Bug 14234 - AudioUnit render callback doesn't return audio data from microphone
Summary: AudioUnit render callback doesn't return audio data from microphone
Status: RESOLVED INVALID
Alias: None
Product: iOS
Classification: Xamarin
Component: XI runtime ()
Version: 6.4.4
Hardware: Macintosh Mac OS
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2013-08-26 07:32 UTC by Mika Aalto
Modified: 2013-08-26 10:23 UTC (History)
2 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:


Attachments
Unit test case for this issue (4.45 KB, application/x-gzip)
2013-08-26 07:32 UTC, Mika Aalto
Details


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Status:
RESOLVED INVALID

Description Mika Aalto 2013-08-26 07:32:38 UTC
Created attachment 4712 [details]
Unit test case for this issue

When using AudioUnit instance to record PCM audio from IOS device microphone, all audio bytes returned in callback method are zeros. On IOS simulator audio data is returned as expected.

Attached unit test case to reproduce this issue. Unit test passes on IOS simulator running on Mac but fails when running on IOS device.

Tested with following software and hardware versions:
Xamarin.iOS version 6.4.3.0
iOS Simulator version 6.0 and SDK version 6.1
iPhone 4S device having iOS version 6.1.3

I'm happy to provide any help or additional information which helps you solving this issue.
Comment 1 Sebastien Pouliot 2013-08-26 10:23:05 UTC
It seems you're mixing Input and Output incorrectly in your test case. The microphone is an input device, while you're setting stuff for output (playback code?).

The test case works for me with the following change:

diff --git a/Users/poupou/Downloads/AudioUnitTest/MicrophoneTests.cs b/Users/poupou/Downloads/AudioUnitTest2/MicrophoneTests.cs
index 2bd75b6..2dfcb24 100644
--- a/Users/poupou/Downloads/AudioUnitTest/MicrophoneTests.cs
+++ b/Users/poupou/Downloads/AudioUnitTest2/MicrophoneTests.cs
@@ -43,7 +43,7 @@ namespace AudioUnitTest
 
                        //Configure audio unit to record PCM audio
                        AudioStreamBasicDescription desc = AudioStreamBasicDescription.CreateLinearPCM (8000, 1, 16, false);
-                       audioUnit.SetAudioFormat(desc, AudioUnitScopeType.Output, 1);
+                       audioUnit.SetAudioFormat(desc, AudioUnitScopeType.Input, 0);
 
                        //Set AudioUnit render callback method
                        status = audioUnit.SetRenderCallback( (actionFlags, timeStamp, busNumber, numberFrames, data) =>