/// <summary>
/// Initialize the underlying WebRTC peer connection.
/// </summary>
/// <remarks>
/// This method is asynchronous and completes its task when the initializing completed.
/// On successful completion, it also trigger the <see cref="OnInitialized"/> event.
/// Note however that this completion is free-threaded and complete immediately when the
/// underlying peer connection is initialized, whereas any <see cref="OnInitialized"/>
/// event handler is invoked when control returns to the main Unity app thread. The former
/// is faster, but does not allow accessing the underlying peer connection because it
/// returns before <see cref="OnPostInitialize"/> executed. Therefore it is generally
/// recommended to listen to the <see cref="OnInitialized"/> event, and ignore the returned
/// <see xref="System.Threading.Tasks.Task"/> object.
/// </remarks>
private async Task <WebRTC.PeerConnection> InitializePluginAsync(CancellationToken token)
{
// Ensure Android binding is initialized before accessing the native implementation
Android.Initialize();
#if UNITY_WSA && !UNITY_EDITOR
if (Library.UsedAudioDeviceModule == AudioDeviceModule.LegacyModule)
{
// Preventing access to audio crashes the ADM1 at startup and the entire application.
bool permissionGranted = await UwpUtils.RequestAccessAsync(StreamingCaptureMode.Audio);
if (!permissionGranted)
{
return(null);
}
}
#endif
// Create the peer connection managed wrapper and its native implementation
var nativePeer = new WebRTC.PeerConnection();
nativePeer.AudioTrackAdded +=
(RemoteAudioTrack track) =>
{
// Tracks will be output by AudioReceivers, so avoid outputting them twice.
track.OutputToDevice(false);
};
Debug.Log("Initializing WebRTC Peer Connection...");
var config = new PeerConnectionConfiguration();
foreach (var server in IceServers)
{
config.IceServers.Add(new IceServer
{
Urls = { server.ToString() },
TurnUserName = IceUsername,
TurnPassword = IceCredential
});
}
try
{
await nativePeer.InitializeAsync(config, token);
return(nativePeer);
}
catch (OperationCanceledException canceled) { throw canceled; }
catch (Exception ex)
{
nativePeer.Dispose();
token.ThrowIfCancellationRequested();
EnsureIsMainAppThread();
var errorMessage = new StringBuilder();
errorMessage.Append("WebRTC plugin initializing failed. See full log for exception details.\n");
errorMessage.Append($"Exception: {ex.Message}");
OnError.Invoke(errorMessage.ToString());
throw ex;
}
}
private Task <bool> RequestAccessAsync(CancellationToken token)
{
#if !UNITY_EDITOR && UNITY_ANDROID
// Ensure Android binding is initialized before accessing the native implementation
Android.Initialize();
// Check for permission to access the camera
if (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
{
// Display dialog requesting user permission. This will return immediately,
// and unfortunately there's no good way to tell when this completes.
Permission.RequestUserPermission(Permission.Microphone);
// As a rule of thumb, application should lose focus, so check when focus resumes should
// be sufficient without having to poll every frame.
// Monitor the OnApplicationFocus(true) event during the next 5 minutes,
// and check for permission again each time
var tcs = new TaskCompletionSource <bool>();
lock (_androidPermissionRequestLock)
{
Debug.Assert(_androidPermissionRequestTcs == null);
_androidPermissionRequestTcs = tcs;
}
Task.Delay(TimeSpan.FromMinutes(5)).ContinueWith(_ =>
{
lock (_androidPermissionRequestLock)
{
// Check if the component is still waiting on the same permission request.
// If it has been disabled and then re-enabled, _androidPermissionRequestTcs will be different.
if (_androidPermissionRequestTcs == tcs)
{
Debug.LogError("User denied RecordAudio (microphone) permission; cannot use MicrophoneSource.");
_androidPermissionRequestTcs.SetResult(false);
_androidPermissionRequestTcs = null;
}
}
});
// If the initialization is canceled, end the task and reset the TCS.
token.Register(() =>
{
lock (_androidPermissionRequestLock)
{
// Check if the component is still waiting on the same permission request.
// If the request has completed or timed out, _androidPermissionRequestTcs will be null.
if (_androidPermissionRequestTcs != null)
{
Debug.Assert(_androidPermissionRequestTcs == tcs);
_androidPermissionRequestTcs.SetCanceled();
_androidPermissionRequestTcs = null;
}
}
});
return(tcs.Task);
}
// Already has permission.
return(Task.FromResult(true));
#elif UNITY_WSA && !UNITY_EDITOR
return(UwpUtils.RequestAccessAsync(StreamingCaptureMode.Audio));
#else
return(Task.FromResult(true));
#endif
}