Improvements in the soundsystem (was: Re: cvs commit: src/sys/sys param.h soundcard.h src/sys/dev/sound/pcm buffer.c buffer.h channel.c channel.h channel_if.m dsp.c dsp.h mixer.c mixer.h sound.c sound.h)

Quoting Sam Leffler <sam_at_errno.com> (Sat, 23 Sep 2006 14:23:17 -0700):

> Can you please post something about what this addition means to users?
> e.g. you can now run xyz apps that previously didn't work or were crippled.

I'm not aware of an application which makes use of those features. ATM
you can think about it as pure infrastructure work.

As soon as some parts are pushed down into drivers, you have better
control about your hardware. ATM the mixer only shows hardcoded stuff.
There are less controls than there are output jacks on some soundcards.
These changes provide the kernel interface to change the drivers to
control the volume of each output channel the card provides.

Ariff has some other changes in the wings which allow us to work better
with multi-channel stuff (e.g., 5.1 surround instead of only stereo).
But AFAIK this is just about the internals of the soundsystem. The SoC
project provides a kernel interface to some of this new stuff.

When 4Front freezes the API (there are parts which aren't fully set in
stone yet) we will be able to give names to some parts of the
soundsystem, query the name of the currently running song (if set) and
some other nice stuff. Already possible is the synchronized start of
multiple channels (even across devices), but an application has to
contain code to use this feature. There's also better control of
mute/pause, but again, I'm not aware of an application which uses this
ATM.

And while I'm at it: I want to highlight the docs of the functions in
the kernel. I'm generating a PDF with doxygen right now and it will be
available from http://www.Leidinger.net/FreeBSD/src_docs/ later (have a
look at the date, it should be recent and not from last month as it is
as of this writting).

Bye,
Alexander.

-- 
      ...and that is how we know the Earth to be banana-shaped.
http://www.Leidinger.net  Alexander _at_ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org     netchild _at_ FreeBSD.org  : PGP ID = 72077137