1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
|
<!--
$NCDId: @(#)nas.man,v 1.1 1994/08/11 22:12:24 greg Exp $
-->
<!-- manual page source format generated by PolyglotMan v3.0.8+X.Org, -->
<!-- available at http://polyglotman.sourceforge.net/ -->
<html>
<head>
<title>"NETWORK(AUDIO) manual page</title>
</head>
<body bgcolor='#efefef' text='black' link='blue' vlink='#551A8B' alink='red'>
<a href='#toc'>Table of Contents</a><p>
<h2><a name='sect0' href='#toc0'>Name</a></h2>
Network Audio System - a portable, network-transparent audio system
<h2><a name='sect1' href='#toc1'>Synopsis</a></h2>
<p>
The Network Audio System service is a network-transparent system
developed at Network Computing Devices for playing, recording, and manipulating
audio data over a network. It uses the client/server model to separate
application code from the software drivers needed to control specific audio
input and output devices.
<h2><a name='sect2' href='#toc2'>Description</a></h2>
The Network Audio System service provides
applications with the ability to send and receive audio data such as voice,
sound effects, and music in a network environment. A audio server inside
the desktop terminal or personal computer controls the various input and
output devices in response to messages sent from client programs running
on other hosts. <p>
A variety of utility programs are provided that can be used
to play or record audio using shell scripts or command-line procedures.
More ambitious applications can communicate directly with the audio server
using a C-language programming library. <p>
The Network Audio System service
supports a variety of the common formats used to store sound data. Audio
inputs and outputs can run at a any of a range of sampling rates. The audio
server automatically converts all data to the designed format or rate. <p>
Streams
of data from multiple inputs can be mixed together and directed to any
attached output device. Sounds that are used many times can be stored in
the server so that they do not need to be transmitted over the network
each time they are played. Furthermore, inputs can be hooked directly to
outputs (for example, a CD player can be connected to a set of speakers)
so that data can be played without requiring any client intervention or
network traffic.
<h2><a name='sect3' href='#toc3'>Audio Server Names</a></h2>
<p>
Each audio server has a name that is
used by applications in establishing a connection. The format of the name
depends upon the type of network being used. In TCP/IP environments, audio
server names look like: <p>
<center>tcp/<i>hostname</i>:<i>portnum</i></center> <p>
where <i>hostname</i> is the name
or numeric IP address of the desktop machine to be contacted and <i>portnum</i>
is the port number on which the server is listening. If the ``tcp/'' prefix
is not given, 8000 is automatically added to <i>portnum</i> so that the audio
server name is compatible with the X Window System display name. <p>
In DECnet
environments, audio server names look like: <p>
<center>decnet/<i>nodename</i>::<i>num</i></center> <p>
where
<i>nodename</i> is the name or numeric DECnet address of the desktop machine
to be contacted and <i>num</i> is the DECnet task AUDIO$<i>num</i>. If the ``decnet/'' prefix
is omitted, it is automatically added so that the audio server name is
compatible with the X Window System display name. <p>
Most audio utilities accept
a command line argument <i>-audio servername</i> for specifying the audio server
to be contacted. <p>
<br>
<pre> % auinfo -audio tcp/ncdunit:8000
</pre><p>
If no server is specified on the command line, the AUDIOSERVER environment
variable is checked to see if a name has been stored there. Otherwise,
the DISPLAY environment variable used by X Window System applications
is checked and the corresponding audio server is used.
<h2><a name='sect4' href='#toc4'>Sample Programs</a></h2>
<p>
Several
sample programs that use the Network Audio System service are provided
by NCD:
<dl>
<dt><b>auplay</b> </dt>
<dd>This program simply plays the files listed on its command
line. It is typically used from shell scripts, command-line procedures,
or other programs that just need to ``dump'' sound data to the audio server.
</dd>
<dt><b>audemo</b> </dt>
<dd>This program allows the user to select and play pre-recorded sound
files or to record new sound files. It provides a simple control panel
for dynamically changing the volume while a sound is being played and for
aborting a sound. </dd>
<dt><b>audial</b> </dt>
<dd>This program generates North American telephone
touch tones correspond to a given string. <i>audial</i> can also recognize touch
tones and produce the corresponding string. </dd>
<dt><b>autool</b> </dt>
<dd>This program is compatible
with the Sun <i>audiotool</i> program and is typically used to play prerecorded
sound files. Unlike <i>auplay</i> it provides a graphical interface to allow the
user to replay or cancel the data. </dd>
<dt><b>auinfo</b> </dt>
<dd>This program lists information
describing the capabilities of an audio server. </dd>
<dt><b>auctl</b> </dt>
<dd>This program can be
used to change various device parameters. </dd>
<dt><b>auscope</b> </dt>
<dd>This program is an audio
protocol filter that can be used to view the network packets being sent
between an application and an audio server. </dd>
<dt><b>aupanel</b> </dt>
<dd>This program provides
an X-based window-oriented interface allowing the user to adjust the attributes
of the devices provided by the Network Audio System service. </dd>
<dt><b>auedit</b> </dt>
<dd>This
program provides an X-based window-oriented interface allowing the user to
edit audio files. </dd>
<dt><b>auconvert</b> </dt>
<dd>This program allows the user to perform various
conversion operations on sound files. </dd>
<dt><b>auphone</b> </dt>
<dd>This program provides an X-based
window-oriented interface allowing two-way real time voice communication
between two audio servers. </dd>
<dt><b>aurecord</b> </dt>
<dd>This program is used to record audio
data from an audio server into a file. </dd>
<dt><b>auwave</b> </dt>
<dd>This program provides an X-based
window-oriented interface demonstrating the use of waveform elements. </dd>
</dl>
<h2><a name='sect5' href='#toc5'>Audio
Files</a></h2>
<p>
The audio programming library and utility programs can be used to
read and write files in any of the following file formats:
<dl>
<dt><b>Sun/NeXT</b></dt>
<dd>These
files typically have a '.au' or '.snd' extension. They are usually produced by
Sun or NeXT workstations. </dd>
<dt><b>Creative Labs</b></dt>
<dd>These files typically have a '.voc'
extension. They are usually produced by by Soundblaster audio cards on
IBM PC compatible computers. </dd>
<dt><b>Microsoft WAVE</b></dt>
<dd>These files typically have a
'.wav' extension. They are usually produced by IBM PC compatible computers.
