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Chapter 11 Audio ToolAudio Tool is an application that is used to record, play, and edit audio files. Audio Tool works in conjunction with the Audio Control application, which controls and configures the desktop's audio capabilities. Audio Tool also works with Multimedia Mail Tool to provide the audio capabilities for composing, sending, and receiving Multimedia Mail. About This ChapterThe first part of this chapter explains how to perform common Audio Tool tasks, such as playing, recording, editing, and saving audio files. The rest of the chapter, which is in a reference format, contains detailed descriptions of Audio Tool's base window and the File, Edit, and Volume menus. Refer to these reference sections for more information about a particular button or menu option. Audio Tool CapabilitiesBefore using Audio Tool, make sure that your machine supports, at a minimum, basic (monaural) audio capabilities and that a speaker and microphone are installed. Refer to your system's documentation for this information. Many computers support stereo and higher-quality audio, such as CD and DAT quality. Audio Tool automatically recognizes the capabilities of the computer's audio devices. Therefore, the features of Audio Tool that you can use depend on your particular system configuration. This chapter describes all of the features and controls of Audio Tool. However, if your computer supports only monaural audio, you will not see some controls, such as a balance slider. Required AccessoriesFor recording (creating) voice audio files, use the microphone that is shipped with your computer or a commercial-variety microphone. Connect the microphone to your computer's microphone jack. You can listen to audio output in one of these ways; either from your computer's speaker, or headphones, or from externally powered speakers connected to the speaker output. Invoking Audio ToolYou can invoke Audio Tool in several ways:
Refer to the audiotool(1) manual page for information about the Audio Tool command's syntax. About Audio Tool's Base WindowThe Audio Tool base window, shown in Figure 11-1, contains all of the controls needed to play, record, and edit a sound file. Figure 11-1 Audio Tool Base Window
The top center of the Audio Tool window displays the name of a sound file along with the file's status. Three menu buttons are located near the top of the window ( Loading and Playing an Audio FileTo load and play an audio file, do the following:
Recording SoundTo record an audio file, do the following:
Saving an Audio FileTo save your file, do the following:
Editing an Audio FileBecause you can see an audio file graphically, you can determine which portions are sound and which are silence. This feature allows you to edit audio files such as voice messages. For instance, you might want to edit out long pauses (silence) between sentences or phrases. To modify the sound file, you edit the audio file as you would edit a text file in Text Editor, using cut, copy, and paste commands from the Edit menu. To cut a portion of sound from one location and paste it in another, do the following:
Undoing an EditYou can undo the last edit you made by choosing Edit -> Undo. Tips for Editing Audio Files
Sending a Voice Mail MessageYou can create an audio file from Mail Tool by selecting Attach Voice... in the Mail Tool Compose window. The audio file you create is automatically bound to Audio Tool and to an audio file glyph. The glyph is automatically attached to an electronic mail message when you notify the application that you have finished recording. The mail recipient can hear the contents of the audio file by double-clicking SELECT on the audio attachment glyph from Mail Tool. Refer to Chapter 4, Multimedia Mail Tool for information on using Mail Tool. To record an audio file and attach it to a mail message, do the following:
Listening to a Voice Mail MessageIf you have a machine equipped with a built-in speaker or an attached speaker, you can listen to the audio file by doing the following:
Audio Tool ReferenceThis part of the chapter provides information about Audio Tool's File, Edit, and Volume menus. Base WindowThe Audio Tool base window, shown in Figure 11-11, contains all of the controls needed to play, record, and edit a sound file. Figure 11-11 Audio Tool Base Window
Audio Tool IconWhen you iconize the Audio Tool base window, you'll see the icon shown in Figure 11-12. Double click SELECT on the icon to restore the window. Figure 11-12 Audio Tool Icon
Display CanvasThe display canvas provides a region for the graphic representation of audio data. Sound data is represented graphically as a box. Silence is represented as a thin horizontal line. Sound and silence data can be selected using the SELECT and ADJUST mouse buttons. An entire sound or silence segment is selected by double-clicking SELECT in the segment. Using ADJUST extends the selection to segment boundaries or to the hairline cursor position. Triple-click SELECT to select the entire audio file. (Audio selection in Audio Tool follows the same general conventions that are used for text selection throughout the Open Windows environment.) In Figure 11-11, the selected audio data includes both sound and silence. Once a segment has been selected, clicking SELECT on Play activates only that selection. Selected data can be dragged and dropped into other applications, such as Mail Tool and File Manager, or other invocations of Audio Tool. Using multiple Audio Tool windows enables you to assemble audio data from multiple files or break large files into smaller sections. Audio