Bluetooth music, remote display of songs, the Sound Menu, and my car

[Stuart Langridge]

My car is a Bluetooth receiver, rather excellently. This means that I 
can just have my phone in my pocket, play music on it, and have that 
music play through the car speakers while I'm driving. Also, the car 
controls -- the steering wheel controls and the ones on the console -- 
happily skip forward and backward between tracks. Equally, for a couple 
of apps on my phone, the name of the currently playing song appears on 
the display of the car, which surprised me no end.

However, I use, at least sometimes, Grooveshark, an HTML5 app which runs 
in the browser, to play music. It does none of these things; I cannot 
skip back and forth in tracks, and the current song is not displayed.

It occurs to me that three things are the case:

1. Ubuntu is coming, soon, on phones
2. Ubuntu has the Sound Menu, and the Sound Menu knows what's playing by 
artist and album and title, and permits skipping back and forth between 
tracks
3. Ubuntu has webapps, meaning that a web application like Grooveshark's 
HTML5 app or Google Music or Ubuntu One's web music player shows up 
correctly in the Sound Menu

This suggests to me that it ought to be possible to have the Sound Menu 
be the thing which talks Bluetooth to connected Bluetooth music playing 
devices. If this were the case, then each app would not have to 
understand how to report its music data to the Bluetooth stack; they 
just report their data to the Sound Menu, which they should be doing to 
be on Ubuntu anyway, and have no idea and no concern whether we're using 
a Bluetooth output, and yet that Bluetooth output will correctly allow 
skipping between tracks and correctly display what's playing by name, 
because it's talking to the Sound Menu.

This would mean that any music app on an Ubuntu phone, including web 
applications that play music, would work perfectly in a car, on a 
Bluetooth headset, on wireless BT speakers; would show what's playing; 
would allow skipping. Even apps in the web browser. No other platform 
can do this. No other platform can even come *close* to doing this. This 
would be a wonderful thing to happen.

It sounds to me like making this happen is something this mailing list 
could do. I know almost nothing about the underlying technology here. 
But if the Sound Menu took care of being the Bluetooth communicator with 
all external devices, then every app on Ubuntu would correctly work in 
detail with Bluetooth receivers with no extra work done by any app; we'd 
need to implement support for complex Bluetooth standards like reporting 
current song metadata and allowing skipping in the Sound Menu, and every 
other app just talks to the Sound Menu via MPRIS as it currently does 
without any app needing to understand or even care about Bluetooth at all.

Is this a rational thing to hope for? I'm quite sure that this would 
require work outside the Bluetooth stack, but it seems to me a thing 
that this mailing list could push for, could drive into Ubuntu, and then 
everyone's ilfe gets a little better.

sil