BufCt1

creates a function table of ilen seconds for recording

Description

creates an "empty" function table (filled with zeros) of ilen seconds, using GEN02, for recording sound

Syntax

ift BufCt1 ilen [, inum]

Initialization

ilen - length in seconds
inum - if zero (which is also the default), the number of the function table is given by Csound. Any other positive integer will represent the function table, but the user must take care of not using a number twice
ift - table number as output

Code

  opcode BufCt1, i, io
ilen, inum xin 
ift        ftgen     inum, 0, -(ilen*sr), 2, 0
           xout      ift
  endop

Examples

<CsoundSynthesizer>
<CsOptions>
-d -iadc -odac
</CsOptions>
<CsInstruments>
sr = 44100
ksmps = 32
nchnls = 1
0dbfs = 1


  opcode BufCt1, i, io
;creates a function table of ilen seconds
ilen, inum xin ;inum=0 (default): automatic generated number, any other positive number is the number of the function table
ift        ftgen     inum, 0, -(ilen*sr), 2, 0
           xout      ift
  endop

  opcode BufRec1, k, aikkkk
ain, ift, krec, kstart, kend, kwrap xin
		setksmps	1
kendsmps	=		kend*sr ;end point in samples
kendsmps	=		(kendsmps == 0 || kendsmps > ftlen(ift) ? ftlen(ift) : kendsmps)
kfinished	=		0
krec		init		0
knew		changed	krec ;1 if record just started
 if krec == 1 then
  if knew == 1 then
kndx		=		kstart * sr - 1 ;first index to write minus one
  endif
  if kndx >= kendsmps-1 && kwrap == 1 then
kndx		=		-1
  endif
  if kndx < kendsmps-1 then
kndx		=		kndx + 1
andx		=		kndx
		tabw		ain, andx, ift
  else
kfinished	=		1
  endif
 endif
 		xout		kfinished
  endop

  opcode BufPlay1, ak, ikkkkkk
ift, kplay, kspeed, kvol, kstart, kend, kwrap xin
;kstart = begin of playing the buffer in seconds
;kend = end of playing in seconds. 0 means the end of the table
;kwrap = 0: no wrapping. stops at kend (positive speed) or kstart (negative speed). this makes just sense if the direction does not change and you just want to play the table once 
;kwrap = 1: wraps between kstart and kend
;kwrap = 2: wraps between 0 and kend
;kwrap = 3: wraps between kstart and end of table
;CALCULATE BASIC VALUES
kfin		init		0
iftlen		=		ftlen(ift)/sr ;ftlength in seconds
kend		=		(kend == 0 ? iftlen : kend) ;kend=0 means end of table
kstart01	=		kstart/iftlen ;start in 0-1 range
kend01		=		kend/iftlen ;end in 0-1 range
kfqbas		=		(1/iftlen) * kspeed ;basic phasor frequency
;DIFFERENT BEHAVIOUR DEPENDING ON WRAP:
if kplay == 1 && kfin == 0 then
 ;1. STOP AT START- OR ENDPOINT IF NO WRAPPING REQUIRED (kwrap=0)
 if kwrap == 0 then
kfqrel		=		kfqbas / (kend01-kstart01) ;phasor freq so that 0-1 values match distance start-end
andxrel	phasor 	kfqrel ;index 0-1 for distance start-end
andx		=		andxrel * (kend01-kstart01) + (kstart01) ;final index for reading the table (0-1)
kfirst		init		1 ;don't check condition below at the first k-cycle (always true)
kndx		downsamp	andx
kprevndx	init		0
 ;end of table check:
  ;for positive speed, check if this index is lower than the previous one
  if kfirst == 0 && kspeed > 0 && kndx < kprevndx then 
kfin		=		1
 ;for negative speed, check if this index is higher than the previous one
  else
kprevndx	=		(kprevndx == kstart01 ? kend01 : kprevndx) 
   if kfirst == 0 && kspeed < 0 && kndx > kprevndx then
kfin		=		1
   endif
kfirst		=		0 ;end of first cycle in wrap = 0
  endif
 ;sound out if end of table has not yet reached
asig		table3		andx, ift, 1	
kprevndx	=		kndx ;next previous is this index
 ;2. WRAP BETWEEN START AND END (kwrap=1)
 elseif kwrap == 1 then
kfqrel		=		kfqbas / (kend01-kstart01) ;same as for kwarp=0
andxrel	phasor 	kfqrel 
andx		=		andxrel * (kend01-kstart01) + (kstart01) 
asig		table3		andx, ift, 1	;sound out
 ;3. START AT kstart BUT WRAP BETWEEN 0 AND END (kwrap=2)
 elseif kwrap == 2 then
kw2first	init		1 
  if kw2first == 1 then ;at first k-cycle:
		reinit		wrap3phs ;reinitialize for getting the correct start phase
kw2first	=		0 
  endif
kfqrel		=		kfqbas / kend01 ;phasor freq so that 0-1 values match distance start-end
wrap3phs:
andxrel	phasor 	kfqrel, i(kstart01) ;index 0-1 for distance start-end
		rireturn	;end of reinitialization
andx		=		andxrel * kend01 ;final index for reading the table 
asig		table3		andx, ift, 1	;sound out
 ;4. WRAP BETWEEN kstart AND END OF TABLE(kwrap=3)
 elseif kwrap == 3 then
kfqrel		=		kfqbas / (1-kstart01) ;phasor freq so that 0-1 values match distance start-end
andxrel	phasor 	kfqrel ;index 0-1 for distance start-end
andx		=		andxrel * (1-kstart01) + kstart01 ;final index for reading the table 
asig		table3		andx, ift, 1	
 endif
else ;if either not started or finished at wrap=0
asig		=		0 ;don't produce any sound
endif
  		xout		asig*kvol, kfin
  endop

  opcode KeyOnce, kk, kkk
;returns '1' just in the k-cycle a certain key has been pressed (kdown) or released (kup)
key, kd, kascii    xin ;sensekey output and ascii code of the key (e.g. 32 for space)
knew      changed   key
kdown     =         (key == kascii && knew == 1 && kd == 1 ? 1 : 0)
kup       =         (key == kascii && knew == 1 && kd == 0 ? 1 : 0)
          xout      kdown, kup
  endop


instr 1 ;creates the buffer and starts instrument 2
          prints    "PRESS THE SPACE BAR FOR RECORDING!\n"
gibuf     BufCt1    3 ;buffer of 3 seconds
key,kd    sensekey
ktr,k0    KeyOnce   key, kd, 32 ;ktr becomes '1' when space bar is pressed
          schedkwhen ktr, .1, 5, 2, 0, 6 ;starts instr 2 for record and play
endin


instr 2 ;records for 3 seconds and plays it back
          prints    "RECORDING AND PLAYING BACK AFTER 3 SECONDS!\n"
krec      init      0 ;reset krec for multiple triggering
ain       inch      1 ;audio input from channel 1
kplay     BufRec1   ain, gibuf, krec, 0, 0, 0 ;record buffer without wrap
aout,k0   BufPlay1  gibuf, kplay, 1, 1, 0, 0, 0 ;play back buffer
          out       aout
krec      =         1
endin


</CsInstruments>
<CsScore>
i 1 0 1000
</CsScore>
</CsoundSynthesizer>

Credits

joachim heintz 2010