Information processing apparatus and method and computer program for enabling a function change

摘要

In an embodiment of the present invention, the control section of a tuner reads the subunit identifier descriptor of a digital video cassette recorder (DVCR) through an IEEE 1394 bus in a step S1, and a procedure proceeds to a step S2. In the step S2, the control section determines whether the DVCR is an audio-visual (AV) unit of new type. When it is determined that the DVCR is an AV unit of old type, the processing is finished. When it is determined that the DVCR is a new-type unit, the control section sends a NOTIFY command to the DVCR in a step S3. In a step S4, the control section receives an INTERIM response from the DVCR, which indicates that the DVCR has received the NOTIFY command. The control section determines in a step S5 whether it receives a CHANGED response, which shows that a function has been changed. If it is determined that a CHANGED response has not been received, the step S5 is repeated. When it is determined that a CHANGED response has been received, the processing returns to the step S1, and the subsequent steps are repeated.