[MPlayer-dev-eng] audio_out.c question

Rich Felker dalias at aerifal.cx
Thu Mar 23 10:56:05 CET 2006


On Thu, Mar 23, 2006 at 10:37:22AM +0100, Clemens Ladisch wrote:
> Rich Felker wrote:
> > On Wed, Mar 22, 2006 at 10:09:59PM -0500, Mitch Golden wrote:
> > > I would point out is that it's not artsd that takes control of /dev/dsp, 
> > > but rather that no two applications can have /dev/dsp open at once - not 
> > > even two separate instances of mplayer.  In that regard, the thing that is 
> > > broken is OSS really.
> > 
> > No, it's an underlying limitation of the hardware. If you want
> > multiple programs playing audio at the same time, get hardware that
> > supports this. In sane users' minds this is useless though. Why would
> > you need to play and mp3 and a movie at the same time? You'll just
> > mess up your ability to hear either.
> 
> Some users want to hear "You have new spam^Wmail" notifications when
> playing other sounds.

Stupid windows-ism. There's a PC-speaker bell for things like that.

> The multi-stream capability of most sound cards is just a side effect of
> the wavetable synthesizer that must be able to play several instrument
> voices at once.

Regardless, it's available. Users who insist on this misguided feature
should buy cards that can handle it, not insist on broken software
emulation which will always have bugs.

> > > As I understand it, that issue was one of the major 
> > > reasons that alsa was written.
> > 
> > ALSA's dmix is much more broken. It does resampling and mixing behind
> > the user's back,
> 
> We don't have much choice in this -- the wailing and gnashing of teeth
> would be much louder if we didn't use dmix by default on most sound
> cards.
> 
> > forking behind the calling program's back which
> > introducing all sorts of bugs, and breaks A/V sync.
> 
> Bug number?

STFml (S=search)

> > > Is there any issue with using alsa in preference to OSS, at least for 
> > > audio only files?
> > 
> > Yes. ALSA will use dmix, etc. crap. The OSS emulation layer is immune
> > to all these userspace hacks and thus is not buggy.
> 
> Except when using aoss.  And you know that we're planning to redirect
> OSS emulation devices back to userspace so that we can inflict the same
> features on them?  ;-)

It can't be done. You can have a separate _daemon_ in userspace do it,
but it can't be the evil forking crap you do right now.

Anyway WHY IN GOD'S NAME do you insist on inflicting these horrors on
users?? And what's worse, Linux had dropped support for OSS, so
fucking please do not make everyone who wants sound run this
abomination of userspace emulation! I've spent enough time rewriting
libc and now a linker/dynamic linker already. I don't want to have to
rewrite a kernel too because Linux is becoming such crap...

Rich




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