Direct call

This page explains key functions of direct call consisting of how to make, receive, handle, and end a call from your app.

This object represents a 1-to-1 call. It has the following properties and functions:

Initiate a call by providing the callee’s user ID into the SendBirdCall.dial() method. Use the CallOptions object to choose a call’s initial settings.

let params = DialParams(calleeId: CALLEE_ID, callOptions: CallOptions())

let directCall = SendBirdCall.dial(with: params) { directCall, error in
    // The call has been created successfully
}

directCall.delegate = self

In a video call, configure the video view settings prior to making the call so that the transition from a voice call to a video call will be seamless. Create SendBirdVideoView instances to render local and remote video streams as shown below:

let localSBView = SendBirdVideoView(frame: self.localVideoView?.frame ?? CGRect.zero)
let remoteSBView = SendBirdVideoView(frame: self.remoteVideoView?.frame ?? CGRect.zero)

// When making a call or accepting an incoming call.
let callOptions = CallOptions(
            isAudioEnabled: true,
            isVideoEnabled: true,
            localVideoView: localSBVideoView,
            remoteVideoView: remoteSBVideoView)

// Or when updating local/remote view
self.call.updateLocalVideoView(localSBView)
self.call.updateRemoteVideoView(remoteSBView)

To receive an incoming call, a SendBirdCallDelegate event delegate should already be registered in the callee’s client app. Accept or decline the call using the directCall.accept() or the directCall.end() method. If the call is accepted, a media session will automatically be established by the Calls SDK.

Before accepting the call, the call-specific DirectCallDelegate event delegate must be added to the call object. It enables the callee’s app to react to events during the call through its delegate methods.

class MyClass: SendBirdCallDelegate {
    func didStartRinging(_ call: DirectCall) {
        call.delegate = self
    }
}

The callee’s client app receives an incoming call through either the established connection with Sendbird server or PushKit if the app uses CallKit. To use the Calls SDK in the callee’s client app, the SendBirdCall instance must deliver received PushKit messages to the Calls SDK.

class AppDelegate: PKPushRegistryDelegate {
    func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
        SendBirdCall.pushRegistry(registry, didReceiveIncomingPushWith: payload, for: type)
    }
}

If a client app has CallKit implemented and propagates PushKit messages through the PKPushRegistryDelegate’s pushRegistry(:didReceiveIncomingPushWith:for:completion) method, incoming calls displayed by PushKit messages should be delivered to the didStartRinging delegate method as shown below:

func didStartRinging(_ call: DirectCall) {
    // IMPORTANT: An incoming call should be delivered to this delegate method when you receive a PushKit push message for the call.
    let provider = CXProvider(configuration: CXProviderConfiguration)
    let update = CXCallUpdate()
    update.remoteHandle = CXHandle(type: .generic, value: CALLER_ID)
    provider.reportNewIncomingCall(with: uuid, update: update) { (error) in
        completion()
    }
}

During an active call, both the caller and callee’s audio can be muted or unmuted by the directCall.muteMicrophone() or directCall.unmuteMicrophone() method. If one party changes audio settings, the other party receives an event callback through the DirectCallDelegate.didRemoteAudioSettingsChange(_:) delegate method.

// Mute my microphone
call.muteMicrophone()
// Unmute my microphone
call.unmuteMicrophone()
class MyClass: SendBirdCallDelegate {
    func didRemoteAudioSettingsChange(_ call: DirectCall) {
        if (call.isRemoteAudioEnabled) {
            // The remote user has been unmuted.
            // Update UI components accordingly
        } else {
            // The remote user has been muted.
            // Update UI components accordingly
        }
    }
}

During an active call, both the caller and callee’s video can be enabled or disabled by the directCall.startVideo() or directCall.stopVideo() method. If one party changes audio settings, the other party receives an event callback through the DirectCallDelegate.didRemoteVideoSettingsChange(_:) delegate method.

// Start my local video
call.startVideo()
// Stop my local video
call.stopVideo()

// Receive the event
class MyClass: DirectCallDelegate {
    func didRemoteVideoSettingsChange(_ call: DirectCall) {
        if (call.isRemoteVideoEnabled) {
            // The remote user has started video.
        } else {
            // The remote user has ended video.
        }
    }
}

The directCall.end() method ends an ongoing call of either the caller or callee’s side. If one party ends an ongoing call, the other party receives an event callback through the DirectCallDelegate.didEnd() method.

