Dave Dave - 5 months ago 19
Android Question

Android AudioRecord initialization fails every time

My problem is simple to explain -- I am trying to create a AudioRecord object but it fails to initialize (ie after the constructor, getState returns 0, indicating failure). I am running this from Eclipse on a MotoDroid 1 running OS 2.2.1. My AndroidManifest.xml is, AFAIK, using the right permission, RECORD_AUDIO (I don't know how to confirm this):

<application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<activity android:name=".SphinxMic"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>


I do the following to create the AudioRecord:

bufferSize = AudioRecord.getMinBufferSize(8000, CHANNEL_IN_MONO, ENCODING_PCM_8BIT);
audioRecorder = new AudioRecord(AudioSource.MIC, 8000, CHANNEL_IN_MONO, ENCODING_PCM_8BIT, 50*bufferSize);
if (audioRecorder.getState() != AudioRecord.STATE_INITIALIZED)
throw new Exception("AudioRecord init failed");


audioRecorder.getState() returns 0 (ie STATE_UNINITIALIZED)

I have not found any complete examples of using this API and I'm very much an Android beginner so the solution may well be something simple. What can I do to find out why it fails?

A few people have asked similar questions, but they must have been having different problems than me because the fixes they approve haven't helped me. Most notably this. But the approved solution is perplexing and didn't work for me anyway. I have also tried a variety of bit rates (8000, 16000, 11025, 44100), both mono and stereo and 8 and 16 bit. No combination comes back as successfully initialized.

Answer

I spent some hours solving this problem, and found out that moving

<uses-permission android:name="android.permission.RECORD_AUDIO" />

outside the application block actually solved it!

...
    </application>

    <uses-permission android:name="android.permission.RECORD_AUDIO" /> 
</manifest>