how to write mute logic when mute state is unknown

Question

I'm writing an indicator-sound clone for OSS4. Setting the volume works fine now, but I'm having trouble with the muting aspect of my program.

A couple of facts about muting in OSS4:

• vmix doesn't have a mute (and we use vmix for volume control)
• also, the 'media keys' way of controlling volume doesn't set a mute control, but rather, volume = 0

The problem with this is, when reading the vmix volume and encountering zero, we don't know if the user has actually set it to zero, or has it set to some other value, but has mute on.

How should I write my muting logic when there is no concept of a central mute in OSS4's vmix and other volume controllers handle mute internally?

git code, if that helps

Answer 1

I'm not familiar with vmix or OSS so this might be way off...

You can add two variables to your own system: a flag to maintain the mute state, and a value to maintain the most recent unmuted volume.

OnMuteEvent
    if MuteFlag //we were muted, now unmuting
        MuteFlag = False
        vmix current volume = LastVolume
    else //we were unmuted, now muting
        MuteFlag = True
        LastVolume = vmix current volume
        vmix current volume = 0

When the user turns mute on, you set the mute flag, which you can reflect on your UI, and log the volume value, then set the volume to 0. When the user unmutes, set the volume back to the logged value and clear the flag.

If your application can be launched when the user might have already set the mute state, you can initialize as follows:

if vmix.volume is 0 //might be mute!
    MuteFlag = True //assume it was due to being muted
    LastVolume = MaxVolume/2 //some sensible volume for when we unmute