Add Cast PLI support on sender side.

media/cast/net/rtcp/rtcp_utility.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/rtcp/rtcp_utility.h"
 
 #include <stdint.h>
 
 #include <cmath>
 
@@ skipping 15 matching lines @@
 const double kMagicFractionalUnit = 4.294967296E3;
 
 }  // namespace
 
 RtcpParser::RtcpParser(uint32_t local_ssrc, uint32_t remote_ssrc)
     : local_ssrc_(local_ssrc),
       remote_ssrc_(remote_ssrc),
       has_sender_report_(false),
       has_last_report_(false),
       has_cast_message_(false),
-      has_receiver_reference_time_report_(false) {}
+      has_receiver_reference_time_report_(false),
+      received_picture_loss_indicator_(false) {}
 
 RtcpParser::~RtcpParser() {}
 
 bool RtcpParser::Parse(base::BigEndianReader* reader) {
   // Reset.
   has_sender_report_ = false;
   sender_report_ = RtcpSenderInfo();
   has_last_report_ = false;
   receiver_log_.clear();
   has_cast_message_ = false;
   has_receiver_reference_time_report_ = false;
+  received_picture_loss_indicator_ = false;
 
   while (reader->remaining()) {
     RtcpCommonHeader header;
     if (!ParseCommonHeader(reader, &header))
       return false;
 
     base::StringPiece tmp;
     if (!reader->ReadPiece(&tmp, header.length_in_octets - 4))
       return false;
     base::BigEndianReader chunk(tmp.data(), tmp.size());
 
+    // Check for receiving PLI.

[miu, 2016/02/26 23:36:07]

Please move this to the case kPacketTypePayloadSpecific block below.

[xjz, 2016/02/27 05:53:32]

Done.

+    if ((header.IC == 1) && (header.P == 0) &&

[miu, 2016/02/26 23:36:07]

OOC, why do we check header.P?  Doesn't seem to matter.

[xjz, 2016/02/27 05:53:32]

Removed.

+        (header.PT == kPacketTypePayloadSpecific) &&
+        (header.length_in_octets == 12)) {
+      return ParsePli(&chunk, header);
+    }
+
     switch (header.PT) {
       case kPacketTypeSenderReport:
         if (!ParseSR(&chunk, header))
           return false;
         break;
 
       case kPacketTypeReceiverReport:
         if (!ParseRR(&chunk, header))
           return false;
         break;
@@ skipping 108 matching lines @@
 
   if (ssrc == local_ssrc_) {
     last_report_ = last_report;
     delay_since_last_report_ = delay;
     has_last_report_ = true;
   }
 
   return true;
 }
 
+bool RtcpParser::ParsePli(base::BigEndianReader* reader,
+                          const RtcpCommonHeader& header) {
+  uint32_t receiver_ssrc, sender_ssrc;
+  if (!reader->ReadU32(&receiver_ssrc))
+    return false;
+  // Ignore this  Rtcp if the receiver ssrc does not match.
+  if (receiver_ssrc != remote_ssrc_)
+    return true;
+  if (!reader->ReadU32(&sender_ssrc))
+    return false;
+  // Ignore this  Rtcp if the sender ssrc does not match.

[miu, 2016/02/26 23:36:07]

nit: extra space

[xjz, 2016/02/27 05:53:32]

Done.

+  if (sender_ssrc != local_ssrc_)
+    return true;
+
+  received_picture_loss_indicator_ = true;
+  return true;
+}
+
 bool RtcpParser::ParseApplicationDefined(base::BigEndianReader* reader,
                                          const RtcpCommonHeader& header) {
   uint32_t sender_ssrc;
   uint32_t name;
   if (!reader->ReadU32(&sender_ssrc) ||
       !reader->ReadU32(&name))
     return false;
 
   if (sender_ssrc != remote_ssrc_)
     return true;
@@ skipping 281 matching lines @@
   uint32_t ssrc_of_sender;
   base::BigEndianReader big_endian_reader(
       reinterpret_cast<const char*>(rtcp_buffer), length);
   big_endian_reader.Skip(4);  // Skip header.
   big_endian_reader.ReadU32(&ssrc_of_sender);
   return ssrc_of_sender;
 }
 
 }  // namespace cast
 }  // namespace media