Audio output is a tone related to the striking of a metal block as found in a vibraphone. The method is a physical model developed from Perry Cook, but re-coded for Csound.
ihrd -- the hardness of the stick used in the strike. A range of 0 to 1 is used. 0.5 is a suitable value.
ipos -- where the block is hit, in the range 0 to 1.
imp -- a table of the strike impulses. The file marmstk1.wav is a suitable function from measurements and can be loaded with a GEN01 table. It is also available at ftp://ftp.cs.bath.ac.uk/pub/dream/documentation/sounds/modelling/.
ivfn -- shape of vibrato, usually a sine table, created by a function
idec -- time before end of note when damping is introduced
idoubles (optional) -- percentage of double strikes. Default is 40%.
itriples (optional) -- percentage of triple strikes. Default is 20%.
kamp -- Amplitude of note.
kfreq -- Frequency of note played.
kvibf -- frequency of vibrato in Hertz. Suggested range is 0 to 12
kvamp -- amplitude of the vibrato
Here is an example of the vibes opcode. It uses the files vibes.orc, vibes.sco, and marmstk1.wav.
Example 411. Example of the vibes opcode.
/* vibes.orc */ ; Initialize the global variables. sr = 22050 kr = 2205 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; kamp = 20000 ; kfreq = 440 ; ihrd = 0.5 ; ipos = 0.561 ; imp = 1 ; kvibf = 6.0 ; kvamp = 0.05 ; ivibfn = 2 ; idec = 0.1 a1 vibes 20000, 440, 0.5, 0.561, 1, 6.0, 0.05, 2, 0.1 out a1 endin /* vibes.orc */
/* vibes.sco */ ; Table #1, the "marmstk1.wav" audio file. f 1 0 256 1 "marmstk1.wav" 0 0 0 ; Table #2, a sine wave for the vibrato. f 2 0 128 10 1 ; Play Instrument #1 for four seconds. i 1 0 4 e /* vibes.sco */