uses XceedBinaryEncodingLib_TLB; 

var
  xBinEncode : TXceedBinaryEncoding; 
  xBase64Format : XceedBase64EncodingFormat; 
  vaBytesRead : OleVariant; 
  vaEncoded : OleVariant; 
begin
  xBinEncode := TXceedBinaryEncoding.Create( self ); 
  xBinEncode.License( 'your license key' ); 

  xBase64Format := CoXceedBase64EncodingFormat.Create();  

  xBinEncode.EncodingFormat := xBase64Format;

  try 
    vaEncoded := xBinEncode.ReadFile( 'c:\temp\source.txt', 0, 0, bfpEncode, true, 
                                      vaBytesRead );  

    ShowMessage( 'Encoding successful!' ); 
  except 
    on xErr : Exception do 
      ShowMessage( xErr.Message ); 
  end; 

  xBinEncode.Free(); 
end;