// End a call.
call.end()

// Receiving the end event.
class MyClass: DirectCallDelegate {
    func didEnd(_ call: DirectCall) {
        // Update UI components accordingly.
    }

    ...
}

During an active call, users can hold and resume the call. Users can talk to each other on a single active call at a time while putting other ongoing calls on hold. An active call and calls on hold are ongoing calls. By holding a call, users can accept an incoming call or switch between ongoing calls.

Note: Credit usage and billing for a call on hold is the same as with an active call because they are both considered as ongoing calls.

During an active call, a user can hold the call by using the directCall.hold() method. When an active call is put on hold, audio and video also stops for the call. Therefore, functionalities that require audio and video such as screen share, local recording, and screen capture will not be available for a call that is put on hold.

call.hold { error in
    // Call is successfully put on hold.
}

When a call is placed on hold, the value of directCall.isOnHold changes to true and the users will receive a notification on the change of the hold status of the call through the DirectCallDelegate.didUserHoldStatusChange method.

A user can only remove their own hold on a call by using the directCall.unhold() method.

call.unhold { error in
    // A hold is successfully removed from the call.
}

If you try to call the directCall.unhold() method on a call that is on hold while there is an active call, an error will be returned. If you wish to override this error, you have to forcefully end the active call by calling the directCall.unhold() method with the force parameter as true.

When a hold is removed from a call, users will receive a notification on the change of the hold status of the call through the DirectCallDelegate.didUserHoldStatusChange method.

Both the caller and callee must return to the same ongoing call in order to resume a call to talk to each other. The users should either hold or end other ongoing calls except for the call they would like to return to. By using the directCall.unhold() method, the users can remove a hold on the same ongoing call. Once both users remove their holds from the call, audio and video also becomes available for the call which will be resumed.

When the both users remove holds on the same ongoing call, the value of directCall.isOnHold changes to false and users will receive a notification on the change of the hold status of the call through the DirectCallDelegate.didUserHoldStatusChange method.

You can accept an incoming call while there is an active call. Because there can only be one active call at a time, the active call must be either ended or put on hold before the incoming call is accepted.

To end an active call and accept an incoming call, use the directCall.accept() method. The active call will end and the end result will show as .completed.

To hold an active call and accept an incoming call, use the directCall.accept() method with AcceptParams.holdActiveCall set to true. The active call will be placed on hold and the incoming call will become the active call.

func didStartRinging(_ call: DirectCall) {
    let acceptParams = AcceptParams()
    acceptParams.holdActiveCall = true
    call.accept(with: acceptParams)
}

When there are multiple calls on hold, you can retrieve a list of all ongoing calls by using the SendBirdCall.getOngoingCalls() method.

let callOnHold = SendBirdCall.getOngoingCalls().filter { $0.isOnHold }.first
callOnHold.unhold()

You can retrieve a list of all incoming calls by using the SendBirdCall.getIncomingCalls() method.

let incomingCalls = SendBirdCall.getIncomingCalls()

You can receive notifications when a local or remote user puts a call on hold or removes a hold from a call. When the hold status of the user changes, the DirectCallDelegate.didUserHoldStatusChange(_:isLocalUser:isUserOnHold:) delegate method will be called. The isLocalUser and isUserOnHold parameters can be used to identify which user has put certain calls on hold. To identify which calls are put on hold by either or both users, use the directCall.isOnHold property.

class MyClass: DirectCallDelegate {
    func didUserHoldStatusChange(_ call: DirectCall, isLocalUser: Bool, isUserOnHold: Bool) {
        // Use `isLocalUser` and `isUserOnHold` to identify the users' hold status of a call.
        // Use the updated `call.isOnHold` value to update the call view.
    }
}

With custom items, you can store additional information to a call in addition to default values in the DirectCall object. These key-value custom items are delivered as a [String: String] dictionary and can be updated during the call. Examples of items that could be included in the call are customer service, refund, or inquiry for better user experience.

Custom items can be added to a call either by a caller or a callee. When dialing, the caller can add a [String: String] to the customItems of DialParam. The default value of customItems is an empty dictionary.

let customItemsToAdd = ["key1": "value1", "key2": "value2"]
call.updateCustomItems(customItems: customItemsToAdd) { (addedCustomItems, addedCustomItemKeys, error) in
    // Handle added custom items.
}

During a call, custom items can be modified by directly updating or deleting custom items of a given call. You can use directCall.updateCustomItems(:completionHandler:) to update current custom items with new custom items. If keys for the new custom items don't exist, new custom items will be added to the existing list of items. Otherwise, existing items will be replaced with new custom items.

