1 /*
2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 // This sub-API supports the following functionalities:
12 //
13 //  - Callbacks for RTP and RTCP events such as modified SSRC or CSRC.
14 //  - SSRC handling.
15 //  - Transmission of RTCP sender reports.
16 //  - Obtaining RTCP data from incoming RTCP sender reports.
17 //  - RTP and RTCP statistics (jitter, packet loss, RTT etc.).
18 //  - Redundant Coding (RED)
19 //  - Writing RTP and RTCP packets to binary files for off-line analysis of
20 //    the call quality.
21 //
22 // Usage example, omitting error checking:
23 //
24 //  using namespace webrtc;
25 //  VoiceEngine* voe = VoiceEngine::Create();
26 //  VoEBase* base = VoEBase::GetInterface(voe);
27 //  VoERTP_RTCP* rtp_rtcp  = VoERTP_RTCP::GetInterface(voe);
28 //  base->Init();
29 //  int ch = base->CreateChannel();
30 //  ...
31 //  rtp_rtcp->SetLocalSSRC(ch, 12345);
32 //  ...
33 //  base->DeleteChannel(ch);
34 //  base->Terminate();
35 //  base->Release();
36 //  rtp_rtcp->Release();
37 //  VoiceEngine::Delete(voe);
38 //
39 #ifndef WEBRTC_VOICE_ENGINE_VOE_RTP_RTCP_H
40 #define WEBRTC_VOICE_ENGINE_VOE_RTP_RTCP_H
41 
42 #include <vector>
43 #include "webrtc/common_types.h"
44 
45 namespace webrtc {
46 
47 class VoiceEngine;
48 
49 // VoERTPObserver
50 class WEBRTC_DLLEXPORT VoERTPObserver {
51  public:
52   virtual void OnIncomingCSRCChanged(int channel,
53                                      unsigned int CSRC,
54                                      bool added) = 0;
55 
56   virtual void OnIncomingSSRCChanged(int channel, unsigned int SSRC) = 0;
57 
58  protected:
~VoERTPObserver()59   virtual ~VoERTPObserver() {}
60 };
61 
62 // CallStatistics
63 struct CallStatistics {
64   unsigned short fractionLost;
65   unsigned int cumulativeLost;
66   unsigned int extendedMax;
67   unsigned int jitterSamples;
68   int64_t rttMs;
69   size_t bytesSent;
70   int packetsSent;
71   size_t bytesReceived;
72   int packetsReceived;
73   // The capture ntp time (in local timebase) of the first played out audio
74   // frame.
75   int64_t capture_start_ntp_time_ms_;
76 };
77 
78 // See section 6.4.1 in http://www.ietf.org/rfc/rfc3550.txt for details.
79 struct SenderInfo {
80   uint32_t NTP_timestamp_high;
81   uint32_t NTP_timestamp_low;
82   uint32_t RTP_timestamp;
83   uint32_t sender_packet_count;
84   uint32_t sender_octet_count;
85 };
86 
87 // See section 6.4.2 in http://www.ietf.org/rfc/rfc3550.txt for details.
88 struct ReportBlock {
89   uint32_t sender_SSRC;  // SSRC of sender
90   uint32_t source_SSRC;
91   uint8_t fraction_lost;
92   uint32_t cumulative_num_packets_lost;
93   uint32_t extended_highest_sequence_number;
94   uint32_t interarrival_jitter;
95   uint32_t last_SR_timestamp;
96   uint32_t delay_since_last_SR;
97 };
98 
99 // VoERTP_RTCP
100 class WEBRTC_DLLEXPORT VoERTP_RTCP {
101  public:
102   // Factory for the VoERTP_RTCP sub-API. Increases an internal
103   // reference counter if successful. Returns NULL if the API is not
104   // supported or if construction fails.
105   static VoERTP_RTCP* GetInterface(VoiceEngine* voiceEngine);
106 
107   // Releases the VoERTP_RTCP sub-API and decreases an internal
108   // reference counter. Returns the new reference count. This value should
109   // be zero for all sub-API:s before the VoiceEngine object can be safely
110   // deleted.
111   virtual int Release() = 0;
112 
113   // Sets the local RTP synchronization source identifier (SSRC) explicitly.
114   virtual int SetLocalSSRC(int channel, unsigned int ssrc) = 0;
115 
116   // Gets the local RTP SSRC of a specified |channel|.
117   virtual int GetLocalSSRC(int channel, unsigned int& ssrc) = 0;
118 
119   // Gets the SSRC of the incoming RTP packets.
120   virtual int GetRemoteSSRC(int channel, unsigned int& ssrc) = 0;
121 
122   // Sets the status of rtp-audio-level-indication on a specific |channel|.
