-----Original Message-----
From: Qian Chen 
To: Csound 
Date: 28. mai 1998 09:38
Subject: Qs:pvoc,soundin/diskin


>Dear Csounders,
>
>I have the following questions recently:
>
>1. When I used pvanal.exe to analysis wave files, and then used pvoc
>to resynthesis them, I always got audible distortion.  The parameters
>are as the following:
> sample rate: 44100
> Channels: 1
> STFT frame size:1024
> Window overlap: 4
>Should I make STFT frame size bigger or use hopsize parameter?
>

What kind of distortion?
I think your parameters should be ok, but it may depend on the type of sound
and how critical you are.
FFT is under the uncertainity principle, either you have good resolution in
the frequency or time.
Using long framesizes  gives smearing of the sound, using short framesizes
gives less frequency information.

.. Or it may be something wrong with your orchestra.

>2. This one is still about pvoc.  When I compiled my Csound orc & sco
>files, I got the following warnings:
>SECTION 1:
>new alloc for instr 1:
>file c:\essay\af/95-vc04L.pvc (11753912 bytes) loaded into memory
>file c:\essay\af/95-vc04R.pvc (11753912 bytes) loaded into memory
>WARNING: PVOC ktimpnt truncated to last frame
>WARNING: PVOC ktimpnt truncated to last frame
>B  0.000 .. 16.639 T 16.639 TT 16.639 M:  19956.8  20469.2
>What do they mean?

I think this warning is triggered when csound have reached the end of the
pvoc-file. It then
uses only the last frame for the rest of the note. Try make the duration the
same length as the analysis file
or whatever ktimpnt you have.

>
>
>3.I have a suggestion - if some of you disagree it, please advise:
>  Both soundin and diskin can read a sound file skipping some time of
>the file.  Therefore, why isn't there a parameter to specify the
>duration a user wants it to read?  For example, if I want to skip 2
>seconds and just read 5 seconds but not the whole files after the 2
>seconds, I could use that parameter.  Of course, I know I could use an
>analysis file to realize it.  But I do think it must be easier and
>quicker if we add a parameter to soundin and diskin.
>
>Any comment is welcomed and thanks for your bandwidth.
>
>Qian Chen
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>
>