[LAU] Auto switching outputs

[Will Light]

On Sun, Aug 1, 2010 at 8:12 PM, Erik de Castro Lopo
<mle+la at mega-nerd.com> wrote:
> Paul Davis wrote:
>
>> On Sun, Aug 1, 2010 at 9:59 PM, Erik de Castro Lopo
>> <mle+la at mega-nerd.com> wrote:
>> > Hi all,
>> >
>> > I've acquired a pair of wireless headphones; the type thathas a USB
>> > dongle that plus into amy machine and uses analog FM to communicate
>> > with the headphones.
>> >
>> > These JustWorked(tm) under linux, but now I'd like to have audio
>> > (either PulseAudio or ALSA) auto switch to the headphones whenever
>> > they are plugged in.
>> >
>> > Is this doable? Any hints?
>>
>> ALSA can definitely detect the jack insertion.
>
> Not a jack in this case, a USB device that identifies itself as a
> USB audio device.
>
>> However, it requires a
>> user-space app that is paying attention to the "switch".
>
> Would this info be available over DBus?
>

It's my understanding that HAL is being phased out in favor of
libudev.  Writing an application like what you're describing (i.e.
watch for a specific USB device to appear or disappear) is very simple
with the udev_monitor functions.

-w