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1996-01-07
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GoldWave Manual
Copyright (C) 1993-1995 Chris S. Craig
This file contains the text of the GoldWave manual in plain
ASCII format. Diagrams, figures, and equations are available
only in the printed manual included with deluxe registrations.
-----------------------------------------------------------------
Table of Contents
1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . .1
Features. . . . . . . . . . . . . . . . . . . . . . . . . .1
How to Use This Manual. . . . . . . . . . . . . . . . . . .2
Notation Used in This Manual. . . . . . . . . . . . . . . .2
2 Getting Started . . . . . . . . . . . . . . . . . . . . . . .3
System Requirements . . . . . . . . . . . . . . . . . . . .3
Installation. . . . . . . . . . . . . . . . . . . . . . . .3
Installation From a Downloaded Zip File. . . . . . . .4
Installation From the Deluxe Diskette. . . . . . . . .4
3 Using GoldWave. . . . . . . . . . . . . . . . . . . . . . . .5
Window Overview . . . . . . . . . . . . . . . . . . . . . .5
Device Controls Overview. . . . . . . . . . . . . . . . . .6
Setup. . . . . . . . . . . . . . . . . . . . . . . . .6
Graph type. . . . . . . . . . . . . . . . . . . .6
Controls. . . . . . . . . . . . . . . . . . . . .7
Save. . . . . . . . . . . . . . . . . . . . . . .7
User play button. . . . . . . . . . . . . . . . .7
Positioning . . . . . . . . . . . . . . . . . . .7
Options . . . . . . . . . . . . . . . . . . . . .7
Output and Input buttons. . . . . . . . . . . . .8
Playing Sounds . . . . . . . . . . . . . . . . . . . .8
Pausing Playback . . . . . . . . . . . . . . . . . . .8
Stopping Playback. . . . . . . . . . . . . . . . . . .8
Rewinding and Fast Forwarding. . . . . . . . . . . . .9
Recording Sounds . . . . . . . . . . . . . . . . . . .9
Volume and Balance Scroll Bar. . . . . . . . . . . . .9
Speed Scroll Bar . . . . . . . . . . . . . . . . . . .9
Editing Overview. . . . . . . . . . . . . . . . . . . . . 10
Selecting Part of a Sound. . . . . . . . . . . . . . 10
Direct Editing with the Mouse. . . . . . . . . . . . 11
Combining Audio Layers (Mixing). . . . . . . . . . . 11
Storage Overview. . . . . . . . . . . . . . . . . . . . . 11
Direct-to-Disk . . . . . . . . . . . . . . . . . . . 11
RAM. . . . . . . . . . . . . . . . . . . . . . . . . 12
Flash. . . . . . . . . . . . . . . . . . . . . . . . 12
Keyboard Overview . . . . . . . . . . . . . . . . . . . . 12
File Menu Commands. . . . . . . . . . . . . . . . . . . . 13
New. . . . . . . . . . . . . . . . . . . . . . . . . 13
Open and Supported File Types. . . . . . . . . . . . 14
Close. . . . . . . . . . . . . . . . . . . . . . . . 15
Save . . . . . . . . . . . . . . . . . . . . . . . . 15
Save as. . . . . . . . . . . . . . . . . . . . . . . 15
Exit . . . . . . . . . . . . . . . . . . . . . . . . 15
File History . . . . . . . . . . . . . . . . . . . . 15
Edit Menu Commands. . . . . . . . . . . . . . . . . . . . 16
Undo . . . . . . . . . . . . . . . . . . . . . . . . 16
Cut. . . . . . . . . . . . . . . . . . . . . . . . . 16
Copy . . . . . . . . . . . . . . . . . . . . . . . . 16
Paste and Paste at . . . . . . . . . . . . . . . . . 17
Mix. . . . . . . . . . . . . . . . . . . . . . . . . 17
Delete . . . . . . . . . . . . . . . . . . . . . . . 17
Trim . . . . . . . . . . . . . . . . . . . . . . . . 18
Insert silence . . . . . . . . . . . . . . . . . . . 18
Select view. . . . . . . . . . . . . . . . . . . . . 18
Channel. . . . . . . . . . . . . . . . . . . . . . . 18
Deflash. . . . . . . . . . . . . . . . . . . . . . . 19
Effects Menu Commands . . . . . . . . . . . . . . . . . . 19
Special Controls for Effects . . . . . . . . . . . . 19
Presets . . . . . . . . . . . . . . . . . . . . 19
Shape Controls. . . . . . . . . . . . . . . . . 20
Distortion . . . . . . . . . . . . . . . . . . . . . 20
Doppler. . . . . . . . . . . . . . . . . . . . . . . 20
Echo . . . . . . . . . . . . . . . . . . . . . . . . 21
Exchange channels. . . . . . . . . . . . . . . . . . 21
Filter . . . . . . . . . . . . . . . . . . . . . . . 21
Noise Gate. . . . . . . . . . . . . . . . . . . 21
User defined. . . . . . . . . . . . . . . . . . 22
Interpolate. . . . . . . . . . . . . . . . . . . . . 23
Invert . . . . . . . . . . . . . . . . . . . . . . . 23
Mechanize. . . . . . . . . . . . . . . . . . . . . . 23
Offset . . . . . . . . . . . . . . . . . . . . . . . 23
Pan. . . . . . . . . . . . . . . . . . . . . . . . . 24
Reverse. . . . . . . . . . . . . . . . . . . . . . . 24
Silence. . . . . . . . . . . . . . . . . . . . . . . 24
Volume . . . . . . . . . . . . . . . . . . . . . . . 24
Change. . . . . . . . . . . . . . . . . . . . . 25
Fade in . . . . . . . . . . . . . . . . . . . . 25
Fade out. . . . . . . . . . . . . . . . . . . . 25
