This library implements a general-purpose encoder/decoder for Reed-Solomon error correcting codes. The decoder supports erasures. The user can specify the parameters for any size code, limited only by machine resources. Hard-coded routines for the CCSDS-standard (255,223) code are also included.
DSP implements several low-level digital signal processing (DSP) primitives accelerated, when available, by the Intel/AMD SIMD instruction sets MMX/SSE/SSE2. Portable C versions are provided for compatibility on non-IA32 machines. Routines are provided to compute 16-bit integer dot products (FIR filtering, correlation); sum-of-squares (signal energy measurement), and peak sample detection (for automatic gain control, etc.).
PED is a dialogue management system that uses a probabilistic nested belief model to choose dialogue strategies. The dialogue system designer need only supply a set of plan rules to PED as a dialogue grammar with preconditions. Using this grammar, PED constructs game trees (like the one below) to represent the outcomes of the dialogue, so that a dialogue strategy can be chosen for the current turn in the dialogue. PED automatically maintains a belief model by a belief revision process that uses the observed acts in the dialogue. The game tree is evaluated in the context of this belief model. PED is efficient because it uses probabilistic estimates of belief rather than a plain logical belief model.
Freeverb3 is a signal processing library. It includes many types of audio processing effects and signal generators including a linear feedback shift register (LFSR) maximum length sequence (MLS) generator, multiple types of high quality mono+stereo reverb effects, a multi slot impulse response processor, multiband hardknee+softknee compressor and limiter, a stereo enhancer, a limiter, and many types of infinite impulse respose (IIR) and finite impulse response (FIR) filters. Also available is Freeverb3VST, a VST effects plugins package based on the Freeverb3 library.
Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.
eXtace is a visual sound display/analysis program. It requires Esound (esd) for its audio source. It includes various fast fourier transforms of the audio data in realtime. Its displays include a 3D wireframe flying landscape, a 3D textured flying landscape, a 16-256 channel graphic EQ, three types of scopes, a 3D "spike" flying landscape, and two forms of spectragrams. The 3D traces can be picked up, manipulated, and displayed at nearly any angle. eXtace also features a 3D direction control widget for controlling the angle and speed at which the trace runs away and a gradient/colormap editor for changing the colormap to suit your needs. No OpenGL is required.
Baudline is a time-frequency browser designed for scientific visualization of the spectral domain. Signal analysis is performed by Fourier, correlation, and raster transforms that create colorful spectrograms with vibrant detail. Conduct test and measurement experiments with the built in function generator, or play back audio files with a multitude of effects and filters. The baudline signal analyzer combines fast digital signal processing, versatile high speed displays, and continuous capture tools for hunting down and studying elusive signal characteristics.