问题
We're currently using Linphone library to make VOIP calls and they have their own solution for audio playback. However, we would like to display a visualizer for the audio that Linphone is outputting from within our own app. Is there a way that we can intercept this data (maybe through sample buffering) in order to draw up audio waves/volume meter in the user interface?
AVAudioPlayer or AVPlayer is out of the question since we do not have access to those objects. Is there a solution in place for AVAudioSession or in CoreAudio?
回答1:
Only if the audio output app is exporting the audio data using Inter-App-audio or Audiobus. Otherwise the iOS security sandbox will hide that audio output from your app.
来源：https://stackoverflow.com/questions/49061264/is-there-a-way-to-intercept-audio-output-from-within-your-app-to-display-back-an