Keyboard volume buttons

Keyboard volume buttons

[Harsha, Priya]

Hi,

Can anyone tell me how keyboard's volume buttons are converted into real volume change? Will there be an application that monitors the keyboard volume button events and call ALSA API to set the volume?

Thanks
Harsha

Re: Keyboard volume buttons

[Vedran Miletić]

On Fri, Feb 27, 2009 at 3:20 AM, Harsha, Priya <priya.harsha@intel.com> wrote:
> Hi,
>
> Can anyone tell me how keyboard's volume buttons are converted into real volume change? Will there be an application that monitors the keyboard volume button events and call ALSA API to set the volume?
>
> Thanks
> Harsha
>
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>

Yes, X catches keypress and lets the window manager know about it. In
case of metacity, which is what GNOME uses, if that key is bound to a
volume control action, it calls gnome-volume-control to do the
apropriate change. I _believe_ it is so, never checked source code.

Vedran Miletić
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Re: Keyboard volume buttons

[Takashi Iwai]

At Fri, 27 Feb 2009 08:06:43 +0100,
Vedran Miletić wrote:
> 
> On Fri, Feb 27, 2009 at 3:20 AM, Harsha, Priya <priya.harsha@intel.com> wrote:
> > Hi,
> >
> > Can anyone tell me how keyboard's volume buttons are converted into real volume change? Will there be an application that monitors the keyboard volume button events and call ALSA API to set the volume?
> >
> > Thanks
> > Harsha
> >
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> >
> 
> Yes, X catches keypress and lets the window manager know about it. In
> case of metacity, which is what GNOME uses, if that key is bound to a
> volume control action, it calls gnome-volume-control to do the
> apropriate change. I _believe_ it is so, never checked source code.

For most ACPI-events, yes, it works like that.  The window manager is
responsible for the volume control.

In some cases, the volume is changed in the driver side.  For example,
some devices issue an IRQ per volume-control action.  Some HD-audio
codecs have the volume-knob widget that is required to be handled by
the codec driver via unsolicited events.

Also, some (old) thinkpads have their own hardware layer and the h/w
volume is handled differently.


Takashi
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Re: Keyboard volume buttons

[Lennart Poettering]

On Fri, 27.02.09 08:06, Vedran Miletić (rivanvx@gmail.com) wrote:

> On Fri, Feb 27, 2009 at 3:20 AM, Harsha, Priya <priya.harsha@intel.com> wrote:
> > Hi,
> >
> > Can anyone tell me how keyboard's volume buttons are converted into real volume change? Will there be an application that monitors the keyboard volume button events and call ALSA API to set the volume?
> >
> > Thanks
> > Harsha
> >
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> >
> 
> Yes, X catches keypress and lets the window manager know about it. In
> case of metacity, which is what GNOME uses, if that key is bound to a
> volume control action, it calls gnome-volume-control to do the
> apropriate change. I _believe_ it is so, never checked source code.

It is actually not the window manager.

In GNOME it is a little daemon that runs in the session and is called
gnome-settings-daemon. It does a lot of little thinks, one of them
handling volume key events and showing a nice OSD for it.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4
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Re: Keyboard volume buttons

[Harsha, Priya]

Thanks a lot. That helps!

>-----Original Message-----
>From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-bounces@alsa-project.org]
>On Behalf Of Lennart Poettering
>Sent: Saturday, February 28, 2009 12:30 PM
>To: alsa-devel@alsa-project.org
>Subject: Re: [alsa-devel] Keyboard volume buttons
>
>On Fri, 27.02.09 08:06, Vedran Miletić (rivanvx@gmail.com) wrote:
>
>> On Fri, Feb 27, 2009 at 3:20 AM, Harsha, Priya <priya.harsha@intel.com> wrote:
>> > Hi,
>> >
>> > Can anyone tell me how keyboard's volume buttons are converted into real volume
>change? Will there be an application that monitors the keyboard volume button events and
>call ALSA API to set the volume?
>> >
>> > Thanks
>> > Harsha
>> >
>> > _______________________________________________
>> > Alsa-devel mailing list
>> > Alsa-devel@alsa-project.org
>> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>> >
>>
>> Yes, X catches keypress and lets the window manager know about it. In
>> case of metacity, which is what GNOME uses, if that key is bound to a
>> volume control action, it calls gnome-volume-control to do the
>> apropriate change. I _believe_ it is so, never checked source code.
>
>It is actually not the window manager.
>
>In GNOME it is a little daemon that runs in the session and is called
>gnome-settings-daemon. It does a lot of little thinks, one of them
>handling volume key events and showing a nice OSD for it.
>
>Lennart
>
>--
>Lennart Poettering                        Red Hat, Inc.
>lennart [at] poettering [dot] net         ICQ# 11060553
>http://0pointer.net/lennart/           GnuPG 0x1A015CC4
>_______________________________________________
>Alsa-devel mailing list
>Alsa-devel@alsa-project.org
>http://mailman.alsa-project.org/mailman/listinfo/alsa-devel