AUDEMO(1)AUDEMO(1)NAMEaudemo - Network Audio System record and play demo
SYNOPSISaudemo [-audio servername] [-toolkitoption ...] [direc_
tory]
DESCRIPTIONaudemo provides an X-based window-oriented user interface
to the Network Audio System service. It allows the user
to play pre-recorded sound files, record new sound files
and to manipulate Network Audio System buckets.
AUDEMO AND THE ATHENA WIDGET SETaudemo uses the X Toolkit Intrinsics and the Athena Widget
Set. For more information, see the Athena Widget Set doc
umentation.
SCREEN LAYOUTaudemo starts out with a single window divided into sev
eral areas:
o A collection of command buttons.
o A left and right level meter.
o A volume indicator and control slider.
o An information window.
o An editable field containing the directory to be
searched for sound files.
o An editable field containing a list of sound files to
search for.
o A window containing the list of sound files that may
be selected for playing or loading into buckets.
PLAYING A SOUND FILE
To play a sound file you must first select it from the
list of files in the file window. You can control which
files are listed in this window by editing the Directory
and/or Template fields and clicking on the Rescan button.
To select a file, single-click on the filename. This will
highlight the filename and display information about the
file in the information window. The information displayed
includes:
Filename
The full pathname of the file.
File Format
The file format of the audio file.
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Data Format
The encoding format of the audio data.
Tracks
The number of tracks of audio data.
Frequency
The frequency at which the audio data was sampled.
Duration
The duration of the audio data in seconds.
Text
Any text information stored in the file.
Once the file has been selected, you can start it playing
by clicking on the Play command button. A shortcut for
playing a file is to double-click on the file name. This
will select the file and start it playing. When a file is
playing, the Play command button is highlighted. To stop
the playing of a file, click on the highlighted Play but
ton. To enable the left and right level meters, click on
the Meter button before starting to play the file. To
disable the left and right level meters, click again on
the highlighted Meter button. To adjust the volume level,
use the volume slider.
RECORDING TO A FILEaudemo can record sound files in any supported file and
data format. To record a sound file you must first bring
up the record window by clicking on the Record command
button. This will bring up a window containing the fol
lowing fields and controls:
Filename
The name of the file you wish to create. Unless a
path is specified here, the file will be created in
the current directory.
File Format
A menu of file formats.
Data Format
A menu of data formats. Note that each file format
does not necessarily support all of the data formats
listed.
Max Duration
See RECORDING TO A BUCKET.
Read Only
See RECORDING TO A BUCKET.
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AUDEMO(1)AUDEMO(1)
Frequency
The sampling rate (in hertz) for the recording.
Higher sampling rates yield better quality sound but
take up more disk and memory space. Common sampling
rates are 8000 (good for voice annotations), 11000,
22000, and 44000.
Mic(rophone)
This button tells the audio server if you've got a
microphone attached to the audio input jack. Clicking
this button will highlight it and cause the audio
server to boost the input gain to a level suitable for
recording with a microphone.
Comment
Text (such as a description) you wish to put into the
audio file.
Gain
This slider is used to adjust the recording gain
level.
Record
This button starts or stops the recording.
Monitor
This button enables or disables monitoring.
New Bucket
See RECORDING TO A BUCKET.
Dismiss
This button stops recording and monitoring and closes
the record window.
Once you have selected the filename, file and data for
mats, frequency, mic level, comment and gain, you are
ready to record. To listen in on the audio that will be
recorded you can click on the Monitor button. This will
direct all the audio received from the audio input jack to
be played on the speaker. When you're ready to record,
click on the Record button. All the audio received from
the audio input jack will now be recorded into the file.
The recording will continue until you click on the Record
button again or click on the Dismiss button. NOTE: Audio
data can accumulate very rapidly, especially at high sam
pling rates, resulting in large files.
BUCKETS
The Network Audio System service provides the capability
to create server resident sound objects called buckets.
audemo allows the user to create buckets, record into
them, play from them, load them with data from a file and
dump their contents into a file. Note that buckets
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created by audemo are destroyed when audemo is terminated.
These options are available when you bring up the buckets
window by clicking on the Buckets button in the main win
dow. The buckets windows is divided into two areas:
o A collection of command buttons.
o A table of buckets currently accessible. This table
contains the following columns:
Description
The text description.