attachments to a mail file are discussed earlier in this chapter, as well as in the Mail Tool chapter. Cursor and Pointer LocationCursor and Pointer locations are displayed in the upper right corner of the Audio Tool window with time offset of (MM:SS.d), where MM is minutes, SS is seconds, and d is tenths of seconds. Whenever the mouse position marker is moved into the display canvas (and when a file is loaded) the marker is shown as a thin vertical line (hairline cursor), and its location is displayed as a time offset. In Figure 11-11, the cursor is located near the beginning of the audio file, location 0:01.4. The Play/Record pointer information shows the location of the play/record position pointer in the display canvas. The position pointer marks the data that is currently being played, recorded, or where playing or recording will begin when the Play or Rec button is pressed. It also marks where include, drag and drop, and paste operations will occur. Clicking SELECT while the cursor is in the canvas moves the pointer to the hairline cursor location. Drag and Drop TargetThe drag and drop target is where you can drop sound data into or drag sound data out of Audio Tool. For example, you can drag and drop sound data to and from the File Manager. Sound data dropped on the drag and drop target replaces any data in the display canvas. Press SELECT on the drag and drop target and drag out of the target to copy the current audio file to another application. When sound data is dropped directly into the display canvas, the data is inserted at the play position pointer location. If data is selected (highlighted) in the display canvas, the insertion occurs at that specific location, replacing the selected data. Level MeterThe level meter, which looks like an LED indicator, is active during play and record. On color monitors, the indicators are green and red. During recording, there should generally be 5-to-7 green LEDs displayed. If the red LEDs are lit all of the time, the recording level is too high. Status InformationThe lower left corner of the Audio Tool window is the status message display area. If any status information or error messages occur while using Audio Tool, the information is displayed here. For example, the current audio format is displayed there. The lower right corner of the Audio Tool window displays the length of a recorded file (e.g., Length: 0:08.5). Whenever a sound segment is selected in the display canvas, brackets appear indicating the length of the selection (e.g., Length: 0:08.5 [0:00.9]). These brackets also appear when recording is initiated, and display the length of the newly recorded data (which is updated periodically). Rev (Reverse) ButtonThis button controls the backward movement of the play position pointer. Click SELECT on the Rev button to move the play position pointer backward. If there is no selection in the canvas, clicking SELECT on the Rev button causes the pointer to jump backward, segment by segment, until it reaches the beginning of the file. (A segment is the start of a sound "box" in the display canvas.) If there is a selection, the pointer's movement is constrained to the selection. Hold down SELECT on the Rev button to play the selection in reverse at an accelerated speed until you release SELECT or until the play position pointer reaches the beginning of the selection. Play ButtonThis button controls the playing of an audio file. If you've selected part of an audio file, only that part of the file is played. Otherwise, the entire file is played. Click SELECT on the Play button to start playing from the current play position pointer location to the end of the selection or file. If the play position pointer is at the end of a selection or file, clicking SELECT on the Play button moves the pointer to the beginning of the selection or file before playing starts. Once selected, this button changes from Play to Stop, so to stop playing, click SELECT on the Stop button. If Auto Play on Selection in Audio Tool: Properties options is set "on," playing starts automatically whenever you make a selection. Fwd (Fast Forward) ButtonThis button controls the forward movement of the play position pointer. Click SELECT on the Fwd button to move the play position pointer forward. If there is no selection in the canvas, clicking SELECT on the Fwd button causes the pointer to jump forward, segment by segment, until it reaches the end of the file. If there is a selection, the pointer's movement is constrained to the selection. Hold down SELECT on the Fwd button to play the selection at an accelerated speed until you release SELECT or until the play position pointer reaches the end of the selection. Rec (Record)/Stop ButtonThis button controls the starting and stopping of recording. Click SELECT on the Rec button to start recording at the current play position pointer location. Recorded audio data is inserted into the sound file at the play position pointer. The existing data is moved forward in the file--it is not overwritten. However, if a sound segment is selected when record is activated, the selected segment is cut from the audio file and placed on the clipboard. Once selected, this button changes from Record to Stop, so to stop recording, click SELECT on the Stop button. You can click SELECT on New from the File menu to delete the current sound and record from scratch. Note - Clicking SELECT on the Play button during a recording session causes the recording to stop and the segment that was just recorded to be automatically selected and played back. File MenuItems on the File menu handle opening, including, and saving files.