You can modify custom items without directly referring to the DirectCall object. The custom items of the call from the SendBirdCall can also be modified by calling the same set of methods with an additional callId parameter. If a call with the corresponding callId exists, the SendBirdCall will update the custom items of that call.

You can delete a specific custom item with its given key by using directCall.deleteCustomItems(:completionHandler:) or delete all the items associated with the call by using directCall.deleteAllCustomItems(:). Through a completion handler, you will receive the updated custom items, a list of keys of the modified custom items, and an error from Sendbird server.

let customItemsToModify = ["key1": "value3", "key2": "value4"]
call.updateCustomItems(customItems: customItemsToModify) { (modifiedCustomItems, modifiedCustomItemKeys, error) in
    // Handle updated custom items.
}

let customItemKeysToDelete = ["key1", "key2"]
call.deleteCustomItems(customItemKeys: customItemKeysToDelete) { (deletedCustomItems, deletedCustomItemKeys, error) in
    // Handle deleted custom items.
}

call.deleteAllCustomItems { (deletedCustomItems, deletedCustomItemKeys, error) in
    // Handle deleted custom items.
}

To receive events from Sendbird server when custom items are modified, you can implement didUpdateCustomItems() and didDeleteCustomItems() from the DirectCallDelegate. Events contain the DirectCall object of changed custom items and updatedKeys or deletedKeys. Custom items can always be modified, however these events will only be delivered if the call is ongoing. If the call ends, events are not delivered to the DirectCallDelegate. You can always access modified custom items even after the call ends with the Calls API or by using the directCall.customItems.

class MyClass: DirectCallDelegate {
    ...

    func didUpdateCustomItems(call: DirectCall, updatedKeys: [String]) {
        // Handle updated custom items with 'call.customItems' and 'updatedKeys'.
    }

    func didDeleteCustomItems(call: DirectCall, deletedKeys: [String]) {
        // Handle deleted custom items with 'call.customItems' and 'deletedKeys'.
    }
    ...

}

One party’s information can be retrieved through the directCall.localUser property while the other party’s information through the directCall.remoteUser property.

A user’s call history can be retrieved using the next() method of a DirectCallLogListQuery instance which returns a list of call objects.

let params = DirectCallLogListQuery.Params()
params.myRole = .caller     // Filter for current user’s role in the call
params.endResultsArray = [.cancel, .decline, .complete]     // Filter for end results of the call
params.limit = 25       // Number of call logs to be returned at once.
let listQuery = SendBirdCall.createDirectCallLogListQuery(with: params)

if listQuery.hasNext {
    listQuery.next() { [weak listQuery] (callLogs, error) in
        // The 'listQuery.next()' can be called once more to fetch more call logs.
    }
}

The call log can be immediately obtained after a call has ended. However, in the caller’s case, only the local log will be retrieved unless the sync has been made with the server. If you want to check whether a call log is synchronized with the server or not, use the directCallLog.isFromServer. To retrieve call history from the server instead of the local log, use the SendBirdCall.DirectCallLogListQuery.

class MyClass: DirectCallDelegate {
    ...

    func didEnd(_ call: DirectCall) {
        ...

        let callLog = call.callLog
        // Appropriately add this callLog object to the callLog list.
    }
}

You can receive and be notified of new incoming calls through push notifications. However, if you're unable to do so due to issues with push notifications, you can use the SendBirdCall.retrieveMissedDirectCalls() method to pick up the incoming call. The incoming call will be received through SendBirdCallDelegate.didStartRinging().

SendBirdCall.retrieveMissedDirectCalls { error in
 // Handle error. 
}


class MyClass: SendBirdCallDelegate {
  func didStartRinging(_ call: DirectCall) { 
    // If you called `retrieveMissedDirectCalls()`, `call.ringingSource` will be `.retrieval`
    // If the call is received through push notifications, `call.ringingSource` will be `.push`
    }
}

If you received a push notification of an incoming call through SendBirdCallDelegate.didStartRinging() but failed to process it, you can get a list of all incoming calls, including ones that are currently ringing, through SendBirdCall.getIncomingCalls().

Note: SendBirdCall.retrieveMissedDirectCalls() is automatically triggered internally when the Calls SDK has been successfully authenticated.

You can also identify where a call is coming from through the DirectCall.ringingSource property.

