BufFiCtNd1

creates a non deferred function table from a mono soundfile and returns its length

Description

Creates a non deferred function table from a mono soundfile and returns its length. This can be useful is you want to use opcodes (for instance table3) which do not work with deferred size function tables

Syntax

ift, ilen BufFiCtNd1 Sfilenam [, ichn [, iftnum [, inorm]]]

Initialization

Sfilenam - file name or path as string
ichn - channel in Sfilenam to read (default=1)
iftnum - 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
inorm - if zero, the table is not normalized. This is also the default, while any other number creates a normalized table
ift - output table number
ilen - length of the function table created (which is also the length of the soundfile in samples)

Code

  opcode BufFiCtNd1, ii, Spoo
Sfilenam, ichn, iftnum, inorm xin
igen      =         (inorm == 0 ? -1 : 1)
ifttmp    ftgen     0, 0, 0, igen, Sfilenam, 0, 0, ichn
ilen      tableng   ifttmp
ift       ftgen     iftnum, 0, -ilen, -2, 0
          vcopy_i   ift, ifttmp, ilen
          ftfree    ifttmp, 0
          xout      ift, ilen
  endop

Examples

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

  opcode BufFiCtNd1, ii, Spoo
;creates a non deferred function table from a soundfile and returns its length
Sfilenam, ichn, iftnum, inorm xin ;filename, channel (default=1), number of ftable (0=automatic(=default)), normalization (1=yes, 0=no(=default))
igen      =         (inorm == 0 ? -1 : 1)
ifttmp    ftgen     0, 0, 0, igen, Sfilenam, 0, 0, ichn
ilen      tableng   ifttmp
ift       ftgen     iftnum, 0, -ilen, -2, 0
          vcopy_i   ift, ifttmp, ilen
          ftfree    ifttmp, 0
          xout      ift, ilen
  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
    
	
instr 1
gift,ilen BufFiCtNd1 "fox.wav" ;creates a non-deferred function table containing the sample
endin

instr 2
aout,k0   BufPlay1	 gift, 1, p4, 1, p5, p6, p7 ;speed (vol) start end wrap
          out       aout
endin


</CsInstruments>
<CsScore>
i 1 0 41
;         speed start end wrap
i 2 0 5   1     0     0   0   ;play all but stop (wrap=0) after reaching the end
i . 6 5   2     1     2   0   ;play from sec 1 to 2 in the file in double speed
i . 12 5  -.5   0.5   2   0   ;play from sec 2 to 0.5 backwards, half speed
i . 18 5  1     0.5   2   1   ;wrap between start and end
i . 24 5  -1    0.5   2   1   ;the same backwards
i . 30 5  1     1     2   2   ;start at sec 1, then wrap between 0 and end
i . 36 5  1     1     2   3   ;wrap between start and end of table
e
</CsScore>
</CsoundSynthesizer>

Credits

joachim heintz 2010