A new audio-visual control using message object transmission

This paper presents a method for controlling audio-visual (AV) devices using message object transmission. The validity of the new method is verified using a trial model. This method realizes system software for performing processes like startup, control and display using the object-oriented concept. A control object is transmitted from an AV terminal device to another AV terminal device when they are connected. For startup or control, the first AV terminal does not use a control code as was done in the conventional control of AV terminals. Instead it transmits a message object corresponding to a control object which has been transmitted in advance. The advantages of using this method include the following: (1) it is possible to absorb the differences between devices, for instance the difference in control codes; (2) users need have no knowledge about the device drivers; and (3) the memory capacity required to control the AV controllers can be minimized. Furthermore, if the AV terminal´s control microcomputer has an RPC (remote procedure call) function, it is possible to control the AV terminals in a distributed network environment. This can be done by sending a procedure call to the AV terminal device in the form of a message to startup the object in the AV terminal device