1 /** |
|
2 * Java RTP Library (jlibrtp) |
|
3 * Copyright (C) 2006 Arne Kepp |
|
4 * |
|
5 * This library is free software; you can redistribute it and/or |
|
6 * modify it under the terms of the GNU Lesser General Public |
|
7 * License as published by the Free Software Foundation; either |
|
8 * version 2.1 of the License, or (at your option) any later version. |
|
9 * |
|
10 * This library is distributed in the hope that it will be useful, |
|
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
13 * Lesser General Public License for more details. |
|
14 * |
|
15 * You should have received a copy of the GNU Lesser General Public |
|
16 * License along with this library; if not, write to the Free Software |
|
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
|
18 */ |
|
19 package jlibrtp; |
|
20 |
|
21 /** |
|
22 * RTCP packets for RTP Feedback Messages |
|
23 * |
|
24 * In line with RFC 4585, this packet currently only supports NACKs |
|
25 * |
|
26 * @author Arne Kepp |
|
27 */ |
|
28 public class RtcpPktRTPFB extends RtcpPkt { |
|
29 /** If this packet was for a different SSRC */ |
|
30 protected boolean notRelevant = false; |
|
31 /** SSRC we are sending feeback to */ |
|
32 protected long ssrcMediaSource = -1; |
|
33 /** RTP sequence numbers of lost packets */ |
|
34 protected int PID[]; |
|
35 /** bitmask of following lost packets, shared index with PID */ |
|
36 protected int BLP[]; |
|
37 |
|
38 /** |
|
39 * Constructor for RTP Feedback Message |
|
40 * |
|
41 * @param ssrcPacketSender SSRC of sender, taken from RTPSession |
|
42 * @param ssrcMediaSource SSRC of recipient of this message |
|
43 * @param FMT the Feedback Message Subtype |
|
44 * @param PID RTP sequence numbers of lost packets |
|
45 * @param BLP bitmask of following lost packets, shared index with PID |
|
46 */ |
|
47 protected RtcpPktRTPFB(long ssrcPacketSender, long ssrcMediaSource, int FMT, int[] PID, int[] BLP) { |
|
48 super.packetType = 205; //RTPFB |
|
49 super.itemCount = FMT; |
|
50 this.PID = PID; |
|
51 this.BLP = BLP; |
|
52 } |
|
53 |
|
54 /** |
|
55 * Constructor that parses a raw packet to retrieve information |
|
56 * |
|
57 * @param aRawPkt the raw packet to be parsed |
|
58 * @param start the start of the packet, in bytes |
|
59 * @param rtpSession the session on which the callback interface resides |
|
60 */ |
|
61 protected RtcpPktRTPFB(byte[] aRawPkt, int start, RTPSession rtpSession) { |
|
62 if(RTPSession.rtpDebugLevel > 8) { |
|
63 System.out.println(" -> RtcpPktRTPFB(byte[], int start)"); |
|
64 } |
|
65 |
|
66 rawPkt = aRawPkt; |
|
67 |
|
68 if(! super.parseHeaders(start) || packetType != 205 || super.length < 2) { |
|
69 if(RTPSession.rtpDebugLevel > 2) { |
|
70 System.out.println(" <-> RtcpPktRTPFB.parseHeaders() etc. problem"); |
|
71 } |
|
72 super.problem = -205; |
|
73 } else { |
|
74 //FMT = super.itemCount; |
|
75 |
|
76 ssrcMediaSource = StaticProcs.bytesToUIntLong(aRawPkt,8+start); |
|
77 |
|
78 if(ssrcMediaSource == rtpSession.ssrc) { |
|
79 super.ssrc = StaticProcs.bytesToUIntLong(aRawPkt,4+start); |
|
80 int loopStop = super.length - 2; |
|
81 PID = new int[loopStop]; |
|
82 BLP = new int[loopStop]; |
|
83 int curStart = 12; |
|
84 |
|
85 // Loop over Feedback Control Information (FCI) fields |
|
86 for(int i=0; i< loopStop; i++) { |
|
87 PID[i] = StaticProcs.bytesToUIntInt(aRawPkt, curStart); |
|
88 BLP[i] = StaticProcs.bytesToUIntInt(aRawPkt, curStart + 2); |
|
89 curStart += 4; |
|
90 } |
|
91 |
|
92 rtpSession.rtcpAVPFIntf.RTPFBPktReceived( |
|
93 super.ssrc, super.itemCount, PID, BLP); |
|
94 } |
|
95 } |
|
96 |
|
97 |
|
98 |
|
99 if(RTPSession.rtpDebugLevel > 8) { |
|
100 System.out.println(" <- RtcpPktRTPFB()"); |
|
101 } |
|
102 } |
|
103 |
|
104 /** |
|
105 * Encode the packet into a byte[], saved in .rawPkt |
|
106 * |
|
107 * CompRtcpPkt will call this automatically |
|
108 */ |
|
109 protected void encode() { |
|
110 super.rawPkt = new byte[12 + this.PID.length*4]; |
|
111 |
|
112 byte[] someBytes = StaticProcs.uIntLongToByteWord(super.ssrc); |
|
113 System.arraycopy(someBytes, 0, super.rawPkt, 4, 4); |
|
114 someBytes = StaticProcs.uIntLongToByteWord(this.ssrcMediaSource); |
|
115 System.arraycopy(someBytes, 0, super.rawPkt, 8, 4); |
|
116 |
|
117 // Loop over Feedback Control Information (FCI) fields |
|
118 int curStart = 12; |
|
119 for(int i=0; i < this.PID.length; i++ ) { |
|
120 someBytes = StaticProcs.uIntIntToByteWord(PID[i]); |
|
121 super.rawPkt[curStart++] = someBytes[0]; |
|
122 super.rawPkt[curStart++] = someBytes[1]; |
|
123 someBytes = StaticProcs.uIntIntToByteWord(BLP[i]); |
|
124 super.rawPkt[curStart++] = someBytes[0]; |
|
125 super.rawPkt[curStart++] = someBytes[1]; |
|
126 } |
|
127 writeHeaders(); |
|
128 } |
|
129 |
|
130 /** |
|
131 * Get the FMT (Feedback Message Type) |
|
132 * @return value stored in .itemcount, same field |
|
133 */ |
|
134 protected int getFMT() { |
|
135 return this.itemCount; |
|
136 } |
|
137 |
|
138 /** |
|
139 * Debug purposes only |
|
140 */ |
|
141 protected void debugPrint() { |
|
142 System.out.println("->RtcpPktRTPFB.debugPrint() "); |
|
143 System.out.println(" ssrcPacketSender: " + super.ssrc + " ssrcMediaSource: " + ssrcMediaSource); |
|
144 |
|
145 if(this.PID != null && this.PID.length < 1) { |
|
146 System.out.println(" No Feedback Control Information (FCI) fields"); |
|
147 } |
|
148 |
|
149 for(int i=0; i < this.PID.length; i++ ) { |
|
150 System.out.println(" FCI -> PID: " + PID[i] + " BLP: " + BLP[i]); |
|
151 } |
|
152 System.out.println("<-RtcpPktRTPFB.debugPrint() "); |
|
153 } |
|
154 } |
|