Simplify public interface of ProducerFec.

webrtc/modules/rtp_rtcp/source/producer_fec.h

 /*
  *  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 41 matching lines @@
   void SetFecParameters(const FecProtectionParams* params,
                         int num_first_partition);
 
   // Adds a media packet to the internal buffer. When enough media packets
   // have been added, the FEC packets are generated and stored internally.
   // These FEC packets are then obtained by calling GetFecPacketsAsRed().
   int AddRtpPacketAndGenerateFec(const uint8_t* data_buffer,
                                  size_t payload_length,
                                  size_t rtp_header_length);
 
-  // Returns true if the excess overhead (actual - target) for the FEC is below
-  // the amount |kMaxExcessOverhead|. This effects the lower protection level
-  // cases and low number of media packets/frame. The target overhead is given
-  // by |params_.fec_rate|, and is only achievable in the limit of large number
-  // of media packets.
-  bool ExcessOverheadBelowMax() const;
-
-  // Returns true if the number of added media packets is at least
-  // |min_num_media_packets_|. This condition tries to capture the effect
-  // that, for the same amount of protection/overhead, longer codes
-  // (e.g. (2k,2m) vs (k,m)) are generally more effective at recovering losses.
-  bool MinimumMediaPacketsReached() const;
-
-  // Returns true if there are generated FEC packets available.
-  bool FecAvailable() const;
-
   size_t NumAvailableFecPackets() const;
 
   size_t MaxPacketOverhead() const;
 
   // Returns generated FEC packets with RED headers added.
   std::vector<std::unique_ptr<RedPacket>> GetFecPacketsAsRed(
       int red_payload_type,
       int ulpfec_payload_type,
       uint16_t first_seq_num,
       size_t rtp_header_length);
 
  private:
-  void DeleteMediaPackets();
+  // Overhead is defined as relative to the number of media packets, and not
+  // relative to total number of packets. This definition is inherited from the
+  // protection factor produced by video_coding module and how the FEC
+  // generation is implemented.
   int Overhead() const;
+
+  // Returns true if the excess overhead (actual - target) for the FEC is below
+  // the amount |kMaxExcessOverhead|. This effects the lower protection level
+  // cases and low number of media packets/frame. The target overhead is given
+  // by |params_.fec_rate|, and is only achievable in the limit of large number
+  // of media packets.
+  bool ExcessOverheadBelowMax() const;
+
+  // Returns true if the number of added media packets is at least
+  // |min_num_media_packets_|. This condition tries to capture the effect
+  // that, for the same amount of protection/overhead, longer codes
+  // (e.g. (2k,2m) vs (k,m)) are generally more effective at recovering losses.
+  bool MinimumMediaPacketsReached() const;
+
   std::unique_ptr<ForwardErrorCorrection> fec_;
   ForwardErrorCorrection::PacketList media_packets_;
   std::list<ForwardErrorCorrection::Packet*> generated_fec_packets_;
   int num_protected_frames_;
   int num_important_packets_;
   int min_num_media_packets_;
   FecProtectionParams params_;
   FecProtectionParams new_params_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_PRODUCER_FEC_H_