Multicast RTP on Android 4.0+

Question

Android now has native RTP and Multicast APIs. What about multicast and/or broadcast RTP? I didn't see anything in the the docs on how to enable this? I'm interested in both client and server.

Answer 1

As far as I can tell, from a lot of research and testing with the android.net.rtp package, it is possible to send to a multicast address (audio) using AudioStream and AudioGroup , but if you try to use AudioStream.associate() with a multicast address, you will not receive anything.

I have opened a bug report for this on the Android issue tracker, here: https://code.google.com/p/android/issues/detail?id=61289

Bear in mind that many Android devices do not in fact support sending IGMP join packets to the network ( http://www.programmingmobile.com/2012/01/multicast-and-android-big-headache.html is one example of many pieces of information regarding this).

Because of this you will need to make sure your network infrastructure is set up to deliver multicast UDP packets to your device(s). Some networks allow static multicast groups to be set up on the switch/router/access point etc.