Add Cast PLI support on sender side.

media/cast/net/rtcp/sender_rtcp_session.cc

 // Copyright 2015 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 <algorithm>
 #include <limits>
 #include <utility>
 
 #include "base/big_endian.h"
 #include "base/time/time.h"
@@ skipping 61 matching lines @@
   return std::make_pair(
       value1, static_cast<uint64_t>(event_timestamp.ToInternalValue()));
 }
 
 }  // namespace
 
 SenderRtcpSession::SenderRtcpSession(
     const RtcpCastMessageCallback& cast_callback,
     const RtcpRttCallback& rtt_callback,
     const RtcpLogMessageCallback& log_callback,
+    const RtcpPliCallback pli_callback,
     base::TickClock* clock,
     PacedPacketSender* packet_sender,
     uint32_t local_ssrc,
     uint32_t remote_ssrc)
     : clock_(clock),
       packet_sender_(packet_sender),
       local_ssrc_(local_ssrc),
       remote_ssrc_(remote_ssrc),
       cast_callback_(cast_callback),
       rtt_callback_(rtt_callback),
       log_callback_(log_callback),
+      pli_callback_(pli_callback),
       largest_seen_timestamp_(base::TimeTicks::FromInternalValue(
           std::numeric_limits<int64_t>::min())),
       parser_(local_ssrc, remote_ssrc),
       ack_frame_id_wrap_helper_(kFirstFrameId - 1) {}
 
 SenderRtcpSession::~SenderRtcpSession() {}
 
 bool SenderRtcpSession::IncomingRtcpPacket(const uint8_t* data, size_t length) {
   // Check if this is a valid RTCP packet.
   if (!IsRtcpPacket(data, length)) {
     VLOG(1) << "Rtcp@" << this << "::IncomingRtcpPacket() -- "
             << "Received an invalid (non-RTCP?) packet.";
     return false;
   }
 
   // Check if this packet is to us.
   uint32_t ssrc_of_sender = GetSsrcOfSender(data, length);
   if (ssrc_of_sender != remote_ssrc_) {
     return false;
   }
 
   // Parse this packet.
   base::BigEndianReader reader(reinterpret_cast<const char*>(data), length);
   if (parser_.Parse(&reader)) {
+    if (parser_.has_picture_loss_indicator())
+      OnReceivedPli();

[Irfan, 2016/02/29 16:01:23]

For readability, perhaps a few of these OnReceived functions can be eliminated
and code inlined here since it is a callback invocation

[xjz, 2016/02/29 19:48:58]

Done.

     if (parser_.has_receiver_reference_time_report()) {
       base::TimeTicks t = ConvertNtpToTimeTicks(
           parser_.receiver_reference_time_report().ntp_seconds,
           parser_.receiver_reference_time_report().ntp_fraction);
       if (t > largest_seen_timestamp_) {
         largest_seen_timestamp_ = t;
       } else if ((largest_seen_timestamp_ - t).InMilliseconds() >
                  kOutOfOrderMaxAgeMs) {
         // Reject packet, it is too old.
         VLOG(1) << "Rejecting RTCP packet as it is too old ("
@@ skipping 133 matching lines @@
   cast_callback_.Run(cast_message);
 }
 
 void SenderRtcpSession::OnReceivedReceiverLog(
     const RtcpReceiverLogMessage& receiver_log) {
   if (log_callback_.is_null())
     return;
   log_callback_.Run(receiver_log);
 }
 
+void SenderRtcpSession::OnReceivedPli() {
+  if (pli_callback_.is_null())
+    return;
+  pli_callback_.Run();
+}
+
 }  // namespace cast
 }  // namespace media