[MPlayer-dev-eng] audio_out.c question

[The Wanderer]

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.

I know of two types of instance in which I might want to have two
different programs able to produce sound 'at the same time':

One, something my brother once liked to do: to play back two similar but
not identical audio files virtually simultaneously. I forget the
details, but I believe he did this to test whether or not they were
effectively the same so he could decide whether or not we needed to keep
both. (Other times, it was just for the interesting audible effect.)

Two, a rather more common situation: when I'm doing something which
makes constant use of the audio device (listening to music in the
background while reading or coding or whatever, playing a game which can
produce sound and so takes over the audio device when run, et cetera), I
sometimes want to be able to have audio from other programs to alert me
that something has happened - the most common example being an IM bell,
telling me that I might want to jump over to where I keep my open IM
windows because someone has just sent me a new message.I've long since
lost track of the number of IMs, and potentially desirable
conversations, I've missed because I was playing MP3s and didn't realize
that a new comment had come in... not to mention how bothersome it gets
when I've been playing an MP3, paused it (by backgrounding the process -
I do my audio playing mostly through Moosic), forgotten I had done so,
gone to watch a video file, and had MPlayer hang on me and have to be
killed because it couldn't deal with the audio device being already in
use in that circumstance. (The "hang" is "display video frame and then
do nothing even in response to keyboard commands", after having
'detected' NAS audio output; probably this just means that I shouldn't
have NAS audio output available in my build of MPlayer, since I don't
really have support for it.)

The ability to play sound through two different programs simultaneously
is not something which is never useful in the real world. If you're
fortunate enough that its lack is not a problem for you, that's fine for
you, but it doesn't help those of us who *do* encounter the lack - nor
does it justify your claiming that it is useless without even attempting
to counter the argument presented by the second instance above, which
I've described in one way or another in your presence in the past.

-- 
       The Wanderer

Warning: Simply because I argue an issue does not mean I agree with any
side of it.

Secrecy is the beginning of tyranny.