= Getting Started: Building for Apple iPhone, iPad and iPod Touch =
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Apple iOS target is supported by PJSIP version 1.7 and later.

== Features ==

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
    * input latency setting
    * output latency setting
 - supports for the built-in iLBC codec
 - Note: video (from 2.x) is not yet supported on iOS.

== Requirements ==

 - iOS SDK, part of Xcode. Apple iPad is supported starting with iPhone SDK 3.2 onwards.

 - {{{Command Line Tools}}} for Xcode: download from [https://developer.apple.com/downloads/index.action Apple Developer Downloads] then install.

== Video ==

=== Features ===
Video on iOS is supported since PJSIP version 2.3. It has the following features:
 - native capture
 - native preview
 - native OpenGL ES renderer
 - H.264 codec (via OpenH264 library, see below)

=== Requirements ===

 - libyuv

 - OpenH264

== Build Preparation ==

 1. [wiki:Getting-Started/Download-Source Get the source code], if you haven't already.
 2. Set your [wiki:Getting-Started/Build-Preparation 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
 }}}

For iPhone 5, use armv7s architecture:

 {{{
$ cd /path/to/your/pjsip/dir
$ ARCH='-arch armv7s' ./configure-iphone
$ make dep && make clean && make
 }}}

Open {{{ipjsua.xcodeproj}}} using Xcode in [source:pjproject/trunk/pjsip-apps/src/pjsua/ios pjproject/pjsip-apps/src/pjsua/ios] and build the project. You will see telnet instructions on the device's screen. Telnet to this address to operate the application. See [wiki:PJSUA-CLI PJSUA CLI Manual] for commands available. (For release 2.1 and below, ipjsua is located in [source:pjproject/trunk/pjsip-apps/src/ipjsua pjproject/pjsip-apps/src/ipjsua] and does not have CLI telnet feature).

Notes:
 * 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 [wiki:Getting-Started/Autoconf Building with GNU] page.

== Simulator ==

To configure the build system for the iPhone simulator:

 {{{
export DEVPATH=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer
ARCH="-arch i386" CFLAGS="-O2 -m32 -mios-simulator-version-min=5.0" LDFLAGS="-O2 -m32 -mios-simulator-version-min=5.0" ./configure-iphone
make dep && make clean && make
 }}}

Note that the exact paths may vary according to your SDK version.
If you use iOS SDK '''before''' version 7.0, you can configure it this way instead:
{{{
ARCH="-arch i386" CFLAGS="-O2 -m32 -miphoneos-version-min=4.0" LDFLAGS="-O2 -m32 -miphoneos-version-min=4.0" ./configure-iphone
}}}


== OpenSSL Suport ==

Follow the instructions below to enable TLS transport by using OpenSSL:
 1. Build and install OpenSSL-1.0.0 for iPhone by following [http://www.x2on.de/2010/07/13/tutorial-iphone-app-with-compiled-openssl-1-0-0a-library/ these instructions] or OpenSSL-0.9.8o with [http://www.x2on.de/2010/02/01/tutorial-iphone-app-with-compiled-openssl-library/ these instructions].
 1. 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${OPENSSL}/lib"
./configure-iphone
 }}}
 And check that OpenSSL is detected by the configure script:
 {{{
...
checking for OpenSSL installations..
checking openssl/ssl.h usability... yes
checking openssl/ssl.h presence... no
aconfigure: WARNING: openssl/ssl.h: accepted by the compiler, rejected by the preprocessor!
aconfigure: WARNING: openssl/ssl.h: proceeding with the compiler's result
checking for openssl/ssl.h... yes
checking for ERR_load_BIO_strings in -lcrypto... yes
checking for SSL_library_init in -lssl... yes
OpenSSL library found, SSL support enabled
...
 }}}
 1. Build the libraries:
 {{{
make dep && make
 }}}
 1. In XCode project setting of your application (for example, ipjsua), add {{{libssl.a}}} and {{{libcrypto.a}}} from OpenSSL ARM directory to the project's Libraries:
  a. In '''Group & Files''' pane, expand '''ipjsua''', then right click '''Libraries''', and select '''Add -> Existing Files...'''.
  a. Find {{{libssl.a}}} and {{{libcrypto.a}}} from OpenSSL ARM directory (for example, {{{${HOME}/openssl/openssl_arm}}}) and add them to the project.
 1. 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.

=== Audio session management issue (iOS7) ===

Since the deprecation of C-interface Audio Session API in iOS 7 SDK, PJSIP now uses AVAudioSession to set audio session category (to PlayAndRecord) and activate/deactivate audio session. Application will need to do its own audio session management to handle input/output route and notifications (interruption, media server reset, etc). Please refer to [https://developer.apple.com/library/IOS/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/Basics/Basics.html#//apple_ref/doc/uid/TP40007875-CH2-SW1 Apple's official doc on Audio Session Programming Guide] and our ticket #1697.

=== Audio issue (no audio) (iOS7) ===

There are a few reports that the audio is not working on iOS 7 (so far it's only reported to happen in iPhone 5) after getting the following error:

{{{
iPhone mediaserverd[45] <Error>: 10:53:59.986 ERROR:     [0x240b000] 740: _vp: initialize hw input: fs mismatched! REF=0.000000Hz, MIC=44100.000000Hz
iPhone mediaserverd[45] <Error>: Resampler2 bad sample rate(s) :        0.00    16000.00
}}}

One solution is to set the sound device's clock rate to 44100 Hz as to avoid resampling.

