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1 /** |
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2 * Java RTP Library (jlibrtp) |
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3 * Copyright (C) 2006 Arne Kepp |
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4 * |
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5 * This library is free software; you can redistribute it and/or |
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6 * modify it under the terms of the GNU Lesser General Public |
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7 * License as published by the Free Software Foundation; either |
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8 * version 2.1 of the License, or (at your option) any later version. |
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9 * |
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10 * This library is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 * Lesser General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU Lesser General Public |
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16 * License along with this library; if not, write to the Free Software |
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17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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18 */ |
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19 package jlibrtp; |
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20 |
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21 import java.util.Enumeration; |
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22 import java.net.DatagramSocket; |
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23 import java.net.InetAddress; |
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24 import java.net.MulticastSocket; |
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25 import java.util.LinkedList; |
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26 import java.util.Hashtable; |
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27 import java.util.ListIterator; |
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28 import java.util.Arrays; |
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29 |
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30 |
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31 /** |
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32 * This class acts as an organizer for most of the information |
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33 * and functions pertaining to RTCP packet generation and reception |
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34 * |
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35 * @author Arne Kepp |
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36 * |
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37 */ |
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38 public class RTCPSession { |
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39 /** Parent session */ |
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40 protected RTPSession rtpSession = null; |
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41 |
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42 /** Unicast socket */ |
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43 protected DatagramSocket rtcpSock = null; |
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44 /** Multicast socket */ |
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45 protected MulticastSocket rtcpMCSock = null; |
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46 /** Multicast group */ |
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47 protected InetAddress mcGroup = null; |
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48 |
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49 /** RTCP Receiver thread */ |
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50 protected RTCPReceiverThread recvThrd = null; |
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51 /** RTCP Sender thread */ |
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52 protected RTCPSenderThread senderThrd = null; |
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53 |
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54 /** Previous time a delay was calculated */ |
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55 protected long prevTime = System.currentTimeMillis(); |
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56 /** Delay between RTCP transmissions, in ms. Initialized in start() */ |
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57 protected int nextDelay = -1; // |
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58 /** The average compound RTCP packet size, in octets, including UDP and IP headers */ |
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59 protected int avgPktSize = 200; // |
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60 /** Pessimistic case estimate of the current number of senders */ |
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61 protected int senderCount = 1; |
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62 /** Whether next RTCP packet can be sent early */ |
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63 protected boolean fbAllowEarly = false; |
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64 /** Feedback queue , index is SSRC of target */ |
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65 protected Hashtable<Long, LinkedList<RtcpPkt>> fbQueue = null; |
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66 /** APP queue , index is SSRC of target */ |
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67 protected Hashtable<Long, LinkedList<RtcpPktAPP>> appQueue = null; |
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68 /** Are we just starting up? */ |
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69 protected boolean initial = true; |
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70 /** Is there a feedback packet waiting? SSRC of destination */ |
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71 protected long fbWaiting = -1; |
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72 |
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73 /** |
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74 * Constructor for unicast sessions |
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75 * |
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76 * @param parent RTPSession that started this |
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77 * @param rtcpSocket the socket to use for listening and sending |
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78 */ |
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79 protected RTCPSession(RTPSession parent, DatagramSocket rtcpSocket) { |
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80 this.rtcpSock = rtcpSocket; |
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81 rtpSession = parent; |
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82 } |
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83 |
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84 /** |
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85 * Constructor for multicast sessions |
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86 * |
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87 * @param parent parent RTPSession |
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88 * @param rtcpSocket parent RTPSession that started this |
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89 * @param multicastGroup multicast group to bind the socket to |
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90 */ |
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91 protected RTCPSession(RTPSession parent, MulticastSocket rtcpSocket, InetAddress multicastGroup) { |
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92 mcGroup = multicastGroup; |
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93 this.rtcpSock = rtcpSocket; |
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94 rtpSession = parent; |
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95 } |
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96 |
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97 /** |
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98 * Starts the session, calculates delays and fires up the threads. |
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99 * |
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100 */ |
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101 protected void start() { |
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102 //nextDelay = 2500 + rtpSession.random.nextInt(1000) - 500; |
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103 this.calculateDelay(); |