123   virtual int SetSendAudioLevelIndicationStatus(int channel,
124                                                 bool enable,
125                                                 unsigned char id = 1) = 0;
126 
127   // Sets the status of receiving rtp-audio-level-indication on a specific
128   // |channel|.
129   virtual int SetReceiveAudioLevelIndicationStatus(int channel,
130                                                    bool enable,
131                                                    unsigned char id = 1) {
132     // TODO(wu): Remove default implementation once talk is updated.
133     return 0;
134   }
135 
136   // Sets the status of sending absolute sender time on a specific |channel|.
137   virtual int SetSendAbsoluteSenderTimeStatus(int channel,
138                                               bool enable,
139                                               unsigned char id) = 0;
140 
141   // Sets status of receiving absolute sender time on a specific |channel|.
142   virtual int SetReceiveAbsoluteSenderTimeStatus(int channel,
143                                                  bool enable,
144                                                  unsigned char id) = 0;
145 
146   // Sets the RTCP status on a specific |channel|.
147   virtual int SetRTCPStatus(int channel, bool enable) = 0;
148 
149   // Gets the RTCP status on a specific |channel|.
150   virtual int GetRTCPStatus(int channel, bool& enabled) = 0;
151 
152   // Sets the canonical name (CNAME) parameter for RTCP reports on a
153   // specific |channel|.
154   virtual int SetRTCP_CNAME(int channel, const char cName[256]) = 0;
155 
156   // TODO(holmer): Remove this API once it has been removed from
157   // fakewebrtcvoiceengine.h.
GetRTCP_CNAME(int channel,char cName[256])158   virtual int GetRTCP_CNAME(int channel, char cName[256]) { return -1; }
159 
160   // Gets the canonical name (CNAME) parameter for incoming RTCP reports
161   // on a specific channel.
162   virtual int GetRemoteRTCP_CNAME(int channel, char cName[256]) = 0;
163 
164   // Gets RTCP data from incoming RTCP Sender Reports.
165   virtual int GetRemoteRTCPData(int channel,
166                                 unsigned int& NTPHigh,
167                                 unsigned int& NTPLow,
168                                 unsigned int& timestamp,
169                                 unsigned int& playoutTimestamp,
170                                 unsigned int* jitter = NULL,
171                                 unsigned short* fractionLost = NULL) = 0;
172 
173   // Gets RTP statistics for a specific |channel|.
174   virtual int GetRTPStatistics(int channel,
175                                unsigned int& averageJitterMs,
176                                unsigned int& maxJitterMs,
177                                unsigned int& discardedPackets) = 0;
178 
179   // Gets RTCP statistics for a specific |channel|.
180   virtual int GetRTCPStatistics(int channel, CallStatistics& stats) = 0;
181 
182   // Gets the report block parts of the last received RTCP Sender Report (SR),
183   // or RTCP Receiver Report (RR) on a specified |channel|. Each vector
184   // element also contains the SSRC of the sender in addition to a report
185   // block.
186   virtual int GetRemoteRTCPReportBlocks(
187       int channel,
188       std::vector<ReportBlock>* receive_blocks) = 0;
189 
190   // Sets the Redundant Coding (RED) status on a specific |channel|.
191   // TODO(minyue): Make SetREDStatus() pure virtual when fakewebrtcvoiceengine
192   // in talk is ready.
193   virtual int SetREDStatus(int channel, bool enable, int redPayloadtype = -1) {
194     return -1;
195   }
196 
197   // Gets the RED status on a specific |channel|.
198   // TODO(minyue): Make GetREDStatus() pure virtual when fakewebrtcvoiceengine
199   // in talk is ready.
GetREDStatus(int channel,bool & enabled,int & redPayloadtype)200   virtual int GetREDStatus(int channel, bool& enabled, int& redPayloadtype) {
201     return -1;
202   }
203 
204   // This function enables Negative Acknowledgment (NACK) using RTCP,
205   // implemented based on RFC 4585. NACK retransmits RTP packets if lost on
206   // the network. This creates a lossless transport at the expense of delay.
207   // If using NACK, NACK should be enabled on both endpoints in a call.
208   virtual int SetNACKStatus(int channel, bool enable, int maxNoPackets) = 0;
209 
210  protected:
VoERTP_RTCP()211   VoERTP_RTCP() {}
~VoERTP_RTCP()212   virtual ~VoERTP_RTCP() {}
213 };
214 
215 }  // namespace webrtc
216 
217 #endif  // #ifndef WEBRTC_VOICE_ENGINE_VOE_RTP_RTCP_H
218