Audio Signal Processing
The constant-Q transform (CQT) is a valuable tool for music information retrieval, e.g. for chroma calculation and harmonic analysis. In this E-Brief, we propose a block based, real-time capable, efficient analysis algorithm resting upon a subsampling technique performed with fast Fourier transform. In addition, advanced features such as time resolution enhancement towards lower frequencies and a robust CQT-based tuner are presented. Finally a reference-implementation in C++ in form of a VST3-Plugin is introduced. The plugin's source code will be available openly for further development.