Maximize (Normalize). . . . . . . . . . . . . . 25
Shape . . . . . . . . . . . . . . . . . . . . . 26
Playback rate. . . . . . . . . . . . . . . . . . . . 26
Resample . . . . . . . . . . . . . . . . . . . . . . 26
Transpose. . . . . . . . . . . . . . . . . . . . . . 26
View Menu Commands. . . . . . . . . . . . . . . . . . . . 27
All. . . . . . . . . . . . . . . . . . . . . . . . . 27
Selection. . . . . . . . . . . . . . . . . . . . . . 27
User . . . . . . . . . . . . . . . . . . . . . . . . 28
Other. . . . . . . . . . . . . . . . . . . . . . . . 28
Zoom 10:1 and 5:1. . . . . . . . . . . . . . . . . . 28
Zoom 1:1 . . . . . . . . . . . . . . . . . . . . . . 28
Zoom 1:10 and 1:100. . . . . . . . . . . . . . . . . 28
Start and Finish . . . . . . . . . . . . . . . . . . 28
Tools Menu Commands . . . . . . . . . . . . . . . . . . . 29
Cue Points . . . . . . . . . . . . . . . . . . . . . 29
Expression evaluator . . . . . . . . . . . . . . . . 30
CD Player. . . . . . . . . . . . . . . . . . . . . . 30
Device Controls. . . . . . . . . . . . . . . . . . . 30
Options Menu Commands . . . . . . . . . . . . . . . . . . 31
Colours. . . . . . . . . . . . . . . . . . . . . . . 31
File . . . . . . . . . . . . . . . . . . . . . . . . 31
Sound files . . . . . . . . . . . . . . . . . . 31
Temporary . . . . . . . . . . . . . . . . . . . 31
Undo. . . . . . . . . . . . . . . . . . . . . . 31
Flash open. . . . . . . . . . . . . . . . . . . 31
Temporary storage . . . . . . . . . . . . . . . 31
Window . . . . . . . . . . . . . . . . . . . . . . . 32
Main window size. . . . . . . . . . . . . . . . 32
Main window size. . . . . . . . . . . . . . . . 32
User zoom . . . . . . . . . . . . . . . . . . . 32
Window Menu Commands. . . . . . . . . . . . . . . . . . . 32
Help Menu Commands. . . . . . . . . . . . . . . . . . . . 32
4 General Information . . . . . . . . . . . . . . . . . . . . 33
Warranty, Trademarks, and Copyrights. . . . . . . . . . . 33
Support and Updates . . . . . . . . . . . . . . . . . . . 33
Appendix A: An Introduction to Digital Audio . . . . . . . . . 35
Digital Audio Attributes. . . . . . . . . . . . . . . . . 35
Problems with Recording . . . . . . . . . . . . . . . . . 37
Frequency Spectrums . . . . . . . . . . . . . . . . . . . 38
Appendix B: Expression Evaluator . . . . . . . . . . . . . . . 41
Overview. . . . . . . . . . . . . . . . . . . . . . . . . 41
Evaluation Range, Variables, and Constants. . . . . . . . 42
Using Time in an Expression. . . . . . . . . . . . . 43
Using the Sample Index in an Expression. . . . . . . . . . . . 43
User Variable f. . . . . . . . . . . . . . . . . . . 44
Conversion Between Variables . . . . . . . . . . . . 45
Group name and Expression name. . . . . . . . . . . . . . 45
Valid Operators and Functions . . . . . . . . . . . . . . 46
Signal Generation . . . . . . . . . . . . . . . . . . . . 47
Filters . . . . . . . . . . . . . . . . . . . . . . . . . 48
Appendix C: Trouble Shooting and Q&A . . . . . . . . . . . . . 49
Troubleshooting . . . . . . . . . . . . . . . . . . . . . 49
Common Questions and Answers. . . . . . . . . . . . . . . 50
-----------------------------------------------------------------
1 Introduction
GoldWave is a comprehensive digital audio editor that allows you
to play, record, edit, and convert audio on your computer.
Features
* An Expression Evaluator allows you to generate
everything from simple dial tones to bandpass filters.
It supports more than 20 common functions and
operations. Expressions can be stored in groups
for quick retrieval. Expressions for dial tones,
waves, and effects are included.
* An independent Device Controls window provides easy
access to audio devices. It contains controls for
playback, rewind / fast forward, recording, volume,
and speed. LED meters and oscilloscopes graphically
display the sound during playback and recording. The
oscilloscopes can be configured to display graphs in
several different formats.
* A multiple document interface (MDI) allows many files
to be opened at one time, making file-to-file editing
easy.
* All editing operations, such as paste and mix, are
intelligent. This means that clipboard audio data is
automatically converted to a compatible format before
the data is used. When editing files with different
sample rates, bit resolution, or number of channels,
intelligent editing simplifies the process.
* Huge files can be edited using hard disk editing.
Small files can be edited quickly using RAM based
editing.
* Sounds are displayed graphically and the level of
detail can be changed by zooming in or out. Samples can
be edited directly with the mouse when zoomed in to a
sub-sample level (the level at which individual samples
are easily visible).
* Many audio effects, such as Reverse, Echo, Pan, Flange,
and Distortion allow you to enhance, distort, or alter
sounds in various ways.
