Compiling X,KDE: ALSA, PulseAudio, etc.?

Hello,

I'm compiling Xorg and KDE4, and I'm just wondering if I should check all these boxes for things like GStreamer, ALSA, PulseAudio, PortAudio?, JACK, etc.? Do I only need OSS? Many thanks for any clarifications anyone can provide.

JAFN

If you don't know what they are, pick the defaults. Enable or disable options only when you know and understand what they do.

I think KDE4 FreeBSD port defaults to pulseaudio and if you are building a default kde4 FreeBSD desktop it would make sense to enable pulseaudio options when installing non-kde4 apps that have an option to support pulseaudio.

I don't think you need JACK unless you have a good soundcard and are going to be using two or more stereo channel inputs or otherwise are building a system with hardware and software for advanced audio processing. Jack might also be necessary if you are going to stream your audio channels but you can do that with gstreamer.

People seem to recommend ALSA over pulseaudio backend. Alsa works well with GSstreamer. You can build a kde4 system using an alsa backend if you choose the alsa backend instead of the default. You just need to make sure that when installing other apps that provide an option of using pulseaudio or alsa that you select the option for whatever backend you chose. When you build KDE4 with the alsa option, KDE4 will pull in and use GStreamer.

Given that I don't know what I am doing, I'd suggest as a general guide to a typical desktop (w/o hardware typically used for audio work) that you choose either alsa or pusleaudio and then select options that go with one or the other. It's not too hard to get sound working for programs launched by kde4 going with either alsa or pulseaudio. If you are going to use different window managers, e.g. gnome, enlightenment, do a little research to find out whats the best audio backend/front end for the desktop environment. Different X desktop managers are more easily configure with one or the other. I don't think twm or startx default Xorg window manager has any installation hooks that tie into audio components, but, if you install a typical modern desktop manager something more than a window manager like twm, the desktop environment manager installation options (at least from ports) should tell you whatever audio back-to-font ends are appropriate. It is important to be consistent for selecting options for either pulseaudio or alsa backends and/or for whatever desktop environment manager you are using.

Actually KDE4 does not default to pulseaudio on FreeBSD. KDE use the abstraction layer multimedia/phonon which can optionally use audio/pulseaudio. However there isn't really a need to enable pulseaudio on FreeBSD as it was created to address some of ALSA's shortcomings on Linux. Why add a sound server if FreeBSD's OSS implementation can do the job properly? AFAIK pulsaudio is present in the ports tree because there are some applications which explicitly depend on it. Also note that the version in ports is getting old.

Also note that ALSA on FreeBSD is just a compatibility layer. When audio/alsa-plugins is used, by default it's just FreeBSD's OSS underneath with no additional sound server required. This is why this option is generally preferred over pulseaudio.