remoting/protocol/rtp_video_reader.h

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef REMOTING_PROTOCOL_RTP_VIDEO_READER_H_
#define REMOTING_PROTOCOL_RTP_VIDEO_READER_H_

#include "base/compiler_specific.h"
#include "base/time.h"
#include "base/memory/scoped_ptr.h"
#include "remoting/protocol/rtcp_writer.h"
#include "remoting/protocol/rtp_reader.h"
#include "remoting/protocol/video_reader.h"

namespace base {
class MessageLoopProxy;
}  // namespace base

namespace remoting {
namespace protocol {

class RtcpWriter;
class RtpReader;
class Session;

class RtpVideoReader : public VideoReader {
 public:
  RtpVideoReader(base::MessageLoopProxy* message_loop);
  virtual ~RtpVideoReader();

  // VideoReader interface.
  virtual void Init(protocol::Session* session,
                    VideoStub* video_stub,
                    const InitializedCallback& callback) OVERRIDE;
  virtual bool is_connected() OVERRIDE;

 private:
  friend class RtpVideoReaderTest;

  // Following struct is used to store pending packets in |packets_queue_|.
  // Each entry may be in three different states:
  //  |received| == false, |packet| == NULL - packet with the corresponding
  //    sequence number hasn't been received.
  //  |received| == true, |packet| != NULL - packet with the corresponding
  //    sequence number has been received, but hasn't been processed, still
  //    waiting for other fragments.
  //  |received| == true, |packet| == NULL - packet with the corresponding
  //    sequence number has been received and processed. Ignore any additional
  //    packet with the same sequence number.
  struct PacketsQueueEntry {
    PacketsQueueEntry();
    bool received;
    const RtpPacket* packet;
  };

  typedef std::deque<PacketsQueueEntry> PacketsQueue;

  void OnChannelReady(bool rtp, net::Socket* socket);

  void OnRtpPacket(const RtpPacket* rtp_packet);
  void CheckFullPacket(const PacketsQueue::iterator& pos);
  void RebuildVideoPacket(const PacketsQueue::iterator& from,
                          const PacketsQueue::iterator& to);
  void ResetQueue();

  // Helper method that sends RTCP receiver reports if enough time has
  // passed since the last report. It is called from
  // OnRtpPacket(). Interval between reports is defined by
  // |kReceiverReportsIntervalMs|.
  void SendReceiverReportIf();

  Session* session_;

  bool initialized_;
  InitializedCallback initialized_callback_;

  scoped_ptr<net::Socket> rtp_channel_;
  RtpReader rtp_reader_;
  scoped_ptr<net::Socket> rtcp_channel_;
  RtcpWriter rtcp_writer_;

  PacketsQueue packets_queue_;
  uint32 last_sequence_number_;

  base::Time last_receiver_report_;

  // The stub that processes all received packets.
  VideoStub* video_stub_;

  DISALLOW_COPY_AND_ASSIGN(RtpVideoReader);
};

}  // namespace protocol
}  // namespace remoting

#endif  // REMOTING_PROTOCOL_RTP_VIDEO_READER_H_