tt> only
* contains a port number and no address.
*
* @param rtcpAttrValue the SDP <tt>Attribute</tt> where we are supposed to
* look for an RTCP address and port (could be <tt>null</tt> if there was no
* such field in the incoming SDP);
* @param defaultAddr the address that we should use to construct the result
* <tt>InetSocketAddress</tt> in case <tt>rtcpAttribute</tt> is
* <tt>null</tt> or in case <tt>rtcpAttribute</tt> only contains a port
* number.
* @param defaultPort the port that we should use to construct the result
* <tt>InetSocketAddress</tt> in case <tt>rtcpAttribute</tt> is
* <tt>null</tt>.
* @return an <tt>InetSocketAddress</tt> instance indicating the destination
* where should be sending RTCP.
* @throws IllegalArgumentException if an error occurs while parsing the
* <tt>rtcpAttribute</tt>.
*/
private static InetSocketAddress determineRtcpAddress(
String rtcpAttrValue,
InetAddress defaultAddr,
int defaultPort)
throws IllegalArgumentException
{
if (rtcpAttrValue == null)
{
//no explicit RTCP attribute means RTCP goes to RTP.port + 1
return new InetSocketAddress(defaultAddr, defaultPort);
}
if (rtcpAttrValue == null || rtcpAttrValue.trim().length() == 0)
{
//invalid attribute. return default port.
return new InetSocketAddress(defaultAddr, defaultPort);
}
StringTokenizer rtcpTokenizer
= new StringTokenizer(rtcpAttrValue.trim(), " ");
// RTCP attribtutes are supposed to look this way:
// rtcp-attribute = "a=rtcp:" port [nettype space addrtype space
// connection-address] CRLF
// which gives us 2 cases: port only (1 token), or port+addr (4 tokens)
int tokenCount = rtcpTokenizer.countTokens();
//a single token means we only have a port number.
int rtcpPort;
try
{
rtcpPort = Integer.parseInt( rtcpTokenizer.nextToken() );
}
catch (NumberFormatException exc)
{
//rtcp attribute is messed up.
throw new IllegalArgumentException(
"Error while parsing rtcp attribute: " + rtcpAttrValue, exc);
}
if ( tokenCount == 1 )
{
//that was all then. ready to return.
return new InetSocketAddress(defaultAddr, rtcpPort);
}
else if ( tokenCount == 4)
{
rtcpTokenizer.nextToken();//nettype
rtcpTokenizer.nextToken();//addrtype
//address
String rtcpAddrStr = rtcpTokenizer.nextToken();
InetAddress rtcpAddress = null;
try
{
rtcpAddress = NetworkUtils.getInetAddress(rtcpAddrStr);
}
catch (UnknownHostException exc)
{
throw new IllegalArgumentException(
"Failed to parse address " + rtcpAddress, exc);
}
return new InetSocketAddress(rtcpAddress, rtcpPort);
}
else
{
//rtcp attribute is messed up: too many tokens.
throw new IllegalArgumentException(
"Error while parsing rtcp attribute: "
+ rtcpAttrValue + ". Too many tokens! ("
+ tokenCount + ")");
}
}
/**
* Encodes in an SDP string all <tt>format</tt> specific codec parameters.
*
* @param format a reference to the <tt>MediaFormat</tt> instance whose
* parameters we'd like to encode.
* @return a String representation of the <tt>format</tt>s codec parameters.
*/
private static String encodeFmtp(MediaFormat format)
{
Iterator<Map.Entry<String, String>> formatParamsIter = format
.getFormatParameters().entrySet().iterator();
StringBuffer fmtpBuff = new StringBuffer();
while (formatParamsIter.hasNext())
{
Map.Entry<String, String> ntry = formatParamsIter.next();
fmtpBuff.append(ntry.getKey()).append("=").append(ntry.getValue());
// add a separator in case we'd need to add more parameters
if (formatParamsIter.hasNext())
fmtpBuff.append(";");
}
return fmtpBuff.toString();
}
/**
* Returns a <tt>MediaStreamTarget</tt> instance reflecting the address pair
* (RTP + RTCP) where we should send media in this stream. The method takes
* into account the possibility to have a connection (i.e. c=) parameter in
* either the media description (i.e. <tt>mediaDesc</tt>) or (i.e.
