AUNewTimePitch distorted on iOS device but fine in simulator
AUNewTimePitch distorted on iOS device but fine in simulator
- Subject: AUNewTimePitch distorted on iOS device but fine in simulator
- From: Matthew Daugherty <email@hidden>
- Date: Mon, 26 Nov 2012 14:26:59 -0500
I am trying to put together a simple iOS 6 app that reads an audio file from the bundle and plays it back with variable speed.
I have created the following AU Graph:
AUAudioFilePlayer -> AUNewTimePitch -> AURemoteIO
I have set the audio format of AUAudioFilePlayer and AURemoteIO to match the format used by AUNewTimePitch. CAShow() confirms that all the units are using the same data format:
AudioUnitGraph 0x2C17001:
Member Nodes:
node 1: 'auou' 'rioc' 'appl', instance 0x1d857c00 O I
node 2: 'augn' 'afpl' 'appl', instance 0x1d863120 O I
node 3: 'aufc' 'vari' 'appl', instance 0x1d863290 O I
Connections:
node 2 bus 0 => node 3 bus 0 [ 2 ch, 44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
node 3 bus 0 => node 1 bus 0 [ 2 ch, 44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
CurrentState:
mLastUpdateError=0, eventsToProcess=F, isRunning=F
If I run this app in the simulator it works fine. If I run it on my iPhone 5 the sound is distorted; my hearing is not that great but it sounds like the audio is being amplified and clipped. This is true even if I set the kNewTimePitchParam_Rate to 1.0.
As I was looking for answers to this I came across Chris Adamson's sample app from CocoaConf Portland that does exactly what I wanted. Unfortunately his app has the exact same behavior; it sounds fine in the simulator but is distorted when run from the device.
If I remove the AUNewTimePitch unit and connect AUAudioFilePlayer directly to AURemoteIO everything sounds fine on the device. If I replace AUNewTimePitch with a different unit such as Varispeed it also sounds fine.
I would appreciate any help or suggestions.
Thanks,
Matt
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden