[PD] about fiddle~

[Miller Puckette]

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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