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.<
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