[PD] about fiddle~
mpuckett at imusic1.ucsd.edu
Fri Jan 11 19:45:17 CET 2008
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).
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
> PD-list at iem.at mailing list
> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
More information about the Pd-list