Click MENU on the Whenever a command cannot be performed, the corresponding menu item is dimmed. For example, Save is dimmed when there is no new data to be saved. NewUse the New menu to clear the current audio file or select a new audio data format. Press MENU on New and drag to the right to display a pop-up menu with format choices. (If you click SELECT on New, the display canvas is cleared and retains the current format.) The selected audio format stays in effect until the next New operation (or other operation that loads a new audio file, such as Open). When recording a new file, you have the option of saving in the current format or in a new format. If there is an unsaved sound file in the display canvas, a confirmation message appears, saying that the file is modified and asking if you want to discard the edited data. Click SELECT on the Continue button to clear the display canvas and begin recording. The confirmation message can be disabled in the Edit Properties... window. You cannot undo a New operation. Audio Format ChoicesClick SELECT on the format of your choice. You can retain the current format or choose one of the standard formats--Voice, CD, or DAT. (If an audio format is not supported by the audio hardware, the corresponding menu item is disabled.) User defined formats may also be included and you can choose New Format... to define a new format. New Format...Click SELECT on the New Format... choice in the New menu to select, create, or edit the characteristics of a recording format. The Audio Tool: New Format window, shown in Figure 11-13, is displayed. Figure 11-13 Audio Tool: New Format Window
Encoding:Open this menu with a MENU click to select a type of encoding. Then, click SELECT on your choice of 8-bit m-law, 8-bit A-law, or 16-bit linear. The 16-bit linear encoding provides better accuracy (signal-to-noise ratio) than the two 8-bit encodings. However, the 16-bit linear encoding requires twice the storage capacity. Stereo audio data must use 16-bit linear encoding to play on a machine with stereo capability. Sample Rate:Open this menu with a MENU click to select a sample rate. Higher sample rates provide better high-frequency response (at the cost of larger file sizes). Click SELECT on your choice. Channels:Open this menu with a MENU click and click SELECT on your choice of channels (mono or stereo). New Format ButtonClick SELECT on the New Format button to clear the current audio file and reset the data format to match the currently selected audio format. Reset ButtonClick SELECT on the Reset button to restore the panel so that it displays the current audio format. + ButtonClick SELECT on the + button in the New Format window to display an extended window, shown in Figure 11-14. The Format scrolling list displays the formats available to you. Note that formats are stored on a per-user basis, so that the formats listed (other than the standard Voice, CD, and DAT) have been created under your user name. Note - Audio formats and preferences are stored in the $HOME/.audiorc file (where $HOME is the name of your home directory). You can use the New Format window to name a format type to appear in the New and Save As... menus. You can also use this window to add, change, or delete an audio format. Click SELECT the - button to close the extended part of the New Format window. Figure 11-14 New Format Window Extensions
To create a new format:
Open...Open... enables you to open a directory or file. Click SELECT on the Figure 11-15 Audio Tool: Open Window
Go To:To change directories, type the pathname of the new directory in the Go To: field, then click SELECT on the Go To: button or press Return. Notice that if you click MENU on the Go To: button, a directory stack is displayed that includes the recently visited directories, as well as the directories specified in the AUDIOPATH environment variable. Path Scrolling ListThe scrolling list displays the names of directories and files. Double-click SELECT on the first item in the scrolling list to move to the parent directory. Double-click SELECT on any of the directories in the scrolling list (indicated by folder icons) to change the current directory. All Files Button and Audio Files ButtonIf you click SELECT on the All Files button, the path scrolling list displays the names of all directories and files. However, non-audio files are dimmed and cannot be loaded. If you click SELECT on the Audio Files button, the scrolling list displays the names of audio files only; other file types are omitted from the display. Open ButtonClick SELECT on this button to open the specified audio file and load it into Audio Tool's display canvas. If the selected item is a directory, click SELECT to open the directory. You can also open a sound file by following these steps.