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104 recvThrd = new RTCPReceiverThread(this, this.rtpSession); |
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105 senderThrd = new RTCPSenderThread(this, this.rtpSession); |
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106 recvThrd.start(); |
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107 senderThrd.start(); |
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108 } |
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109 |
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110 /** |
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111 * Send bye packets, handled by RTCP Sender thread |
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112 * |
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113 */ |
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114 protected void sendByes() { |
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115 senderThrd.sendByes(); |
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116 } |
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117 |
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118 /** |
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119 * Calculate the delay before the next RTCP packet can be sent |
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120 * |
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121 */ |
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122 protected void calculateDelay() { |
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123 switch(rtpSession.rtcpMode) { |
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124 case 0: calculateRegularDelay(); break; |
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125 default: |
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126 System.out.println("RTCPSession.calculateDelay() unknown .mode"); |
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127 } |
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128 } |
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129 |
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130 /** |
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131 * Calculates a delay value in accordance with RFC 3550 |
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132 * |
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133 */ |
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134 protected void calculateRegularDelay() { |
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135 long curTime = System.currentTimeMillis(); |
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136 |
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137 if(rtpSession.bandwidth != 0 && ! this.initial && rtpSession.partDb.ssrcTable.size() > 4) { |
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138 // RTPs mechanisms for RTCP scalability |
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139 int rand = rtpSession.random.nextInt(10000) - 5000; //between -500 and +500 |
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140 double randDouble = ((double) 1000 + rand)/1000.0; |
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141 |
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142 |
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143 Enumeration<Participant> enu = rtpSession.partDb.getParticipants(); |
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144 while(enu.hasMoreElements()) { |
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145 Participant part = enu.nextElement(); |
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146 if(part.lastRtpPkt > this.prevTime) |
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147 senderCount++; |
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148 } |
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149 |
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150 double bw; |
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151 if(rtpSession.rtcpBandwidth > -1) { |
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152 bw = rtpSession.rtcpBandwidth; |
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153 }else { |
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154 bw = rtpSession.bandwidth*0.05; |
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155 } |
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156 if(senderCount*2 > rtpSession.partDb.ssrcTable.size()) { |
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157 if(rtpSession.lastTimestamp > this.prevTime) { |
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158 //We're a sender |
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159 double numerator = ((double) this.avgPktSize)*((double) senderCount); |
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160 double denominator = 0.25*bw; |
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161 this.nextDelay = (int) Math.round((numerator/denominator)*randDouble); |
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162 } else { |
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163 //We're a receiver |
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164 double numerator = ((double) this.avgPktSize)*((double) rtpSession.partDb.ssrcTable.size()); |
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165 double denominator = 0.75*bw; |
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166 this.nextDelay = (int) Math.round((numerator/denominator)*randDouble); |
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167 } |
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168 } else { |
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169 double numerator = ((double) this.avgPktSize)*((double) rtpSession.partDb.ssrcTable.size());; |
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170 double denominator = bw; |
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171 this.nextDelay = (int) Math.round(1000.0*(numerator/denominator)) * (1000 + rand); |
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172 } |
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173 } else { |
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174 // Not enough data to scale, use random values |
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175 int rand = rtpSession.random.nextInt(1000) - 500; //between -500 and +500 |
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176 if(this.initial) { |
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177 // 2.5 to 3.5 seconds, randomly |
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178 this.nextDelay = 3000 + rand; |
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179 this.initial = false; |
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180 } else { |
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181 // 4.5 to 5.5 seconds, randomly |
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182 this.nextDelay = 5500 + rand; |
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183 } |
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184 |
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185 } |
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186 |
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187 // preflight check |
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188 if(this.nextDelay < 1000) { |
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189 int rand = rtpSession.random.nextInt(1000) - 500; //between -500 and +500 |
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190 System.out.println("RTCPSession.calculateDelay() nextDelay was too short (" |
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191 +this.nextDelay+"ms), setting to "+(this.nextDelay = 2000 + rand)); |
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192 } |
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193 this.prevTime = curTime; |
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194 } |
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195 |
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196 /** |
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197 * Update the average packet size |
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198 * @param length of latest packet |
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199 */ |
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200 synchronized protected void updateAvgPacket(int length) { |
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201 double tempAvg = (double) this.avgPktSize; |
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202 tempAvg = (15*tempAvg + ((double) length))/16; |
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203 this.avgPktSize = (int) tempAvg; |
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204 } |
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205 |
