Abstract: A digital signal processing apparatus for processing a plurality of video signals and a plurality of audio signals is provided, and comprises a computer comprising a system bus and a main CPU connected to the system bus and an extension processor comprising a plurality of signal processing circuits for processing the plurality of video signals and/or the plurality of audio signals, and a local CPU for controlling the plurality of signal processing circuits so as to allow for the processing of the video signals and audio signals in real time. The extension processor further comprises an extension system bus extended from the system bus, a digital audio video (DAV) bus for transmitting the plurality of video signals and the plurality of audio signals between the plurality of signal processing circuits and a local CPU bus for transmitting control signals outputted from the local CPU.

Abstract: An image data processing apparatus such as an image synthesizing apparatus that synthesizes an image produced by a computer in accordance with tables stored in pages. A picture data conversion circuit converts picture data of red, blue and green color signals or picture data of luminance and color difference signals to predetermined converted picture data. A page change circuit switches the page of the picture data conversion circuit on the basis of alpha data representing transparency of the color picture data. An image data processing apparatus generates virtual addresses based on predetermined reference addresses in an address space larger than the frame memory addresses for accessing a plurality of frame memories at a low-order bit of the virtual address by selecting and outputting the image data outputted from the plurality of frame memories on the basis of a high-order bit of the virtual address.