slab3d - home page

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slab3d is a real-time virtual acoustic environment rendering system originally developed in the Spatial Auditory Displays Lab at NASA Ames Research Center. slab3d performs spatial 3D-sound processing allowing the arbitrary placement of sound sources in auditory space. It is released free to the public under the NASA Open Source Agreement. This is a non-NASA website maintained by Joel D. Miller to support both NASA and non-NASA slab3d development. slab3d was previously known as SLAB.

slab3d release contents

Applications
- SLABScape renders an audio-visual virtual environment. Several scene parameters can be manipulated in real-time. Spatial sound processing is performed using the SRAPI library.
- SLABWireDemo demonstrates the features of the slabwire library. It includes wave, spectrum, and spectrally-triggered OpenGL displays.
- SLABSurface is a control surface interface to slab3d, primarily used for prototyping synthesis patches.
- SLABSound provides ASIO, DirectSound, Waveform API, and Wave (RIFF) file information.
- SLABCall places a Voice-over-IP (VoIP) call to slab3d.
- slabcon is a Microsoft Visual Studio console application demonstrating SRAPI-based development.
- mcon is a C# version of slabcon demonstrating the managed use of SRAPI.
- and other assorted demo and test applications...

Libraries
- SRAPI (SLAB Render API) renders an auditory display and/or virtual acoustic environment (VAE). Using SRAPI, the user can allocate sound sources, define an acoustic scene, select sound output destinations, configure frame-accurate callbacks, automatically modify scene parameters, load scripts and macros, and control rendering. SRAPI is also the interface between user applications and Render Plugins (see below).
- slabwire is used to configure a StreamIn-DSP-StreamOut processing chain. It is used internally by SRAPI but it can also be used as a stand-alone library.
- traklib provides a high-level interface for the Polhemus Fastrak electromagnetic tracker.
Render Plugins encapsulate the VAE rendering engine and auditory display processing. Plugins can be swapped in and out while rendering allowing for the comparison of different rendering strategies. Plugins also allow for the construction of tailored displays for specific applications (e.g., a spatial communications system).
Generator Plugins provide the signal generator sound sources available to SRAPI and slabwire. The plugin format allows users to conveniently add additional signal generation algorithms without modifying slab3d itself. slab3d includes two Generator Plugins:
- gslab contains sine, square, noise, triangle, amplitude modulation, and impulse signal generators.
- gstk contains all of the STK v4.2.0 instruments.

HRTF (Head-Related Transfer Function) databases are included for binaural processing.
slabtools are MATLAB tools for HRTF database manipulation and VAE processing visualization.
- slab archive (sarc) is an HRTF database archiving format. Utilities are included for creating and viewing sarc data.
- HRTF Lab (hlab) is an HRTF analysis MATLAB application.
Source code is included for all slab3d components.
Documentation is included in the release and available online.
A complete list of contents by release is available in the Version History "Contents" section.

slab3d specs

System
Operation Systems:	Windows 2000/XP/Vista
Sound Sources:	Waveform-Audio device ASIO device direct-from-disk file (8,16-bit PCM) memory-buffered file (8,16-bit PCM) recorded input (track recorder) real-time user samples Voice-over-IP (VoIP) DIS frequency DIS radio HTTP URL-specified internet file (8,16-bit PCM, 32-bit float) source submix signal generator plugins channel link
Sound Outputs:	Waveform-Audio device ASIO device DirectSound device direct-to-disk file memory-buffered file splitter
Sample Rate:	Sound Sources: arbitrary, resampled to engine rate as needed Engine (processing and output): arbitrary Spatial Renderer (HRTF and material filters): 8000, 8192, 11025, 22050, 44100, 48000 Hz
API Latency:	4.3ms (ASIO buffer size = 64 samples, fs = 44.1kHz), 23ms (DirectSound buffer size = 1024 stereo samples, fs = 44.1kHz)
Full-Duplex Latency:	6.1ms (ASIO buffer size = 64 samples, fs = 44.1kHz)
Delay Lines:	2x upsampled (optional), linearly interpolated
Frame Size:	32 samples
Acoustic Scene
Number of Sound Sources:	arbitrary, limited by CPU resources
Number of Listeners:	1
Room:	rectangular room, image model, 6 first-order reflections
Environment Modeling:	sound source location (x,y,z), wall location (length, width, depth), listener position (x,y,z,pitch,roll,yaw), head tracker sensor location (x,y,z); Render Plugin parameters for sound propagation delay, spherical spreading loss, wall materials, head and pinna (HRTF database HRIR and ITD interpolation)
Scene Update Rate:	arbitrary, 120 Hz typical
Numerical Precision:	double-precision floating-point scene geometry calculations
Spatial Render Plugin
Environment Modeling:	sound propagation delay, spherical spreading loss, wall materials, head and pinna (HRIR and ITD)
DSP Update Rate:	delay line indexing = every sample (22.7us), FIR taps = every 64 samples (1.45ms), leaky integrator parameter tracking
HRIR FIR Taps:	variable, typical: direct sound path = 128 taps, reflections = 32 taps
Wall Materials Filter:	first-order IIR filter
Numerical Precision:	single-precision floating-point signal processing calculations

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Last Updated: November 21, 2009