Version 34 (modified by ming, 13 years ago) (diff)


Getting Started: Building for Apple iPhone, iPad and iPod Touch

  1. Features
  2. Requirements
  3. Build Preparation
  4. Building PJSIP
  5. Simulator
  6. OpenSSL Suport
  7. Common problems
    1. Unable to accept incoming call in background mode (iOS4)
    2. Unable to support Bluetooth input
    3. Problem with interruption (by a phone call or an alarm), headset plug/unplug, or Bluetooth input
    4. Problem with deprecated CPU_SUBTYPE_ARM_ALL subtype
    5. Sound not working in the simulator
    6. List of Issues
  8. Other iPhone Projects

Apple iPhone target is supported by PJSIP version 1.7 and later.


Some of the features of the iPhone port:

  • it has a native CoreAudio based audio device, which supports the following features:
    • the built-in/device's echo canceller
    • output volume setting
    • change input route to bluetooth input
    • change output route
    • input latency setting
    • output latency setting
  • supports for the built-in iLBC codec


You'll need an iPhone SDK. We tested mainly with version 3.x SDK/devices, but SDK version 2.x would build fine too. Apple iPad is supported starting with iPhone SDK 3.2.

Build Preparation

  1. Get the source code, if you haven't already.
  2. Set your config_site.h to the following:
    #define PJ_CONFIG_IPHONE 1
    #include <pj/config_site_sample.h>
    This will activate iPhone specific settings in the config_site_sample.h.

Building PJSIP

Just run:

$ cd /path/to/your/pjsip/dir
$ ./configure-iphone
$ make dep && make clean && make

Open ipjsua.xcodeproj using Xcode in pjproject/pjsip-apps/src/ipjsua and build the project.


  • the ./configure-iphone is a wrapper that calls the standard ./configure script with settings suitable for iPhone target.
  • the latest iPhone SDK version will be selected by default. You may change this by setting IPHONESDK environment variable to the desired SDK path. For ipjsua, select Project-Edit Project Settings-Base SDK and Targets-ipjsua-Get Info-Base SDK to change the SDK version.
  • you may pass standard ./configure options to this script too.
  • for more info, run ./configure-iphone --help
  • other customizations are similar to what is explained in Building with GNU page.


To configure the build system for the iPhone simulator:

export DEVPATH=/Developer/Platforms/iPhoneSimulator.platform/Developer
export CC=/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.0
make dep && make clean && make

Note that the exact paths may vary according to your SDK version.

OpenSSL Suport

Follow the instructions below to enable TLS transport by using OpenSSL:

  1. Build and install OpenSSL-0.9.8o for iPhone by following these instructions.
  2. Specify OpenSSL location when running configure-iphone, for example (with Bash):
    export OPENSSL=${HOME}/openssl/openssl_arm
    export CFLAGS="-O2 -Wno-unused-label -I${OPENSSL}/include"
    export LDFLAGS="-L${OPENSSL}/lib"
    And check that OpenSSL is detected by the configure script:
    checking for OpenSSL installations..
    checking openssl/ssl.h usability... yes
    checking openssl/ssl.h presence... no
    aconfigure: WARNING: openssl/ssl.h: accepted by the compiler, rejected by the preprocessor!
    aconfigure: WARNING: openssl/ssl.h: proceeding with the compiler's result
    checking for openssl/ssl.h... yes
    checking for ERR_load_BIO_strings in -lcrypto... yes
    checking for SSL_library_init in -lssl... yes
    OpenSSL library found, SSL support enabled
  3. Build the libraries:
    make dep && make
  4. In XCode project setting of your application (for example, ipjsua), add libssl.a and libcrypto.a from OpenSSL ARM directory to the project's Libraries:
    1. In Group & Files pane, expand ipjsua, then right click Libraries, and select Add -> Existing Files....
    2. Find libssl.a and libcrypto.a from OpenSSL ARM directory (for example, ${HOME}/openssl/openssl_arm) and add them to the project.
  5. Build the app