* Save as can convert sounds to many different file
types. It can convert stereo to mono, 8 to 16 bits, or
any combination of attributes supported by a file type.
* A CD Player plays audio CDs in your CD-ROM drive.
* A sophisticated and intuitive user interface makes
learning easy. Control bar buttons perform commands
with a single click of the mouse. Configurable status
bars present information in a variety of formats.
Page 1
-----------------------------------------------------------------
How to Use This Manual
This manual presents and explains the features in GoldWave.
Section 2, "Getting Started," discusses system requirements and
installation. Section 3, "Using GoldWave," covers the menu
structure. Topics are covered in the order that they appear in
GoldWave's main menu. Section 4, "General Information," provides
support, copyright, and warranty information. Please be sure to
read this section.
For users who are unfamiliar with digital audio, Appendix A
briefly introduces some of the fundamentals. It also provides
some solutions to common recording problems. Appendix C contains
troubleshooting information and answers to common questions.
This manual assumes that you are familiar with Microsoft Windows.
Notation Used in This Manual
Bold text and a vertical bar, "|", are used to indicate menu
commands. For example, File | New means to select the New
command from the File menu. This notation also is used to refer
to other sections within this manual. In the above example, you
can find information by looking for New under the File Menu
Commands section.
* An asterisk emphasizes paragraphs containing helpful
information and techniques.
! An exclamation mark emphasizes warnings and other important
information.
Page 2
-----------------------------------------------------------------
2 Getting Started
System Requirements
The minimum system requirements for GoldWave are:
* 16MHz 386 (or better) IBM PC or compatible
* Microsoft Windows 3.1
* 6 Megabytes of RAM
* 2 Megabytes free on your hard disk
* Mouse
* VGA card and monitor
* Sound card and an MPC software driver (or PC speaker
driver)
A math co-processor is not required, but it is recommended if you
will be using the expression evaluator.
If you need to edit large files, you will need a large amount of
hard disk space. One minute of CD-quality sound requires 10
megabytes of storage. GoldWave may require 20 to 40 megabytes
per minute if you are editing an existing file and the Undo
feature is enabled.
Installation
The following two sections give instructions for installing
GoldWave on your system. Before running GoldWave make sure that
you have installed an appropriate Windows sound driver using the
Control Panel "Drivers" Applet. The driver and installation
instructions should be included with your sound card. If you do
not have a sound card, then you can use the PC-Speaker driver
(you may have to search BBS or ftp sites to find this, since it
is not included with Windows). Note: Since the PC-Speaker driver
does not return control to Windows until after the sound has
finish playing, the oscilloscopes and many of the control buttons
will not work.
To add a GoldWave icon to a Program Group use File | New on the
Program Manager's menu, select Program Item then click on OK.
Type "GoldWave" as the description. Choose Browse, find and
double click on goldwave.exe, then click on OK. To run GoldWave,
either double click on the new GoldWave icon or use File | Run on
the Program Manager's menu.
If you are upgrading to a new version, hold the Alt key and
double click on the GoldWave icon. You can then update the
information for the new version.
Page 3
-----------------------------------------------------------------
GoldWave allows you to choose which devices to use for input and
output. Choose the setup button from the Device Controls window
(the button with a check mark on it) and choose the Output
button. A list of installed output devices and their
capabilities is presented. Select an appropriate device from the
list. A similar list is presented for the Input button.
Be sure to check the readme.txt file for any additional
information not available at the time this manual was printed.
Installation From a Downloaded Zip File
To install GoldWave from a zip file, you will need pkunzip
version 2.04g (or compatible). Unzip the file in your GoldWave
directory. If you have created and saved new expressions, do not
copying the express.eqx file into your windows directory. Doing
so will erase any expressions you have added to the file. In
this case, you may have to edit the old and new files to combine
them.
For example, to install GoldWave in the directory "c:\wave":
C:> pkunzip gldwav30.zip c:\wave
C:> copy c:\wave\express.eqx \windows
Installation From the Deluxe Diskette
To install GoldWave from the deluxe diskette, you can simply copy
all the files from the GoldWave disk to a GoldWave directory or
you can use the install file included on the disk.
For example, to install GoldWave from drive "a:" to the directory
"c:\wave":
C:> copy a:*.* c:\wave
or
C:> a:install c:\wave
Page 4
-----------------------------------------------------------------
3 Using GoldWave
Window Overview
GoldWave is composed of three windows: the Main window, the
Device Controls window, and Sound windows. The Main window
contains the main menu, two rows of control bar buttons, and
status bars (see figure 1). It groups together and manages all
the Sound windows. The function of each button is displayed in
the lower status bar when the mouse pointer is positioned
directly over it. The status bars show attributes of the current
Sound window, including the sampling rate, length, selected
region, channels, and file type. By clicking the mouse pointer
over any status item that shows time, the unit or format for the
status item can be changed.
Sound windows (figure 2) are created when you open a file. These
windows contain a graph of the sound with a time axis near the
bottom. For stereo sounds, two separate graphs are shown with
the top green graph as the left channel and the bottom red graph
as the right channel. The selected part of the sound is
highlighted with a blue background. Near the bottom of the Sound
window, a small "Overview" box shows you what part of the sound
is selected (highlighted green and/or red), what part is
displayed in the above graph (black background), and what part is
not visible in the above graph (dark grey background).
Initially, the entire sound is visible and selected.
The Device Controls window interacts directly with your audio
hardware. It contains buttons to play and record sounds as well
as controls for volume, balance, and playback speed (provided
your audio device supports these features). LED meters and
oscilloscopes graphically display audio data whenever a sound is
played or recorded. Information about the graphical displays and
controls is presented in the next section.
