RFC: KDE4, KMix and a public Mixer API (possibly freedesktop.org)

Christian Esken esken at kde.org
Mon Oct 9 20:45:25 BST 2006

Am Sonntag, 8. Oktober 2006 23:35 schrieb Thiago Macieira:
> Diego Iastrubni wrote:
> >ביום ראשון, 8 באוקטובר 2006, 21:40, נכתב על ידי Thiago Macieira:
> >> Christian Esken wrote:
> >> >I am currently working on a Mixer Service API for KDE4.
> >> >The API is targeted at mixer services (like kmixd), a Mixer (like
> >> > kmix) and several MM apps. It can be used for changing volumes,
> >> > retrieving volume changes, querying for mixers, detecting
> >> > hot-plugged
> >> > soundcards/mixers and some more services.
> >>
> >> Detecting mixers would be nice, but I fail to see why we need this API
> >> as a D-Bus service, rather than something ALSA provides. I am probably
> >> missing something, as I am not familiar with multimedia architectures.

I will only do one example here. There is no notion of a user definable "Master" device in any soundcard driver (Alsa's Master is no Master, it is always "Front" only. This is very wrong if yu got Headphones, or 5.1, or digial out, or ...).

> >I don't think ALSA is working that good on Windows. Also in Solaris. And
> > what about Linux system with OSS and not ALSA...?

Precisely. Also you do NOT want to use alsa-lib if it can be avoided: It is fully undocument and very complicated to use properly if you want to cover all soundcards.

> >The generic way is D-Bus.
> I thought it was Phonon...

It is not. Phonon is not about accessing hardware at all. The audio stream hardware is managed by the backends (e.g. a NMM server), the mixer hardware is done by a Mixer Server (e.g. kmixd). Spoke to Matthias Kretz on K4M and aKademy2006 about that.

> Why do we need to abstract the Phonon abstraction layer?

We don't do.


Is Unix ready for the Desktop? See http://www.kde.org
kde-multimedia mailing list
kde-multimedia at kde.org

More information about the kde-core-devel mailing list