Adding the liblinphone dependency to your iOS project

Liblinphone for iOS is available using Cocoapods, the de-facto standard in the Apple developer world for "dependency management for Swift and Objective-C". Liblinphone can also be compiled from the sources.

Using Cocoapods

For a project named "Myproject"

open Myproject/, use commands:

pod init

Modify the generated Podfile according to your project:

# Uncomment the next line to define a global platform for your project

##For macosx
# platform :osx, '10.9'
#source "https://gitlab.linphone.org/BC/public/podspec-macos.git"

#For iOS
platform :ios, '9.0'
source "https://gitlab.linphone.org/BC/public/podspec.git"

target 'Myproject' do
 use_frameworks!

  # Pods for Myproject
 pod 'linphone-sdk' , '4.3'
end

 To install or update the liblinphone version, do the following command 

pod repo update
pod install

And you're done.

Some alpha (development versions) of liblinphone may also be available. To get them, replace the line:

pod 'linphone-sdk' , '4.3'

by

pod 'linphone-sdk', '> 4.4.0-alpha' 

followed by:

pod install

Compiling linphone-sdk

Linphone-sdk is the name of the git project that contains liblinphone and all its dependencies.

Compilation instructions of the SDK are available at: linphone-sdk/README.md

Once done, cocoapods needs to be invoked to update the Xcode workspace to use your locally built linphone-sdk, as follows:

PODFILE_PATH=<path to linphone-sdk-ios> pod install
where <path to linphone-sdk-ios>  is your build directory of the linphone-sdk project, containing the linphone-sdk.podspec file and a linphone-sdk output directory comprising built frameworks and resources.

Using liblinphone

Liblinphone has a C API, suitable to be used with Objective-C, and a modern Swift API. To use in swift, import the liblinphone swift module in your source file using

import linphonesw

API documentation

You can find the liblinphone C API documentation here.

For Swift, online documentation is available here .

Handling liblinphone log

In order to see liblinphone logs in your IOS app (for example in your Xcode console) follow these steps :

Put in your code at the launching of the app :

linphone_core_set_log_handler(your_log_handler);

This will make the liblinphone logs to call your_log_handler and so be processed as a log from your app.

You can set the liblinphone log level by using the functions documented here.

IOS log handler for liblinphone

Once you have set your log handler, you need to process liblinphone log in order to incorporate them into your app logs.

Here is a short example of how to manage liblinphone log into an IOS app :

void linphone_iphone_log_handler(const char *domain, OrtpLogLevel lev, const char *fmt, va_list args) {
NSString *format = [[NSString alloc] initWithUTF8String:fmt];
NSString *formatedString = [[NSString alloc] initWithFormat:format arguments:args];
NSString *lvl;

if (!domain)
  domain = "lib";
// since \r are interpreted like \n, avoid double new lines when logging network packets (belle-sip)
// output format is like: I/ios/some logs. We truncate domain to **exactly** DOMAIN_SIZE characters to have
// fixed-length aligned logs
switch (lev) {
 case ORTP_FATAL:
   lvl = @"Fatal";
  break;
 case ORTP_ERROR:
   lvl = @"Error";
  break;
 case ORTP_WARNING:
   lvl = @"Warning";
  break;
 case ORTP_MESSAGE:
   lvl = @"Message";
  break;
 case ORTP_DEBUG:
   lvl = @"Debug";
  break;
 case ORTP_TRACE:
   lvl = @"Trace";
  break;
 case ORTP_LOGLEV_END:
  return;
 }
if ([formatedString containsString:@"\n"]) {
 NSArray *myWords = [[formatedString stringByReplacingOccurrencesOfString:@"\r\n" withString:@"\n"]
  componentsSeparatedByString:@"\n"];
 for (int i = 0; i < myWords.count; i++) {
  NSString *tab = i > 0 ? @"\t" : @"";
  if (((NSString *)myWords[i]).length > 0) {
    NSLog(@"[%@] %@%@", lvl, tab, (NSString *)myWords[i]);
   }
  }
 } else {
  NSLog(@"[%@] %@", lvl, [formatedString stringByReplacingOccurrencesOfString:@"\r\n" withString:@"\n"]);
 }
}

Full ipv6 support

 Starting June 1, 2016, all applications submitted to the App Store must work within IPv6-only networks. Linphone supports these requirements since version 3.13.9 released June 15, 2016.

To comply with Apple requirements, you will need to:

  • Update your Linphone-iphone application to 3.13.9 minimum.
  • Make sure not to disable IPV6 accidentally in the application, with 

linphone_core_enable_ipv6()or by setting 

ipv6=0 in 

[net]
section of your linphonerc default or factory configuration files. 

ipv6=1becomes the default in the 3.3.19 linphone-iphone release.

App upgrade

  • For app upgrades, since version 3.13.9 liblinphone automatically switches on IPV6 during installation.

Server side

  • Thanks to NAT64/DNS64, IPV4 SIP servers can still be used without modifications, assuming that there are prepared to receive IPV6 addresses in both, VIA, Contact and SDP fields.
  • As NAT64 implementation leverages features only available since 9.x (I.E NAT64 aware getaddrinfo), NAT64 is only supported on IOS version >= 9.x.

Testing

IOS 10 - Important changes

  • It is no longer possible to listen to a SIP socket in order to detect incoming calls, or new messages, when the application is in background. Now using the push notifications is the only way to do so.
  • Linphone uses VoIP push notifications (from the PushKit framework), in replacement of remote notifications and VoIP sockets, since commit : f84fb0bc0fe5cfa34b0029cb775668cd96a13ce3
  • For IOS 10 and more a new parameter is needed to register for push notifications : pn-token. When registering for push notifications, it is necessary to add "pn-timeout=0" to the request so that the push gateway sends the notifications as soon as possible.
  • FlexiSIP supports VoIP push notifications since commit : a50538897674b2c8cb723e73f6e9d6a969e0b6e0
  • Please find more information about push notifications in FlexiSIP here.

CallKit Integration

Starting from linphone-sdk >= 4.3, Callkit must be integrated in the following way:

  • Add the CallKit framework into your application's dependencies in Xcode.
  • Implement the CXProviderDelegate protocol within your ApplicationDelegate
  • Add the configuration "use_callkit=1" in the section "app" or call linphone_core_enable_callkit before the linphone core starts.
  • Since iOS 13, Apple requests CallKit to be invoked to display the incoming call immediately when a PushKit notification is received. So sometimes you can answer the CallKit before a LinphoneCall is received. In the callback CXAnswerCallAction,  if a LinphoneCall has not yet been received,  you need to configure your AVAudioSession and accept the call when you receive it. Otherwise, accept the call directly.
func provider(_ provider: CXProvider, perform action: CXAnswerCallAction) {
   if (call == nil || call.state != Call.State.IncomingReceived) {
           // configure audio session here. Use 48000 Hz as sampling rate.
    } else {
       // accept call here
    }
    action.fulfill()
}
  • CallKit MUST inform the LinphoneCore when AVAudioSession is activated, as follows:
func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
        lc.activateAudioSession(actived: true)
 }

func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
        lc.activateAudioSession(actived: false)
 }
Tags: IOS