[alsa-devel] [PATCH - amixer] listen to D-Bus for volume-up, volume-down and mute signals.

Lennart Poettering mznyfn at 0pointer.de
Mon Aug 3 18:29:00 CEST 2009

On Mon, 03.08.09 14:13, Takashi Iwai (tiwai at suse.de) wrote:

> > >> The patch introduces D-Bus support in amixer. With --dbus option given amixer
> > >> works continiously (like with the --stdin) waiting for
> > >> org.freedesktop.Hal.Device.Condition with the first argument "ButtonPressed"
> > >> and the second being one of: "volume-up", "volume-down" and "mute". These
> > >> are emmited by the HAL input helper. A single amixer process can controll
> > >> one mixer item. There are options to choose a specific item to controll,
> > >> an input device to listen and a single adjustment step size.
> > >>
> > >> Signed-off-by: Łukasz Stelmach <stlman at poczta.fm>
> > > 
> > > Thanks for the patch.
> > > 
> > > The approach is interesting, but I'm not sure whether we should put
> > > all into amixer in this way since we don't want extra library
> > > dependency.  (Note: amixer could be used in initrd.)
> > > I think it's better to split the code and make it as an individual
> > > daemon instead of additional options of amixer.
> > 
> > No worries ;) there is --with(out)--dbus option for configure to
> > disable all this code which is enough for initrd because most often
> > (AFAIK) initrd binaries are not the same that in the live system.
> Usually same binaries are used for initrd nowadays in many distros.
> So, configure option doesn't help.
> And, I really prefer this as a separate daemon, so it be as small as
> possible.  Seeing amixer as a daemon is somewhat strange...

Also, HAL is obsoleted by udev these days. Adding new HAL support to
software at this point in time is certainly a bad idea. On Fedora 12
we have now considerably dumbed down HAL. It is only shipped as compat
kludge for user applications. And with other distros this isn't much diffrent:


Finally, stuff like this really belongs in the user sessions so that
OSD feedback and so on can be shown. In fact most desktops do include
a tool for this anyway.


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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