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iphoneaudiobackgroundrecording

iPhone AVAudioRecorder pause problem after entering background

I have a problem with pausing AVAudioRecorder after entering background. Basically, it goes like this (_recorder is my AVAudioRecorder instance):

  1. Start recording: 

    [_recorder record];

  2. Press the home button on the device.

  3. Because I've set observer for notification of this case (in viewDidLoad), my custom method applicationDidEnterBackground fires.

  4. In applicationDidEnterBackground I do:

    [_recorder pause];

  5. Now, when I tap application icon, to take app to foreground, recording continous immediately, without taking any action. It's even stranger, because checking property:

    _recorder.recording == YES

returns NO.

I have a function, that is called by NSTimer every 0.1s (to refresh UI etc.), and in that function I have this:

if(_recorder.recording) {
    NSLog(@"recording");
}
else {
    NSLog(@"not recording");
    NSLog(@"time: %f", _recorder.currentTime);
}

It prints on the console:

    ...
    not recording
    time: 9.404082
    not recording
    not recording
    time: 9.473197
    not recording
    time: 9.531179
    not recording
    time: 9.629206
    not recording
    time: 9.728435
    ...

So, as you can see, the recorder's currentTime increases all the time, and the audio is being recorded.

Any Idea how to solve this?

Solution

  • You should add the following code:

    <key>UIBackgroundModes</key>
<array>
    <string>audio</string>
</array>

    to the Info.plist. This will cause the background mode to be responsive for managing audio session, so you can manually pause and resume recording.