vbaplsinit

vbaplsinit --  Configures VBAP output according to loudspeaker parameters.

Description

Configures VBAP output according to loudspeaker parameters.

Syntax

vbaplsinit idim, ilsnum [, idir1] [, idir2] [...] [, idir32]

Initialization

idim -- dimensionality of loudspeaker array. Either 2 or 3.

ilsnum -- number of loudspeakers. In two dimensions, the number can vary from 2 to 16. In three dimensions, the number can vary from 3 and 16.

idir1, idir2, ..., idir32 -- directions of loudspeakers. Number of directions must be less than or equal to 16. In two-dimensional loudspeaker positioning, idirn is the azimuth angle respective to nth channel. In three-dimensional loudspeaker positioning, fields are the azimuth and elevation angles of each loudspeaker consequently (azi1, ele1, azi2, ele2, etc.).

Performance

VBAP distributes the signal using loudspeaker data configured with vbaplsinit. The signal is applied to, at most, two loudspeakers in 2-D loudspeaker configurations, and three loudspeakers in 3-D loudspeaker configurations. If the virtual source is panned outside the region spanned by loudspeakers, the nearest loudspeakers are used in panning.

Examples

Example 1. 2-D panning example with stationary virtual sources

  sr      =          4100
  kr      =           441
  ksmps   =           100
  nchnls  =             4
  vbaplsinit         2, 6,  0, 45, 90, 135, 200, 245, 290, 315 

          instr 1	           
  asig    oscil      20000, 440, 1                    
  a1,a2,a3,a4,a5,a6,a7,a8   vbap8  asig, p4, 0, 20 ;p4 = azimuth
	
  ;render twice with alternate outq statements
  ;  to obtain two 4 channel .wav files:

          outq       a1,a2,a3,a4
  ;       outq       a5,a6,a7,a8
          endin
        

Reference

Ville Pulkki: "Virtual Sound Source Positioning Using Vector Base Amplitude Panning" Journal of the Audio Engineering Society, 1997 June, Vol. 45/6, p. 456.

See Also

vbap16, vbap16move, vbap4, vbap4move, vbap8, vbap8move, vbapz, vbapzmove

Credits

Author: Ville Pulkki

Sibelius Academy Computer Music Studio

Laboratory of Acoustics and Audio Signal Processing

Helsinki University of Technology

Helsinki, Finland

May, 2000 (New in Csound Version 4.07)

John ffitch (vbapz, vbabzmove)

University of Bath/Codemist Ltd.

Bath, UK

May, 2000 (New in Csound Version 4.07)