关键词: 实时变调, 音调, 实时音频处理, Windows音效

Abstract: Pitch scaling, to transpose the tonal pitch of a sound while keeps the rhythm and melody, is needed in many real time audio applications. However, its real time implementation is seldom referred to. A better algorithm and corresponding real time implementation scheme are proposed. By methodic arranging the clocks of CPU and AD/DA, the scheme can not only scale the pitch in two octave range effectively, but also process the real time input audio for synchronous scaling output. The experimental results on Windows platform indicate the modest CPU and memory consumption, so as to meet the requirement of real time applications.

Key words: real time pitch scaling, pitch, real time audio processing, Windows audio effect