ftlen — Returns the size of a stored function table.


Returns the size of a stored function table.


ftlen(x) (init-rate args only)


Returns the size (number of points, excluding guard point) of stored function table, number x. While most units referencing a stored table will automatically take its size into account (so tables can be of arbitrary length), this function reports the actual size if that is needed. Note that ftlen will always return a power-of-2 value, i.e. the function table guard point (see f Statement) is not included.As of Csound version 3.53, ftlen works with deferred function tables (see GEN01).

ftlen differs from nsamp in that nsamp gives the number of sample frames loaded, while ftlen gives the total number of samples without the guard point. For example, with a stereo sound file of 10000 samples, ftlen() would return 19999 (i.e. a total of 20000 mono samples, not including a guard point), but nsamp() returns 10000.


Here is an example of the ftlen opcode. It uses the file ftlen.csd, and mary.wav.

Example 173. Example of the ftlen opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

; Select audio/midi flags here according to platform
; Audio out   Audio in
-odac           -iadc    ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o ftlen.wav -W ;;; for file output any platform

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Print out the size of Table #1.
  ; The size will be the number of points excluding the guard point.
  ilen = ftlen(1)
  print ilen


; Table #1: Use an audio file, Csound will determine its size.
f 1 0 0 1 "mary.wav" 0 0 0

; Play Instrument #1 for 1 second.
i 1 0 1


The audio file “mary.wav” is 154390 samples long. The ftlen opcode reports it as 154389 samples long because it reserves 1 point for the guard point. Its output should include a line like this:

instr 1:  ilen = 154389.000

See Also

ftchnls, ftlptim, ftsr, nsamp


Author: Barry L. Vercoe
Cambridge, Massachussetts

Example written by Kevin Conder.