Newsgroups: comp.speech
Path: pavo.csi.cam.ac.uk!warwick!uknet!pipex!howland.reston.ans.net!usc!elroy.jpl.nasa.gov!decwrl!pacbell.com!att-out!walter!thalia!manolis
From: manolis@thalia.bellcore.com (Manolis M. Tsangaris)
Subject: Re: Network Audio - is this possible?
Message-ID: <CKnMy5.Eo8@walter.bellcore.com>
Keywords: network audio
Sender: news@walter.bellcore.com
Nntp-Posting-Host: thalia.bellcore.com
Organization: Morristown Research and Engineering
References:  <1994Feb3.110321.43848@ucl.ac.uk>
Date: Thu, 3 Feb 1994 15:27:40 GMT
Lines: 215

|> Is it possible to use the audio device of one machine from another
|> machine on the same network?  I'm interested in playing out
|> audio files stored on a Sun SPARC station on a variety of 
|> different platforms including other SPARC stations, a 486 machine
|> running Linux, and a DOS/Windows platform.   Is it possible to
|> do this within the context of X-Windows - i.e. to somehow use the
|> communication channel between Client and Server to carry the 
|> audio signal?

I would suggest you to seriously consider AF (AudioFile) from DEC. It is an
X11 like client/server environment which provides network transparent audio.
Porting the client side to the pc/linux should not be hard.

I include the README file of the distribution:

(I am not affiliated with DEC. I am just a happy user :-)
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                      AudioFile Version 2, Release 2

                                README

Introduction
------------

The AudioFile System (AF) is a device-independent network-transparent
audio server.  With AudioFile, multiple audio applications can run
simultaneously, sharing access to the actual audio hardware.

Network transparency means that application programs can run on
machines scattered throughout the network.  Because AF permits
applications to be device-independent, applications need not be
rewritten to work with new audio hardware. AudioFile does for sound
what the X Window System does for text and graphics.

Development of AudioFile began in 1989 at Digital Equipment
Corporation's Cambridge Research Laboratory, but it builds on ideas
from earlier work.  We originally envisioned AudioFile as a server to
support all the capabilities of the CRL "LoFi" audio hardware running
on the DECstation 5000 workstation, but we soon began adding support
for a variety of other platforms and audio hardware.

This distribution of AudioFile includes device drivers for several
audio devices, server code for a number of platforms, a programming
API and library, out-of-the-box core applications, and a number of
"contributed" applications.  The key difference between the core and
contributed applications is that the many of the contrib clients also
depend on the TCL/Tk graphics toolkits distributed by the University
of California.  (The AudioFile distribution does not include TCL/Tk,
but we tell you where to get it.)

With AudioFile, it is easy to incorporate audio into applications.
Simple "play" and "record" applications are included, or you can write
your own using the AudioFile API and client library.  AudioFile allows
applications to generate and process audio in real-time but it also
permits more leisurely applications.  AudioFile is quite resistant to
the vagaries of scheduling and operating systems that can make
handling audio difficult.  We have successfully used AudioFile for
both trivial applications (audio BIFF) and complex applications
(real-time teleconferencing, speech synthesis and recognition.)
AudioFile may not be appropriate for all purposes, but we have found
it to be a versatile and effective tool.

We believe that AudioFile is highly portable, and that it should be
straightforward to add additional support for other systems equipped
with audio hardware.

AudioFile is distributed in source form, with a copyright allowing
unrestricted use for any purpose except sale (see the Copyright
notice).

We would like to encourage other organizations to add support to
AudioFile for additional platforms, operating systems, and devices,
and to contribute additional applications.

We have set up a mailing list for discussions of AudioFile:

	af@crl.dec.com

send mail to af-request@crl.dec.com to be added to this list.

AudioFile Server
----------------
This distribution of AudioFile includes server support for Digital
RISC systems running Ultrix, Digital Alpha AXP systems running OSF/1,
and Sun Microsystems SPARCstations running SunOS.  The servers support
audio hardware ranging from the built-in CODEC audio on SPARCstations
and Personal DECstations to 48 KHz stereo audio using the DECaudio
TURBOchannel module.  In addition, server support is present for
telephone access devices such as DECaudio.

AudioFile API
-------------
The distribution includes C language bindings to the protocol that
make it easy to write distributed audio applications.

AudioFile Clients
-----------------
This distribution includes a number of core applications for
recording, playback, telephone control, device control, and access
control.

AudioFile "Contrib" Clients
---------------------------
The distribution includes a number of contributed applications
including an audio file browser, an FFT spectrogram display, and
multicast network audio service.

Kit Location
------------

The kit is located at ftp site crl.dec.com (Internet 192.58.206.2) in
/pub/DEC/AF.  The kit is contained in a compressed tar file named
AF2R2.tar.Z.  Use anonymous ftp to retrieve the file,

	% ftp crl.dec.com
	...
	ftp> cd /pub/DEC/AF
	ftp> binary
	ftp> get AF2R2.tar.Z

The kit is shipped as a compressed tar file.  To unpack the kit,

	% cd <audio_root>
	% zcat AF2R2.tar.Z | tar xpBf -

We also provide a sample kit of Hi-Fi sound bites for use with
DECaudio.  If you have a DECaudio, you might considering retrieving
AF2R2-other.tar.Z and unpack this kit in the same manner as described
above.

Other files available in this same directory are the release notes,
copyright notice, and this README file.

Roadmap
-------

Several directories will be created in your local audio root
directory.  The "AF" sub-tree contains the source code for the
AudioFile server, the AudioFile client library, and several AudioFile
client programs.  The "devices" sub-tree contain the device specific
code not related to the AF system.  For example, the LoFi device
library, LoFi device driver, and test programs are included here.
Finally, "sound_files" contains several sound bites you can use while
verifying the kit installation.

The kit requires approximately 6 Megabytes and an additional 8
Megabytes for building and installing the release.  The HiFi sound
files require another 4 Megabytes approximately.

Documents
---------

You should read the following documents prior to installing this software.

o  AF Release Notes - <audio_root>/AF/RELNOTES.{txt,PS}

o  Copyrights information - <audio_root>/COPYRIGHTS

Suggested Sequence
------------------

o  Retrieve the software package and create a local audio hierarchy.

o  Read the documents mentioned above.

o  Build the AudioFile release (after unpacking the kit.)

	% cd <audio_root>

   Customize the build environment for your local site according to
   the information contained in the release notes.  Follow the directions
   there in order to build this release.

   Typing,

	% make Help

   in the <audio_root> directory can be used as a reminder of the steps
   in the build process.

   You might want to save the output of the build and install session
   in order to identify problems should any occur.

o  If you are using LoFi/DECaudio or the native audio on DECstations or
   Alpha AXP workstations for the first time, see the instructions in
   one of these directories for information about the hardware and 
   device drivers.

   For the native DECstation audio device,
		 <audio_root>/devices/maxine/driver/mips.src/bba.4 man page

   For the native Alpha AXP workstation audio device,
		 <audio_root>/devices/axp/driver/README

   For LoFi/DECaudio,

	On Ultrix/RISC (MIPS):
		 <audio_root>/devices/lofi/driver/mips.src/lofi.4 man page

	On DEC OSF/1 Alpha:
		 <audio_root>/devices/lofi/driver/alpha.src/lofi.7 man page
		 <audio_root>/devices/lofi/driver/alpha.src/README

o  Test the AudioFile server and clients.

o  Have fun!

Copyrights
----------

See the file <audio_root>/COPYRIGHTS for the full copyright and 
permission notice.

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