Speaking While Muted

Some calling apps show an indicator when you are trying to speak while you are muted. This is helpful for users that forgot to turn on the microphone when they try to speak.

You can easily add such functionality with the StreamVideo iOS SDK. One approach to achieve this is to add an overlay to the CallView with the indicator. The logic for displaying the popup can be determined by listening to sounds even when the microphone is turned off. When a sound goes over a certain threshold, we will display the indicator.

Here's an example implementation for this approach, using the MicrophoneChecker from the SDK:

struct CustomCallView<Factory: ViewFactory>: View {
    
    @Injected(\.colors) var colors
    
    var viewFactory: Factory
    @ObservedObject var viewModel: CallViewModel
    
    @StateObject var microphoneChecker = MicrophoneChecker()
    @State var mutedIndicatorShown = false
    
    var body: some View {
        CallView(viewFactory: viewFactory, viewModel: viewModel)
            .onReceive(viewModel.$callSettings) { callSettings in
                Task { await updateMicrophoneChecker() }
            }
            .onReceive(microphoneChecker.$$audioLevels, perform: { values in
                guard !viewModel.callSettings.audioOn else { return }
                for value in values {
                    if (value > -50 && value < 0) && !mutedIndicatorShown {
                        mutedIndicatorShown = true
                        DispatchQueue.main.asyncAfter(deadline: .now() + 2.0, execute: {
                            mutedIndicatorShown = false
                        })
                        return
                    }
                }
            })
            .overlay(
                mutedIndicatorShown ?
                VStack {
                    Spacer()
                    Text("You are muted.")
                        .padding(8)
                        .background(Color(UIColor.systemBackground))
                        .foregroundColor(colors.text)
                        .cornerRadius(16)
                        .padding()
                }
                : nil
            )
    }
    
    private func updateMicrophoneChecker() async {
        if !viewModel.callSettings.audioOn {
            await microphoneChecker.startListening()
        } else {
            await microphoneChecker.stopListening()
        }
    }
}

In the implementation, we are listening to the callSettings changes from the view model. Based on that, we decide whether we should listen for sounds from the microphone checker.

Additionally, we are listening to the @Published property called decibels from the MicrophoneChecker, which returns an array of the last 3 decibels. If a value passes our threshold, then we set the mutedIndicatorShown to true, which displays a simple text popup. We reset the value to false after 2 seconds, to hide the popup.

Finally, we need to use the custom call view in the custom ViewFactory:

func makeCallView(viewModel: CallViewModel) -> some View {
    CustomCallView(viewFactory: self, viewModel: viewModel)
}