Cancel ButtonClick SELECT this button to close the Open window. If you open a compressed audio file, the conversion can take a long time. The Cancel button remains active and can be used to cancel the in-progress load conversion. SaveSave enables you to save changes made to the current audio file. Click SELECT on the Save menu item to save the file. If a file has been named and previously saved, clicking SELECT on Save replaces the old copy with the current version. If the audio data has not been saved previously, or has not yet been edited, the Audio Tool: Save As window is displayed. The Save item is dimmed if no audio file is loaded (following a New operation, for example) or if the audio file has not been edited since a previous Save. Save As...Save As... enables you to save a copy of the current sound file to a
new file. Click SELECT on the Figure 11-17 Audio Tool: Save As Window
The Go To: button and field, Current Folder: field, scrolling list, All Files and Audio Files buttons, and the Cancel button work the same as their counterparts in the Open window. The Save As window has additional items that the Open window does not have. Use the Format: and Compress: menus to save an audio file in different formats. Format:Click MENU on the Format button to display the list of formats. The standard formats are Current, Voice, DAT, or CD. Click SELECT on Current Format to match the format that is being used in the display canvas. In the list of formats, click SELECT on New Format... to display the Audio Tool: Save Format window (Figure 11-18). Use the selections in this window to save the audio data in a different format. The buttons in the window work the same as the buttons in the Audio Tool: New Format window (described on "New Format..."). Figure 11-18 Audio Tool: Save Format Window
Compress:Click MENU on the Compress button to display a list of compression techniques. The choices are:
If the size of a file is a concern, choose compression. If loading time is a concern, choose no compression. A compressed file uses less disk space but requires additional loading time because it must be decompressed before it is used. Also, if you choose to compress a file, the audio encoding specified by New Format... is ignored. When you load a compressed file, the format may change from its previous choice (e.g., if you compress an A-law file and reload, the file format changes to m-law). File Size:The File Size field displays the storage requirements of the file (when Audio Tool writes it to disk) and the amount of free disk space that you have available in the file system that contains the selected folder. Open FolderClick SELECT on the Open Folder button to open a folder that you have selected in the file scrolling list. Cancel ButtonClick SELECT on the Cancel button to close the Save As window. If you save a compressed audio file, the conversion can take a long time. The Cancel button remains active and can be used to cancel the in-progress save conversion. Save ButtonClick SELECT on this button to save the specified audio file. If the file selection is not made, this button is dimmed. Include...Include... enables you to insert audio data from another file into the current file. Click SELECT on the Include... menu item to display the Audio Tool: Include window. This window is similar to the Open window shown in Figure 11-15, with the Include button replacing the Open button, and the addition of the Open Folder button. Choose the file you want to include, then click SELECT on the Include button to insert the selected file into the display canvas at the play position pointer. Note that if the file selection is not made, the Include button is dimmed. Note - You can include only files whose formats match the current audio format. All other files are dimmed (if All Files is selected) or are removed from the scrolling list (if Audio Files is selected). Edit MenuThe commands on the Edit menu are common to most DeskSet tools. Click MENU on the Edit button to display the Edit menu. Whenever a command cannot be performed, the corresponding menu item is dimmed. For example, Undo is dimmed when there are no editing operations to undo. ClearThe Clear command removes the current sound data from the display canvas. Click SELECT on Clear when you want to delete all the data in the canvas. Note - The clear operation does not change the name of the file that's being edited. Take care not to accidentally save an empty canvas to an audio file. The clear operation can be undone, and the audio data is retained so that it can be used by a Redo operation. However, since newly recorded data consumes space in the temp file directory, you might consider using the File New operation. This operation, which cannot be undone, recovers the unused space in the filesystem. UndoThe Undo command reverses the effects of the last editing command issued. Click MENU on Undo to display the Undo submenu, which has the following options:
