rtcp::Nack packet moved into own file and got Parse function

webrtc/modules/rtp_rtcp/source/rtcp_packet/nack.h

 /*
  *  Copyright (c) 2015 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_RTCP_PACKET_BYE_H_
-#define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_BYE_H_
+#ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_NACK_H_
+#define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_NACK_H_
 
-#include <string>
 #include <vector>
 
-#include "webrtc/modules/rtp_rtcp/source/rtcp_packet.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/rtpfb.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_utility.h"
 
 namespace webrtc {
 namespace rtcp {
 
-class Bye : public RtcpPacket {
+class Nack : public Rtpfb {
  public:
-  static const uint8_t kPacketType = 203;
+  const uint8_t kFeedbackMessageType = 1;
+  Nack() {}
 
-  Bye();
-  virtual ~Bye() {}
+  virtual ~Nack() {}
 
   // Parse assumes header is already parsed and validated.
   bool Parse(const RTCPUtility::RtcpCommonHeader& header,
              const uint8_t* payload);  // Size of the payload is in the header.
 
-  void From(uint32_t ssrc) { sender_ssrc_ = ssrc; }
-  bool WithCsrc(uint32_t csrc);
-  void WithReason(const std::string& reason);
-
-  uint32_t sender_ssrc() const { return sender_ssrc_; }
-  const std::vector<uint32_t>& csrcs() const { return csrcs_; }
-  const std::string& reason() const { return reason_; }
+  void WithList(const uint16_t* nack_list, size_t length);
+  const std::vector<uint16_t>& packet_ids() const { return packet_ids_; }
 
  protected:
   bool Create(uint8_t* packet,
               size_t* index,
               size_t max_length,
               RtcpPacket::PacketReadyCallback* callback) const override;
 
- private:
-  static const int kMaxNumberOfCsrcs = 0x1f - 1;  // First item is sender SSRC.
-
   size_t BlockLength() const override;
 
-  uint32_t sender_ssrc_;
-  std::vector<uint32_t> csrcs_;
-  std::string reason_;
+ private:
+  const size_t kNackItemLength = 4;
+  struct PackedNack {
+    uint16_t first_pid;
+    uint16_t bitmask;
+  };
 
-  RTC_DISALLOW_COPY_AND_ASSIGN(Bye);
+  void Pack();    // Fills packed_ using packed_ids_. (used in WithList).
+  void Unpack();  // Fills packet_ids_ using packed_. (used in Parse).
+
+  std::vector<PackedNack> packed_;
+  std::vector<uint16_t> packet_ids_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(Nack);
 };
 
 }  // namespace rtcp
 }  // namespace webrtc
-#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_BYE_H_
+#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_NACK_H_