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206 |
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207 /** |
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208 * Adds an RTCP APP (application) packet to the queue |
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209 * |
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210 * @param targetSsrc the SSRC of the recipient |
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211 * @param aPkt |
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212 */ |
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213 synchronized protected void addToAppQueue(long targetSsrc, RtcpPktAPP aPkt) { |
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214 aPkt.time = System.currentTimeMillis(); |
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215 |
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216 if(this.appQueue == null) |
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217 this.appQueue = new Hashtable<Long, LinkedList<RtcpPktAPP>>(); |
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218 |
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219 LinkedList<RtcpPktAPP> ll = this.appQueue.get(targetSsrc); |
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220 if(ll == null) { |
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221 // No list, create and add |
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222 ll = new LinkedList<RtcpPktAPP>(); |
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223 this.appQueue.put(targetSsrc, ll); |
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224 } |
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225 |
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226 ll.add(aPkt); |
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227 } |
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228 |
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229 |
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230 /** |
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231 * Adds an RTCP APP (application) packet to the queue |
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232 * |
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233 * @param targetSsrc the SSRC of the recipient |
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234 * @return array of RTCP Application packets |
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235 */ |
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236 synchronized protected RtcpPktAPP[] getFromAppQueue(long targetSsrc) { |
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237 if(this.appQueue == null) |
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238 return null; |
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239 |
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240 LinkedList<RtcpPktAPP> ll = this.appQueue.get(targetSsrc); |
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241 if(ll == null || ll.isEmpty()) { |
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242 return null; |
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243 } else { |
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244 RtcpPktAPP[] ret = new RtcpPktAPP[ll.size()]; |
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245 ListIterator<RtcpPktAPP> li = ll.listIterator(); |
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246 int i = 0; |
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247 while(li.hasNext()) { |
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248 ret[i] = li.next(); |
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249 i++; |
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250 } |
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251 return ret; |
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252 } |
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253 } |
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254 |
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255 |
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256 /** |
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257 * Cleans the TCP APP (application) packet queues of any packets that are |
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258 * too old, defined as 60 seconds since insertion. |
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259 * |
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260 * @param ssrc The SSRC of the user who has left, negative value -> general cleanup |
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261 */ |
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262 synchronized protected void cleanAppQueue(long ssrc) { |
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263 if(this.appQueue == null) |
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264 return; |
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265 |
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266 if(ssrc > 0) { |
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267 this.appQueue.remove(ssrc); |
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268 } else { |
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269 Enumeration<LinkedList<RtcpPktAPP>> enu = this.appQueue.elements(); |
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270 long curTime = System.currentTimeMillis(); |
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271 |
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272 |
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273 while(enu.hasMoreElements()) { |
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274 ListIterator<RtcpPktAPP> li = enu.nextElement().listIterator(); |
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275 while(li.hasNext()) { |
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276 RtcpPkt aPkt = li.next(); |
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277 //Remove after 60 seconds |
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278 if(curTime - aPkt.time > 60000) { |
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279 li.remove(); |
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280 } |
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281 } |
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282 } |
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283 } |
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284 } |
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285 |
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286 |
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287 |
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288 /** |
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289 * Check the feedback queue for similar packets and adds |
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290 * the new packet if it is not redundant |
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291 * |
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292 * @param aPkt |
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293 * @return 0 if the packet was added, 1 if it was dropped |
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294 */ |
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295 synchronized protected int addToFbQueue(long targetSsrc, RtcpPkt aPkt) { |
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296 if(this.fbQueue == null) |
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297 this.fbQueue = new Hashtable<Long, LinkedList<RtcpPkt>>(); |
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298 |
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299 LinkedList<RtcpPkt> ll = this.fbQueue.get(targetSsrc); |
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300 if(ll == null) { |
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301 // No list, create and add |
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302 ll = new LinkedList<RtcpPkt>(); |
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303 ll.add(aPkt); |
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304 this.fbQueue.put(targetSsrc, ll); |
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305 } else { |
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306 // Check for matching packets, else add to end |
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307 ListIterator<RtcpPkt> li = ll.listIterator(); |
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308 while(li.hasNext()) { |
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309 RtcpPkt tmp = li.next(); |
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310 if(equivalent(tmp, aPkt)) |
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311 return -1; |
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312 } |
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313 ll.addLast(aPkt); |
