The audiorecord application program records an audio file using the Multimedia Services product. The file is written in WAVE format. Files recorded by audiorecord may be played back using the audioplay program and DECsound.

Pressing Ctrl/C pauses the recording, which can be resumed by pressing Return. The program is terminated by pressing a second Ctrl/C.

To determine the device number and formats supported for an audio input device, use the audiodevices program.

4.1 Syntax for audiorecord

To invoke audiorecord create a foreign command. The following example defines the symbol audiorecord as a foreign command:

$ audiorecord :== $SYS$SYSTEM:MMOV$AUDIORECORD.EXE

audiorecord uses the following command line options:

[-filename filename]
is the file name to use to save audio input. This file name defaults to tempfile.wav .

[-idevice #]
is the input device number. The default is the first available device.

[-channels #]
is the number of channels. The channel may be mono (1) or stereo (2). The default is mono (1).

[-bitspersample #]
is the number of bits per sample. The default is 16.

[-rate #]
is the sample rate in Hz. The default is 11025.

[-time #]
is the maximum time to record, in seconds. The recording can be terminated sooner by pressing Ctrl/C.

[-encoding format]
describes the audio encoding format. Valid entries are pcm for PCM or mulaw for mulaw. The default is pcm.

[-numbuffers #]
is the number of buffers. The default is 4.

[-sizebuffers #]
is the size, in bytes, of each buffer.

If values are entered for [-sizebuffers #] and [-msbuffers #] , the
[-msbuffers #] value is used and the [-sizebuffers #] value is ignored.

By default, the byte size of each buffer is dependent on the value for
[-msbuffers #] .

[-msbuffers #]
is the size, in milliseconds, of each buffer. Unless [-sizebuffers #] overrides this value, the default value is 250 milliseconds.

[-verbose]
prints various status messages while recording.

[-help]
displays help information.

The audioselectports program selects input or output ports for audio devices, using the Multimedia Services product. The availability of the ports and how many may be selected will depend on what the particular device supports. Once set, the ports will be used for all applications using Multimedia Services, such as DECsound and audiorecord , until the ports are reset or the mmeserver process is restarted.

If no port setting is specified, audioselectports will display the available ports for the audio devices as well as which ports are currently selected.

5.1 Syntax for audioselectports

To invoke audioselectports , create a foreign command. The following example defines audioselectports as a foreign command:

$ audioselectports :== $SYS$SYSTEM:MMOV$AUDIOSELECTPORTS.EXE

audioselectports uses the following command line options:

[-idevice #]
is the input device number. The default is display all.

[-odevice #]
is the output device number. The default is display all.

[-port #] ...
are the ports to be enabled. If the device supports multiple ports, then each port specified will be enabled. The default is display port information. If no port information is entered, the default is to display port information for a specified device, or if no device is specified, then port information is displayed for all devices.

[-verbose]
prints various status messages.

[-help]
displays help information.

DECsound is a software application that you can use to record and play audio messages that you can mail to other users or include in documents and presentations.

DECsound functions are similar to those of a tape recorder---you can play, record, fast-forward, and rewind recordings. You can also edit your recordings using the on-screen waveform display.

With DECsound, you record messages using a microphone that you connect to your workstation. You can also use any other source connected to the selected port of your audio device. Audio port selection can be accomplished using other applications such as Audio Control. You can play back messages on your workstation's built-in speaker or on headphones connected to your workstation. You can also use a headset that combines a microphone and headphones.

You can perform basic editing tasks on your recordings. For example, you can use cut-and-paste operations on a DECsound recording in the same way as you would use them on a piece of text. DECsound also provides a library of sound effects that you can use separately or with your own recordings.

6.1 Syntax for DECsound

To invoke DECsound, create a foreign command. The following example defines the symbol decsound as a foreign command:

$ decsound :== $SYS$SYSTEM:MMOV$DECSOUND.EXE

DECsound uses the following command line options:

[-file filespec]
specifies the file name to use for the DECsound session. If the file exists, the DECsound window displays the recording. If the file does not exist, DECsound creates a new recording. DECsound uses .au as the default file type.

[-play filespec]
plays the specified file without displaying the DECsound window.

[-file -]
outputs a recording to SYS$OUTPUT. Data written to SYS$OUTPUT is in mono 8 kHz mulaw raw audio format only. When you make a recording and choose Save from either the main screen or the File menu, the recording is written to SYS$OUTPUT. There are some restrictions on functions that can be performed when DECsound is run in this mode, and the corresponding buttons and menu entries will be dimmed.

[-play -]
plays audio data from SYS$INPUT without bringing up the user interface. Data read from SYS$INPUT should be in mono 8 kHz mulaw raw audio format only. For example, if an .aud-formatted file is read from SYS$INPUT, the file header will be played as data, causing additional noise when data is played as audio.