Duration
The duration of the audio data in seconds.
Tracks
The number of tracks of audio data.
Frequency
The frequency at which the audio data was sampled.
Format
A code letter indicating the encoding format of
the audio data. A key to the format code letters
can be displayed by clicking on the Format Key
button.
Access
A combination of code letters indicating the
access mode of the bucket. A key to the access
code letters can be displayed by clicking on the
Access Key button.
CREATING A BUCKET FROM A FILE
To create a bucket from from an audio data file, select
the filename from the list of files in the file window
then click the Load button in the buckets window. The
first line of the buckets table should now contain the
information about the newly created bucket.
PLAYING FROM A BUCKET
To play a bucket, select the bucket you wish to play by
clicking on it's information in the buckets table. The
entry you click on should be highlighted. Then click on
the Play button in the buckets window. A shortcut for
playing from a bucket is to double-click on the bucket
information. This will select the bucket and start play
ing from it. To stop the playing of a bucket, click on
the highlighted Play button in the buckets window. The
level meters and volume level can be controlled in the
same way as when playing from a file.
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AUDEMO(1)AUDEMO(1)RECORDING TO A BUCKET
To record into a new bucket, click on the Record button in
the buckets window. This will bring up the record window.
This record window is the same as the one used for record
ing to files. Instead of specifying a filename, in the
Max Duration field, enter the maximum duration (in sec
onds) of data that the bucket is to hold. Clicking on the
Read Only button will prevent other applications from
writing into or destroying the bucket. The frequency, mic
level, format and comment are used in the same way as when
recording to files. Once all of the fields are set appro
priately, click the New Buckett button. This will create
a new bucket according to the specifications given. The
first line of the buckets table should now contain the
information about the newly created bucket. To begin
recording into the bucket, select the bucket by clicking
on it's information in the buckets table. Then click the
Record button in the record window. All the audio
received from the audio input jack will now be recorded
into the bucket. The recording will continue until you
click on the Record button again, click on the Dismiss or
the bucket is filled. The Gain slider and the Monitor
button operate the same as when recording to a file.
SAVING A BUCKET TO A FILE
To save a bucket to a file, first select the bucket by
clicking on its information in the buckets table. Then
click on the Save button in the buckets window. A dialog
box will pop up prompting you for the name of the file in
which to save the bucket data, and the file format. The
data format used will be that of the bucket. Note that
each file format may only support selected data formats.
If no path is given in the filename, the file will be cre
ated in the current directory. Clicking on Ok or pressing
the RETURN key will cause the file to be created and the
data from the bucket to be written to the file.
DELETING A BUCKET
To delete a bucket, first select the bucket by clicking on
it's information in the buckets table. Then click on the
Delete button in the buckets window. If the audemo has
the appropriate access permissions for the bucket, the
bucket will be deleted and it's information will be
removed from the bucket table.
EXITING AUDEMO
Clicking on the Quit button will cause audemo to exit,
stopping any playing or recording operations and destroy
ing any buckets that were created.
COMMAND LINE OPTIONS-audio servername
This option specifies the Network Audio System
server to which audemo should connect.
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directory
The directory name that audemo will use to build
the list of selectable file names. When directory
is not specified on the command line, the current
working directory is used.
EXAMPLES
In the following example, in a TCP/IP network, mcxterm is
the name of the desktop machine running the audio server.
The default port is 8000 and sound files are located in
~/snd:
audemo-audio tcp/mcxterm:8000 ~/snd
In the following example, the shortened form of the audio
server name is used and sound files from the current work
ing directory will be used:
audemo-audio mcxterm:0
ENVIRONMENT
In addition to the standard toolkit environment variables,
the following environment variables are used by audemo:
AUDIOSERVER
This variable specifies the default audio server
to contact if -audio is not specified on the com
mand line. If this variable is not set and the
-audio is not specified on the command line,
audemo will attempt to connect to the audio server
running on the X Window System display.
BUGS
Warning: audemo is the xterm of the Network Audio System.
It was written to test features as the Network Audio Sys
tem was being developed. It was also the author's first
Xt program. Consequently, it's pretty ugly and should be
completely re-written from scratch.
SEE ALSOnas(1), X(1)COPYRIGHT
Copyright 1993, 1994 Network Computing Devices, Inc.
AUTHOR
Greg Renda, Network Computing Devices, Inc.
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