playing a video with MPMoviePlayerController while recording with AudioQueue

2
votes

i'm developing an app which requires to play a video from an URL using MPMoviePlayerController while acquiring audio samples using AudioQueue from the microphone to further analyze them.

The problem is that I cannot record when the video starts playing (and also when it finishes). Simply the audio sampling stops. Instead, if I disable the video play, audio recording goes well. I've tried setting up an AudioSession with property kAudioSessionProperty_OverrideCategoryMixWithOthers but with no success (it returns error). Moreover I think that it's useless setting a property in AudioSession when using AudioQueue. Even setting useApplicationAudioSession = NO for MPMoviePlayerController does not give any help.

Hereby the core code where the player is created:

   audioManager = [[AudioController alloc] init]; 
   //setting AudioQueue: audio buffer, sample rate, format ID (PCM), bits per channel 
   audioManager.delegate = self;
   [audioManager startAudioRecording];  //starts recording with AudioQueue
   self.playerVC = [[[MPMoviePlayerController alloc] init] autorelease];
   layerVC.view.frame = self.viewPlayer.bounds;
   [self.viewPlayer addSubview:playerVC.view];
   playerVC.useApplicationAudioSession = YES; //if NO nothing changes
   [playerVC setContentURL:[NSURL URLWithString:@"http://www......."]];
   [playerVC prepareToPlay];
   [playerVC play];
1
iphoneiosaudiovideoaudio-recording

1 Answers

2
votes

You're on the right way. First, set the kAudioSessionProperty_OverrideCategoryMixWithOther to true. This will allow your app's sound mixes with sounds from another apps.

UInt32 allowMixing = true;
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(allowMixing), &allowMixing);

After that, you will need to set MPMoviePlayerController to not use your app's AudioSession:

[yourMPMoviePlayerControllerInstance setUseApplicationAudioSession:NO];