GEN01

GEN01 — Transfers data from a soundfile into a function table.

Description

This subroutine transfers data from a soundfile into a function table.

Syntax

f#  time  size  1  filcod  skiptime  format  channel

Performance

size -- number of points in the table. Ordinarily a power of 2 or a power-of-2 plus 1 (see f statement); the maximum tablesize is 16777216 (224) points. The allocation of table memory can be deferred by setting this parameter to 0; the size allocated is then the number of points in the file (probably not a power-of-2), and the table is not usable by normal oscillators, but it is usable by a loscil unit. The soundfile can also be mono or stereo.

filcod -- integer or character-string denoting the source soundfile name. An integer denotes the file soundin.filcod ; a character-string (in double quotes, spaces permitted) gives the filename itself, optionally a full pathname. If not a full path, the file is sought first in the current directory, then in that given by the environment variable SSDIR (if defined) then by SFDIR. See also soundin.

skiptime -- begin reading at skiptime seconds into the file.

channel -- channel number to read in. 0 denotes read all channels.

format -- specifies the audio data-file format:


1 - 8-bit signed character    4 - 16-bit short integers 
2 - 8-bit A-law bytes         5 - 32-bit long integers 
3 - 8-bit U-law bytes         6 - 32-bit floats
        

If format = 0 the sample format is taken from the soundfile header, or by default from the CSound -o command-line flag.

[Note] Note

  • Reading stops at end-of-file or when the table is full. Table locations not filled will contain zeros.

  • If p4 is positive, the table will be post-normalized (rescaled to a maximum absolute value of 1 after generation). A negative p4 will cause rescaling to be skipped.

  • GEN01 also works with WAV and OGG and a dozen and more other sound formats; these file formats depend on libsndfile, see http://www.mega-nerd.com/libsndfile/

Examples

Here is an example of the GEN01 routine. It uses the files gen01.csd and several sound files.

Example 1060. An example of the GEN01 routine.

<CsoundSynthesizer>
<CsOptions>
 
; Select audio/midi flags here according to platform 
-odac     ;;;realtime audio out 
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too 
; For Non-realtime ouput leave only the line below: 
; -o gen01.wav -W ;;; for file output any platform 
</CsOptions>
<CsInstruments>
 

sr = 44100 
ksmps = 32 
nchnls = 2 
0dbfs  = 1 

instr 1	;plays deferred and non-deferred sounds with loscil

ifn = p4
ibas = 1

asig loscil 1, 1, ifn, ibas
     outs asig, asig
    
endin

instr 2	;plays only non-deffered sound            

isnd  = p4
aread line   sr*p3, p3, 0				;play this backward
asig  tablei aread, isnd				;use table 1
      outs   asig, asig
        
endin
</CsInstruments>
<CsScore>
f 1 0 131072 1 "beats.wav" 0 0 0			;non-deferred sound
f 2 0    0   1 "flute.aiff" 0 0 0			;& deferred sounds in 
f 3 0    0   1 "beats.ogg" 0 0 0			;different formats					

i 1 0 1 1
i 1 + 1 2
i 1 + 1 3

i 2 4 2 1	;non-deffered sound for instr. 2
e
</CsScore>
</CsoundSynthesizer>


These are the diagrams of the waveforms of the GEN01 routines, as used in the example:

f 1 0 131072 1 "beats.wav" 0 0 0 - non-deferred sound

f 1 0 131072 1 "beats.wav" 0 0 0 - non-deferred sound

f 2 0 0 1 "flute.aiff" 0 0 0 - deferred sound

f 2 0 0 1 "flute.aiff" 0 0 0 - deferred sound

f 3 0 0 1 "beats.ogg" 0 0 0 - deferred sound

f 3 0 0 1 "beats.ogg" 0 0 0 - deferred sound

Credits

September 2003. Thanks goes to Dr. Richard Boulanger for pointing out the references to the AIFF file format.