Ok, I'm seeing correct muting behavior on both the headunit and the empeg now.

I also wanted to pause the player when it was muted, so I read up on hijack/extmute and ir_translate. My original:

extmute_on=0x00b94609e
extmute_off=0x00b94609e

approach of toggling the top "play/pause" command didn't work 1/4 of the time, the empeg would stay paused after a hangup. Well, actually, the status icons would flicker between play and pause a bit, then remain on pause. I think the parrot "bounces" the mute on hangup. Something akin to this happens:

1. Call comes in.
2. Parrot grounds mute line.
3. Call ends.
4. Parrot, all within a second or so:
4a. ungrounds the mute line
4b. grounds it again
4c.then ungrounds it

You can hear the (speaker bypass?) relay clicking a few times on hang up, vs. just once on pickup, so I wouldn't be surprised if the mute line was controlled by the same logic. I theorized that this quick succession of toggles is causing extmute transitions too often for hijack to either catch them, for hijack to generate proper IR commands, or for the player to digest them.

I then tried this:

[hijack]
...
extmute_on=0x73
extmute_off=0x74
[ir_translate]
73=00b949615,00b94614,00b94609e,null
74=00b949614,00b94615,00b94609e,null

I thought maybe jiggling with the volume twice before play/pause toggle might have an effect. Nope. Problem still there, exactly the same. Huh.

Looked around some more, read up on the ir_translate docs (brain hurts) and matthew's posts. Not knowing anything about what *exactly* triggers the exmute events, and how quickly they can transition, and on a hunch that the empeg is seeing odd sequences at the on-mute-and-then-hangup point like "extmute_on, exmute_off" or "extmute_off, extmute_off" I thought I'd try some experiments with Shift. This final approach worked, not 100% sure why yet:

[hijack]
...
extmute_on=0x73
extmute_off=0x74
[ir_translate]
73.N=00b949615,00b94614,00b94609e,null.S
73.S=null
74.S=00b949614,00b94615,00b94609e,null.S
74.N=null

I probably don't need the volume twitching in there, but it's working, so I'm not touching it.

-brendan