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314 } |
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315 return 0; |
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316 } |
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317 |
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318 /** |
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319 * Checks whether there are ny feedback packets waiting |
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320 * to be sent. |
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321 * |
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322 * @param ssrc of the participant we are notifying |
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323 * @return all relevant feedback packets, or null |
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324 */ |
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325 synchronized protected RtcpPkt[] getFromFbQueue(long ssrc) { |
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326 if(this.fbQueue == null) |
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327 return null; |
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328 |
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329 LinkedList<RtcpPkt> ll = this.fbQueue.get(ssrc); |
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330 |
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331 if(ll == null) |
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332 return null; |
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333 |
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334 ListIterator<RtcpPkt> li = ll.listIterator(); |
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335 if(li.hasNext()) { |
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336 long curTime = System.currentTimeMillis(); |
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337 long maxDelay = curTime - rtpSession.fbMaxDelay; |
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338 long keepDelay = curTime - 2000; |
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339 int count = 0; |
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340 |
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341 //TODO below the indeces should be collected instead of looping twice |
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342 |
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343 // Clean out what we dont want and count what we want |
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344 while(li.hasNext()) { |
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345 RtcpPkt aPkt = li.next(); |
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346 if(aPkt.received) { |
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347 //This is a packet received, we keep these for |
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348 // 2000ms to avoid redundant feedback |
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349 if(aPkt.time < keepDelay) |
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350 li.remove(); |
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351 } else { |
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352 //This is a packet we havent sent yet |
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353 if(aPkt.time < maxDelay) { |
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354 li.remove(); |
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355 } else { |
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356 count++; |
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357 } |
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358 } |
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359 } |
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360 |
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361 // Gather what we want to return |
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362 if(count != 0) { |
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363 li = ll.listIterator(); |
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364 RtcpPkt[] ret = new RtcpPkt[count]; |
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365 |
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366 while(count > 0) { |
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367 RtcpPkt aPkt = li.next(); |
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368 if(! aPkt.received) { |
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369 ret[ret.length - count] = aPkt; |
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370 count--; |
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371 } |
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372 } |
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373 return ret; |
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374 } |
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375 } |
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376 |
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377 return null; |
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378 } |
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379 |
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380 /** |
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381 * Cleans the feeback queue of any packets that have expired, |
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382 * ie feedback packet that are no longer relevant. |
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383 * |
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384 * @param ssrc The SSRC of the user who has left, negative value -> general cleanup |
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385 */ |
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386 synchronized protected void cleanFbQueue(long ssrc) { |
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387 if(this.fbQueue == null) |
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388 return; |
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389 |
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390 if(ssrc > 0) { |
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391 this.fbQueue.remove(ssrc); |
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392 } else { |
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393 Enumeration<LinkedList<RtcpPkt>> enu = this.fbQueue.elements(); |
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394 long curTime = System.currentTimeMillis(); |
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395 long maxDelay = curTime - rtpSession.fbMaxDelay; |
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396 long keepDelay = curTime - 2000; |
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397 |
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398 while(enu.hasMoreElements()) { |
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399 ListIterator<RtcpPkt> li = enu.nextElement().listIterator(); |
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400 while(li.hasNext()) { |
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401 RtcpPkt aPkt = li.next(); |
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402 if(aPkt.received) { |
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403 //This is a packet received, we keep these for |
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404 // 2000ms to avoid redundant feedback |
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405 if(aPkt.time < keepDelay) |
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406 li.remove(); |
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407 } else { |
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408 //This is a packet we havent sent yet |
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409 if(aPkt.time < maxDelay) |
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410 li.remove(); |
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411 } |
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412 } |
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413 } |
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414 } |
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415 } |
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416 |
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417 /** |
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418 * Check whether the conditions are satisfied to send a feedbkac packet immediately. |
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419 * |
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420 * @return true if they are, false otherwise |
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421 */ |
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422 protected boolean fbSendImmediately() { |