Users can select a device for video output during a video call. The list of available video devices can be accessed by the DirectCall.availableVideoDevices() method. In order to change the current video output device to one of the other available video devices, the DirectCall.selectVideoDevice(completionHandler:) method should be called.

let availableCapturers = self.call.availableVideoDevices
guard let oppositeCamera = availableCapturers.first(where: { $0.position != self.call.currentVideoDevice?.position }) else {
    return
}
self.call.selectVideoDevice(oppositeCamera) { (error) in
    // Current video device has been changed to the `oppositeCamera` with error.
}

To turn on the switch between the front and back cameras function, use the switchCamera(completionHandler:) method.

self.call.switchCamera { (error)
    // Switching between the front and back cameras function has been turned on.
}

During a video call, the caller and callee can capture the images of their streaming video by using either the captureLocalVideoView() or captureRemoteVideoView() methods when needed.

self.call.captureLocalVideoView { [weak self] (image, error) in
    guard let image = image, error == nil else {
        // Handle error.
        return
    }

    self?.localImage = image
    // Implement code for handling a successfully-captured image.
}

self.call.captureRemoteVideoView { [weak self] (image, error) in
    guard let image = image, error == nil else {
        // Handle error.
        return
    }

    self?.remoteImage = image
    // Implement code for handling a successfully-captured image.
}

Note: For errors that may occur when capturing video views, see the Error codes page.

When making a direct call with Sendbird Calls, audio and video recordings for both local and remote users are available. The recorded file will be saved on the user’s local file storage and users can transfer or process the file.

Only one ongoing recording session is allowed, which means that the current recording session must be stopped in order to start another recording. However, several sessions can be recorded throughout the call, thus multiple recording files created from one call.

The SendBirdCall currently supports five recording types:

Start recording a call using the directCall.startRecording() method. You can customize the type and the name of the recording as well as the output path where a recorded file will be saved with a RecordingOptions object.

If the name of a file isn't specified for the filename parameter in the method, the recorded file’s name will follow the default pattern of {recording_type}_{call_id}_{timestamp}.

let options = RecordingOptions(type: .remoteAudioAndVideo, directoryPath: OUTPUT_PATH, fileName: FILE_NAME)
// Record remote user’s audio and video, with output URL of `OUTPUT_PATH/FILE_NAME.mp4`

call.startRecording(options: options) { (recordingId, error) in
    ...
}

A recordingId is delivered through the completion handler of the directCall.startRecording() method when the recording starts successfully. Make sure to save the recordingId to stop the recording session. If the recordingId is invalid or missing when the directCall.stopRecording() method is called, you can’t stop the recording session when needed.

Note: The SendBirdCall doesn’t check for file read and write permissions or any other permissions related to the media. Make sure that the application can write at the specified destination folder before starting a recording session.

Stop recording a call using the directCall.stopRecording() method with the recordingId received from the completion handler of the directCall.startRecording() method. If a recording session isn’t stopped by the time the call has ended, the recording session automatically ends as well.

call.stopRecording(recordingId: recordingId)
// Stop a recording session with the given ‘recordingId’.
// If the provided ‘recordingId’ is invalid, the request will be ignored.

After the recording is finished, the SendBirdRecordingDelegate.didSaveRecording() event delegate method will be called.

In order to receive events about the completion of the recordings, add a device-specific SendBirdRecordingDelegate by using the SendBirdCall.addRecordingDelegate(:) delegate method. Once the event delegate is added, your app can handle the following two events as shown below:

SendBirdCall.addRecordingDelegate(self, identifier: UNIQUE_ID)

class MyClass: SendBirdRecordingDelegate {
    ...

    func didSaveRecording(call: DirectCall, recordingId: String, options: RecordingOptions, outputURL: URL) {
        // Recording was successfully saved to ‘outputURL’.
    }

    func didFailToSaveRecording(call: DirectCall, recordingId: String, error: SBCError) {
        // Recording wasn’t saved due to an ‘error’.
    }
}

You can remove the device-specific SendBirdRecordingDelegate as shown below:

SendBirdCall.removeRecordingDelegate(identifier: UNIQUE_ID)
// Remove a recording delegate with the specified identifier.

SendBirdCall.removeAllRecordingDelegates()
// Remove all recording delegates from the application.

Note: The SendBirdRecordingDelegate.didFailToSaveRecording() event delegate method won’t be called if errors occur at the start of recording sessions after calling the directCall.startRecording() method.

While streaming audio or video is being recorded, it is transcoded almost simultaneously to convert the stream into an MP4 file regardless of the recording option. After your recording is done, it typically takes less than a second to save the recording as an MP4 file.

Recorded videos will have a fixed frame size of 1280x720 pixels. Video recording uses around 20 MB of data per minute, but this may vary depending on the type of the recording content.

The SendBirdCall doesn’t handle anything related to managing recorded files. If there isn’t enough storage to save the recorded file, SendBirdRecordingDelegate.didFailToSaveRecording will be called.