Page 5
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Device Controls Overview
The Device Controls window (see figure 3) is an easy to use
interface to your audio hardware and drivers. On the bottom half
of this window are oscilloscopes in which sound is graphed during
playback and recording. On the top left section of the window is
a standard set of audio controls, including play, stop, record,
rewind, pause, and fast forward. A descriptions for each control
is provided in the online help. LED meters are located below
these controls. In the top right section of the window are
controls to set the device's output volume, balance, and playback
speed.
* The Device Controls window can be resized to change the size of
the oscilloscopes or to hide them. Use the setup button to save
the window's position and size for the next session.
Setup
The setup button presents a dialog containing many configurable
options for the Device Controls window. These options are
described below.
Graph type
This group allows you to set the type of oscilloscopes to
display. Clicking on an oscilloscope also changes the type.
Amplitude shows the sound as a series of amplitudes (right
oscilloscope, figure 3). Spectrum shows the sound as a
frequency spectrum. Spectrum bar displays a frequency bar
graph commonly found on stereo systems (left oscilloscope,
figure 3). Spectrogram shows the sound as a coloured
frequency spectrum, with frequency on the vertical axis and
time on the horizontal axis. The colours represent the
magnitude of the frequency. In increasing magnitude, they
are black, purple, blue, cyan, green, yellow, red, and white.
Page 6
-----------------------------------------------------------------
The frequency range of the three spectrum graph types
depends on the sampling rate and the current device speed.
For a speed of 1.00, the frequency range is 0 to one half
the sampling rate. A sound sampled at 22050 Hz, for
example, would have frequencies from 0 to 11025 Hz shown in
the graph. More information about frequency spectrums is
available in Appendix A.
Controls
This group lets you configure the speed of the fast forward
and rewind buttons. By entering a value of 3.00 for the
Rewind speed, for example, the rewind button will move the
current position backwards through the sound three times
faster than regular playback speed. By entering small
numbers (such as 0.1) the rewind and fast forward buttons
will play very slowly. This is useful for finding pops or
clicks, since the oscilloscopes will move slowly through the
data.
Save
If Setup is checked, all the values in the Device Setup
dialog will be saved. If Window position is checked, the
position and size of the Device Controls window will be
saved.
User play button
This group configures the user play button to play and/or
loop sections of the sound. If All is selected, the entire
sound will be played. If Selection is chosen, the sound
between the start and finish markers will be played. If
Unselected is chosen, the regions outside the start and
finish markers will be played. This lets you quickly test
how a cut or delete will sound without actually changing the
sound. Intro/loop/end is a special playback feature that
plays the sound in three section. The beginning of the
sound, outside the selection, is played first. Then the
selection is play and looped. Finally the end of the sound,
outside the selection, is played. This is useful for
musical accompaniment or looped instrument samples. Loop
specifies the number of times playback should be repeated.
A zero value loops forever.
Positioning
This group lists several methods for determining the current
position when a sound is played or recorded. This position
is used to synchronize the oscilloscopes and the white,
current position line in Sound windows. GoldWave relies
heavily on correct positioning for many of the device
controls such as rewind, fast forward, and speed adjustment.
Options
Monitor input connects the input to the oscilloscopes and
LED meters so you can adjust input levels before recording.
The Triple buffering check box enables triple buffering
(checked) or double buffering (unchecked) for playback and
recording. Buffering acts as an intermediary between
storage and the audio driver. Triple buffering produces the
best quality playback and recording and should be disabled
only if you experience problems with your audio driver. The
Input and Output buffer boxes control the size of the
buffers, in seconds, to use for recording and playback.
Three input buffers and three output buffers are 7created.
Increasing the buffer size may reduce the number of pops and
clicks, but will require more memory (about half a megabyte
per second for CD quality). Large buffers also take longer
to fill, resulting in a delay before playback.
Output and Input buttons
These buttons allow you to select a new output or input
device. A device selection dialog box is presented with a
drop down list that shows you the names of audio device
drivers. Below the list is a table that tells you what
sound attributes the driver supports. All boxes with check
marks in them are supported by the currently selected
driver. You can select any driver to see its capabilities.
To play or record CD quality, the driver must support 16
bit, stereo, 44100 Hz.
Playing Sounds
After opening a sound, you can use the play button or the user
play button to play it. The play button plays the selection.
The user play button can play or loop the entire sound or certain
parts of the sound. This button is configured by using the
Device Controls setup button described previously.
While a sound is playing, it is shown graphically on the
oscilloscopes and LED meters. The current position is displayed
in the graph of the Sound window as a vertical white line. In
some cases, your audio hardware may not support the sound's
format or attributes. You can use File | Save as to convert a
sound to a playable format.
* To play the entire sound, configure the user play button to
play All. To select the entire sound, use the control bar
buttons All and Sel Vw.
Pausing Playback
While a sound is playing, you can pause it with the pause button.
Remember to use either play or stop later. Pause freezes the
oscilloscopes and the current position marker so you can see the
shape of the sound or move the selection markers.
Stopping Playback
Playback can be stopped immediately with the stop button. The
current position is reset to the beginning. The audio device is
released so that it may be used by other applications. Recording
is stopped using a different button.
Page 8
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Rewinding and Fast Forwarding
During playback, you can use the rewind button or fast forward
button to quickly move back and forward through the sound. The
current position is displayed in the graph of the Sound window as
a vertical white line. You can adjust the speed of rewind and
fast forward with the Device Controls setup button described in a
previous section.
