问题:

I want to develop a app which uses 3G for video calling where secondary camera will be use for video call.

Is that possible to make video call? If it is possible please give me some reference or tutorial.

回答1:

you should look for SIP protocol stack in android. There are various open source projects out there. look for SipDroid, IMSDroid is also a good example. And Sip Api is also available in Android after API level 9.

回答2:

Another one worth looking at is the CSipSimple project. It is using pjsua as SIP library. The video call is developed in a branch of the project.

I have not tested it yet but it seems to work according to an issue. The issue starts getting interesting from comment 27 onwards since after that video calls seem to be working.

Check it out and look into it. It will probably take some time to find your way around the code at first.