如何从iOS设备的蓝牙耳机录制声音？

Question

I have an application that needs to record voice from Bluetooth headset. It needs work like Siri or Google Assistant. When I press button in App, it records voice from Bluetooth MIC rather than build in Mic. Is that possible? My understanding is 1) either the Bluetooth is an Apple certificated External Accessory 2) or the Headset can implement a HFP like protocol to active a HFP link ? Any hints?

Answer 1

If all you need is recording, it's quite straight if your bluetooth device is paired with iOS. All bluetooth headset with microphone will work well.

When you start to record, I think you have already changed your audio session category to play and record.

Then you can check all your available input route with

-[AVAudioSession availableInputs]

and iterate to find the bluetooth, then set it with

-[AVAudioSession setPreferredInput:error:]

Sometimes it will fail, you need to check the output parameter error to find if there is something wrong.