DSP algorithms

[blümchen]

pustekuchen,

i tried out yr detunator plugin:
it really sounds good...

... but i get those crackles, too.
used the plugin in Audiomulch and Tracktion;
both the same:
unprocessed wavefile
processed wavefile

the crackles seem to depend on the input sound:
pads & slowly evolving sounds -> no crackles;
short attack/release sounds -> crackles.

cheers,
tl.

What format are those wave files?
Are not playable with the Windows Media Player.

Althought I'll download those and examine with WaveLab.

Thanks.

.

[blümchen]

Well.
I am able to reconstruct that now.

It seems to be a problem with my automatic input detection switch, which switches the pitch shifters off when the signal is zero over a certain amount of time and switches on again, if signal is detected...

I found that a good idea, because else the effect would consume permanently processor power, like most audio effects ...

I'll try to fix that.

Thanks.

[tl]

hope that i could help,
cause i have great respect for yr work.

p.s.
i really like Omnivox & Audiopitch.

Cheers,
tl.

[blümchen]

The file is updated now.

- I switched off the auto input detection (requires some more time to trace down the problem with that). So the crackle should be gone now. But the plug consumes permanently power (like most audio effects).

- I fixed a bug, which wrongly reseted (and initialized) the detune parameter on resume (was obviously not a FruityLoops problem )

http://devilswhisper.com/detunator.zip

Please tell me, what FL now does, if the "use constant blocksize" is switched off.

.

[blümchen]

hope that i could help,
cause i have great respect for yr work.

p.s.
i really like Omnivox & Audiopitch.

Cheers,
tl.

Thank you!

.

[tl]

Works like a charm now...

tl.

[blümchen]

Works like a charm now...

tl.

Yes! Because you are obviously a VERY GOOD beta tester, providing me usefull information and samples!!! That way it (fixing bugs) can be done in few minutes ...

.

[tl]

Questions by a real DSP dufus:
How come this plug doesn't seem to have latency?
What's the difference between this plug & Audiopitch concerning pitchshift?
(I understand why Audiopitch has latency: it uses FFT/iFFT)

tl.

[wolf_of_badenoch]

Where about is the setting for "use constant blocksize" in FL Studio ?

Wolf

[blümchen]

Ok, The Automatic Input Detection Switch is now reimplemented.

How do you find the Idea of switching a plugin internally automatically off an on, regarding silent (zero) input?

All possible available audio effects consume permanently processor power with silent input for some reasons ...

I tend to use it generally when building processing intensive plugins.

(That is, by the way, a thingy which must be implemented directly by the plugin (cannot be made by the host for some reasons - i.e. Delays and Reverbs would not work right then anymore but would be cutted wrongly ...)

.

[blümchen]

Questions by a real DSP dufus:
How come this plug doesn't seem to have latency?
What's the difference between this plug & Audiopitch concerning pitchshift?
(I understand why Audiopitch has latency: it uses FFT/iFFT)

tl.

It has some latency, but very low and also regarding the amount of detuning ... (I think at least )
.

Whatsoever.
AudioPitch uses FFT/iFFT (Phase Vocoder). Right.
I build that pitch scaler for purely resurch reasons, to examine, how I could apply formant correction with shifting the human voice. But that failed completely ...


The difference is, that Detunator uses a delay line based algorithm (that is completely time domain). It simply collects short delay buffers, and playes back with different sample rate. Then the (two) delay buffers will be overlapped and added with a windowing function to prevent scattering ...

But that is infact the problem. It tends clearly to scatter with higher amounts of pitch shifting. And it produces Aliasing then (which has to be additionally handled).

Big advantage: It uses low processor power and produces very good results with smaller shifting amounts (200 cent is no problem at all).


A Phase Vocoder pitch scaler (like in AudioPitch) has the advantage of smoother sound with high amounts of pitch scaling and also Aliasing can easiely prevented (in fact very simple by not shifting frequencies about the nyquist frequency). Because the complete frequency analysis was already made before any modification is done.


But big disadvantage: It uses extremely high processor power, has low bass response, tends to smearing and has noticeble latency with larger anylysis windows.

And another big problem is phase drifting (especially with stereo processing), which I wasn't able to solve till now ...

It would not be possible to realize an 8 (16 stereo) voices Detunator with that for performance reasons.

.

[tl]

Thanks for the answer.

New version works, too.
... no crackles.

tl.

[blümchen]

Where about is the setting for "use constant blocksize" in FL Studio ?

Wolf

Answer already made:

And the crackles disappear if you choose 'use fixed size buffers' from the dropdown menu under the icon on the left corner.

Regards,

JMH

[tl]

How do you find the Idea of switching a plugin internally automatically off an on, regarding silent (zero) input?

All possible available audio effects consume permanently processor power with silent input for some reasons ...

I tend to use it generally when building processing intensive plugins.

I think that's a good idea...

Being "neugierig" I tested Omnivox and Audiopitch with 'bs.wav' in Audiomulch:
same crackles...

... Könnte es sein...?

Strange that I never came across
this behavior using those plugs in the past...

It would be great if you could fix Omnivox & Audiopitch the same way you fixed Detunator.

And again great thanks for yr work...

Cheers,
tl.

[birrbits]

It simply collects short delay buffers, and playes back with different sample rate...... It tends clearly to scatter with higher amounts of pitch shifting. And it produces Aliasing then (which has to be additionally handled).

have you tried a LPF prior to resampling?