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Pitch shift w/o the delay?

Posted: Tue Jun 19, 2012 3:58 pm
by dslocum
Is it possible to get a pitch shifter without the delay in the demo software? Or at least minimize the delay significantly?

And a follow-on to that... Is it possible to reduce the slight pulsing effect with or without the delay?

Thanks

Doug

Re: Pitch shift w/o the delay?

Posted: Tue Jun 19, 2012 4:36 pm
by frank
dslocum wrote:Is it possible to get a pitch shifter without the delay in the demo software? Or at least minimize the delay significantly?
You can use a shorter delay length (assuming you are not already using the shortest one) but you will lose shifting of lower frequencies. This is due to the fact we are using a buffer to hold the data and playing it back faster than the data is entering the buffer.
dslocum wrote: And a follow-on to that... Is it possible to reduce the slight pulsing effect with or without the delay?

Thanks

Doug
The pulsing is due to the pointers having to cross-fade from the beginning of the buffer back around to the end. So how much pulsing you hear is due to the audio content, i.e. frequencies with a wavelength that is an integer multiple of the buffer length will exhibit little pulsing while those that are not will exhibit more pulsing.

Possibly use two shifters

Posted: Thu May 02, 2013 12:23 pm
by diydsp
Heya,

I read your post a while back and had a thought...

Since the FV-1 can easily run two pitch scalers at the same time, perhaps you could simultaneously run one with a small buffer and one with a large buffer. That way you'll get a shorter delay on the small buffer. That will make transients sound better. I have never tried this, but it's worth a shot. I believe elsewhere in this forum you can find my code for running two pitch shifters at once.

Posted: Thu May 02, 2013 2:27 pm
by frank
You would be mixing 2 signals with a delay between them, you'll probably get a comb effect. Maybe a moving comb as the pointers on the 2 different delays buffers are always moving the exact delay between the 2 outputs will also always be moving and jumping.