Recording Sounds
The record button allows you to record your own sounds. Audio is
recorded into the selection of the Sound window overwriting any
data that was previously there. To make room for recording
without overwriting the selection, you can use Edit | Insert
space or create a new file using File | New. Recording will
automatically stop when the selection is full. You can stop
recording at any time with the special stop button that appears
in place of the record button.
* Recording is successful only if the driver supports the Sound
window's attributes and format. You can record a new sound
(File | New) and use Edit | Copy and Edit | Paste to overcome
any driver limitations.
* When recording at high quality CD rates, you should resize the
Device Controls window so that the oscilloscopes are hidden.
This will reduce noise and CPU overhead associated with your
video card. Increasing the Record buffer value in the Device
Controls setup may also improve quality.
Volume and Balance Scroll Bar
If your audio device supports volume control, you can use the
volume scroll bar to change the output volume of your audio
device. Move the thumb right or click the right arrow to
increase the volume. Move the thumb left or click the left arrow
to decrease the volume. The current volume is shown numerically
to the left of the scroll bar. A value of 100 is full volume.
If your audio device supports independent left and right volume
control, you can use the balance scroll bar to change the
device's left/right balance. Move the thumb in the direction you
want to shift the balance.
Page 9
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Speed Scroll Bar
The playback speed of the audio device can be changed with the
speed scroll bar. Move the thumb right to increase the speed,
and left to decrease it. The relative speed is shown numerically
to the left of the scroll bar. Note that changing the speed also
changes the pitch.
Editing Overview
Selecting Part of a Sound
Almost all commands in GoldWave operate on the currently selected
part of a sound. The selected part, or selection, is the
highlighted part of the sound between two vertical markers (see
figure 2). The vertical markers are cyan lines located to the
left side (start marker) and right side (finish marker) of the
view.
Note that GoldWave does not use Windows' standard
"click-and-drag" method to make a selection because it does not
allow accurate positioning of the markers. The method below
allows you to independently set the start and finish markers to
the nearest sample (when zoomed in at a 1:1 level or better).
The mouse pointer in figure 4, indicates when the markers can be
moved.
* To move the start marker, click the left mouse button
on the graph at the point where you want to move it.
* To move the finish marker, click the right mouse button
on the graph at the point where you want to move it.
Additional notes and techniques:
* You cannot place the finish marker before the start
marker. The same is true for setting the start marker
after the finish marker.
* To find a certain part of the sound, you can play the
sound and mark it as it plays. GoldWave indicates the
part being played with a white vertical line. You can
use the rewind and fast forward buttons to accurately
locate a specific sound.
* Individual channels of a stereo sound can be selected
using the Edit | Channel command.
* In most cases, editing and effects are performed only
on the selection. Some effects, such as the Expression
evaluator, Resample, Transpose, and Playback rate may
alter the entire sound.
* Window's clipboard is used for most of the editing
commands. If the selection is too large to copy into
the clipboard, GoldWave will automatically create a
temporary file to simulate the clipboard.
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Direct Editing with the Mouse
Direct editing lets you edit individual samples with the mouse.
You can use this to remove pops and clicks or draw new sound
waves of almost any shape. To do this, you must first zoom in so
that individual samples are visible (see View | Zoom 5:1 or View
| Zoom 10:1).
1) Zoom in 5:1 or closer.
2) Place the mouse arrow directly over the sample you want
to edit. The arrow will change into a thin horizontal
line with two small arrows pointing to it (figure 5).
3) Click and hold the left mouse button.
4) Move the mouse up or down to change the sample.
5) Move the mouse left or right to change neighbouring
samples.
6) Release the mouse button.
Combining Audio Layers (Mixing)
The Edit | Mix command superimposes one sound on top of another.
If you wanted to add vocals to music, for example, you would
perform the following steps:
1) Open the sound containing the music.
2) Open the sound containing the vocals.
3) Choose Copy from the Edit menu.
4) Activate the Sound window containing the music (or
select it from the Window menu).
5) Choose Mix from the Edit menu.
6) Enter a volume to mix the vocals (100 = full volume).
* When mixing more than a couple of sounds, you should reduce the
mixing volume and the destination volume to prevent clipping
distortion. The volume of the destination sound can be reduced
before mixing by using the Effects | Volume | Change command.
Storage Overview
GoldWave supports both direct-to-disk editing and RAM editing,
along with a time saving flash feature. These features are
configured by using the Options | File command.
Direct-to-Disk
In direct-to-disk editing, the entire sound is stored in a
temporary file where it can be modified. This allows you to edit
very large files (up to about 1 billion bytes in size) provided
the required disk space is available. Only a small amount of RAM
is required for each opened sound. The drawback 11is that
editing and effects processing take more time since audio data
must be transferred to and from the disk.
RAM
In RAM editing, the entire sound is stored in memory. This
allows you to edit and process files very quickly. It saves time
and reduces the burden on your hard disk. The drawback is that
the size of the files must be small enough to fit in the
available RAM (not including virtual memory).
Flash
The flash feature allows large files to be opened instantly. The
entire file is not copied to temporary storage and only the first
second of the sound is graphed. This can save a great deal of
time if you only want to play a file and not modify it. A
flashed file can be deflashed at any time by using the Edit |
Deflash command.
A flashed file requires no disk space and only a small amount of
RAM, which means that several large files can be opened at once,
regardless of how much free space is available on the disk. The
drawback is that you need a fast system, especially when a file
has to be decompressed before it can be played.
Keyboard Overview
Table 1 summarizes keystrokes used in GoldWave.
