Make rtcp sender use max transfer unit.

Remove packet overhead from rtp sender as unused.

R=philipel, åsapersson

Review URL: https://codereview.webrtc.org/1827953002

Cr-Commit-Position: refs/heads/master@{#12165}

webrtc/modules/rtp_rtcp/source/rtcp_sender.cc

@@ -99,8 +99,10 @@ class PacketContainer : public rtcp::CompoundPacket,
     }
   }
 
-  size_t SendPackets() {
+  size_t SendPackets(size_t max_payload_length) {
-    rtcp::CompoundPacket::Build(this);
+    RTC_DCHECK_LE(max_payload_length, static_cast<size_t>(IP_PACKET_SIZE));
+    uint8_t buffer[IP_PACKET_SIZE];
+    BuildExternalBuffer(buffer, max_payload_length, this);
     return bytes_sent_;
   }
 
@@ -169,6 +171,7 @@ RTCPSender::RTCPSender(
       tmmbr_help_(),
       tmmbr_send_(0),
       packet_oh_send_(0),
+      max_payload_length_(IP_PACKET_SIZE - 28),  // IPv4 + UDP by default.
 
       app_sub_type_(0),
       app_name_(0),
@@ -277,6 +280,10 @@ void RTCPSender::SetTMMBRStatus(bool enable) {
   }
 }
 
+void RTCPSender::SetMaxPayloadLength(size_t max_payload_length) {
+  max_payload_length_ = max_payload_length;
+}
+
 void RTCPSender::SetStartTimestamp(uint32_t start_timestamp) {
   rtc::CritScope lock(&critical_section_rtcp_sender_);
   start_timestamp_ = start_timestamp;
@@ -809,7 +816,7 @@ int32_t RTCPSender::SendCompoundRTCP(
     RTC_DCHECK(AllVolatileFlagsConsumed());
   }
 
-  size_t bytes_sent = container.SendPackets();
+  size_t bytes_sent = container.SendPackets(max_payload_length_);
   return bytes_sent == 0 ? -1 : 0;
 }
 
@@ -1030,8 +1037,9 @@ bool RTCPSender::SendFeedbackPacket(const rtcp::TransportFeedback& packet) {
     // but we can't because of an incorrect warning (C4822) in MVS 2013.
   } sender(transport_, event_log_);
 
+  RTC_DCHECK_LE(max_payload_length_, static_cast<size_t>(IP_PACKET_SIZE));
   uint8_t buffer[IP_PACKET_SIZE];
-  return packet.BuildExternalBuffer(buffer, IP_PACKET_SIZE, &sender) &&
+  return packet.BuildExternalBuffer(buffer, max_payload_length_, &sender) &&
          !sender.send_failure_;
 }
 

webrtc/modules/rtp_rtcp/source/rtcp_sender.h

@@ -132,6 +132,8 @@ class RTCPSender {
 
   void SetTMMBRStatus(bool enable);
 
+  void SetMaxPayloadLength(size_t max_payload_length);
+
   int32_t SetTMMBN(const TMMBRSet* boundingSet);
 
   int32_t SetApplicationSpecificData(uint8_t subType,
@@ -240,6 +242,7 @@ class RTCPSender {
   TMMBRHelp tmmbr_help_ GUARDED_BY(critical_section_rtcp_sender_);
   uint32_t tmmbr_send_ GUARDED_BY(critical_section_rtcp_sender_);
   uint32_t packet_oh_send_ GUARDED_BY(critical_section_rtcp_sender_);
+  size_t max_payload_length_;
 
   // APP
   uint8_t app_sub_type_ GUARDED_BY(critical_section_rtcp_sender_);

webrtc/modules/rtp_rtcp/source/rtp_rtcp_impl.cc

@@ -118,6 +118,7 @@ ModuleRtpRtcpImpl::ModuleRtpRtcpImpl(const Configuration& configuration)
   uint32_t SSRC = rtp_sender_.SSRC();
   rtcp_sender_.SetSSRC(SSRC);
   SetRtcpReceiverSsrcs(SSRC);
+  SetMaxTransferUnit(IP_PACKET_SIZE);
 }
 
 // Returns the number of milliseconds until the module want a worker thread
@@ -479,21 +480,22 @@ int32_t ModuleRtpRtcpImpl::SetTransportOverhead(
     // Ok same as before.
     return 0;
   }
-  // Calc diff.
-  int16_t packet_over_head_diff = packet_overhead - packet_overhead_;
 
