Bus Description.

A bus can be understood as a "collection of data channels" belonging together. It describes a data input or a data output of the plug-in. A VST component can define any desired number of busses. Dynamic usage of busses is handled in the host by activating and deactivating busses. All busses are initially inactive. The component has to define the maximum number of supported busses and it has to define which of them have to be activated by default after instantiation of the plug-in (This is only a wish, the host is allow to not follow it, and only activate the first bus for example). A host that can handle multiple busses, allows the user to activate busses which are initially all inactive. The kMain busses have to place before any others kAux busses.