[PD] about fiddle~

Damien Henry - Voxler damien.henry at voxler.fr
Fri Jan 18 23:18:01 CET 2008

Hi !

Does anybody whant to share an article or a document related to the
sigmund~ object ?

Thanks in advance.


Miller Puckette a écrit :
> HI all,
> I don't know any canonical way to decide when a note is finished, except
> to notice that a new note has started.  But it's probably possible to use
> the "discrete" output of fiddle~ to catch note-on events and then make
> up criteria that define endings of notes based on either pitch deviation
> or falling envelope.
> By the way, the new sigmund~ object outperforms fiddle~ on most tasks and
> might be worth trying.  It's probably best to use the newest one (out
> of pd 0.41 test).
> cheers
> Miller
> On Fri, Jan 11, 2008 at 06:30:08PM +0100, Matteo Sisti Sette wrote:
>>>> Another question about fiddle.
>>>> I'd like to be able to distinguish between a signal with a pitch and a
>>>> signal without a picth. It seems to me that fiddle always outputs its
>>>> "best guess" no matter how reliable it is.
>>> Actually that's not quite true. fiddle~ doesn't output anything at all
>> >from its first outlet unless it's pretty certain a pitch has been found.
>> Yes, he outputs a pitch from the first outlet when he finds one, but then 
>> never outputs anything to tell you that a pitch is no more present. When a 
>> new stable pitch is found, it is output through the first outlet, but how do 
>> you know whether the first pitch had remained stable untill that moment or 
>> if it had stopped existing before?
>> That's why I was looking at the third outlet instead.
>>> However, it does continuously output the first estimated peak location
>>> it uses to make its pitch calculation from its third outlet. It will
>>> also output 0 as a peak location if it can't find a peak,
>> Yes but it seems to me it is a bit too "tolerant" in saying he can find a 
>> pitch, and I was wondering whether there is a way to set the "tolerance".
>>> With the default fiddle~ settings, it seems to output 0 about 15% of the
>>> time, which seems quite a lot to me.
>> With pure noise as an input? Quite a lot?????
>> IF it is supposed to output 0 when it can't find a pitch, I would expect to 
>> output 0 about 90% of the time with pure noise as input!!
>>> Anyhow, I think this is a case of using the wrong tool for the job.
>>> Pitch/f0 estimators (PDAs) are designed to find pitch in a signal, not
>>> to measure noisiness. There are other tools to measure this
>> Maybe. The fact is that I do want to find a pitch, but I consider "none" as 
>> a possible value, i.e. I want to find the pitch if the signal reasonably has 
>> one, and ignore it when it is most probably garbage.
>> I thought there were two kinds of pitch trackers: those which do have a 
>> "none" value, and those which assume a pitch must exist and output their 
>> best estimation always. (well and a "fuzzy" third type, which always give 
>> both a pitch value and an estimated reliability value).
>> I don't fully understant to which type fiddle belongs, because on one side, 
>> it does distinguish whether he does or not detect a stable pitch, since it 
>> only outputs a "cooked" pitch when it becomes stable. However, a new cooked 
>> pitch is output (AFAIU) when the pitch changes to a new one (and here I 
>> don't understand well what it means, for example what is supposed to happen 
>> if the pitch changes very very slowly but continuously...) and this involves 
>> some mechanism to deal with vibrato (one more thing I don't understand how 
>> it works), so I can't imagine it doesn't detect when a stable pitch stops 
>> existing, and I would expect to output this information in some way related 
>> to the cooked pitch stuff.......
>> That is, it is like he says "NOW I detect a stable pitch of 57.2 ..... ..... 
>> ....and NOW I detect a pitch of 60". And what happened in the meantime????
>> However I'll look at the documentation other people pointed me to, so I'll 
>> probably understand all this a bit better.
>>> I find spectral irregularity to be quite a good noisiness metric,
>> How do you measure (or define) spectral irregularity?
>> I may want to use spectral irregularity to estimate whether the signal is 
>> non-noisy and then use fiddle to get the pitch when it is supposed to exist; 
>> I just thought that nobody better than the pitchtracker itself could tell me 
>> how difficult it is for it to find the pitch!
>>> but there are
>>> several others. If you are interested in this, perhaps take a look at
>>> the libxtract feature extraction library, which comes with PD external
>>> that wraps its functionality.
>> Thank you so much. I'll have a look 
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