Always send RED headers if configured.

webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 18 matching lines @@
 namespace webrtc {
 enum { REDForFECHeaderLength = 1 };
 
 RTPSenderVideo::RTPSenderVideo(Clock* clock, RTPSenderInterface* rtpSender)
     : _rtpSender(*rtpSender),
       _videoType(kRtpVideoGeneric),
       _retransmissionSettings(kRetransmitBaseLayer),
       // Generic FEC
       fec_(),
       fec_enabled_(false),
-      red_payload_type_(-1),
-      fec_payload_type_(-1),
+      red_payload_type_(0),
+      fec_payload_type_(0),
       delta_fec_params_(),
       key_fec_params_(),
       producer_fec_(&fec_),
       _fecOverheadRate(clock, NULL),
       _videoBitrate(clock, NULL) {
   memset(&delta_fec_params_, 0, sizeof(delta_fec_params_));
   memset(&key_fec_params_, 0, sizeof(key_fec_params_));
   delta_fec_params_.max_fec_frames = key_fec_params_.max_fec_frames = 1;
   delta_fec_params_.fec_mask_type = key_fec_params_.fec_mask_type =
       kFecMaskRandom;
@@ skipping 112 matching lines @@
     }
     delete fec_packet;
     ++next_fec_sequence_number;
   }
 }
 
 void RTPSenderVideo::SetGenericFECStatus(const bool enable,
                                          const uint8_t payloadTypeRED,
                                          const uint8_t payloadTypeFEC) {
   rtc::CritScope cs(&crit_);
   fec_enabled_ = enable;

[mflodman, 2016/06/03 07:28:16]

I think we should DCHECK the pl types != 0 here, or is that done elsewhere?
Since 0 actually is a valid number I think that might slip though higher layers.

   red_payload_type_ = payloadTypeRED;
   fec_payload_type_ = payloadTypeFEC;
   memset(&delta_fec_params_, 0, sizeof(delta_fec_params_));
   memset(&key_fec_params_, 0, sizeof(key_fec_params_));
   delta_fec_params_.max_fec_frames = key_fec_params_.max_fec_frames = 1;
   delta_fec_params_.fec_mask_type = key_fec_params_.fec_mask_type =
       kFecMaskRandom;
 }
 
 void RTPSenderVideo::GenericFECStatus(bool* enable,
                                       uint8_t* payloadTypeRED,
                                       uint8_t* payloadTypeFEC) const {
   rtc::CritScope cs(&crit_);
   *enable = fec_enabled_;
   *payloadTypeRED = red_payload_type_;
   *payloadTypeFEC = fec_payload_type_;
 }
 
 size_t RTPSenderVideo::FECPacketOverhead() const {
   rtc::CritScope cs(&crit_);
-  if (fec_enabled_) {
+  size_t overhead = 0;
+  if (red_payload_type_ != 0) {
     // Overhead is FEC headers plus RED for FEC header plus anything in RTP
     // header beyond the 12 bytes base header (CSRC list, extensions...)
     // This reason for the header extensions to be included here is that
     // from an FEC viewpoint, they are part of the payload to be protected.
     // (The base RTP header is already protected by the FEC header.)
-    return ForwardErrorCorrection::PacketOverhead() + REDForFECHeaderLength +
-           (_rtpSender.RTPHeaderLength() - kRtpHeaderSize);
+    overhead = REDForFECHeaderLength + (_rtpSender.RTPHeaderLength() -
+      kRtpHeaderSize);
   }
-  return 0;
+  if (fec_enabled_)
+    overhead += ForwardErrorCorrection::PacketOverhead();
+  return overhead;
 }
 
 void RTPSenderVideo::SetFecParameters(const FecProtectionParams* delta_params,
                                       const FecProtectionParams* key_params) {
   rtc::CritScope cs(&crit_);
   RTC_DCHECK(delta_params);
   RTC_DCHECK(key_params);
-  delta_fec_params_ = *delta_params;
-  key_fec_params_ = *key_params;
+  if (fec_enabled_) {
+    delta_fec_params_ = *delta_params;
+    key_fec_params_ = *key_params;
+  }
 }
 
 int32_t RTPSenderVideo::SendVideo(const RtpVideoCodecTypes videoType,
                                   const FrameType frameType,
                                   const int8_t payloadType,
                                   const uint32_t captureTimeStamp,
                                   int64_t capture_time_ms,
                                   const uint8_t* payloadData,
                                   const size_t payloadSize,
                                   const RTPFragmentationHeader* fragmentation,
                                   const RTPVideoHeader* video_header) {
   if (payloadSize == 0) {
     return -1;
   }
 
   std::unique_ptr<RtpPacketizer> packetizer(RtpPacketizer::Create(
       videoType, _rtpSender.MaxDataPayloadLength(),
       video_header ? &(video_header->codecHeader) : nullptr, frameType));
 
   StorageType storage;
-  bool fec_enabled;
+  int red_payload_type;
   bool first_frame = first_frame_sent_();
   {
     rtc::CritScope cs(&crit_);
     FecProtectionParams* fec_params =
         frameType == kVideoFrameKey ? &key_fec_params_ : &delta_fec_params_;
     producer_fec_.SetFecParameters(fec_params, 0);
     storage = packetizer->GetStorageType(_retransmissionSettings);
-    fec_enabled = fec_enabled_;
+    red_payload_type = red_payload_type_;
   }
 
   // Register CVO rtp header extension at the first time when we receive a frame
   // with pending rotation.
   RTPSenderInterface::CVOMode cvo_mode = RTPSenderInterface::kCVONone;
   if (video_header && video_header->rotation != kVideoRotation_0) {
     cvo_mode = _rtpSender.ActivateCVORtpHeaderExtension();
   }
 
   uint16_t rtp_header_length = _rtpSender.RTPHeaderLength();
@@ skipping 42 matching lines @@
       // TODO(guoweis): For now, all packets sent will carry the CVO such that
       // the RTP header length is consistent, although the receiver side will
       // only exam the packets with marker bit set.
       size_t packetSize = payloadSize + rtp_header_length;
       RtpUtility::RtpHeaderParser rtp_parser(dataBuffer, packetSize);
       RTPHeader rtp_header;
       rtp_parser.Parse(&rtp_header);
       _rtpSender.UpdateVideoRotation(dataBuffer, packetSize, rtp_header,
                                      video_header->rotation);
     }
-    if (fec_enabled) {
+    if (red_payload_type != 0) {
       SendVideoPacketAsRed(dataBuffer, payload_bytes_in_packet,
                            rtp_header_length, _rtpSender.SequenceNumber(),
                            captureTimeStamp, capture_time_ms, storage,
                            packetizer->GetProtectionType() == kProtectedPacket);
     } else {
       SendVideoPacket(dataBuffer, payload_bytes_in_packet, rtp_header_length,
                       _rtpSender.SequenceNumber(), captureTimeStamp,
                       capture_time_ms, storage);
     }
 
@@ skipping 32 matching lines @@
   rtc::CritScope cs(&crit_);
   return _retransmissionSettings;
 }
 
 void RTPSenderVideo::SetSelectiveRetransmissions(uint8_t settings) {
   rtc::CritScope cs(&crit_);
   _retransmissionSettings = settings;
 }
 
 }  // namespace webrtc