PM> Install-Package PcapngUtils 

The implementation of these formats is made by wrapping unmanaged WinPcap library. I added the implementation of both formats in a fully managed C #.

public void OpenPcapFile(string filename,CancellationToken token)
{
  using (var reader = new PcapReader(filename))
  {
    reader.OnReadPacketEvent += reader_OnReadPacketEvent;
    reader.ReadPackets(token);
    reader.OnReadPacketEvent -= reader_OnReadPacketEvent;
  }
}  
void reader_OnReadPacketEvent(object context, IPacket packet)
{
Console.WriteLine(string.Format("Packet received {0}.{1}",packet.Seconds, packet.Microseconds ));
}

public void OpenPcapNGFile(string filename,bool swapBytes,CancellationToken token)
{
  using (var reader = new PcapNGReader("test.pcap",swapBytes))
  {
    reader.OnReadPacketEvent += reader_OnReadPacketEvent;
    reader.ReadPackets(token);
    reader.OnReadPacketEvent -= reader_OnReadPacketEvent;
  }
}  
void reader_OnReadPacketEvent(object context, IPacket packet)
{
Console.WriteLine(string.Format("Packet received {0}.{1}",packet.Seconds, packet.Microseconds ));
}

public void OpenPcapORPcapNFFile(string filename,CancellationToken token)
{
  using (var reader = IReaderFactory.GetReader(filename))
  {
    reader.OnReadPacketEvent += reader_OnReadPacketEvent;
    reader.ReadPackets(token);
    reader.OnReadPacketEvent -= reader_OnReadPacketEvent;
  }
}  
void reader_OnReadPacketEvent(object context, IPacket packet)
{
Console.WriteLine(string.Format("Packet received {0}.{1}",packet.Seconds, packet.Microseconds ));
}

public void CloneFile(string inputFileName, string outputFileName, CancellationToken token)
{
  using (var reader = IReaderFactory.GetReader(inputFileName))
  {
    using (var writer = new PcapWriter(outputFileName))
    {
      CommonDelegates.ReadPacketEventDelegate handler = (obj, packet) =>
      {
        writer.WritePacket(packet);
      };
      reader.OnReadPacketEvent += handler;
      reader.ReadPackets(token);
      reader.OnReadPacketEvent -= handler; 
    }                
  }
}

public void CloneFile(string inputFileName, string outputFileName, CancellationToken token)
{
  using (var reader = IReaderFactory.GetReader(inputFileName))
  {
    using (var writer = new PcapNGWriter(outputFileName))
    {
      CommonDelegates.ReadPacketEventDelegate handler = (obj, packet) =>
      {
        writer.WritePacket(packet);
      };
      reader.OnReadPacketEvent += handler;
      reader.ReadPackets(token);
      reader.OnReadPacketEvent -= handler; 
    }                
  }
}