Description

Create an fsig stream by reading a selected channel from a PVOC-EX analysis file loaded into memory, with frame interpolation. Only format 0 files (amplitude+frequency) are currently supported. The operation of this opcode mirrors that of pvoc, but outputs an fsig instead of a resynthesized signal.

Syntax

fsig pvsfread ktimpt, ifn [, ichan]

Initialization

ifn -- Name of the analysis file. This must have the .pvx file extension.

A multi-channel PVOC-EX file can be generated using the extended pvanal utility.

ichan -- (optional) The channel to read (counting from 0). Default is 0.

Performance

ktimpt -- Time pointer into analysis file, in seconds. See the description of the same parameter of pvoc for usage.

Note that analysis files can be very large, especially if multi-channel. Reading such files into memory will very likely incur breaks in the audio during real-time performance. As the file is read only once, and is then available to all other interested opcodes, it can be expedient to arrange for a dedicated instrument to preload all such analysis files at startup.

Examples

Here is an example of the pvsfread opcode. It uses the file pvsfread.csd.

<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 pvsfread.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

instr 1
; create a PVOC-EX (*.pvx) file with PVANAL first
idur  filelen   "kickroll.pvx"		;find duration of (stereo) analysis file
kpos  line      0,p3,idur		;to ensure we process whole file
fsigr pvsfread  kpos,"kickroll.pvx", 1	;create fsig from right channel
aout  pvsynth	fsigr			;resynthesise it
      outs	aout, aout

endin
</CsInstruments>
<CsScore>

i 1 0 10
i 1 11 1
e
</CsScore>
</CsoundSynthesizer>

Credits

New in version 4.13