Sound waves, converted to binary-number data, are stored in computer memory as files by the audio hardware. These files are displayed by VFEditÒ as waveforms, the shapes of which are analogous to the characteristics of the recorded sound. Thus VFEdit lets you "see" the binary numbers that have been stored on your computer by your audio hardware. Just as the contents of a spreadsheet file are made intelligible and useable by a spreadsheet program, so are the binary amplitude values made useful by VFEdit. VFEdit stores these large amounts of data on files on your computer hard disk. Unlike most other editors, VFEdit does not load a copy of its data into memory when you open a sound file-all editing is done directly on the data stored on the hard disk. This allows VFEdit to edit sound files of any size-up to your available disk space.
When Would You Use File?The File Menu is the gateway in to and out of VFEdit and your disk storage areas. You can think of filenames and pathnames as a mailing addresses pointing to where you saved your recordings. Without these filenames and pathnames, the disk drive could never find anything. Filenames and pathnames give the files a "mailing address" so that the disk drive can access it for you. The files themselves are the actual recordings of your audio information, in one and zeroes on magnetic media.
The File Menu lets you open a file that already contains recorded data, or create a new file containing no recorded data. You can save your work to a previously specified file, or save it to a completely new file. At the end of your edit session, you can use this menu to exit the program.
File New creates a fresh file for storing your audio data. Since the file has not yet been named, VFEdit will show it as "Untitled #n". File New presents a dialog box with options for file type and data format identification.
When you activate File New, VFEdit displays the File New dialog box. VFEdit asks us some things about how to set up the data header for the sound file, the data contained in the sound file, and the sampling frequency.
Information required includes:
| File Type: What kind of sound file? These files may contain pure digitized data or digitized data combined with format, control, and annotation information. | |
| Data Format: What kind of data is stored in the file? Which of the many specialized encoding methods does it use? | |
| Frequency: Telephony sampling frequency or higher fidelity? |
VFEdit supports many different file types and data formats. You may need to review information provided by your system vendor to determine which one is best for your particular needs.
File TypesVFEdit
supports three different basic file types: Pure, Indexed, and Wave files.| Pure files contain only the digitized sound. | |
| Indexed files permit you to group related audio segments, then access those segments by specifying an index number. | |
| Wave files contain raw audio data plus additional format, control, and annotation information. |
Following are some industry standard data formats and a brief description. Some of the formats are pretty sophisticated, so it's difficult to provide much more information given the scope of this document. Your version of VFEdit supports many, but not all, of these formats. Please contact VISI regarding specialized or custom formats.
| Pika AVA: Pika Technology 4 bit Adaptive Delta PCM, similar to Dialogic 4 bit ADPCM. | |
| Brooktrout CVSD: Brooktrout Technology 1 bit Continuously Variable Slope Delta Modulation. | |
| Dialogic ADPCM: Dialogic Corporation 4 bit Adaptive Delta PCM. | |
| Dialogic PCM: Dialogic Corporation 8 bit u-law similar to the CCITT G.711 u-law. | |
| Float: 32 bit floating point data with a 24 bit mantissa and 8 bit exponent. This is an IEEE standard. | |
| FFT Real: A 32 bit floating point frequency representation of the real portion of an audio signal. | |
| CCITT (ITU-T) G.711: A-Law (inverted A-Law) or u-law (folded u-law): An international standard 14 bit to 8 bit compression. | |
| CCITT (ITU-T) G.721: An international standard 4 bit sub-band encoded Adaptive Delta PCM. | |
| CCITT G.723 (ITU-T) 3 bit ADPCM: An international standard 3 bit sub-band encoded Adaptive Delta PCM. | |
| Harris CVSD: Harris Semiconductor 1 bit Continuously Variable Slope Delta Modulation. | |
| Multimedia unsigned 8 bit: unsigned 8 bit (0 to 255) linear data samples. | |
| Multimedia linear 16 bit: signed 16 bit normalized (+/- 32,767) linear two's complement data samples. This format is an industry standard for storing digitized sound. | |
| MS Wave ADPCM: Microsoft Adaptive Delta PCM. | |
| New Voice CVSD: New Voice 1 bit Continuously Variable Slope Delta Modulation. | |
| Perception CVSD: Perception Technology 1 bit Continuously Variable Slope Delta Modulation. | |
| Rhetorex 3 bit ADPCM: Rhetorex Corporation super secret proprietary Adaptive Delta PCM. | |
| Rhetorex 4 bit ADPCM: Rhetorex Corporation super secret proprietary Adaptive Delta PCM. | |
| TTI 8 bit: Talking Technology 8 bit unsigned PCM similar to Multimedia unsigned 8 bit. |
The File Open menu command retrieves and displays previously saved audio files. When you select this command, the file selection dialog box appears. Here you can select the name of the file you wish to edit.
This dialog box looks like the usual Windows File Open dialog box, except for the addition of a button named Format. If you click there you will get an additional dialog box that looks much like the File New dialog box. (Note, however, that the File Type button is inactive on this secondary dialog box. The File Type should be selected from the main File Open dialog box.) Use the File Open dialog box to select an existing file; press cancel to return to the main screen. If you type in only the file name, VFEdit assumes that the file is located in the directory shown to the right of the file name.
To select a file from the list of files, double-click the file name with the mouse (or use <TAB>, position the highlight bar and press <ENTER>).
To specify a different directory, move the cursor to the File Name text box and enter the new pathname. Press <ENTER> and a new list of files will appear.
Press OK or <ENTER> and VFEdit will load and display the sound file in the Audio Graph window.
File Name CharactersFile names are limited to a total of eight characters and can be any combination of letters and/ or numbers. The program does not differentiate between capital and lower case letters. You can have as few as one character, but you must have at least one character.
