Hello,

why is there no signal degradation when i give ifftsize very low values?
With low values there are not a lot of bins created, so why is that not
audible?
Here is the csd:

http://csound.1045644.n5.nabble.com/file/n4491254/pvsanalMenno.csd
pvsanalMenno.csd 



; 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 pvsanal.wav -W ;;; for file output any platform



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

instr 1

ifftsize  = p4
ioverlap  = ifftsize / 4
iwinsize  = ifftsize
iwinshape = 1; von-Hann window
Sfile	  = "fox.wav"
ain	  soundin Sfile
fsig	  pvsanal ain, ifftsize, ioverlap, iwinsize, iwinshape; fft-analysis of
the audio-signal
print p4
aout	  pvsynth fsig; resynthesis
	  outs aout, aout

endin


i 1 0 3 32
i 1 + 3 512
i 1 + 3 2048

e




greetings
Menno

--
View this message in context: http://csound.1045644.n5.nabble.com/pvsanal-question-tp4491254p4491254.html
Sent from the Csound - General mailing list archive at Nabble.com.


Send bugs reports to the Sourceforge bug tracker
            https://sourceforge.net/tracker/?group_id=81968&atid=564599
Discussions of bugs and features can be posted here
To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"

On 15/06/2011 14:40, menno wrote:
> Hello,
>
> why is there no signal degradation when i give ifftsize very low
> values? With low values there are not a lot of bins created, so why
> is that not audible? Here is the csd:
>

In the absence of any modifications, the FFT/IFFT pair forms an identity 
operation (in effect, an exactly reversible matrix jugglement), so the 
result is unaffected by the FFT size (indeed, it is a primary test that 
the FFT is working properly). Once you modify a bin (especially a 
frequency value) the changes will become very evident. With low FFT 
sizes, any modification will have far-reaching (but probably 
unpredictable) effects.

Richard Dobson






Send bugs reports to the Sourceforge bug tracker
            https://sourceforge.net/tracker/?group_id=81968&atid=564599
Discussions of bugs and features can be posted here
To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"

Because you are not changing the signal. The Phase Vocoder is supposed  
to be, within wide boundaries, transparent, if the data is not modified.

Victor
On 15 Jun 2011, at 14:40, menno wrote:

> Hello,
>
> why is there no signal degradation when i give ifftsize very low  
> values?
> With low values there are not a lot of bins created, so why is that  
> not
> audible?
> Here is the csd:
>
> http://csound.1045644.n5.nabble.com/file/n4491254/pvsanalMenno.csd
> pvsanalMenno.csd
>
> 
> 
> ; 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 pvsanal.wav -W ;;; for file output any platform
> 
> 
>
> sr = 44100
> ksmps = 32
> nchnls = 2
> 0dbfs  = 1
>
> instr 1
>
> ifftsize  = p4
> ioverlap  = ifftsize / 4
> iwinsize  = ifftsize
> iwinshape = 1; von-Hann window
> Sfile	  = "fox.wav"
> ain	  soundin Sfile
> fsig	  pvsanal ain, ifftsize, ioverlap, iwinsize, iwinshape; fft- 
> analysis of
> the audio-signal
> print p4
> aout	  pvsynth fsig; resynthesis
> 	  outs aout, aout
>
> endin
> 
> 
> i 1 0 3 32
> i 1 + 3 512
> i 1 + 3 2048
>
> e
> 
> 
>
>
> greetings
> Menno
>
> --
> View this message in context: http://csound.1045644.n5.nabble.com/pvsanal-question-tp4491254p4491254.html
> Sent from the Csound - General mailing list archive at Nabble.com.
>
>
> Send bugs reports to the Sourceforge bug tracker
>            https://sourceforge.net/tracker/?group_id=81968&atid=564599
> Discussions of bugs and features can be posted here
> To unsubscribe, send email sympa@lists.bath.ac.uk with body  
> "unsubscribe csound"
>

Dr Victor Lazzarini
Senior Lecturer
Dept. of Music
NUI Maynooth Ireland
tel.: +353 1 708 3545
Victor dot Lazzarini AT nuim dot ie





Send bugs reports to the Sourceforge bug tracker
            https://sourceforge.net/tracker/?group_id=81968&atid=564599
Discussions of bugs and features can be posted here
To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"