src/media/cast/net/rtcp/rtcp.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This class maintains a bi-directional RTCP connection with a remote
   6 // peer.
   7
   8 #ifndef MEDIA_CAST_RTCP_RTCP_H_
   9 #define MEDIA_CAST_RTCP_RTCP_H_
  10
  11 #include <map>
  12 #include <queue>
  13 #include <string>
  14
  15 #include "base/basictypes.h"
  16 #include "base/memory/scoped_ptr.h"
  17 #include "base/memory/weak_ptr.h"
  18 #include "base/time/tick_clock.h"
  19 #include "base/time/time.h"
  20 #include "media/cast/cast_config.h"
  21 #include "media/cast/cast_defines.h"
  22 #include "media/cast/common/clock_drift_smoother.h"
  23 #include "media/cast/net/cast_transport_defines.h"
  24 #include "media/cast/net/cast_transport_sender.h"
  25 #include "media/cast/net/rtcp/receiver_rtcp_event_subscriber.h"
  26 #include "media/cast/net/rtcp/rtcp_builder.h"
  27 #include "media/cast/net/rtcp/rtcp_defines.h"
  28
  29 namespace media {
  30 namespace cast {
  31
  32 class LocalRtcpReceiverFeedback;
  33 class PacedPacketSender;
  34 class RtcpReceiver;
  35 class RtcpBuilder;
  36
  37 typedef std::pair<uint32, base::TimeTicks> RtcpSendTimePair;
  38 typedef std::map<uint32, base::TimeTicks> RtcpSendTimeMap;
  39 typedef std::queue<RtcpSendTimePair> RtcpSendTimeQueue;
  40
  41 class RtpReceiverStatistics {
  42  public:
  43   virtual void GetStatistics(uint8* fraction_lost,
  44                              uint32* cumulative_lost,  // 24 bits valid.
  45                              uint32* extended_high_sequence_number,
  46                              uint32* jitter) = 0;
  47
  48   virtual ~RtpReceiverStatistics() {}
  49 };
  50
  51 // TODO(hclam): This should be renamed to RtcpSession.
  52 class Rtcp {
  53  public:
  54   Rtcp(const RtcpCastMessageCallback& cast_callback,
  55        const RtcpRttCallback& rtt_callback,
  56        const RtcpLogMessageCallback& log_callback,
  57        base::TickClock* clock,  // Not owned.
  58        PacedPacketSender* packet_sender,  // Not owned.
  59        uint32 local_ssrc,
  60        uint32 remote_ssrc);
  61
  62   virtual ~Rtcp();
  63
  64   // Send a RTCP sender report.
  65   // |current_time| is the current time reported by a tick clock.
  66   // |current_time_as_rtp_timestamp| is the corresponding RTP timestamp.
  67   // |send_packet_count| is the number of packets sent.
  68   // |send_octet_count| is the number of octets sent.
  69   void SendRtcpFromRtpSender(
  70       base::TimeTicks current_time,
  71       uint32 current_time_as_rtp_timestamp,
  72       uint32 send_packet_count,
  73       size_t send_octet_count);
  74
  75   // |cast_message| and |rtcp_events| is optional; if |cast_message| is
  76   // provided the RTCP receiver report will append a Cast message containing
  77   // Acks and Nacks; |target_delay| is sent together with |cast_message|.
  78   // If |rtcp_events| is provided the RTCP receiver report will append the
  79   // log messages.
  80   void SendRtcpFromRtpReceiver(
  81       const RtcpCastMessage* cast_message,
  82       base::TimeDelta target_delay,
  83       const ReceiverRtcpEventSubscriber::RtcpEventMultiMap* rtcp_events,
  84       RtpReceiverStatistics* rtp_receiver_statistics);
  85
  86   // Submit a received packet to this object. The packet will be parsed
  87   // and used to maintain a RTCP session.
  88   // Returns false if this is not a RTCP packet or it is not directed to
  89   // this session, e.g. SSRC doesn't match.
  90   bool IncomingRtcpPacket(const uint8* data, size_t length);
  91
  92   // If available, returns true and sets the output arguments to the latest
  93   // lip-sync timestamps gleaned from the sender reports.  While the sender
  94   // provides reference NTP times relative to its own wall clock, the
  95   // |reference_time| returned here has been translated to the local
  96   // CastEnvironment clock.
