Android Oboe Library: 2 streams recording from 2 recording devices possible?

Question

• Device: HUAWEI P smart
  
  
• Android-Version: 8.0.0
  
  
• Generic Application:
  RecDev1 -> PlayDev1
  RecDev2 -> PlayDev2
  \"simult

Answer 1

** according to Don Turner's answer: "Android does not allow you to open input (ie recording) audio streams to more than one audio device at the same time. This use case is not supported."

** More clearly:
- Android does NOT support recording from more than ONE input devices at the same time.
- Android does NOT support playback to more than ONE output devices at the same time.
- and for sure, the combination of the 2 points above does NOT work either.

** This can be easily tested e.g. by running 2 instances of this AAudio Sample in parallel and selecting different output devices. This will just NOT work!

** This VERY IMPORTANT CONSTRAINT is not mentioned anywhere in the official documentation!!!

** Therefore, the following "example use case" is NOT supported by Android (oboe, aaudio, opensl es):

USB-Audio-In ---> In-line-speaker
and at the same time
Mic ----> USB-Audio-Out

** I am quite disappointed, I spent time and money to start something based on this, assuming this was "basic" functionality...now I have to give up :-(

** If I find the right place, then I will enter a "request" to support this "feature", e.g. in AAudio.

** Hope this helps other people before they invest too much time in something beyond the current capabilities offered by Android and the corresponding libraries.

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** A possible workaround indicated by donturner would be instead using a special USB-soundcard with 2 inputs and 2 outputs which are just separate channels in the same device. Unfortunately, this does not really work for me because I was targeting a low-cost solution without additional hardware (using the headset interface).