Table 1: Keystrokes
Keystroke Action
Ctrl+X or Shift+Del Remove selection and copy it into the
clipboard.
Ctrl+C or Ctrl+Ins Copy selection into the clipboard.
Ctrl+V or Shift+Ins Pastes clipboard into the sound at the
start marker's position.
Ctrl+B Pastes clipboard into the sound at the
beginning.
Ctrl+F Pastes clipboard into the sound at the
finish marker's position.
Ctrl+A Pastes clipboard into the sound at the
end (appends the clipboard).
Del Delete the selection, permanently.
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Keystroke Action
Ctrl+M & Shift+Ctrl+Ins Mix clipboard with the sound at the start
marker's position.
Ctrl+T Trim sound. Removes all audio outside
the selection.
Left Scrolls the Sound window view left.
Right Scrolls the Sound window view right.
Pg Up Scrolls the Sound window view left one
page.
Pg Dn Scrolls the Sound window view right one
page.
Home Moves the Sound window view to the start
marker's position.
End Moves the Sound window view to the finish
marker's position.
Ctrl+Home Moves the Sound window view to the
beginning of the sound.
Ctrl+End Moves the Sound window to the end of the
sound.
F1 Starts online help.
Space Plays a sound (only when Main window is
active).
Plays/Stops a sound (when Device Controls
window is active).
F4, F5, F6, F7, F8 Plays, fast forwards, pauses, rewinds,
and stops respectively (only when Main
window is active).
Pause Pauses a sound (only when Main window is
active).
Esc Stops a sound (only when Main window is
active).
Alt+F6 Switch between Main window and Device
Controls window.
Ctrl+F6 Switch between Sound windows.
File Menu Commands
The following commands create, open, close, save, and convert
files. Several features for storing and handling files can be
configured using the Options | File command.
New
Use New to create a new sound with attributes you specify. These
attributes are discussed in Appendix A. Note that GoldWave
allows you to create and edit sounds that may not be playable
with your audio hardware. You can use the Output button on the
Device Controls Setup dialog to determine compatible attributes.
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Open and Supported File Types
The Open command presents a list of files in your sound
directory. The sound directory can be set by using the Options
| File command. All file types having a recognized extension are
listed. You can change the extension to search for different
file types. After you select a file, a Sound window is opened
and its attributes are displayed in the status bar.
GoldWave supports all the sound types listed in Table 2.
Table 2: Supported File Formats
Extension Comments
.au Sun or NeXT format. Supports 8 & 16-bit linear and
mu-law encoded files.
The header block is preserved.
.aif Apple / Macintosh sound files. The blocks NAME,
.afc COPY, ANNO, AUTH, and CHAN are all preserved.
Compressed files are not supported. Markers are not
supported.
.iff Amiga 8SVX format. The blocks NAME, COPY, ANNO,
AUTH, and CHAN are all preserved.
.mat Matlab file. It should contain only one variable.
The data must be normalized (i.e. -1.0 to 1.0) for
double precision data. If the "wavedata" variable is
two dimensional, the data is assumed to be stereo.
GoldWave saves audio data in the "wavedata" variable
and the rate in the "samplingrate" variable. A
11025 Hz sampling rate is assumed if none is present.
.raw Headerless files containing binary data in 8-bit,
12-bit, 16-bit, double precision, mu-law, or A-Law
format.
.snd Raw or NeXT format. NeXT format is automatically
detected. Raw format presents a dialog to specify
the attributes.
.wav This includes RIFF WAVE 8-bit and 16-bit PCM mono or
stereo, A-Law encoded files, mu-law encoded files,
and Microsoft ADPCM compressed files.
Only files with one data chunk are supported. The
chunks LIST INFO, LIST adtl, and cue are detected.
All others are ignored.
.voc Sound Blaster files. The following formats are
supported: 8-bit mono/stereo, 16-bit mono/stereo,
mu-law encoded mono/stereo. ADPCM compressed files
are not supported since the compression algorithm
must be licensed from Creative Labs.
GoldWave presents the Raw File Format dialog if the file is
corrupted, unrecognized, or contains data without header
information (raw files). This dialog allows you to specify
appropriate attributes. If you don't know, experiment with
trial-and-error. Generally, sounds will be noisy if the format
or number of bits is incorrect, in which case you will have to
close and re-open the sound using a different format. If the
sampling rate is wrong, the playback speed will be too fast or
too slow. You can use Effects | Playback rate to quickly
re-adjust this. Appendix A has more information about sound
attributes.
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Close
Use Close to close the current sound. If it has been modified,
you will be asked to save changes.
Save
The sound is saved in a file using its original name and type.
If memory or disk space is low, the file may not be saved
successfully. GoldWave will inform you if this happens. If
Save fails, try deleting some unneeded files and close other
applications. Make sure that the file is saved successfully
before closing GoldWave, otherwise part of the sound may be lost.
! Cue points are saved only in Wave files. If you have added
cues to a non-Wave file, you can use File | Save as to convert
it to Wave.
Save as
Save as allows you to save a sound using a different filename or
file type. To save the sound using a different name, simply type
in the new name in the File Name box. To save the sound using a
different type, select the type from the Save File as Type
listbox and select attributes from the Attributes listbox. Since
each type supports different attributes, always select the type
before selecting attributes.
! Note that just adding a different extension to the filename
does not convert the sound to the type associated with the
extension. The extension must be selected from the type
listbox.
Exit
Exit closes all Sound windows and quits GoldWave. Any playback
or recording is stopped. You will be asked to save any changed
sounds.
File History
A list of five recently closed files is appended to the File
menu. You can quickly open one of these files by selecting it
from the menu.
