1NETWORK AUDIO SYSTEM(1)     General Commands Manual    NETWORK AUDIO SYSTEM(1)
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NAME

6       Network Audio System - a portable, network-transparent audio system
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SYNOPSIS

9       The Network Audio System service is a network-transparent system devel‐
10       oped at Network Computing Devices for playing, recording,  and  manipu‐
11       lating  audio  data over a network.  It uses the client/server model to
12       separate application code from the software drivers needed  to  control
13       specific audio input and output devices.
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DESCRIPTION

16       The Network Audio System service provides applications with the ability
17       to send and receive audio data such as voice, sound effects, and  music
18       in  a  network environment.  A audio server inside the desktop terminal
19       or personal computer controls the various input and output  devices  in
20       response to messages sent from client programs running on other hosts.
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22       A  variety of utility programs are provided that can be used to play or
23       record audio using shell scripts or command-line procedures.  More  am‐
24       bitious applications can communicate directly with the audio server us‐
25       ing a C-language programming library.
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27       The Network Audio System service supports a variety of the common  for‐
28       mats  used  to store sound data.  Audio inputs and outputs can run at a
29       any of a range of sampling rates.  The audio server automatically  con‐
30       verts all data to the designed format or rate.
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32       Streams of data from multiple inputs can be mixed together and directed
33       to any attached output device.  Sounds that are used many times can  be
34       stored  in  the  server so that they do not need to be transmitted over
35       the network each time they are  played.   Furthermore,  inputs  can  be
36       hooked  directly  to outputs (for example, a CD player can be connected
37       to a set of speakers) so that data can be played without requiring  any
38       client intervention or network traffic.
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AUDIO SERVER NAMES

41       Each audio server has a name that is used by applications in establish‐
42       ing a connection.  The format of the name depends upon the type of net‐
43       work being used.  In TCP/IP environments, audio server names look like:
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45                                tcp/hostname:portnum
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47       where hostname is the name or numeric IP address of the desktop machine
48       to be contacted and portnum is the port number on which the  server  is
49       listening.   If the ``tcp/'' prefix is not given, 8000 is automatically
50       added to portnum so that the audio server name is compatible with the X
51       Window System display name.
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53       In DECnet environments, audio server names look like:
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55                                decnet/nodename::num
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57       where nodename is the name or numeric DECnet address of the desktop ma‐
58       chine to be contacted and num is the DECnet  task  AUDIO$num.   If  the
59       ``decnet/''  prefix  is  omitted, it is automatically added so that the
60       audio server name is compatible with the X Window System display name.
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62       Most audio utilities accept a command line argument  -audio  servername
63       for specifying the audio server to be contacted.
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65           % auinfo -audio tcp/ncdunit:8000
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67       If no server is specified on the command line, the AUDIOSERVER environ‐
68       ment variable is checked to see if a name has been stored there.   Oth‐
69       erwise, the DISPLAY environment variable used by X Window System appli‐
70       cations is checked and the corresponding audio server is used.
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SAMPLE PROGRAMS

73       Several sample programs that use the Network Audio System  service  are
74       provided by NCD:
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76       auplay  This program simply plays the files listed on its command line.
77               It is typically used from shell  scripts,  command-line  proce‐
78               dures,  or other programs that just need to ``dump'' sound data
79               to the audio server.
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81       audemo  This program allows the user to select  and  play  pre-recorded
82               sound files or to record new sound files.  It provides a simple
83               control panel for dynamically changing the volume while a sound
84               is being played and for aborting a sound.
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86       audial  This  program  generates  North  American telephone touch tones
87               correspond to a given string.  audial can also recognize  touch
88               tones and produce the corresponding string.
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90       autool  This  program  is compatible with the Sun audiotool program and
91               is typically used to play prerecorded sound files.  Unlike  au‐
92               play it provides a graphical interface to allow the user to re‐
93               play or cancel the data.
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95       auinfo  This program lists information describing the  capabilities  of
96               an audio server.
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98       auctl   This program can be used to change various device parameters.
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100       auscope This  program  is  an audio protocol filter that can be used to
101               view the network packets being sent between an application  and
102               an audio server.
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104       aupanel This  program provides an X-based window-oriented interface al‐
105               lowing the user to adjust the attributes of  the  devices  pro‐
106               vided by the Network Audio System service.
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108       auedit  This  program provides an X-based window-oriented interface al‐
109               lowing the user to edit audio files.
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111       auconvert
112               This program allows the user to perform various conversion  op‐
113               erations on sound files.
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115       auphone This  program provides an X-based window-oriented interface al‐
116               lowing two-way real time voice communication between two  audio
117               servers.
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119       aurecord
120               This  program is used to record audio data from an audio server
121               into a file.
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123       auwave  This program  provides  an  X-based  window-oriented  interface
124               demonstrating the use of waveform elements.
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AUDIO FILES

