AVCaptureSession with only background music

Question

I need to do something like this. That my app do recording using AVCapturesession but it should be able to stream the live feed with background music that I had played.

Remember i am able to play background music with the AVCapturesession,but the problem is that it also involve the sound of surrounding environment.

Here is the audiosession category I am using

     AudioSessionInitialize(NULL, NULL, NULL, self);

    //  //set the audio category
    UInt32 audioCategory = kAudioSessionCategory_PlayAndRecord;
    AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(audioCategory), &audioCategory);

    // mix with others!! this allows using AVCaptureSession and AusioSession simultaniously
    UInt32 doSetProperty = 1;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideCategoryMixWithOthers,  sizeof(doSetProperty), &doSetProperty);

    AudioSessionSetActive(YES);

I have tried out almost all combination of category but I am not able to get required output, SoloAmbient and Ambient don't play sound at all.

I had also tried to disable audioinput of the AVCapturesession but it does not help.

Answer 1

You'll have to remove the AVCaptureInput device that represents the microphone. You can do this by iterating over the AVCaptureSession instance and doing something like this:

AVCaptureSession *currentSession = self.currentSession;
for(AVCaptureInput *input in currentSession.inputs) {

    for (AVCaptureInputPort *port in input.ports) {
        if ([[port mediaType] isEqual:AVMediaTypeAudio]) {
            [currentSession removeInput:input];
            break;
        }
    }
}

now setup your audio as something like this:

AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayAndRecord  withOptions:AVAudioSessionCategoryOptionMixWithOthers|AVAudioSessionCategoryOptionDefaultToSpeaker error:nil];
NSError *activationError = nil;
BOOL success = [session setActive: YES error: &activationError];

SWIFT 3

let currentSession = self.currentSession

for input in currentSession.inputs as! [AVCaptureInput] {
  for port in input.ports as! [AVCaptureInputPort] {
    if port.mediaType == AVMediaTypeAudio {
      currentSession.removeInput(input)
      break
    }
  }
}

do {
  let session = AVAudioSession.sharedInstance()
  try session.setCategory(AVAudioSessionCategoryPlayAndRecord, with: [AVAudioSessionCategoryOptions.mixWithOthers, AVAudioSessionCategoryOptions.defaultToSpeaker])
  try session.setActive(true)
} catch {

}