* <tt>sessDesc</tt>), or both and handles their priority as defined by the
* SDP spec [RFC 4566].
*
* @param mediaDesc the media description that we'd like to extract our RTP
* and RTCP destination addresses.
* @param sessDesc the session description that we received
* <tt>mediaDesc</tt> in.
* @return a <tt>MediaStreamTarget</tt> containing the RTP and RTCP
* destinations that our interlocutor has specified for this media stream.
* @throws IllegalArgumentException in case we couldn't find connection
* data or stumble upon other problems while analyzing the SDP.
*/
public static MediaStreamTarget extractDefaultTarget(
MediaDescription mediaDesc,
SessionDescription sessDesc)
throws IllegalArgumentException
{
//first check if there's a "c=" field in the media description
Connection conn = mediaDesc.getConnection();
if ( conn == null)
{
//no "c=" in the media description. check the session level.
conn = sessDesc.getConnection();
if (conn == null)
{
throw new IllegalArgumentException(
"No \"c=\" field in the following media description nor "
+"in the enclosing session:\n"+ mediaDesc.toString());
}
}
String address;
try
{
address = conn.getAddress();
}
catch (SdpParseException exc)
{
//this can't actually happen as there's no parsing here. the
//exception is just inherited from the jain-sdp api. we are
//rethrowing only because there's nothing else we could do.
throw new IllegalArgumentException(
"Couldn't extract connection address.", exc);
}
InetAddress rtpAddress = null;
try
{
rtpAddress = NetworkUtils.getInetAddress(address);
}
catch (UnknownHostException exc)
{
throw new IllegalArgumentException(
"Failed to parse address " + address, exc);
}
//rtp port
int rtpPort;
try
{
rtpPort = mediaDesc.getMedia().getMediaPort();
}
catch (SdpParseException exc)
{
throw new IllegalArgumentException(
"Couldn't extract port from a media description.", exc);
}
InetSocketAddress rtpTarget = new InetSocketAddress(
rtpAddress, rtpPort);
//by default RTP and RTCP will be going to the same address (which is
//actually going to be the case 99% of the time.
InetAddress rtcpAddress = rtpAddress;
int rtcpPort = rtpPort + 1;
String rtcpAttributeValue;
try
{
rtcpAttributeValue = mediaDesc.getAttribute(RTCP_ATTR);
}
catch (SdpParseException exc)
{
//this can't actually happen as there's no parsing here. the
//exception is just inherited from the jain-sdp api. we are
//rethrowing only because there's nothing else we could do.
throw new IllegalArgumentException(
"Couldn't extract attribute value.", exc);
}
InetSocketAddress rtcpTarget = determineRtcpAddress(
rtcpAttributeValue, rtcpAddress, rtcpPort);
return new MediaStreamTarget(rtpTarget, rtcpTarget);
}
/**
* Extracts and returns the list of <tt>MediaFormat</tt>s advertised in
* <tt>mediaDesc</tt> preserving their oder and registering dynamic payload
* type numbers in the specified <tt>ptRegistry</tt>. Note that this method
* would only include in the result list <tt>MediaFormat</tt> instances that
* are currently supported by our <tt>MediaService</tt> implementation and
* enabled in its configuration. This means that the method could return an
* empty list even if there were actually some formats in the
* <tt>mediaDesc</tt> if we support none of them or if all these we support
* are not enabled in the <tt>MediaService</tt> configuration form.
*
* @param mediaDesc the <tt>MediaDescription</tt> to probe for a list of
* <tt>MediaFormat</tt>s
* @param ptRegistry a reference to the <tt>DynamycPayloadTypeRegistry</tt>
* where we should be registering newly added payload type number to format
* mappings.
* @return an ordered list of <tt>MediaFormat</tt>s that are both advertised
* in the <tt>mediaDesc</tt> description and supported by our
* <tt>MediaService</tt> implementation.
*/
@SuppressWarnings("unchecked")//legacy code from jain-sdp