PCM Spectrum Analyser and Octal FSK Decoder / Encoder

This was a prototyping project to see if I could capture PCM (pulse code modulated) data from my sound card - where the sound was encoded using an octal FSK (frequency shift keyed) method and then decode it. The application displays the captured waveform (amplitude / time domain), a frequency /time domain plot and frequency components using a fast fourier transformt (FFT) of a sampled portion of the original waveform. It also has a waterfall type frequency display which is generated from iterative FFTs over the complete waveform. Not only can the application capture and decode the PCM data - but it can also use an inverse fourier transform (fourier synthesis) to encode data to PCM. It even includes a method to synthesize noise on the generated PCM waveform. The intention is that this prototype will form the basis of an octal FSK encoder / decoder service that allows multiple client applications on a network to send and receive data over a radio channel. Developed in C# making use of DirectX DirectSound and the Exocortex.DSP (http://www.exocortex.org/dsp/) digital signal processing engine.