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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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Receiving kAUGraphErr_CannotDoInCurrentContext when calling AUGraphStart for playback

I'm working with AUGraph and Audio Units API to playback and record audio in my iOS app. Now I have a rare issue when an AUGraph is unable to start with the following error: result = kAUGraphErr_CannotDoInCurrentContext (-10863) The error occurred…
Mando
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How to set kAudioUnitSubType_Distortion

I'm trying to write an iOS app that adds sound effects. I'm trying to put an effect audio unit (ex, distortion and reverb) inbetween the auconverter and remoteIO. After setting up said AU, there is no sound. NewAUGraph(&mAuGraph); …
Masatatsu Nakamura
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iOS: Audio Units vs OpenAL vs Core Audio

Could someone explain to me how OpenAL fits in with the schema of sound on the iPhone? There seem to be APIs at different levels for handling sound. The higher level ones are easy enough to understand. But my understanding gets murky towards the…
P i
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AudioUnit: Error reported by mediaserverd - "Error 'what' getting client format for physical format"

I have a VOIP application that uses AudioUnit. On iOS 9, I see an error message that says the following. I do not see this in iOS 8: mediaserverd[43] : 13:16:38.880 ERROR: [0x1f72d000] >va> 500: Error 'what' getting client format for physical…
evalsyrelec
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iOS app crashes when headphones are plugged in or unplugged

I'm running a SIP audio streaming app on iOS 6.1.3 iPad2 and new iPad. I start my app on my iPad (nothing plugged in). Audio works. I plug in the headphones. The app crashes: malloc: error for object 0x....: pointer being freed was not allocated or…
Angel Martin
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How to prevent iPhone 3GS from filtering low frequencies ( < 150Hz )

I'm developing a bass guitar pitch detection app on iphone 3GS. I found I can't get sound data lower than 150Hz with RemoteIO. However bass guitar may generate tones lower than 50hz. According to the report "iPhone 4 Headset Input Frequency…
Albert
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iOS AudioUnit recording at 8kHz sample rate yields in silence

I'm building a voip application where we need to record audio from the microphone and send it somewhere in 8kHz sample rate. Right now I'm recording it in default sample rate, which in my case was always 44,1k. This is then manually converted to 8k…
Ryupold
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Can I use AVAudioEngine to read from a file, process with an audio unit and write to a file, faster than real-time?

I am working on an iOS app that uses AVAudioEngine for various things, including recording audio to a file, applying effects to that audio using audio units, and playing back the audio with the effect applied. I use a tap to also write the output to…
Greg
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Using VoiceProcessingIO audio unit subtype instead of RemoteIO causes unwanted drop in output volume

I am using RemoteIO in my voice chat application. To enable echo canceling, I changed "kAudioUnitSubType_RemoteIO" to "kAudioUnitSubType_VoiceProcessingIO" after setting "kAudioSessionCategory_PlayAndRecord" as the session type. Now echo canceling…
Sujithra
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Unable to restart recording after answering incoming phone call

I have added an observer for the interrupt notification when recording audio. This works fine when performing an outgoing-call, getting an incoming call and not answering, Siri, etc.. Now my app is running in the background with the red bar at the…
Thizzer
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Unable to convert mp3 into PCM using AudioConverterFillComplexBuffer in AudioFileStreamOpen's AudioFileStream_PacketsProc callback

I have a AudioFileStream_PacketsProc callback set during an AudioFileStreamOpen which handles converting audio packets into PCM using AudioConverterFillComplexBuffer. The issue that I am having is that I am getting a -50 OSStatus (paramErr) after…
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How to record sound produced by mixer unit output (iOS Core Audio & Audio Graph)

I'm trying to record sound produced by a mixer unit output. For the moment, my code is based on the apple MixerHost iOS app demo : A mixer node is connected to a remote IO node on the audio graphe. And i try to set an input callback on the remote IO…
lefakir
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How to record and play audio simultaneously in iOS using Swift?

In Objective-C, recording and playing audio simultaneously is fairly simple. And there are tonnes of sample code on the internet. But I want to record and play audio simultaneously using Audio Unit/Core Audio in Swift. There are very little help and…
user6278161
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iPhone: AudioBufferList init and release

What are the correct ways of initializing (allocating memory) and releasing (freeing) an AudioBufferList with 3 AudioBuffers? (I'm aware that there might be more than one ways of doing this.) I'd like to use those 3 buffers to read sequential parts…
Tom Ilsinszki
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iOS - AudioUnitInitialize returns error code 561017449

I have an app in the App Store which uses AudioUnit for recording audio. About once a week or so I am seeing that for some users in the wild the call to AudioUnitInitialize fails with the error code 561017449 which is also 0x21707269 or "irp!". What…
Chuck Batson
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