These three methods must be defined because of the IUnknown parent class. XXX The first two are a hack to pretend that we are doing reference counting

@brief default constructor

@brief Constructs an empty buffer

One of the following two methods must be defined do to the ISampleGraberCB parent class; this is the way we hear from the grabber. We implement the on

@brief not copyable

@brief Constructor from function pointer and user data pointer.

@brief Constructor from a function

@brief Default constructor, initializes value to specified default.

@brief Constructor, taking the buffer reader

@brief Constructor wrapping an existing device token.

@brief Empty constructor - constructs a config where valid() is false

@brief Protected constructor to force subclassing.

@brief Initialize the flag as false.