[rtp_rtcp] rtcp::Dlrr block moved into own file and got Parse function

webrtc/modules/rtp_rtcp/source/rtcp_packet/dlrr.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_DLRR_H_
+#define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_DLRR_H_
+
+#include <vector>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace webrtc {
+namespace rtcp {
+
+// DLRR Report Block: Delay since the Last Receiver Report (RFC 3611).
+class Dlrr {
+ public:
+  struct SubBlock {
+    // RFC 3611 4.5
+    uint32_t ssrc;
+    uint32_t last_rr;
+    uint32_t delay_since_last_rr;
+  };
+
+  static const uint8_t kBlockType = 5;
+  static const size_t kMaxNumberOfDlrrItems = 100;
+
+  Dlrr() {}
+  Dlrr(Dlrr&&) = default;
+  ~Dlrr() {}
+
+  // Second parameter is value read from block header,
+  // i.e. size of block in 32bits excluding block header itself.
+  bool Parse(const uint8_t* buffer, uint16_t block_length_32bits);
+
+  size_t BlockLength() const;
+  // Fills buffer with the Dlrr.
+  // Consumes BlockLength() bytes.
+  void Create(uint8_t* buffer) const;
+
+  // Max 100 DLRR Items can be added per DLRR report block.
+  bool WithDlrrItem(uint32_t ssrc, uint32_t last_rr, uint32_t delay_last_rr);
+
+  const std::vector<SubBlock>& sub_blocks() const { return sub_blocks_; }
+
+ private:
+  static const size_t kBlockHeaderLength = 4;
+  static const size_t kSubBlockLength = 12;
+
+  std::vector<SubBlock> sub_blocks_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(Dlrr);
+};
+}  // namespace rtcp
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_DLRR_H_