seqnumvalidator.h

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// ##########################################################################
// ####                                                                  ####
// ####                      RTP Audio Server Project                    ####
// ####                    ============================                  ####
// ####                                                                  ####
// #### Sequence Number Validator                                        ####
// ####                                                                  ####
// #### Version 1.00  --  February 16, 2001                              ####
// ####                                                                  ####
// #### Copyright (C) 1999  Thomas Dreibholz                             ####
// ####               2000  Universität Bonn, Abt. IV                    ####
// ####               2001  EMail: dreibh@iem.uni-due.de                 ####
// ####                     WWW:   https://www.uni-due.de/~be0001        ####
// ####                                                                  ####
// ##########################################################################


#ifndef SEQNUMVALIDATOR_H
#define SEQNUMVALIDATOR_H


#include "system.h"


namespace Coral {


class SeqNumValidator
{
   // ====== Constructor ====================================================
   public:
   SeqNumValidator(const cardinal minSequential = 2,
                   const cardinal maxMisorder   = 100,
                   const cardinal maxDropout    = 3000,
                   const card64   seqMod        = (1 << 16));


   // ====== Status functions ===============================================
   inline card64 getPacketsReceived() const;

   inline card64 getPacketsLost() const;

   inline card64 getLastSeqNum() const;

   inline double getFractionLost() const;

   inline double getJitter() const;


   // ====== Sequence number validation =====================================
   enum ValidationResult {
      Valid           = 0,
      SourceProbation = 1,
      Jumped          = 2,
      Invalid         = 10,
      DuplicatePacket = Invalid + 0,
      InvalidSeqNum   = Invalid + 1
   };
   ValidationResult validate(const card64 sequenceNumber,
                             const card32 packetTimeStamp = 0);

   void reset();

   double calculateFractionLost();


   // ====== Private data ===================================================
   private:
   inline void init(const card64 sequenceNumber);


   card64   SeqMod;                // Constants.
   cardinal MaxDropout;
   cardinal MaxMisorder;
   cardinal MinSequential;

   card64   PrevPacketTimeStamp;   // Time stamp of previous packet.
   card64   PrevPacketArrivalTime; // Arrival time of previous packet.
   double   Jitter;                // Estimated jitter.  
   double   FractionLost;          // Fraction lost.

   card64   MaxSeq;                // Highest seq. number seen.
   card64   BaseSeq;               // Base seq. number.
   card64   BadSeq;                // Last 'bad' seq. number + 1.
   card32   Probation;             // Sequential packets till source is valid.

   card64   Cycles;                // Shifted count of seq. number cycles.
   card64   Received;              // Packets received.
   card64   ReceivedPrior;         // Packet received at last interval.
   card64   ExpectedPrior;         // Packet expected at last interval.

   bool     Uninitialized;         // Waiting for the first valid seq. number.
};


}


#include "seqnumvalidator.icc"


#endif