How to implement mute functionality in a PJSIP call on iOS

Question

I wanted to implement Mute button in my call. I am working on a VOIP application for iPhone. Now when a call comes and user picks up, I want to display a Mute button so the user can mute the call or conference. I did the same through the PJSIP API.

-(int) mutethecall
{
    pj_status_t status =   pjsua_conf_adjust_rx_level (0,0);
    status = pjsua_conf_adjust_tx_level (0,0);
    return (PJ_SUCCESS == status);
}
-(int) unmutethecall
{
    pj_status_t status =   pjsua_conf_adjust_rx_level (0,1);
    status = pjsua_conf_adjust_tx_level (0,1);
    return (PJ_SUCCESS == status);
}

The problem is that while this code is working for one to one call, it's not working for conference scenarios.

I wonder if I could turn off the mic directly: could I implement the same using iOS bypassing the PJSIP API?

Is this possible?

Answer 1

You can completely disconnect the microphone from the conference using pjsua_conf_disconnect and pjsua_conf_connect when you want to unmute.

Here's some Objective-C code that does the trick:

+(void)muteMicrophone
{
    @try {
        if( pjsipConfAudioId != 0 ) {
            NSLog(@"WC_SIPServer microphone disconnected from call");
            pjsua_conf_disconnect(0, pjsipConfAudioId);
        }
    }
    @catch (NSException *exception) {
        NSLog(@"Unable to mute microphone: %@", exception);
    }
}

+(void)unmuteMicrophone
{
    @try {
        if( pjsipConfAudioId != 0 ) {
            NSLog(@"WC_SIPServer microphone reconnected to call");
            pjsua_conf_connect(0,pjsipConfAudioId);
        }
    }
    @catch (NSException *exception) {
        NSLog(@"Unable to un-mute microphone: %@", exception);
    }
}

Note that the pjsipConfAudioID was retrieved when the call was established, again in Objective-C...

static void on_call_state(pjsua_call_id call_id, pjsip_event *e)
{
    pjsua_call_info ci;
    PJ_UNUSED_ARG(e);
    pjsua_call_get_info(call_id, &ci);
    pjsipConfAudioId = ci.conf_slot;
    ...
}

Hope that helps!