The following characters can be used in a file name:
a to z, 0 to 9, ! @ # $ % ( ) - ' { } ^
A period can only be used to separate the first part of the file name from the file name extension.
The following characters cannot be used to create a file name:
* + = [ ] : ; " ~ < > ? \ / , or a space.

Sample file "index.vap" opened with the wrong File Type
If you open a file with the wrong File Type, the file may look normal but will have sections of "noise" at the beginning, end, and possibly intermixed. This "noise" is actually header and format information being read as audio data. Simply close the file and re-open it with the proper file type.
Since VFEdit supports many different file types, you may need to review information provided by your system vendor to determine which one will work for you.
If you open a file with the wrong Frequency, the file will usually sound fast or slow but appear normal. Simply close the file and re-open it with the proper frequency.
Since VFEdit supports virtually any frequency, you may need to review information provided by your system vendor to determine the correct one for your particular application.
If you open a file with the wrong Data Format, the file will usually sound like static and appear as a bunch of random lines. Simply close the file and re-open it with the proper data format.
Since VFEdit supports many different data formats, you may need to review information provided by your system vendor to determine which one is best for your particular needs.
VFEdit
supports Pure (raw audio data), Indexed (VBase), and Multimedia Wave (headered) files. Pure files contain only the digitized sound. Indexed and Wave files contain raw audio data plus additional format, control, and annotation information. Indexed files permit you to group related audio segments, then access those segments by specifying an index number. It is important that you select the proper file format when opening a file. The type of file selected appears in text below the "List Files of Type" drop-down box. You can specify the type of file (Pure or Indexed) by clicking the mouse on the drop-down box button.
When you specify Indexed, you will be presented with an additional dialog box from which to select an index number. You can change your selection at any time by using the "Index" menu described later in this manual.
This is the ultimate "Undo" command, that keeps you from losing previous work if you really don't like something that you did. For example, you try to do something elaborate, with a new mode, or a new filter, or a new way of adjusting the volume-and the results are just crazy. With File Revert you can start clean with our previously saved (good) version by choosing File Revert.
File Revert cancels all accumulated changes made to an audio file since the last time you saved it, and returns you to the previous version of the file. This is a useful way to remove unwanted or experimental changes to a file.
File Revert will ask for confirmation to prevent accidental loss of your changes.
The File Save menu command lets you store your current work back to the audio file on disk.
If you made any new recordings, or made any changes to your existing audio file, remember to finish the job by saving to the original file name on disk. File Save will not ask you for a name-VFEdit assumes that you want to save using the current name, and proceeds to do so. If you request File Exit without first saving the current file, VFEdit will remind you by asking whether you wanted to save the changed file. When you select File Save, The pointer may change briefly to an hourglass during the save operation. When the arrow pointer reappears, you can resume your editing.
Save your work regularly, especially if you are in the midst of a complex edit. Frequent saves, as well as regular backups onto other media, ensure that files and changes are not lost due to power failures or other problems.
If your work was previously saved, its file name is displayed in the title bar. If no file name has been specified, you must use the File Save As command to name and save your file.
When you want to save a file for the first time, or to make a copy to a different name, use File Save As. The dialog box looks pretty much the same as the File Open dialog box, except that it does not allow you to change the "File Type" or the "Data Format". (If you need to change the "File Type" or "Data Format", see the File Export menu item discussed later.).
Use File Save As if you wish to save your work with a file name other than the one displayed in the title bar. Saving a file with a different name allows you to modify that work and save a copy of it without disturbing the original. After selecting File Save As you will be presented with a dialog box that enables you to specify the new name for your file.
This menu selection closes the currently selected audio graph window and the sound file associated with it. VFEdit will remind you to save the file if it has been modified since the last time you opened or saved.
Sometimes you need to bring in data from another file in another format. File Import allows you to load a file that was created with another editing tool, or to convert files between different sample formats.
The File Import menu item has a dialog box titled Import that looks much like the File Open and the File Save As dialog boxes. This dialog box, however, lets you specify what kind of filters you will use when reading the existing sound file. If you click on the filter list you will get another dialog box that lets you select the types of filters to use. Please see the chapter About Digital Audio for more information on anti-aliasing filters and re-sampling algorithms.
Paste From Another FileThe File Import menu command lets you insert audio data from another file. After selecting File Import you can select the name of the file from which to retrieve sound. File Import is useful for moving or copying audio segments from one file to another.
To select a file from the list of files, double-click the file name with the mouse (or position the highlight bar and press <ENTER>). To specify a different directory, move the cursor to the directory box and enter the new search specification. You can specify the type of file by clicking the mouse on the "Format" button.
The triangular "At Position" specifies the position in the current file at which to insert the new audio data. When you select a "Paste" point past the end of the file, VFEdit automatically extend the file with silence if the Options Environment setting "Auto-extend file with silence" is turned on.
Sometimes you need to output a sound file in a different format than the one it was originally recorded in. File Export allows you to save a file for use with another editing tool, or to convert files between different sample formats.
Copy To Another FileThe File Export menu command lets you copy all or part of the current voice file to another file. After selecting File Export you can select the name of the destination file. File Export is useful for saving parts of an Indexed or Multimedia Wave file as a "pure" audio file.
To select a file from the list of files, double-click the file name with the mouse (or position the highlight bar and press <ENTER>). To specify a different directory, move the cursor to the directory box and enter the new search specification. When you select a File Export segment that extends past the end of the current edit file, VFEdit automatically resets the segment end point to the total length of the file.
The File Menu maintains a catalog of your recently used files. You can access one of these files by selecting the specific file name.
The File Exit menu command terminates the current edit session and releases the current file. If you have made changes to the current file since last saving, VFEdit will warn you and ask you to save before continuing with File Exit. If you wish to save your changes, you must File Save before exiting.