Common problems

Unable to accept incoming call in background mode (iOS4)

If while in the background, ipjsua (or your application) is unable to detect if there is an incoming call and display the local notification:

  1. Note that background feature only works with TCP.
  2. Make sure that voip is included in the required background modes (UIBackgroundModes) in the application’s Info.plist file.
  3. Make sure that the TCP socket is successfully wrapped with CFReadStreamRef (check if there is a message: "Failed to configure TCP transport for VoIP usage").
  4. Check whether you can accept the incoming call by bringing the app to the foreground. If yes, make sure that the incoming call request comes from the wrapped TCP socket (check the log for the INVITE request).

Note: these steps do not troubleshoot audio problems.

Unable to support Bluetooth input

Since Bluetooth input support is only available for iOS 3.1 or later, you need to specifically specify that your deployment target is iOS 3.1 or above. You can do this either in user.mak:


or in config_site.h:


You need to recompile PJSIP after this.

Problem with interruption (by a phone call or an alarm), headset plug/unplug, or Bluetooth input

For devices running iOS 4.0 or later, you need to enable your application to respond to remote-control events. This allows PJSIP to properly receive and process the above events. You can do this by adding the following code in your application:

[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

For more details, please refer to Apple's doc on Remote Control of Multimedia.

Problem with deprecated CPU_SUBTYPE_ARM_ALL subtype

If you get this warning during compilation:

CPU_SUBTYPE_ARM_ALL subtype is deprecated
warning: -force_cpusubtype_ALL will become unsupported for ARM architectures

Modify your user.mak (this requires at least gcc 4.2.1 so please use r3462 or later (see ticket #1218)):

export CFLAGS += -march=armv6 -march=armv7 -mcpu=arm1176jzf-s -mcpu=cortex-a8
export LDFLAGS += -march=armv6 -march=armv7 -mcpu=arm1176jzf-s -mcpu=cortex-a8

Then rebuild PJSIP. Next, change your XCode setting, tick Targets-ipjsua(or your application name)-Get Info-Build-Build Active Architecture Only-Yes.

Sound not working in the simulator

Go to System Preferences > Sound > Sound Effects and then uncheck and recheck "Play user interface sound effects". If it still doesn't work, you can try some other suggestions here.

List of Issues

iPhone: Echo cancellation may not work on iOS using SDK 4.x
iPhone: Long delay when calling AudioConverterNew() causing timeout in acquiring pjsua lock (thanks Bogdan Krakowski the report)
Incoming TCP connection on iPhone iOS4 BG mode would fail over and over with EAGAIN error (thanks Bogdan Krakowski for the report)
Crash in coreaudio_dev (iPhone OS) when there is no call during a GSM interruption
Fix crash in coreaudio_dev's interruptionListener (iPhone OS) and support for multiple interrupted streams (thanks to Seth Hinze for the patch)
iPhone: Fix problems with echo cancellation and Bluetooth input (SDK 4.x)
iPhone: UDP socket send error after waking up from background mode (thanks Joe Meade for the report)
iPhone (info only): No audio in calls if app is woken up from background mode without network connectivity (thanks Joe Meade for the report)
Long delay in iPhone initialization (thanks Guy Zelkha for the report)
Crash in iPhone iOS when trying to make a call after the application is left running for days (thanks Alejandro Orellana for the report)
Assertion may be raised if iPhone app woken up to perform registration and the server is down (thanks Alejandro Orellana for the report)
Use CFHost API for pj_getaddrinfo() on iPhone OS
Build correctness on non-video platforms (Symbian, iPhone, Windows Mobile)
Fixes assertion when interruptionListener is called from an unregistered thread on iPhone OS (thanks to Ilya Kalinin for the patch)
Disable local host resolution on iPhone OS
iPhone: Solution for application getting killed by iOS 5 due to too many wakeups
Handle socket failure in STUN resolution when coming back from iPhone/iOS background mode

Other iPhone Projects

Also have a look at these PJSIP iPhone ports by pjsip users:

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