Moving src/webrtc into src/.

In order to eliminate the WebRTC Subtree mirror in Chromium, 
WebRTC is moving the content of the src/webrtc directory up
to the src/ directory.

NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
TBR=tommi@webrtc.org

Bug: chromium:611808
Change-Id: Iac59c5b51b950f174119565bac87955a7994bc38
Reviewed-on: https://webrtc-review.googlesource.com/1560
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19845}

modules/rtp_rtcp/source/ulpfec_generator.h

@@ -0,0 +1,115 @@
+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_ULPFEC_GENERATOR_H_
+#define WEBRTC_MODULES_RTP_RTCP_SOURCE_ULPFEC_GENERATOR_H_
+
+#include <list>
+#include <memory>
+#include <vector>
+
+#include "webrtc/modules/rtp_rtcp/source/forward_error_correction.h"
+
+namespace webrtc {
+
+class FlexfecSender;
+
+class RedPacket {
+ public:
+  explicit RedPacket(size_t length);
+
+  void CreateHeader(const uint8_t* rtp_header,
+                    size_t header_length,
+                    int red_payload_type,
+                    int payload_type);
+  void SetSeqNum(int seq_num);
+  void AssignPayload(const uint8_t* payload, size_t length);
+  void ClearMarkerBit();
+  uint8_t* data() const;
+  size_t length() const;
+
+ private:
+  std::unique_ptr<uint8_t[]> data_;
+  size_t length_;
+  size_t header_length_;
+};
+
+class UlpfecGenerator {
+  friend class FlexfecSender;
+
+ public:
+  UlpfecGenerator();
+  ~UlpfecGenerator();
+
+  static std::unique_ptr<RedPacket> BuildRedPacket(const uint8_t* data_buffer,
+                                                   size_t payload_length,
+                                                   size_t rtp_header_length,
+                                                   int red_payload_type);
+
+  void SetFecParameters(const FecProtectionParams& params);
+
+  // 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 there are generated FEC packets available.
+  bool FecAvailable() const;
+
+  size_t NumAvailableFecPackets() const;
+
+  // Returns the overhead, per packet, for FEC (and possibly RED).
+  size_t MaxPacketOverhead() const;
+
+  // Returns generated FEC packets with RED headers added.
+  std::vector<std::unique_ptr<RedPacket>> GetUlpfecPacketsAsRed(
+      int red_payload_type,
+      int ulpfec_payload_type,
+      uint16_t first_seq_num,
+      size_t rtp_header_length);
+
+ private:
+  explicit UlpfecGenerator(std::unique_ptr<ForwardErrorCorrection> fec);
+
+  // 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;
+
+  void ResetState();
+
+  std::unique_ptr<ForwardErrorCorrection> fec_;
+  ForwardErrorCorrection::PacketList media_packets_;
+  std::list<ForwardErrorCorrection::Packet*> generated_fec_packets_;
+  int num_protected_frames_;
+  int min_num_media_packets_;
+  FecProtectionParams params_;
+  FecProtectionParams new_params_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_ULPFEC_GENERATOR_H_