Asgi(1)

NAME
Asgi - a network-transparent audio server for SGI Indigo workstations

SYNOPSIS
The AF audio server is a network transparent system developed at Digital CRL. The audio server described in this manual page supports the SGI Indigo audio hardware and software.

DESCRIPTION
Asgi is an AF server with device dependent support for SGI Indigo and Indigo2 workstations.

STARTING UP
Asgi [:portOffset] [options] &

OPTIONS

-help
    Use the help switch to determine device independent arguments.

-rate sampling-rate
    Specify the sampling rate. Valid sampling rates are all rates supported by the SGI Indigo audio hardware: 8000, 11025, 16000, 22050, 32000, 44100 and 48000 samples/sec. The default is 8000. The sampling rate is used both for recording and for playback, and should not be changed using the apanel utility (in fact the server resets it when it detects it is changed).

AUDIO DEVICES
This server supports three devices, which provide different types of acces to a single audio device: device 0 accepts mono U-LAW samples, device 1 accepts mono 16-bit linear samples, device 1 accepts stereo 16-bit samples. (Don't confuse these devices with the portOffset in the connection name explained below.)

The hardware has a choice of three input sources: input 0 is the line input jack, input 1 is the microphone, input 2 is the digital input. Exactly one of these is selected at any time.

CONNECTION NAME
From the user's prospective, every AF server has an audio connection of the form:

hostname:portOffset

This information is used by the application to determine how it should connect to the server.

hostname
    The hostname specifies the name of the machine to which the audio device is physically connected. If omitted, the local machine is used and the fastest available protocol is chosen (e.g. UNIX sockets or shared memory).

portOffset
    The portOffset is used to identify the audio server's port on hostname. For example, to simultaneously run two audio servers on a given host, you might select 0 or 1 for portOffset.

If the connection name to an audio server is not specified, then the environment variables AUDIOFILE or DISPLAY will be used.

ACCESS CONTROL
The sample server provides two types of access control: an authorization protocol which provides a list of ``magic cookies'' clients can send to request access, and a list of hosts from which connections are always accepted.

BUGS
At high sampling rates the server uses too much CPU when sounds are recorded and played.

If you encounter a repeatable bug in the SGI dependent code, please submit a problem report to guido@cwi.nl and include the source code if possible.

SEE ALSO
AF(1)
Aaxp(1), Amaxine(1), Alofi(1), Ajv(1), Asparc(1), Amsb(1), Aj300(1), aplay(1), arecord(1), apass(1), aset(1), abrowse(1), afft(1), ahost(1), aphone(1), aprop(1), ahs(1), axset(1), xpow(1), afxctl(1), aname2num(1), alsatoms(1), aevents(1), abob(1)

See also apanel(1) and the Digital Audio and MIDI Programming Guide by Silicon Graphics.

COPYRIGHT
See the COPYRIGHTS file.

Copyright 1991-1993, Digital Equipment Corporation and the Massachusetts Institute of Technology.

SGI device dependent code:

Copyright 1993 by Stichting Mathematisch Centrum, Amsterdam, The Netherlands.

All Rights Reserved

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the names of Stichting Mathematisch Centrum or CWI not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

AUTHORS
Digital Cambridge Research Lab (device-independent code)
Guido van Rossum, CWI, Amsterdam (SGI device-dependent code)