As I understand and as Matt already wrote, you wanted a transposition of the phasor~'s frequency (which would change the frequency of the loop but not the sample content), but instead you did the classic up/downsampling-of-the-soundsample transposition.
(The "distortion" you get is due to the difference in spectral content, which should be richer as you transpose upwards since you read a longer portion of the sample.
Also, the end of the loop changes which could mean a harder discontinuity.)

I tried to fix the transposition and I also added an offset in the audio path before tabread4~ that corresponds to the beginning of the loop.

And I'm sure you've already figured everything out, long before you got our emails.


alabala

On 23 April 2010 20:27, Frank Barknecht <fbar@footils.org> wrote:
Hi,

not related to the thread on smoother audio in Pd, I am struggling with doing a smooth
loop player for data stored in tables.

One building block for this is attached: It is a simple tabread4~ lookup that
should loop over a configurable section of a table and play it back with various frequencies.
As you'll easily see, I use a

 [phasor~]
 |
 [*~ loopsize]
 |
 [+~ loopstart]
 |
 [tabread4~ table]

idiom here. Now I would like to avoid enveloping the rewind sections, so I
built an elaborate mechanism to set the loop points as good as possible by
hand. Test sections let you load a sample or try to find the smooth loop points
inside of a sine-wave table graphically.

Now my problem is, that even when I have found a nice and smooth sounding loop
section, as soon as I start to change the frequency played (with the "pd
transpose" things), the sound gets very distorted.

I'm puzzled: Shouldn't the tabread4~ interpolate correctly in this case?  Any
help or explanation is appreciated. (Except anything involving crossfades: I
know I could do that and I guess I also know how.)

Ciao
--
 Frank Barknecht            Do You RjDj.me?          _ ______footils.org__

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ypatios