Callkit loudspeaker bug / how WhatsApp fixed it?

Question

I have an app with Callkit functionality. When I press the loudspeaker button, it will flash and animate to the OFF state (sometimes the speaker is set to LOUD but the icon is still OFF). When I tap on it multiple times... it can be clearly seen that this functionality is not behaving correctly.

However, WhatsApp has at the beginning the loudspeaker turned OFF and after 3+ seconds it activates it and its working. Has anyone encountered anything similar and can give me a solution?

Youtube video link to demonstrate my problem

Answer 1

There is a workaround proposed by an apple engineer which should fix callkit not activating the audio session correctly:

a workaround would be to configure your app's audio session (call configureAudioSession()) earlier in your app's lifecycle, before the -provider:performAnswerCallAction: method is invoked. For instance, you could call configureAudioSession() immediately before calling -[CXProvider reportNewIncomingCallWithUUID:update:completion:] in order to ensure that the audio session is fully configured prior to informing CallKit about the incoming call.

From: https://forums.developer.apple.com/thread/64544#189703

If this doesn't help, you probably should post an example project which reproduces your behaviour for us to be able to analyse it further.

Answer 2

Above answer is correct, "VoiceChat" mode ruin everything.

Swift 4 example for WebRTC. After connection was established call next

let rtcAudioSession = RTCAudioSession.sharedInstance()
rtcAudioSession.lockForConfiguration()
do {
    try rtcAudioSession.setCategory(AVAudioSession.Category.playAndRecord.rawValue, with: 
    AVAudioSession.CategoryOptions.mixWithOthers)
    try rtcAudioSession.setMode(AVAudioSession.Mode.default.rawValue)
    try rtcAudioSession.overrideOutputAudioPort(.none)
    try rtcAudioSession.setActive(true)
} catch let error {
    debugPrint("Couldn't force audio to speaker: \(error)")
}
rtcAudioSession.unlockForConfiguration()

You can use AVAudioSession.sharedInstance() as well instead RTC