RedoThe Redo command restores the effects of the Undo command. Click MENU on Redo to display the Redo submenu, which has the following options:
Making edits to the audio buffer clears any subsequent editing history in the redo list. CutThe Cut command removes the current selection from your sound file and places it on the clipboard. Click SELECT on Cut to cut the selection. CopyThe Copy command copies the current selection to the clipboard, without modifying the original sound file. Click SELECT on Copy to copy the selection. PasteThe Paste command pastes data currently stored on the clipboard into the current audio file at the location specified by the play position pointer. For example, after doing a Cut or Copy, the next step is often to paste the stored data to some new location. Click SELECT on Paste to paste the selection. DeleteThe Delete command removes the current selection from the sound file, without modifying the contents of the clipboard. Use Delete instead of Cut when something is on the clipboard that should not be overwritten or when you are sure you do not want to use the selection again. Click MENU on Delete to display the Delete submenu with the following options:
PropertiesProperties... enables you to modify the functionality of Audio Tool.
Click SELECT on this menu item to display the Figure 11-19 Audio Tool: Properties Window
The controls on the
Note - Silence detection is automatically suppressed for audio file formats that have a sample rate greater than 16kHz, regardless of the silence detection setting in the Edit Properties... window.
Note - Recorded audio can quickly use up disk space. Set the temp file directory to a file system that contains adequate disk space. Also, if you are using high sampling rates (e.g., CD or DAT format), you may have difficulty recording to a remotely mounted temp file system. In addition, there are two buttons at the bottom of the Properties window, Apply and Reset. Use these buttons as follows:
Edit Pop-Up MenuA pop-up menu with commonly-used audio editing commands is available when you click MENU in the display canvas (Figure 11-20). Note that many of these choices also appear in the Edit menu under Clear and Delete. Figure 11-20 Edit Pop-Up Menu
Reset PointerThis command clears the current selection and places the pointer at the beginning of the file. ClearThis command removes the current sound data from the display canvas. Delete UnselectedThis command deletes everything in the display canvas that is not selected. Delete All SilenceThis command deletes all silent segments (which are indicated by horizontal lines). Delete Silent EndsThis command deletes only the silent segments at the beginning and end of the file. Select AllThis command selects all of the audio data in the display canvas. This is the same as triple-clicking SELECT in the display canvas. Volume MenuThe Volume menu has options for controlling play volume and recording level. These functions are part of Audio Control--a separate application that cooperates with Audio Tool. Click MENU on Volume to display these options. Play...Play... controls audio output. Click SELECT on Play... to display the Audio Control: Play window, shown in Figure 11-21. The controls on this panel affect the entire desktop audio environment. Figure 11-21 Audio Control: Play Window
Note - Depending on the audio capabilities of your computer, you may or may not see all of the choices shown in the figure (e.g., if your computer does not support stereo, the balance slider is not displayed) Speaker, Headphone, and Line Out ButtonsClick SELECT on these buttons to select audio output devices. The buttons that are available depend on your hardware configuration. For example, some configurations support only speakers and headphones. Other configurations support all three devices, and some configurations allow you to select more than one device at a time. Also, some configurations recognize whether a plug has been inserted into a jack. In these configurations, the corresponding button is dimmed when no plug is inserted into a jack. Play VolumeThis slider controls the audio output volume. You can also type in a volume level (0-100). BalanceIf your computer has stereo capability, use the Balance slider to adjust the balance. The slider has a "detent" at the 50-50 balance point. Record...This button displays the Audio Control: Record window, which is described in "Record...". MuteThis button mutes the audio output to the selected devices. The audio file or selected audio segment continues to play. Click SELECT on the button to turn off muting so that you can hear the audio. Audio Tool turns muting off when you adjust the play volume. Record...Record... controls the adjustment of volume gain during recording. Click SELECT on Record... to display the Audio Control: Record window, shown in Figure 11-22. Note - If recording difficulty is experienced with a commercial microphone, use an external pre-amp to boost the recording gain level. Figure 11-22 Audio Control: Record Window
