[LAU] [LAA] Qtractor 0.1.3 (frugal damsel) released!

Mark Knecht markknecht at gmail.com
Sun May 4 15:34:24 EDT 2008


On Sun, May 4, 2008 at 12:05 PM, Rui Nuno Capela <rncbc at rncbc.org> wrote:
>
> Mark Knecht wrote:
>
> > On Sun, May 4, 2008 at 10:23 AM, Rui Nuno Capela <rncbc at rncbc.org> wrote:
> >
> > > Mark Knecht wrote:
> > >
> > <SNIP>
> >
> > >
> > > >
> > > > >  ok. we already have the "Root note", "Beats", "Meter" and "Tempo"
> > > > >
> > > >
> > > fields in
> > >
> > > >
> > > > > sight, which is a fair start imo.
> > > > >
> > > > >
> > > > Well, sndfile-info writes the word 'tempo' but I'm not completely
> > > > comfortable that we know where the tempo values are. Both of the
> > > > examples I provided say 120BPM. Unfortunately neither loop library is
> > > > actually recorded at that tempo!
> > > >
> > > >
> > > >
> > >  that is *bad* news :( so the meta-data we get from libsndfile is bogus?
> > >
> > >  i guess we're back to square one (or is it zero?:).
> > >
> > >
> >
> > No, I really don't thin kit's quite that bad. In fact I thought it
> > worked better than it did so maybe part of the problem is just lack of
> > attention over the last few years and some bug creeping in here or
> > there. Some of what's there is right, I think.
> >
> > I really believe that just finding a couple of folks who have an
> > interest and digging in will probably figure it out pretty quickly.
> >
> > <SNIP>
> >
> > >  we'll have to resort that audio files must be integral in length to
> ever
> > > get some kind of loop auto-fitting ...
> > >
> > >
> >
> > Well, independent of what the tempo is in a session, if I know an
> > 8-bar pre-recorded loop is 120000 samples long (available from the
> > loop's meta-data) and I know my session requires 140,000 samples to
> > meet whatever the tempo is set to for 8 bars, then the resampling can
> > be done on the fly.
> >
> > To be clear, Acid Pro does NOT resample on the fly with extremely high
> > quality. The quality is good but if I change a 68 BMP loop to 160 BPM
> > I am absolutely going to hear artifacts all over the place. My
> > experience is, however, that this gives 'character' to my work. It
> > sounds real, funky, fun. Most of the time what I hear when I listen to
> > a single resampled loop by itself is completely covered up when the
> > song is done. If it's not then and only then would I bother with
> > external, high quality resampling. 99.99% of the time it's just not an
> > issue for me.
> >
> >
>
>  but qtractor *does* time-stretching (what you call resample) on-the-fly!
>
>  you have two options here, being a trade-off between quality and cpu
> intensiveness:
>
>  1) soundtouch based, wsola-like algorithm - very fast but artifact
> prone--maybe with similar results as acid on-the-fly mode, you tell me
>
>  2) rubberband - good quality but resource intensive; might not be
> appropriate for heavy loaded sessions and/or older cpu's
>
>  just to let you know. qtractor does *not* touch any of your audio sample
> files, nor it creates any unless you're recording or exporting one--almost
> everything is or can be done on-the-fly ;)

OK, certainly I'm confused about the current feature set. I thought
this was all a discussion for the future and that what qtractor
supported today was pitch shifting.

Let me spend time in the program and see what it actually does.

Cheers,
Mark



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