Real-time Pitch Shifting on the iPhone

Solution 1:

you can use dirac-2 from dsp dimension for pitch shifting on the iphone. quote: -

"DIRAC2 is available as both a commercial object library offering unlimited sample rates and phase locked multichannel support and as a free single channel, 44.1/48kHz LE version."

Solution 2:

use the soundtouch open source project to change pitch

Here is the link : http://www.surina.net/soundtouch/

Once you add soundtouch to your project, you have to give the input sound file path, output sound file path and pitch change as the input.

Since it takes more time to process your sound its better to modify soundtouch so that when you record the voice, directly give the data for processing. It will make your application better.

Solution 3:

I know it's too late for the person who asked but it is really a valuable link (As I found) for any one else who is looking for the solution of the same problem.

So Here we have latest DIRAC3 with it's own audio player classes which will take care of run time pitch and speed(explore for god knows what more) shifting. Run the sample and have huge round of applause for that.

Solution 4:

Try Dirac - it's the best technology out there and it's available on Win, Linux, MacOS X and iOS. We're using it in all our products (and a couple of others do as well, search for "Capo" on the App Store). They're at version 3 now which has seen a huge increase in performance since previous versions. Hope this helps.