=== Audio issues (inability to mute, volume control center synchronization, playback reduced volume) (iOS7) ===

There are several issues with the use of Voice Processing IO Audio Unit in iOS 7, such as unable to mute the volume using the side volume button, unable to synchronize with the control center volume slide bar, significantly reduced volume for audio playback to speaker after a call. Currently there is no workaround for this. Please refer to ticket #1697 for more details.

=== Supporting multiple architectures (armv6, armv7, armv7s, and so on) ===

You need to compile separately for each architecture. If your iPhone SDK has '''{{{llvm-gcc}}}''' compiler (which is the supported compiler starting iOS SDK 5) or '''{{{clang}}}''', then you need to set '''{{{ARCH}}}''' environment variable to the desired architecture before running {{{configure-iphone}}}, for example:
{{{
export ARCH = "-arch armv6"
}}}

Then you need to combine the resulting libraries using the '''{{{lipo}}}''' command. For example:

{{{
lipo -arch armv6 lib/armv6/libpjlib.a -arch armv7 lib/armv7/libpjlib.a -create -output lib/libpjlib.a
}}}

=== 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}}}''':
{{{
export CFLAGS += -D__IPHONE_OS_VERSION_MIN_REQUIRED=30100
}}}
or in '''{{{config_site.h}}}''':
{{{
#define __IPHONE_OS_VERSION_MIN_REQUIRED 30100
}}}
You need to recompile PJSIP after this.

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

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 [http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/RemoteControl/RemoteControl.html Remote Control of Multimedia].

=== Audio lost after interruption (iOS 7) === #interruption2

It has been reported that any time an audio interruption happens, audio is lost until the application is killed/restarted, also reported that this occurs only on iOS7.

Here is the reported working solution:
 - application should be configured to receive interruption events, see also [#interuption problem with interruption].
 - forcefully shutdown the sound device when interruption begins, e.g: using {{{pjsua_set_no_snd_dev())}}} for pjsua, or {{{AudDevManager.setNoDev()}}} for pjsua2
 - restart the sound device after interruption ends, e.g: using {{{pjsua_set_snd_dev()}}} for pjsua, or {{{AudDevManager.setPlaybackDev()+setCaptureDev()}}} for pjsua2.

Also note this is the recommended outline of the normal flow for audio interruption:
 - on interruption begin
   1. hold the calls
   1. stop any other media if any (i.e. disconnect all connections in the bridge)
   1. by default, sound device will be stopped after some idle period after there is no connection in the bridge, or alternatively just forcefully shutdown the sound device.

 - on interruption end
   1. unhold the calls
   1. resume any other media if any
   1. if sound device was not shutdown forcefully, first connection to the bridge will cause sound device to be started, otherwise manual restarting the sound device, by setting playback & capture device, is required.


=== 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 [http://stackoverflow.com/questions/302399/sound-not-working-in-iphone-simulator here].

=== SIP transport keepalive while in background === #keepalive

As the process is normally suspended when application is in the background, the worker thread that handles TCP keepalive timer is also suspended. So basically application needs to schedule periodic wakeup to allow the library send TCP keep-alive. Sample code:
{{{
- (void)keepAlive {
    /* Register this thread if not yet */
    if (!pj_thread_is_registered()) {
        static pj_thread_desc   thread_desc;
        static pj_thread_t     *thread;
	pj_thread_register("mainthread", thread_desc, &thread);
    }

    /* Simply sleep for 5s, give the time for library to send transport
     * keepalive packet, and wait for server response if any. Don't sleep
     * too short, to avoid too many wakeups, because when there is any
     * response from server, app will be woken up again (see also #1482).
     */
    pj_thread_sleep(5000);
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    /* Send keep alive manually at the beginning of background */
    pjsip_endpt_send_raw*(...);

    /* iOS requires that the minimum keep alive interval is 600s */
    [application setKeepAliveTimeout:600 handler: ^{
	[self performSelectorOnMainThread:@selector(keepAlive)
              withObject:nil waitUntilDone:YES];
    }];
}
}}}

Make sure that keepalive feature of SIP transport is not disabled, see [http://www.pjsip.org/docs/latest/pjsip/docs/html/group__PJSIP__CONFIG.htm#ga02217f4919a7c575d71eed407be63d04 PJSIP_TCP/TLS_KEEP_ALIVE_INTERVAL] docs, and the keepalive interval is set to less than 600s.

Alternatively, configuring server to send keepalive ping packet, if possible, and client responds back by sending keepalive pong to the server, so we have two-way traffic. As there is no way to detect incoming ping from server, currently application can just always send pong packet whenever it becomes active (application will be woken up when receiving TCP packet), e.g: send pong packet in UIApplication::applicationDidBecomeActive().

=== List of Issues ===

[[TicketQuery(type=defect&summary~=iphone)]]

== Other iPhone Projects ==

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

 * [http://code.google.com/p/siphon/ Siphon] Project by Samuel Vinson
 * [http://code.google.com/p/pjsip-iphone-audio-driver/ iPhone Audio Driver] by [http://www.voalte.com/ Voalté]
 * [http://code.teluu.com/tabikphone/ TabikPhone], an adaptation of Sipphone code from V-Net Corp