Change PacketKey to be unique for each frame packet by including

media/cast/net/pacing/paced_sender.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_CAST_NET_PACING_PACED_SENDER_H_
 #define MEDIA_CAST_NET_PACING_PACED_SENDER_H_
 
 #include <map>
+#include <tuple>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/default_tick_clock.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "media/cast/logging/logging_defines.h"
 #include "media/cast/net/cast_transport_config.h"
 
 namespace media {
 namespace cast {
 
 // Meant to use as defaults for pacer construction.
 static const size_t kTargetBurstSize = 10;
 static const size_t kMaxBurstSize = 20;
 
-// Use std::pair for free comparison operators.
-// { capture_time, ssrc, packet_id }
 // The PacketKey is designed to meet two criteria:
 // 1. When we re-send the same packet again, we can use the packet key
 //    to identify it so that we can de-duplicate packets in the queue.
 // 2. The sort order of the PacketKey determines the order that packets
-//    are sent out. Using the capture_time as the first member basically
-//    means that older packets are sent first.
-typedef std::pair<base::TimeTicks, std::pair<uint32, uint16> > PacketKey;
+//    are sent out.
+// 3. The PacketKey is unique for each RTP (frame) packet.
+struct PacketKey {
+  enum PacketType { RTCP = 0, RTP = 1 };
+
+  PacketType packet_type;
+  uint32 frame_id;
+  uint32 ssrc;
+  uint16 packet_id;
+
+  bool operator<(const PacketKey& key) const {
+    return std::tie(packet_type, frame_id, ssrc, packet_id) <
+           std::tie(key.packet_type, key.frame_id, key.ssrc, key.packet_id);
+  }
+};
+
 typedef std::vector<std::pair<PacketKey, PacketRef> > SendPacketVector;
 
 // Information used to deduplicate retransmission packets.
 // There are two criteria for deduplication.
 //
 // 1. Using another muxed stream.
 //    Suppose there are multiple streams muxed and sent via the same
 //    socket. When there is a retransmission request for packet X, we
 //    will reject the retransmission if there is a packet sent from
 //    another stream just before X but not acked. Typically audio stream
@@ skipping 13 matching lines @@
 class PacedPacketSender {
  public:
   virtual bool SendPackets(const SendPacketVector& packets) = 0;
   virtual bool ResendPackets(const SendPacketVector& packets,
                              const DedupInfo& dedup_info) = 0;
   virtual bool SendRtcpPacket(uint32 ssrc, PacketRef packet) = 0;
   virtual void CancelSendingPacket(const PacketKey& packet_key) = 0;
 
   virtual ~PacedPacketSender() {}
 
-  static PacketKey MakePacketKey(const base::TimeTicks& ticks,
+  static PacketKey MakePacketKey(PacketKey::PacketType,
+                                 uint32 frame_id,
                                  uint32 ssrc,
                                  uint16 packet_id);
 };
 
 class PacedSender : public PacedPacketSender,
                     public base::NonThreadSafe,
                     public base::SupportsWeakPtr<PacedSender> {
  public:
   // |recent_packet_events| is an externally-owned vector where PacedSender will
   // add PacketEvents related to sending, retransmission, and rejection.  The
@@ skipping 133 matching lines @@
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<PacedSender> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PacedSender);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_NET_PACING_PACED_SENDER_H_