Important Issue(s) when Developing Android Apps

  • Unable to Make or Receive Call (Problem with sending and receiving large (INVITE) requests over TCP)

    The issue is documented in #1488. The solution is to try using port other than 5060 in both client and server, and/or reducing the SIP message size.

  • Garbage Collector May Crash Your App (Pjsua2 API)

    Please check this pjsua2 book page about problems with GC.

  • OpenSLES audio device deadlock upon shutdown

    As reported in Android NDK forum, when shutting down OpenSLES sound device backend, it may block forever:

    W/libOpenSLES(6434): frameworks/wilhelm/src/itf/IBufferQueue.c:57: pthread 0x5fce71c0 (tid 6670) sees object 0x5fcd0080 was locked by pthread 0x5f3a2cb0 (tid 6497) at frameworks/wilhelm/src/itf/IObject.c:411

    Currently, the only workaround is to use PJSIP’s Android JNI sound device instead (one way to do this is by defining PJMEDIA_AUDIO_DEV_HAS_ANDROID_JNI to 1 and PJMEDIA_AUDIO_DEV_HAS_OPENSL to 0).

  • Bad audio recording quality on some devices

    Reported that audio quality recorded on the microphone is bad and the speed is twice what it should be, it only happens on some devices. It could be fixed by setting audio mode via AudioManager to MODE_IN_COMMUNICATION in the application, e.g:

    AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    int original_mode = am.getMode();
    /* Set audio mode before using audio device, for example before making/answering a SIP call */
    /* Restore back to the original mode after finished with audio device */