Apologies for delay in response. Yes, using M4M you can control Microphone input. We have release version on dynamic control of microphone. Please share your email address with me via "Private Messages", I will send you the code snippet.
M4M build with feature enabled shared directly with customer and has been confirmed by the customer through private message. If you come across any issue please start a new thread on Media forum - https://software.intel.com/en-us/forums/intel-media-sdk.
Apologies for slow response. It weird that you are still seeing microphone issues with the release version of M4M. I have sent a mail directly, let me know with your reply, error message you are seeing including details about HW device and Android OS version on the device.
Quick update for you :)
I eventually found that I could mute the microphone using AudioManager.setMicrophoneMute( true ); providing I set the correct permissions:
However, I quickly discovered that M4M uses the microphone to capture the audio, so if I mute the microphone or the user turns the device volume down/off, audio won't be captured. Regrettably, I've had to abandon using the M4M library for this reason.
Thanks for the update. Yes, M4M uses microphone to capture the audio during capturing and with release build you can dynamically control Microphone. But for your use case scenario turning off device volume or muting the microphone, audio capturing will be missed.