Cast: Move retransmission to the transport

media/cast/net/rtp/rtp_sender.cc

 // 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.
 
 #include "media/cast/net/rtp/rtp_sender.h"
 
 #include "base/big_endian.h"
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "media/cast/net/cast_transport_defines.h"
@@ skipping 99 matching lines @@
         UpdateSequenceNumber(&packet_copy->data);
         packets_to_resend.push_back(std::make_pair(packet_key, packet_copy));
       } else if (cancel_rtx_if_not_in_list) {
         transport_->CancelSendingPacket(it->first);
       }
     }
     transport_->ResendPackets(packets_to_resend, dedupe_window);
   }
 }
 
+void RtpSender::CancelSendingFrames(const std::set<uint32>& frame_ids) {
+  // Cancel resends of acked frames.
+  MissingFramesAndPacketsMap missing_frames_and_packets;
+  PacketIdSet missing;
+  for (std::set<uint32>::const_iterator it = frame_ids.begin();
+       it != frame_ids.end(); ++it) {
+    missing_frames_and_packets[*it] = missing;
+  }
+  ResendPackets(missing_frames_and_packets, true, base::TimeDelta());

[hubbe, 2014/08/12 18:24:11]

Why go through ResendPackets()?
Seems like you just need to call transport_->CancelSendingPacket() a few times
here...

[Alpha Left Google, 2014/08/12 23:57:39]

Done.

+}
+
+void RtpSender::ResendFrameForKickstart(uint32 frame_id,
+                                        base::TimeDelta dedupe_window) {
+  // Send the last packet of the encoded frame to kick start
+  // retransmission. This gives enough information to the receiver what
+  // packets and frames are missing.
+  MissingFramesAndPacketsMap missing_frames_and_packets;
+  PacketIdSet missing;
+  missing.insert(kRtcpCastLastPacket);
+  missing_frames_and_packets.insert(std::make_pair(frame_id, missing));
+
+  // Sending this extra packet is to kick-start the session. There is
+  // no need to optimize re-transmission for this case.
+  ResendPackets(missing_frames_and_packets, false, dedupe_window);
+}
+
 void RtpSender::UpdateSequenceNumber(Packet* packet) {
   // TODO(miu): This is an abstraction violation.  This needs to be a part of
   // the overall packet (de)serialization consolidation.
   static const int kByteOffsetToSequenceNumber = 2;
   base::BigEndianWriter big_endian_writer(
       reinterpret_cast<char*>((&packet->front()) + kByteOffsetToSequenceNumber),
       sizeof(uint16));
   big_endian_writer.WriteU16(packetizer_->NextSequenceNumber());
 }
 
 }  //  namespace cast
 }  // namespace media