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Questions tagged [audiounit]

Audio Units are plug-ins for Apple's CoreAudio framework which generate or process audio streams.

Audio Units (commonly referred to as simply "AU") are plug-ins for Apple's CoreAudio system which are capable of generating or processing audio streams. Although Audio Units were originally created to compete with Steinberg's VST SDK, they have evolved in quite different directions.

Currently Mac OSX and iOS are the only platforms which support the Audio Unit SDK. Both OSX and iOS ship with a number of default Audio Units for basic audio stream operations, though it is possible to write custom Audio Units on both platforms.

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using AUGraph vs direct connections between Audio Units by means of a GCD queue

So i've gone thru the Audio Unit Hosting Guide for iOS and they hint all along that one might always want to use an AUGraph instead of direct connections between AUs. Among the most notable reasons they mention a high-priority thread, being able to…
SaldaVonSchwartz
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How can I play a synth sound in a C++ app on OSX?

I want to play instrumental sounds in my app. The duration of the sounds is flexible so MIDI seems the best solution. I am using Open Framework for now. Using Audio Units, I managed to process an input sound, not to play through an instrument. I…
BaptisteB
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Using VoiceProcessingIO along with AUSampler

I'm trying to implement something similar to flute that when you blow the mic it's going to start play one note from the speaker. For this reason I was trying to use VoiceProcessingIO to substract playbacked note (output speaker) from input…
pzo
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Is there a recent (2013) guide for developing Audio Units in Mac OS X Mountain Lion?

I am working on developing some Audio Units. I am wondering if there exists a "getting started" guide that is more up-to-date than this one on Apple's website from…
chaimp
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Specifying number of frames to process in audiounit render callback on iOS

I setup the audio unit render callback: AURenderCallbackStruct input; input.inputProc = RenderAudioBuffer; input.inputProcRefCon = self; err = AudioUnitSetProperty(audioPlaybackUnit, …
ssk
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iOS: AudioSession properties being reset when user closes & reopens app?

I'm using AudioUnit for access to RemoteIO for high-performance audio. My app decodes signals which are embedded in audio received from the microphone. For accuracy, I need to keep audio filtering & manipulation down to a minimum. I do this to the…
Keith
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IOS Audio units

I am trying to implement a low pass filter in core audio on IOS but when I use the code below an error is generated stating "The operation could not be completed", which is very undescriptive of the problem. And I can see what about this operation…
aerlfredith
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How to add kAudioUnitSubType_Varispeed audiounit to AUGraph in iOS6

I’m studying AudioUnits in iOS and trying to implement such graph: ------------------- ----------------- | | | | -->| FormatConverter | --->| bus 0 | | (Varispeed) | | …
Ted Harner
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Using iOS Reverb effect

kAudioUnitSubType_Reverb2 effect doesn't work in my Audio Unit graph. When I exclude its node from graph everything works fine. I tried to add converters between previous node and reverb node and after reverb. I did set the stream format of the…
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Possible Output Sampling Rates in Audio Units

I am trying to set different sampling rates (like 32kHz, 24kHz etc..) to the input stream of Remote I/O audio unit. But the output is always played at one of these sampling rates - 22.05kHz, 33.1kHz, 11.0kHz irrespective of what I set. And…
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Add Effect to Mic input and play to speaker output using Audio Unit

I am in the practice of Audio Unit API. I've added the kAudioUnitType_Effect to a sound buffer offline and play the sound with reverb sucessfully , as demo in the official demo code: "AVCaptureToAudioUnit" The AUGraph is AUconverter->AUeffect->RIO…
Vincent Chen
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AUSampler Audio Drop-out

I am developing an iPad application that uses the AUSampler AudioUnit, in conjunction with other AudioUnits, to play audio. The AUSampler loads a preset from a SoundFont2 file. When too many notes are played at once or notes are played too quickly,…
Jayson
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How do I set higher priority for audio processing thread, so my RemoteIO Audio Unit would perform without glitches?

I noticed there are audible sound gaps with audio units rendering when something heavy happens on UI main thread, for instance, first show of UIAlertView or some heavy ui controller. Please take a look at the sample project. There is only one remote…
Roman B.
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Voice Recording while music playing at the same time using AudioUnit in the iPhone

I am trying to record voice to file while playing music. I think AudioUnit is good choice for doing this, but I cannot find any simple sample code for doing this. Any advice or help?
ttotto
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How to real-time convert the PCM buffer to AAC data when recording for iOS?

I'm using Remote.IO to get the audio buffer from PCM, but the raw data is too big to send to remote-side by cellular network (3G network). I did reference some articles, but most of them suggest converting file to the other format file. Is there any…
PatrickSCLin
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