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423 if(rtpSession.partDb.ssrcTable.size() > this.rtpSession.fbEarlyThreshold |
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424 && rtpSession.partDb.receivers.size() > this.rtpSession.fbEarlyThreshold) |
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425 return false; |
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426 |
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427 return true; |
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428 } |
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429 |
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430 |
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431 /** |
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432 * Check whether the conditions are satisfied to send a feedbkac packet immediately. |
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433 * |
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434 * @return true if they are, false otherwise |
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435 */ |
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436 protected boolean fbSendEarly() { |
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437 if(rtpSession.partDb.ssrcTable.size() > this.rtpSession.fbRegularThreshold |
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438 && rtpSession.partDb.receivers.size() > this.rtpSession.fbRegularThreshold) |
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439 return false; |
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440 |
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441 return true; |
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442 } |
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443 |
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444 /** |
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445 * Wake the sender thread because of this ssrc |
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446 * |
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447 * @param ssrc that has feedback waiting. |
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448 */ |
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449 protected void wakeSenderThread(long ssrc) { |
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450 this.fbWaiting = ssrc; |
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451 this.senderThrd.interrupt(); |
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452 |
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453 // Give it a chance to catch up |
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454 try { Thread.sleep(0,1); } catch (Exception e){ }; |
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455 } |
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456 |
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457 /** |
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458 * Compares two packets to check whether they are equivalent feedback messages, |
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459 * to avoid sending the same feedback to a host twice. |
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460 * |
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461 * Expect false negatives, but not false positives. |
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462 * |
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463 * @param one packet |
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464 * @param two packet |
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465 * @return true if they are equivalent, false otherwise |
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466 */ |
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467 private boolean equivalent(RtcpPkt one, RtcpPkt two) { |
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468 // Cheap checks |
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469 if(one.packetType != two.packetType) |
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470 return false; |
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471 |
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472 if(one.itemCount != two.itemCount) |
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473 return false; |
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474 |
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475 if(one.packetType == 205) { |
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476 // RTP Feedback, i.e. a NACK |
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477 RtcpPktRTPFB pktone = (RtcpPktRTPFB) one; |
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478 RtcpPktRTPFB pkttwo = (RtcpPktRTPFB) two; |
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479 |
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480 if(pktone.ssrcMediaSource != pkttwo.ssrcMediaSource) |
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481 return false; |
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482 |
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483 if(Arrays.equals(pktone.BLP,pkttwo.BLP) |
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484 && Arrays.equals(pktone.BLP,pkttwo.BLP)) |
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485 return true; |
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486 |
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487 return true; |
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488 } else if(one.packetType == 206) { |
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489 RtcpPktPSFB pktone = (RtcpPktPSFB) one; |
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490 RtcpPktPSFB pkttwo = (RtcpPktPSFB) two; |
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491 |
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492 if(pktone.ssrcMediaSource != pkttwo.ssrcMediaSource) |
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493 return false; |
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494 |
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495 switch(one.itemCount) { |
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496 case 1: // Picture Loss Indication |
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497 return true; |
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498 |
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499 case 2: // Slice Loss Indication |
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500 // This will not work if the slice loss indicators are in different order |
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501 if(pktone.sliFirst.length == pkttwo.sliFirst.length |
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502 && Arrays.equals(pktone.sliFirst, pkttwo.sliFirst) |
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503 && Arrays.equals(pktone.sliNumber, pkttwo.sliNumber) |
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504 && Arrays.equals(pktone.sliPictureId, pkttwo.sliPictureId)) |
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505 return true; |
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506 break; |
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507 case 3: // Reference Picture Selection Indication |
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508 if(Arrays.equals(pktone.rpsiBitString, pkttwo.rpsiBitString)) |
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509 return true; |
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510 break; |
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511 case 15: // Application Layer Feedback Messages |
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512 // This will not work if the padding scheme is different |
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513 if(pktone.sliFirst.length == pkttwo.sliFirst.length |
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514 && Arrays.equals(pktone.alfBitString, pkttwo.alfBitString)) |
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515 return true; |
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516 break; |
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517 default: |
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518 |
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519 } |
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520 return true; |
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521 } else { |
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522 System.out.println("!!!! RTCPSession.equivalentPackets() encountered unexpected packet type!"); |
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523 } |
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524 return false; |
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525 } |
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526 } |
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527 |