What is KoalaSAN Broadcaster?

KoalaSAN is a broadcasting application for iOS (iPhone, iPad, iPod touch). It runs on recent devices (iPhone 4S+, iPod 4th generation+, iPad2+) and iOS 5.0 is the minimum requirement. KoalaSAN can broadcast audio streams to Icecast 2 and Shoutcast servers using three different formats, AAC, Ogg-Vorbis and Opus.

At the moment (May 2013) the stable Icecast release (version 2.3.3) supports Ogg Vorbis streams while the beta release 2.4beta3 supports Opus streams too. Shoutcast servers just supports AAC.

KoalaSAN can run on older devices too (it has been tested succesfully on 3GS iPhone running iOS 6.1.3) at the cost of a higher CPU load.

Where can I get KoalaSAN?

KoalaSAN is available on the Apple AppStore at this URL.

What about audio sources?

KoalaSAN can capture audio from:

  • Internal mic devices
  • External mic correctly recognized by the system (bluetooth microphones, audio devices, microphones plugged into the mini-jack or dock connectors)
  • AudioBus Apps

In case you are using an external microphone on the mini-jack plug, please start KoalaSAN and plug the microphone device while the app is in the foreground. This will allow for correct audio routing.

You can capture audio from other applications via AudioBus. You will have to get AudioBus on the AppStore, clearly, and then you will be able to receive audio from other AudioBus-enabled applications.

Does KoalaSAN work while in background?

Yes, it will both records and/or broadcasts while in background.

Can stream disconnect? Will KoalaSan reconnect?
Yes, broadcasting can interrupt for many reasons, mostly due to networking conditions (connection loss, bitrate too high to handle on your current connection, servers stopping, no data to send). KoalaSan, at the moment, has no reconnecting routine.

Do I need a server? Is KoalaSAN acting as a server?

KoalaSAN is just a component in the broadcasting workflow, it is a source.


You will need an Icecast server to which the audio flow will be transmitted. Listeners, using a client of their choice, will connect to the server and enjoy the stream!

Icecast is a free server, you can install on your box. Anyway, if you’re not feeling like doing it by yourself, just look on the net for someone selling Icecast services.

Can I have several configurations?

KoalaSAN has support for storing different configurations. Just go to the “Settings” tab and tap the “+” button on the upper right of the navigation bar. A new window will be showed with all the parameters. Not all of the fields are mandatory. Enter your settings and click on the “Save” button.

Be aware that only one configuration at a time can be activated (and will be used once you tap the “Play” button on the “Stream” tab.

Can I dump my stream?

Yes, you can get a recording of the stream. Just set the “Dump” switch ON in your configuration. Recording starts when you tap  the play button and stops when you press the stop button. You can even make a configuration just to record (with broadcasting disabled) at the selected bitrate/quality with the selected codec. If connection drops, stream dumping automatically stops.

Recording files will then be available in the “Recordings” tab. You will be able to transfer them with iTunes or to your personal Dropbox account.


We did our best to make KoalaSAN accessible via VoiceOver. For reference you can listen to this excellent walkthrough.

Why these codecs?

Ogg-Vorbis and Opus are two patent-free audio codecs providing at the same time great audio quality, even at mid-low bitrates.

Opus is really new and not widely implemented. Some resources you may find useful are this post and the Wikipedia entry.

AAC is a really popular codec, KoalaSan is using the AAC encoder shipped by Apple with iOS.

Which clients support Ogg Vorbis and/or Opus?

While AAC is widely supported, people can listen to your transmissions in Vorbis and Opus formats using different tools on different platforms.

Multiplatform (Linux, Mac OS X, Windows)

  • Firefox Browser: stable versions of Firefox supports both Ogg Vorbis and Opus. You can just open the URL assigned to your web-radio (e.g. open http://radio.shift-left.net:8050/tryphone  in Firefox)
  • Chrome/Chromium Browser: stable version supports Ogg Vorbis. Chrome 26/27 supports Opus too, but you will have to enable it. Go to URL chrome://flags and look for an entry about enabling Opus in <video> elements. Once enabled, pointing to the radio URL will start reproducing audio.

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  • VLC: VideoLan Client supports both of the codecs
  • Mplayer: Mplayer supports Ogg-Vorbis and recent builds support Opus


  • Foobar 2000: the windows player foobar supports Ogg Vorbis and Opus streams
  • Winamp: supports Ogg Vorbis streams. For some reason Winamp expects that your mountpoint will be terminated by the “.ogg” suffix. There are reports of an Opus plugin (untested).


  • TuneIn Radio: supports Ogg Vorbis streams
  • Oplayer: supports Ogg Vorbis streams

Hey, what about Ogg Vorbis “quality” setting?

If you think that the “quality” setting does not tell you that much, here is a conversion table quality -> bitrate (Kbit/s).

  •  -1 -> 48
  • 0 -> 64
  • 1 -> 80
  • 2 -> 96;
  • 3 -> 112
  • 4 -> 128
  • 5 -> 160
  • 6 -> 192
  • 7 -> 224
  • 8 -> 256
  • 9 -> 320
  • 10 -> 360

I never used the username field on Icecast, help!!

Icecast servers always expect a username. The default username is “source” and many applications use that by default, without telling you explicitly. So, if you never used to pass the username parameter before, try to use “source” (without quotes).