Method and apparatus for simultaneously generating an output signal from digital audio - data and by means of midi synthetic music ized

摘要

A method and apparatus are disclosed for simultaneously outputting digital audio and MIDI synthesized music utilizing a single digital signal processor. The Musical Instrument Digital Interface (MIDI) permits music to be recorded and/or synthesized utilizing a data file containing multiple serially listed program status messages and matching note on and note off messages. In contrast, digital audio is generally merely compressed, utilizing a suitable data compression technique, and recorded. The audio content of such a digital recording may then be restored by decompressing the recorded data and converting that data utilizing a digital-to-analog convertor. The method and apparatus of the present invention selectively and alternatively couples portions of a compressed digital audio file and a MIDI file to a single digital signal processor which alternately decompresses the digital audio file and implements a MIDI synthesizer. Decompressed audio and MIDI synthesized music are then alternately coupled to two separate buffers. The contents of these buffers are then additively mixed and coupled through a digital- to-analog convertor to an audio output device to create an output having concurrent digital audio and MIDI synthesized music.