127       The  audio programming library and utility programs can be used to read
128       and write files in any of the following file formats:
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130       Sun/NeXT
131              These files typically have a '.au' or  '.snd'  extension.   They
132              are usually produced by Sun or NeXT workstations.
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134       Creative Labs
135              These files typically have a '.voc' extension.  They are usually
136              produced by by Soundblaster audio cards  on  IBM  PC  compatible
137              computers.
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139       Microsoft WAVE
140              These files typically have a '.wav' extension.  They are usually
141              produced by IBM PC compatible computers.
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143       AIFF
144              These files typically have an '.aiff' or '.aif' extension.  They
145              are usually produced by SGI workstations or Apple computers.
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147       Amiga IFF/8SVX
148              These files typically have an '.iff' extension.
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150       Due  to  the  nature of the file formats, only the Sun/NeXT file format
151       can be piped through standard input and/or standard output.   The  con‐
152       vention  for  specifying  standard input or standard output is to use a
153       hyphen ("-") as the file name.
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PROGRAMMING

156       Application developers may create their own  audio  clients  using  the
157       Network Audio System programming library.
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ENVIRONMENT VARIABLES

160       The  following  environment  variables are used by Network Audio System
161       programs:
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163       AUDIOSERVER
164               This specifies the name of default audio server to  contact  if
165               no name is explicitly given on the command line.
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167       DISPLAY This  specifies  the  name  of  an X Window System display that
168               should be assumed to also have a  corresponding  Network  Audio
169               System server.
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SEE ALSO

172       auplay(1),  audemo(1),  audial(1), autool(1), auinfo(1), auctl(1), aus‐
173       cope(1), aupanel(1), auedit(1), auconvert(1), auphone(1),  aurecord(1),
174       auwave(1)
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176       Network Audio System Overview and Programmers Guide
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179       The  following  copyright and permission notice applies to all files in
180       the Network Audio System application programming libraries and  example
181       programs provided in source form by Network Computing Devices:
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183       Copyright 1993, 1994 Network Computing Devices, Inc.
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185       Permission to use, copy, modify, distribute, and sell this software and
186       its documentation for any purpose is hereby granted without  fee,  pro‐
187       vided  that  the  above  copyright notice appear in all copies and that
188       both that copyright notice and this permission notice  appear  in  sup‐
189       porting  documentation,  and  that  the name Network Computing Devices,
190       Inc. not be used in advertising or publicity pertaining to distribution
191       of this software without specific, written prior permission.
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193       THIS  SOFTWARE  IS  PROVIDED `AS-IS'.  NETWORK COMPUTING DEVICES, INC.,
194       DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING  WITH‐
195       OUT LIMITATION ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
196       PARTICULAR PURPOSE, OR NONINFRINGEMENT.  IN NO EVENT SHALL NETWORK COM‐
197       PUTING  DEVICES,  INC., BE LIABLE FOR ANY DAMAGES WHATSOEVER, INCLUDING
198       SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING  LOSS  OF  USE,
199       DATA,  OR  PROFITS, EVEN IF ADVISED OF THE POSSIBILITY THEREOF, AND RE‐
200       GARDLESS OF WHETHER IN AN ACTION IN CONTRACT, TORT OR NEGLIGENCE, ARIS‐
201       ING  OUT  OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFT‐
202       WARE.
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TRADEMARKS

205       NCD, NCD Display Station, and NCDware are  all  trademarks  of  Network
206       Computing Devices, Inc.
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208       X  Window System is a trademark of the Massachusetts Institute of Tech‐
209       nology.
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AUTHORS

212       Greg Renda, Jim Fulton, David Lemke
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216                                     1.9.5             NETWORK AUDIO SYSTEM(1)
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