[PD-dev] Debugging PdLib on iPod Touch

Chris Niven cjniven at gmail.com
Fri Nov 26 20:16:15 CET 2010

Hey Peter, list —

I've been testing out PdLib's objc glue with the xcode project included in your git repo, and was able to get it to run successfully on an iPhone 3G, which is cool but — I noticed in the readme that audio doesn't work on iPod Touch 2G, as well as a few other devices.

Is there any reason for this? I've been trying to debug it (my main testing device is an iPod Touch 2G) and it seems that in PdAudio's initializeAudioSession, the sampling rate does not get set properly with the call to

AudioSessionSetProperty(kAudioSessionProperty_PreferredHardwareSampleRate sizeof(sampleRate), &sampleRate);

I set the sampling rate to 22050Hz, which works fine for the iPhone 3G — but the iPod Touch always reverts to the sampling rate of 44.1Hz, and audio is never played. 

I'm going to keep looking at it, but any ideas as to why this is happening in the first place would be appreciated — I'm curious as to why I can run RJDJ on my iPod Touch fine, but PdLib does not work even though it is based on the same code.


Chris Niven
B.Mus., Music Technology

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