[-file - -play] [-play -file -]
brings up the DECsound user interface and loads audio data from SYS$INPUT (instead of from a file). This audio data can then be played back, edited, or written to a file as usual. Data read from SYS$INPUT should be in mono 8 kHz mulaw raw audio format only. For example, if an .aud-formatted file is read from SYS$INPUT, the file header will be played as data, causing additional noise when data is played as audio. There are some restrictions on the functions that can be performed when DECsound is run in this mode.

[-device number]
specifies the number of the audio device on your system to be used for playback and recording.

[-help]
displays help information.

The following table describes the default resources in the sound_editor_resources.dat file used by DECsound:

Resource	Description	Values
DECsoundEditor.MaxRecordLength	Maximum recording length in seconds	Default is 120
DECsoundEditor.AutoRepeat	Toggle autorepeat for playback	Values are 0 (false) and 1 (true)
DECsoundEditor.SaveFormat	Default file save format	Values are 0 (Sun AU) 1 (DDIF) and 2 (WAVE)

6.2 Editing Concepts

DECsound provides some editing operations you can perform on your recordings. You can cut and paste parts of a recording in the same way that you would cut and paste parts of a text file. By using multiple DECsound sessions, you can paste part of one recording into another recording. You can create interesting sound effects by experimenting with the cut-and-paste operations and with the sample files that are provided with DECsound.

6.2.1 Waveforms

Before using the DECsound editing operations, you must select the part of the recording that you want to modify. DECsound displays a waveform that represents the recording. You select parts of the recording by selecting parts of the waveform.

DECsound displays the waveform in two formats:

• Samples, which show the values recorded by the DECsound software and hardware
• Energy levels, which show the variations in sound energy in the DECsound recording

Choose Display Samples from the DECsound View menu to display the waveform in the samples format. Choose Display Energy to display the waveform in the energy levels format. Figure 6-1 displays the DECsound control panel with a waveform display window.

Figure 6-1 DECsound Control Panel with Display Energy Enabled

By default, the waveform display window displays the waveform in the samples format.

6.2.2 Selecting Part of a Recording

Before using the Edit menu items, you must select the part of the recording that you want to modify. Select part of a recording by dragging MB1 across the recording. DECsound highlights the selected part of the recording.

When you select part of a recording, you can extend the selection by pressing the Shift key while dragging MB1. You can select an entire recording by choosing Select All from the Edit menu.

6.2.3 Clipboard

Like many other applications based on Windows, DECsound has a clipboard, which is a temporary (invisible) storage area. When you cut or copy part of a DECsound recording, DECsound stores the selected part of the recording in the clipboard. When you use the Paste menu item, DECsound pastes the contents of the clipboard into the recording.

The clipboard stores only the most recently cut or copied part of a recording. When you cut or copy part of a recording to the clipboard, the recording overwrites the current contents of the clipboard.

6.2.4 Quick Copy

DECsound provides a Quick Copy function, which copies the selected part of a recording to the current position in the waveform. To use the Quick Copy function, follow these steps:

1. Select the part of the recording that you want to copy.
2. Position the pointer at the point in the waveform where you want to insert the selected part of the recording.
3. Click MB2.

DECsound supports reading and writing of files in DDIF, Sun AU, and WAVE formats. DDIF and Sun AU files can be read and written in mono, 8 kHz 8-bit mulaw audio format only. WAVE files can be read and written in the following audio encoding formats:

Sample Rate	Channels	Sample Size	Encoding
8 kHz	Mono	8 bit	Mulaw
11.025 kHz	Mono and Stereo	8 and 16 bit	Linear
22.05 kHz	Mono and Stereo	8 and 16 bit	Linear
44.1 kHz	Mono and Stereo	8 and 16 bit	Linear

RIFF WAVE is a format developed by Microsoft and IBM, and is the most popular format on the Microsoft Windows platforms. WAVE files usually have .wav extensions.

Files encoded in the Sun audio format usually have .au extensions. These files can be created on many workstations. They most often come in mono,
8 kHz 8-bit mulaw audio encoding.

DDIF (Digital Document Interchange Format) is the standard document format used by CDA, a component of Compaq's Network Application Support (NAS) architecture that defines standards for compound documents and enables file interchange among all compliant applications. DDIF files have .aud extensions.

6.4 DECsound Menus

The following sections describe the DECsound menus.

6.4.1 File Menu

The items on the File menu allow you to create and maintain files that contain DECsound recordings.

6.4.1.1 New

Choose New from the File menu to clear the current DECsound recording and begin a new one. If you have not saved the current recording, DECsound asks you if you want to save it before beginning the new recording. Before a new file can be created, you will be prompted to specify the sampling rate, number of channels, and sample size for the new file.