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Edit Menu Commands
This section assumes that you are familiar with the terms
introduced in the Editing Overview section.
Undo
Undo reverses the most recent change made to a sound. Only one
undo is possible across all Sound windows. The undo feature
keeps a copy of the original data in a temporary file. This file
is created in the undo directory specified by the Options | File
command.
Since the undo feature copies large amounts of data, you will
notice a slight delay before each modification. It can be
disabled by using the Options | File command.
Cut
Use Cut to remove the selection from the sound and put it in the
clipboard. The contents of the clipboard can then be superimposed
or inserted into a Sound window using Mix or Paste. Note that if
only one channel is selected in a stereo sound, then only that
channel is removed. Since it is not possible for one channel to
be longer than the other, the end of the cut channel is padded
with silence (this is also true for Delete).
To cut:
1) Move the start and finish markers to the part of the
sound you want to cut.
2) Choose Cut from the Edit menu or click on the Cut
button.
Copy
The Copy command copies the selection into the clipboard. The
selection is not removed from the sound. The contents of the
clipboard can then be superimposed or inserted into a Sound
window using Mix or Paste.
To copy:
1) Move the start and finish markers to the part of the
sound you want to copy.
2) Choose Copy from the Edit menu or click on the Copy
button.
* You can copy individual channels of a stereo sound by using the
Edit | Channel command.
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Paste and Paste at
These commands insert the clipboard into the sound. For Paste,
the clipboard is inserted at the start marker's position. For
Paste at, the sound is inserted at the location you specify. The
length of the sound is increased so that the clipboard will fit.
The clipboard is automatically converted to match the attributes
of the sound.
To insert the clipboard into the sound:
1) Move the start marker to the place where you want to
paste the clipboard sound.
2) Choose Paste from the Edit menu or click on the Paste
button.
To append the clipboard to the end of the sound:
1) Choose Paste at from the Edit menu.
2) Choose End from the Paste at menu.
* By copying a small selection and pasting it several times, a
stutter effect can be achieved.
Mix
Use Mix to blend (superimpose) the clipboard with the sound.
Mixing essentially allows two sounds to be played at the same
time. You are asked for the volume to apply to the clipboard as
it is being mixed. A value of 100 is full volume.
To mix the clipboard with the sound:
1) Move the start marker to the place where you want to
mix the clipboard.
2) Choose Mix from the Edit menu or click on the Mix
button.
3) Enter the mix volume for the clipboard.
4) Choose OK.
Delete
Delete permanently removes the selection from the sound. The
selection is not copied to the clipboard. Note that if only one
channel is selected in a stereo sound, then only that channel is
removed. Since it is not possible for one channel to be longer
than the other, the end of the deleted channel is padded with
silence (this is also true for Cut).
To delete:
1) Move the start and finish markers to the part of the
sound you want to delete.
2) Choose Delete from the Edit menu or click on the Delete
button.
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Trim
Trim permanently removes everything outside the selection. The
selection is not affected. Note that if only one channel of a
stereo sound is trimmed, the end of that channel will be padded
with silence.
To trim:
1) Move the start and finish markers to the part of the
sound you want to keep.
2) Choose Trim from the Edit menu or click on the Trim
button.
Insert silence
This command inserts some blank space in the sound at the start
marker's position. You are asked how long (in seconds) the space
should be. This command can be used to increase recording time
or to insert a delay. The command appears on the control bar as
the Space button.
Select view
Use Select view to select all of the sound currently shown in the
Sound window. The start and finish markers are moved to the far
left and far right of the view. This command appears on the
control bar as the Sel Vw button.
* By using the All button and the Sel Vw button, you can quickly
select the entire sound.
Channel
The Channel pop-up menu controls which channel of a stereo sound
will be used or modified by editing or effects. You can use this
feature to copy a single channel from a stereo sound or apply an
effect to only one channel. The currently selected channel is
shown in the status bar. When recording or using effects such as
the Expression evaluator, Resample, Transpose, and Playback rate,
Pan, Exchange channels, the channel setting has no effect and
both the left and right channels will be modified.
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Deflash
Usually a flashed file will be deflashed automatically. If you
are trying to play a compressed file on a slow system or convert
a file to another type, you can use this command to decompress
the file into temporary storage. The flash feature can be
configured using the Options | File command.
Effects Menu Commands
This section assumes that you are familiar with the terms
introduced in the Editing Overview section.
With these commands, you can change a sound or create new sounds.
The commands are similar to font menu commands in word
processors. For example, using font commands, you can change the
size of the letters. In GoldWave, using the "Volume" effect
changes the "size" (amplitude/volume) of a sound. Note that even
though the word "volume" is used throughout this section for
readability, "amplitude" would be more precise.
Special Controls for Effects
Presets
Presets store parameters and Shapes (described below) in the
gwpreset.ini file so they can be recalled again the next
time the effect is used. Controls for presets consist of a
drop down list box, a [+] button, and [-] button.
To add a new preset:
1) Enter in all the new parameters and/or draw the
new shape.
2) Type in a new name for the preset in the drop down
list. This name cannot be the same as one
currently in the list.
3) Choose the [+] button.
To delete a preset:
1) Select the preset from the drop down list.
2) Choose the [-] button.
To change a preset:
1) Delete the preset, as above. When you delete a
preset, the current parameters and name remain on
the screen so they can be changed.
2) Change the parameters and/or name.
3) Add the preset, as above.
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Shape Controls
Several effects in GoldWave use Shape Controls to set
graphical parameters or dynamically alter the effect across
the selection. Shape Controls usually consists of a graph
window, a Clear button and shape presets (described above).