-  // Store new.
+  size_t mtu = rtp_sender_.MaxPayloadLength() + packet_overhead_;
+  size_t max_payload_length = mtu - packet_overhead;
   packet_overhead_ = packet_overhead;
-
+  rtcp_sender_.SetMaxPayloadLength(max_payload_length);
-  uint16_t length =
+  rtp_sender_.SetMaxPayloadLength(max_payload_length);
-      rtp_sender_.MaxPayloadLength() - packet_over_head_diff;
+  return 0;
-  return rtp_sender_.SetMaxPayloadLength(length, packet_overhead_);
 }
 
-int32_t ModuleRtpRtcpImpl::SetMaxTransferUnit(const uint16_t mtu) {
+int32_t ModuleRtpRtcpImpl::SetMaxTransferUnit(uint16_t mtu) {
-  RTC_DCHECK_LE(mtu, IP_PACKET_SIZE) << "Invalid mtu: " << mtu;
+  RTC_DCHECK_LE(mtu, IP_PACKET_SIZE) << "MTU too large: " << mtu;
-  return rtp_sender_.SetMaxPayloadLength(mtu - packet_overhead_,
+  RTC_DCHECK_GT(mtu, packet_overhead_) << "MTU too small: " << mtu;
-                                         packet_overhead_);
+  size_t max_payload_length = mtu - packet_overhead_;
+  rtcp_sender_.SetMaxPayloadLength(max_payload_length);
+  rtp_sender_.SetMaxPayloadLength(max_payload_length);
+  return 0;
 }
 
 RtcpMode ModuleRtpRtcpImpl::RTCP() const {

webrtc/modules/rtp_rtcp/source/rtp_sender.cc

@@ -133,7 +133,6 @@ RTPSender::RTPSender(
       transport_(transport),
       sending_media_(true),                      // Default to sending media.
       max_payload_length_(IP_PACKET_SIZE - 28),  // Default is IP-v4/UDP.
-      packet_over_head_(28),
       payload_type_(-1),
       payload_type_map_(),
       rtp_header_extension_map_(),
@@ -375,15 +374,12 @@ int RTPSender::SendPayloadFrequency() const {
   return audio_ != NULL ? audio_->AudioFrequency() : kVideoPayloadTypeFrequency;
 }
 
-int32_t RTPSender::SetMaxPayloadLength(size_t max_payload_length,
+void RTPSender::SetMaxPayloadLength(size_t max_payload_length) {
-                                       uint16_t packet_over_head) {
   // Sanity check.
   RTC_DCHECK(max_payload_length >= 100 && max_payload_length <= IP_PACKET_SIZE)
       << "Invalid max payload length: " << max_payload_length;
   rtc::CritScope lock(&send_critsect_);
   max_payload_length_ = max_payload_length;
-  packet_over_head_ = packet_over_head;
-  return 0;
 }
 
 size_t RTPSender::MaxDataPayloadLength() const {
@@ -405,8 +401,6 @@ size_t RTPSender::MaxPayloadLength() const {
   return max_payload_length_;
 }
 
-uint16_t RTPSender::PacketOverHead() const { return packet_over_head_; }
-
 void RTPSender::SetRtxStatus(int mode) {
   rtc::CritScope lock(&send_critsect_);
   rtx_ = mode;

webrtc/modules/rtp_rtcp/source/rtp_sender.h

@@ -67,7 +67,6 @@ class RTPSenderInterface {
   virtual uint16_t SequenceNumber() const = 0;
   virtual size_t MaxPayloadLength() const = 0;
   virtual size_t MaxDataPayloadLength() const = 0;
-  virtual uint16_t PacketOverHead() const = 0;
   virtual uint16_t ActualSendBitrateKbit() const = 0;
 
   virtual int32_t SendToNetwork(uint8_t* data_buffer,
@@ -146,7 +145,7 @@ class RTPSender : public RTPSenderInterface {
 
   void SetCsrcs(const std::vector<uint32_t>& csrcs);
 
-  int32_t SetMaxPayloadLength(size_t length, uint16_t packet_over_head);
+  void SetMaxPayloadLength(size_t max_payload_length);
 
   int32_t SendOutgoingData(FrameType frame_type,
                            int8_t payload_type,
@@ -247,7 +246,6 @@ class RTPSender : public RTPSenderInterface {
   size_t RTPHeaderLength() const override;
   uint16_t AllocateSequenceNumber(uint16_t packets_to_send) override;
   size_t MaxPayloadLength() const override;
-  uint16_t PacketOverHead() const override;
 
   // Current timestamp.
   uint32_t Timestamp() const override;
@@ -437,7 +435,6 @@ class RTPSender : public RTPSenderInterface {
   bool sending_media_ GUARDED_BY(send_critsect_);
 
   size_t max_payload_length_;
-  uint16_t packet_over_head_;
 
   int8_t payload_type_ GUARDED_BY(send_critsect_);
   std::map<int8_t, RtpUtility::Payload*> payload_type_map_;