Interactive DSP educational platform for real-time subband audio coding

We present an interactive educational DSP platform for realtime subband audio coding. The tool integrates a DSP course on advanced audio coding and focuses on wavelets, subband coding, and signal quantization. The package consists of a Windows control application running on a PC and real-time DSP code implemented on a Texas Instruments DSP Starter Kit (DSK), which performs the actual audio encoding and decoding process. The tool is interactive since students can customize the codec by changing some encoding parameters through the PC interface and then verify the effect on the coding process. The DSP codec accepts audio samples in real-time via the DSK audio analog input port and sends the reconstructed samples to the output port. The graphical user interface allows to choose the type of filter-bank and scalar quantization; the availability of the full source code and of a DSK makes possible to experience first-hand the main aspects of real-world DSP development, e.g., real-time programming, arithmetic precision and algorithmic delay. The software is available at http://multimedia.polito.it/dspwavelab.