[nas] Exporting audio output

[Jon Trulson]

On Wed, 11 Feb 2004, Shardool wrote:

> From: Shardool <shardool at iiita.ac.in>
> Date: Wed, 11 Feb 2004 16:58:18 +0530 (IST)
> Subject: Re: [nas] Exporting audio output
> To: nas at radscan.com
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> > On Tue, 10 Feb 2004, Shardool wrote:
> >
> >> Date: Tue, 10 Feb 2004 17:09:49 +0530 (IST)
> >> From: Shardool <shardool at iiita.ac.in>
> >> To: nas at radscan.com
> >> Subject: [nas] Exporting audio output
> >>
> >> HI,
> >>
> >> I am a newbie and have recently installed NAS. I came across NAS while
> >> trying to find a solution to a problem which is as follows:
> >> I have two systems that are connected over a network the first one is a
> >> P4
> >> with an 80GB hard disk. The second one is a P3 with a small 10GB disk
> >> space.
> >> I have to use both the systems frequently but the major volume of my
> >> work
> >> is confined to the first system.
> >> I was looking for a way to export the X-server of the first system on
> >> the
> >> second one so that i could utilize to resources of the first one
> >> especially while watching movies and playing games. I was able to do it
> >> using XDMCP.
> >> The problem is that although the x-server was exported successfully,
> >> complete with the login screen etc. i was not able to get the sound
> >> generated by the  applications on the first system on the second one.
> >> That means when i play a movie (or any application) on the first system
> >> using XDMCP i get the video output on the second one but the audio still
> >> plays on the first one.
> >> Is there any way i can direct the audio output of the first system to
> >> that
> >> of the second one?
> >> Using a protocol like NFS or SMB to mount the file systems of the first
> >> system on the second one is not a solution.
> >>
> >> I tried using NAS to somehow solve the problem. I stared nasd on the
> >> second system and directed the audio output of the first system to the
> >> second one using using a pipe on the first one
> >> mkfifo temp
> >> dd if=/dev/dsp of=temp
> >> and tried to play 'temp' on the second system using auplay. But i
> >> suppose
> >> auplay requires a regular file as an argument.
> >>
> >> I also tried directing the output of 'temp' of the first system to the
> >> /dev/dsp of the second system using cat and ssh.
> >> by the following command n the first system:
> >> cat temp| ssh -l username second_system -- dd of=/dev/dsp
> >> but i got some garbled noise as the output on the second system.
> >>
> >> Any suggestions are welcome.
> >
> > You can use libaudiooss for NAS: http://www.mo.himolde.no/~knan/linux.html
> > on the client side to get sound working. (However your the sound
> > quality will be bad if you have low networking bandwidth)
> >
> > 				Matthias
>
> I tried libaudiooss from the site you mentioned. It worked partially for
> xmms but didnt't work for any other application (including mplayer).
> Any other suggestions?

	There is a native NAS plugin for xmms at

	ftp://ftp.stack.nl/pub/users/willem/

	I use it all the time.  In general, it will be better to use the
native application's NAS support, if available.  libaudiooss is an
LD_PRELOAD library that intercepts accesses to /dev/{mixer,audio,dsp} and
converts them into NAS protocol requests.

	You should use this lib on apps that do not grok NAS, but use
direct OSS access instead.

-- 
Jon Trulson    mailto:jon at radscan.com
ID: 1A9A2B09, FP: C23F328A721264E7 B6188192EC733962
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