</dd>
<dt><b>AIFF</b></dt>
<dd><br>
These files typically have an '.aiff' or '.aif' extension. They are usually produced
by SGI workstations or Apple computers. </dd>
<dt><b>Amiga IFF/8SVX</b></dt>
<dd>These files typically
have an '.iff' extension. </dd>
</dl>
<p>
Due to the nature of the file formats, only the Sun/NeXT
file format can be piped through standard input and/or standard output.
The convention for specifying standard input or standard output is to
use a hyphen ("-") as the file name.
<h2><a name='sect6' href='#toc6'>Programming</a></h2>
<p>
Application developers may
create their own audio clients using the Network Audio System programming
library.
<h2><a name='sect7' href='#toc7'>Environment Variables</a></h2>
<p>
The following environment variables are used
by Network Audio System programs:
<dl>
<dt><b>AUDIOSERVER</b> </dt>
<dd>This specifies the name of
default audio server to contact if no name is explicitly given on the
command line. </dd>
<dt><b>DISPLAY</b> </dt>
<dd>This specifies the name of an X Window System display
that should be assumed to also have a corresponding Network Audio System
server. </dd>
</dl>
<h2><a name='sect8' href='#toc8'>See Also</a></h2>
<p>
<a href='auplay.1.html'>auplay(1)</a>
, <a href='audemo.1.html'>audemo(1)</a>
, <a href='audial.1.html'>audial(1)</a>
, <a href='autool.1.html'>autool(1)</a>
, <a href='auinfo.1.html'>auinfo(1)</a>
, <a href='auctl.1.html'>auctl(1)</a>
,
<a href='auscope.1.html'>auscope(1)</a>
, <a href='aupanel.1.html'>aupanel(1)</a>
, <a href='auedit.1.html'>auedit(1)</a>
, <a href='auconvert.1.html'>auconvert(1)</a>
, <a href='auphone.1.html'>auphone(1)</a>
, <a href='aurecord.1.html'>aurecord(1)</a>
,
<a href='auwave.1.html'>auwave(1)</a>
<p>
<i>Network Audio System Overview and Programmers Guide</i>
<h2><a name='sect9' href='#toc9'>Copyright</a></h2>
<p>
The
following copyright and permission notice applies to all files in the Network
Audio System application programming libraries and example programs provided
in source form by Network Computing Devices: <p>
Copyright 1993, 1994 Network
Computing Devices, Inc. <p>
Permission to use, copy, modify, distribute, and
sell this software and its documentation for any purpose is hereby granted
without fee, 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 name Network Computing Devices,
Inc. not be used in advertising or publicity pertaining to distribution
of this software without specific, written prior permission. <p>
THIS SOFTWARE
IS PROVIDED `AS-IS'. NETWORK COMPUTING DEVICES, INC., DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE, INCLUDING WITHOUT LIMITATION ALL IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NONINFRINGEMENT.
IN NO EVENT SHALL NETWORK COMPUTING DEVICES, INC., BE LIABLE FOR ANY DAMAGES
WHATSOEVER, INCLUDING SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING
LOSS OF USE, DATA, OR PROFITS, EVEN IF ADVISED OF THE POSSIBILITY THEREOF,
AND REGARDLESS OF WHETHER IN AN ACTION IN CONTRACT, TORT OR NEGLIGENCE,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
<h2><a name='sect10' href='#toc10'>Trademarks</a></h2>
<p>
NCD, NCD Display Station, and NCDware are all trademarks of Network
Computing Devices, Inc. <p>
X Window System is a trademark of the Massachusetts
Institute of Technology.
<h2><a name='sect11' href='#toc11'>Authors</a></h2>
<p>
Greg Renda, Jim Fulton, David Lemke <p>
<hr><p>
<a name='toc'><b>Table of Contents</b></a><p>
<ul>
<li><a name='toc0' href='#sect0'>Name</a></li>
<li><a name='toc1' href='#sect1'>Synopsis</a></li>
<li><a name='toc2' href='#sect2'>Description</a></li>
<li><a name='toc3' href='#sect3'>Audio Server Names</a></li>
<li><a name='toc4' href='#sect4'>Sample Programs</a></li>
<li><a name='toc5' href='#sect5'>Audio Files</a></li>
<li><a name='toc6' href='#sect6'>Programming</a></li>
<li><a name='toc7' href='#sect7'>Environment Variables</a></li>
<li><a name='toc8' href='#sect8'>See Also</a></li>
<li><a name='toc9' href='#sect9'>Copyright</a></li>
<li><a name='toc10' href='#sect10'>Trademarks</a></li>
<li><a name='toc11' href='#sect11'>Authors</a></li>
</ul>
</body>
</html>
|