During a voice or video call, users can notify each other if the call is being recorded.

If a user starts or stops local recording on their device, the other user will be able to receive an event callback through the DirectCallDelegate.didRemoteRecordingStatusChange(_ call: DirectCall) delegate method. Users can also check the recording status of the other user with DirectCall.remoteRecordingStatus.

// Recording status of the local user
call.localRecordingStatus
// Recording status of the remote user
call.remoteRecordingStatus

class MyClass: DirectCallDelegate {
    func didRemoteRecordingStatusChange(_ call: DirectCall) {
        // When the remote user is recording the call, call.remoteRecordingStatus == .recording
        // When the remote user has finished recording the call, call.remoteRecordingStatus == .none
    }
}

During a video call, both the caller and callee can share their screens with each other by using Apple’s ReplayKit.

let recorder = RPScreenRecorder.shared()

self.call.startScreenShare { (bufferHandler, error) in
    guard error == nil else { return }

    recorder.startCapture { (buffer, bufferType, error) in
        bufferHandler?(buffer, error)
    } completionHandler: { (error) in
        Guard error == nil else { return } // Handle error
        print("Successfully started screen share.")
    }
}

When the startScreenShare method is called, both the local user's localVideoView and the remote user’s remoteVideoView will be replaced with the screen share view. Currently, displaying the local camera view and the local screen share view together is not supported. If RPScreenRecorder.startCapture is invoked, the operating system will automatically ask the user to confirm the permission to record the screen.

Note: There is a known issue in iOS that if the user is recording the remote video view while the remote user is sharing the screen, it will result in a distorted video view.

You can stop sharing your screen and return to the video view as shown below:

let recorder = RPScreenRecorder.shared()
recorder.stopCapture { (error) in
    self.call.stopScreenShare()
}

Note: To learn more about implementing screen sharing, see our tutorial.

You can use different sound effects to enhance the user experience for events that take place while using Sendbird Calls.

To add sound effects, use the SendBirdCall.addDirectCallSound(_:forType:) method for the following events: dialing, ringing, reconnecting, and reconnected. Remember to set sound effects before the mentioned events occur. To remove sound effects, use the SendBirdCall.removeDirectCallSound(_:forType:) method.

To set the dialing sound effect in silent mode, use the setDirectCallDialingSoundOnWhenSilentMode(isEnabled:) method.

// Play on a caller’s side when making a call.
SendBirdCall.addDirectCallSound("dialing.mp3", forType: .dialing)

// Set up dialing sound when silent mode.
SendBirdCall.setDirectCallDialingSoundOnWhenSilentMode(isEnabled: true)

// Play on a callee’s side when receiving a call.
SendBirdCall.addDirectCallSound("ringing.mp3", forType: .ringing)

// Play when a connection is lost, but the SDK immediately attempts to reconnect.
SendBirdCall.addDirectCallSound("reconnecting.mp3", forType: .reconnecting)

// Play when the connection is re-established.
SendBirdCall.addDirectCallSound("reconnected.mp3", forType: .reconnected)

If you’re using Apple’s CallKit framework, you should use CXProviderConfiguration.ringtoneSound instead to add sound effects as ringtones like the following:

let configuration = CXProviderConfiguration()
configuration.ringtoneSound = "ringing.mp3"
...

For more information about sound effects, refer to our Calls SDK GitHub repository's README.

Users can receive notifications about the changes in call quality so that they can check their network connection to avoid any interruption during an active call.

To detect changes in call quality, you need to set ConnectionQualityDelegate and select a monitoring mode by calling the setConnectionQualityDelegate() method. Based on the specified monitoring mode, the didConnectionQualityUpdate method will be called.

class MyClass: ConnectionQualityDelegate { 
    func didConnectionQualityUpdate(metrics: ConnectionMetrics) {
        // Quality changed to `metrics.connectionQuality`.
    }
}

directCall.setConnectionQualityDelegate(myClass, monitoringMode: .connectionQualityChange)

The connection quality in the ConnectionMetrics class represents the quality of the call based on the value of Mean Opinion Score (MOS). MOS is a subjective measure that is used to evaluate the overall quality of direct calls. Scores range from 0.0 to 4.5 and has the following quality states.

Depending on the ConnectionQuality enum, you can determine the current quality of the call and take appropriate actions to improve the call quality. For example, you can choose to show a quality degradation alert to the user if the connection quality drops below average.

Call the removeConnectionQualityDelegate() method to remove all previous settings.

directCall.removeConnectionQualityDelegate()