  97   bool GetLatestLipSyncTimes(uint32* rtp_timestamp,
  98                              base::TimeTicks* reference_time) const;
  99
 100   void OnReceivedReceiverLog(const RtcpReceiverLogMessage& receiver_log);
 101
 102   // If greater than zero, this is the last measured network round trip time.
 103   base::TimeDelta current_round_trip_time() const {
 104     return current_round_trip_time_;
 105   }
 106
 107   static bool IsRtcpPacket(const uint8* packet, size_t length);
 108   static uint32 GetSsrcOfSender(const uint8* rtcp_buffer, size_t length);
 109
 110  protected:
 111   void OnReceivedNtp(uint32 ntp_seconds, uint32 ntp_fraction);
 112   void OnReceivedLipSyncInfo(uint32 rtp_timestamp,
 113                              uint32 ntp_seconds,
 114                              uint32 ntp_fraction);
 115
 116  private:
 117   void OnReceivedDelaySinceLastReport(uint32 last_report,
 118                                       uint32 delay_since_last_report);
 119
 120   void OnReceivedCastFeedback(const RtcpCastMessage& cast_message);
 121
 122   void SaveLastSentNtpTime(const base::TimeTicks& now,
 123                            uint32 last_ntp_seconds,
 124                            uint32 last_ntp_fraction);
 125
 126   // Remove duplicate events in |receiver_log|.
 127   // Returns true if any events remain.
 128   bool DedupeReceiverLog(RtcpReceiverLogMessage* receiver_log);
 129
 130   const RtcpCastMessageCallback cast_callback_;
 131   const RtcpRttCallback rtt_callback_;
 132   const RtcpLogMessageCallback log_callback_;
 133   base::TickClock* const clock_;  // Not owned by this class.
 134   RtcpBuilder rtcp_builder_;
 135   PacedPacketSender* packet_sender_;  // Not owned.
 136   const uint32 local_ssrc_;
 137   const uint32 remote_ssrc_;
 138
 139   RtcpSendTimeMap last_reports_sent_map_;
 140   RtcpSendTimeQueue last_reports_sent_queue_;
 141
 142   // The truncated (i.e., 64-->32-bit) NTP timestamp provided in the last report
 143   // from the remote peer, along with the local time at which the report was
 144   // received.  These values are used for ping-pong'ing NTP timestamps between
 145   // the peers so that they can estimate the network's round-trip time.
 146   uint32 last_report_truncated_ntp_;
 147   base::TimeTicks time_last_report_received_;
 148
 149   // Maintains a smoothed offset between the local clock and the remote clock.
 150   // Calling this member's Current() method is only valid if
 151   // |time_last_report_received_| is not "null."
 152   ClockDriftSmoother local_clock_ahead_by_;
 153
 154   // Latest "lip sync" info from the sender.  The sender provides the RTP
 155   // timestamp of some frame of its choosing and also a corresponding reference
 156   // NTP timestamp sampled from a clock common to all media streams.  It is
 157   // expected that the sender will update this data regularly and in a timely
 158   // manner (e.g., about once per second).
 159   uint32 lip_sync_rtp_timestamp_;
 160   uint64 lip_sync_ntp_timestamp_;
 161
 162   // The last measured network round trip time.  This is updated with each
 163   // sender report --> receiver report round trip.  If this is zero, then the
 164   // round trip time has not been measured yet.
 165   base::TimeDelta current_round_trip_time_;
 166
 167   base::TimeTicks largest_seen_timestamp_;
 168
 169   // For extending received ACK frame IDs from 8-bit to 32-bit.
 170   FrameIdWrapHelper ack_frame_id_wrap_helper_;
 171
 172   // Maintains a history of receiver events.
 173   typedef std::pair<uint64, uint64> ReceiverEventKey;
 174   base::hash_set<ReceiverEventKey> receiver_event_key_set_;
 175   std::queue<ReceiverEventKey> receiver_event_key_queue_;
 176
 177   DISALLOW_COPY_AND_ASSIGN(Rtcp);
 178 };
 179
 180 }  // namespace cast
 181 }  // namespace media
 182
 183 #endif  // MEDIA_CAST_RTCP_RTCP_H_