6.4.1.2 Open...

Choose Open... from the File menu to open an existing DECsound file. DECsound displays the Open File dialog box, which lists all the DECsound files in your current directory. To select a file, double click on a file name in the list or enter the file name directly in the Selection text-entry field. When you select the file name, click on OK. DECsound removes the Open File dialog box and loads the file you specify in the DECsound window.

6.4.1.3 Save

Choose Save from the File menu to save a revised version of a DECsound file with the current file name.

6.4.1.4 Save As...

Choose Save As... from the File menu to save a DECsound file under a new name. DECsound displays the Save File dialog box, which lists all the DECsound files in your current directory. When you save a DECsound recording under a new file name, the new file name becomes the current file name. The file format for the file to be saved can be selected from the list of available formats in the dialog box.

When you select a file name, click on OK. DECsound saves the file and removes the Save File dialog box.

6.4.1.5 Exit

Choose Exit from the File menu to exit from DECsound. DECsound saves the current recording, using the current file name. If there is no current file name, DECsound displays the Confirmation dialog box.

DECsound displays the Confirmation dialog box when you try to exit from DECsound and one of the following conditions applies:

Condition	What to do
You edited a recording or made a new recording, but you did not save the recording in a file.	Click on OK to exit from DECsound without saving the recording, or click on Cancel to cancel the Exit command and continue using DECsound.
You made changes in the Settings dialog box, but you did not click on Save in the dialog box.	Click on OK to exit from DECsound without saving the changes to the dialog box settings, or click on Cancel to cancel the Exit command and continue using DECsound.

6.4.2 Edit Menu

The items on the Edit menu allow you to modify part or all of a recording. You can perform simple editing tasks on your recordings. DECsound displays the waveform for a recording in the DECsound window. You can perform cut, copy, and paste operations on the waveform in the same way as you would perform them on text in a text editor or word-processing application.

6.4.2.1 Cut

Choose Cut from the Edit menu to transfer the selected part of a recording to the clipboard. DECsound deletes the selected part of the recording from the display area.

6.4.2.2 Copy

Choose Copy from the Edit menu to copy the selected part of a recording to the clipboard. The recording is unchanged.

Choose Paste from the Edit menu to paste the contents of the clipboard into the recording at the point indicated in the waveform displayed in the DECsound window.

6.4.2.4 Clear

Choose Clear from the Edit menu to delete the selected part of the recording. DECsound deletes the selected part of the recording from the display area, but the Clear operation does not affect the contents of the clipboard. If you use the Clear operation without selecting part of the recording, the entire recording is cleared.

6.4.2.5 Select All

Choose Select All from the Edit menu to select the entire recording. When you choose an edit operation after choosing Select All, the edit operation applies to the entire recording.

6.4.3 View Menu

The items on the View menu allow you to control the DECsound display area. During edit operations, DECsound displays the audio waveform in the display area. For more information about a particular View menu item, double click on that item in the list of additional topics.

6.4.3.1 Hide Waveform Display

Choose Hide Waveform Display from the View menu to turn off the waveform display.

6.4.3.2 Display Energy

Choose Display Energy from the View menu to display the energy of the waveform. The energy waveform shows the variations in audio energy levels in the waveform.

6.4.3.3 Display Samples

Choose Display Samples from the View menu to display the amplitude of the audio waveform.

6.4.4 Options Menu

The items on the Options menu allow you to tailor the DECsound environment in the following ways:

• Specify whether a recording plays repeatedly
• Specify your preferences for the settings that DECsound applies at startup
• Save your preferences so that DECsound applies them in future sessions
• Restore your last saved preferences

Choose Auto Repeat from the Options menu to enable DECsound to play a recording repeatedly when you click on Play. You can stop the playback by clicking on Stop.

6.4.4.2 Settings...

Choose Settings... from the Options menu to open the Settings dialog box and specify the following defaults to automatically take effect when you start DECsound. Figure 6-2 shows the DECsound Settings dialog box.

Figure 6-2 DECsound Settings Dialog Box

The DECsound Settings dialog box has the following default settings:

• Maximum Recording Length
• Default Save File Format
• Playback Auto Repeat

You can specify the following defaults for DECsound sessions:

• The Max Recording Length area of the Settings dialog box contains a slider that allows you to specify the maximum length of a DECsound recording. This prevents long recordings from being initiated by accidentally clicking on the Record button.
• The Default Save File Format area of the Settings dialog box contains an option box that allows you to specify the default file format for save file operations.
• Choose Playback Auto Repeat from the Settings dialog box to enable DECsound to play a recording repeatedly when you click on Play. You can stop the playback by clicking on Stop.

To save your current settings, choose Save Settings from the Options menu. If you change the device type during a DECsound session, the new setting does not take effect until the next session. The settings are saved in sound_editor_resources.dat.