Microphone and Line In ButtonsClick SELECT on one of these buttons to select an audio input device (if they are supported by your hardware configuration). Record Volume:This slider controls the recording volume gain. You can also type in a volume level (0-100). Balance:If your computer has stereo capability, you can use the Balance slider to adjust the balance. The slider has a "detent" at the 50-50 balance point. Typically, you'll only want to change the record balance if your audio inputs are not at the same level. Before adjusting the record balance, make sure that the play balance is calibrated for your output configuration. You can do this by using the Audio Tool: Save As window to convert a monaural file to stereo and then adjusting the play balance until the left and right speakers produce the same output level. Once the play balance is calibrated, you can record a segment of audio data and play it back to determine if the record balance is correct. Note - On systems that support the monitor function, the record balance may not affect the monitor output. To determine the actual effect of record-balance changes, you must record and play back a sample of stereo audio. Monitor Volume:This slider controls the volume of the audio input signal that is channeled through the output port. (You can also type in a monitor-volume level (0-100).) This is useful when an audio source, such as a CD player or tape deck, is connected to the selected input jack. By adjusting the monitor volume, the audio input is heard without having to record any data. Auto-Adjust ButtonThis button enables you to automatically set the optimum recording level. This is recommended before a recording session begins or whenever the microphone is moved or the input source is changed. Click SELECT on Auto-Adjust to initiate scanning of the input sound data to determine its loudness. The current level of the input signal is examined and, if necessary, minor adjustments are made to set a Record level. If no signal is found, the Record level jumps to the maximum, then automatically adjusts down until the optimal level is achieved. An LED-like input level meter displays the sound level. During the auto-adjust operation, no data is recorded. The auto-adjust procedure continues until a satisfactory level has been maintained for three to five seconds. To adjust the level of your voice, talk into the microphone in a normal speaking voice. Speak continuously during the entire time (for instance, counting) until the auto-adjust operation ends. If the input signal does not register on the level meter, check the ON/OFF switch on the microphone or replace the microphone battery. You should also use the auto-adjust operation to set the optimal recording level for input sources connected directly to the microphone jack, such as a CD player or tape deck. For best results, play the loudest section of your audio source during the auto-adjust operation. You can use the Monitor Volume to listen to the source while you are setting the volume level (as well as while you are recording). Note - If you cannot achieve a satisfactory signal level with a commercial microphone, it may be necessary to speak closer to the microphone, or to obtain a microphone preamplifier. Using the Audio Control Status PanelThe Audio Control application includes a status window that displays the current state of the audio device. The status window provides information that can be useful for debugging audio applications and for determining whether applications are holding an audio device open. To display the status window (Figure 11-23), click MENU in the background of the Audio Control: Play or Audio Control: Record windows, then click SELECT on the Status... button. The check boxes display the status of the tool. (The check boxes are informational; you cannot modify them.) Click SELECT on the Status Change button to cause the displays to be updated only when one of the status items changes. Click SELECT on the Continuous button to cause the displays to be updated continuously. Refer to the audio(7) manual page for a description of status indicators. Figure 11-23 Audio Control: Status Window
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