The graph window initially contains a single line with two
endpoints (shown as large dots). By clicking the left mouse
button anywhere inside this window, you can add new points
to bend the line into a variety of zigzag shapes. To move
a point, click on it and drag it to a new location. To
remove a point, click the right mouse button over the point.
The Clear button removes all the points and reset the end
points. Note that endpoints cannot be removed.
Distortion
Distortion alters the amplitude mapping of the selection. It can
limit, compress, or expand a range of amplitudes. The amplitude
mapping is set using Shape Controls, where x-axis and y-axis both
have a range of -1 to 1. When the line stretches diagonally from
the lower left corner to the upper right corner, the input
amplitude (x) and output amplitude (y) are the same for every
point on the line. By changing the line, the output will differ
from the input.
Figure 6 shows an example of amplitude mapping. Point P1 has an
input value of -0.4 and an output value of -0.4. Therefore no
change occurs to the amplitude. Point P2, on the other hand, has
an input value of 0.8 and an output value of 0.5. In this
example, all input amplitudes in the range of -0.5 to 0.5 remain
unchanged. Any values outside this range will be limited to
+/-0.5. This means that the sound will have no amplitude
magnitudes greater than 0.5.
Doppler
The Doppler effect is defined as a change in frequency of a wave
caused by motion. It can often be heard during auto racing when
a fast car passes in front of you. The pitch of the engine
appears to drop slowly as the car speeds away.
In GoldWave the Doppler command dynamically alters or bends the
pitch of the selection. Shape Controls are presented where the
pitch can be varied over the selection from 0.5 to 1.5 times
normal. You can use Effects | Volume | Shape to dynamically
alter the volume as well.
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Echo
Echo produces an echo or reverb effect in the selection. The
echo delay, volume, and reverb parameters can be entered after
choosing this command. The delay determines how long it takes
for the echo to bounce back. Try values less than 0.1 for a
large room, 0.3 for a baseball stadium, above 0.3 for a canyon
echo. The volume controls how loud the echo will be. Values less
than 50 give good results.
Reverb makes the echo sound deeper. If you check the Reverb box,
the echo will be regenerated at intervals specified by the delay.
This means that if the delay was 0.1 seconds, the echo at 0.1s is
regenerated at 0.2s, and this new echo is regenerated at 0.3s,
and so on. The volume is applied to each regeneration. If the
volume was 50%, the first echo volume is one half the original,
the second echo volume is one quarter, and so on.
* To make the echo sound correct, the effect extends slightly
outside the end of the selection. This may increase the length
of the sound or alter sound outside the selection.
To add an echo:
1) Move the start and finish markers to the part of the
sound you want to add an echo.
2) Choose Echo from the Effects menu.
3) Enter the delay time.
4) Enter the volume.
5) Check Reverb if appropriate.
6) Choose OK.
Exchange channels
This command exchanges the left and right channels of a stereo
sound (i.e. the right channel becomes the left channel and the
left channel becomes the right channel).
Filter
Filters are used to remove a range of frequencies from a sound.
They can produce a variety of effects. A pop-up menu is
displayed listing several filter related commands.
Noise Gate
Noise gates remove background hiss from quiet parts of the
selection. You can use this after recording to clean up
some of the noise created by the audio device when it
converted the sound to digital data. Noise gates do not
remove background hiss from louder parts of the selection.
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The Decay time is the amount of time (in milliseconds) that
it takes for the noise gate to fully close. When the gate
is closed, no sound can pass and this leaves only silence.
Values less than 200 milliseconds are common.
The Threshold is the amplitude level at which the gate will
start to open and let sound pass. If you specify a value of
0.05, for example, all samples with amplitudes from 0.05 to
1.0 will be allowed to pass, but samples with amplitudes
from 0 to 0.05 are blocked. If you still notice a hiss in
quiet sections, increase this value.
User defined
The User Defined Filter dialog allows you to specify
coefficients to use for filtering. Up to 15 coefficients
can be given. Almost any kind of linear filter can be
created with this command because it exploits the general
digital filter equation:
In GoldWave, this becomes:
b(0)y(n)+b(1)y(n-1)+ ... +b(14)y(n-14)
= a(0)x(n)+a(1)x(n-1)+ ... +a(14)x(n-14)
For speed, fixed point calculations are used. Coefficients
can be floating point values with magnitudes from 0.0001 to
500. Values outside this range cannot be converted to fixed
point values. The number of coefficients entered for a and
b must be the same. For FIR filters, you would usually
enter a one followed by a number of zeros for b.
* You can use Ctrl+C and Ctrl+V to copy and paste
coefficients. The Clear button quickly removes all
coefficients from the coefficient edit boxes.
Some predefined filters are included in the Coefficient
Sets. The number following a lowpass filter preset
indicates what percentage of frequencies are kept. Lowpass
25, for example, keeps the lower 25% of frequencies. The
number following a highpass filter preset indicates the
percentage discarded. Highpass 10, for example, discards
the lower 10% of frequencies. The actual frequencies kept
or discarded depends on the sampling rate of the sound.
Lowpass 25 on a 22050 Hz sound will remove frequencies from
about 2700 Hz to 11025 Hz.
* To fully use this command requires a detailed knowledge of
digital filter theory, which is beyond the scope of this
manual. A brief introduction is provided in Appendix B.
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Interpolate
Interpolate uses linear interpolation to smooth out samples
between the start and finish markers. Use this command on a tiny
selection to remove a pop or click.
Invert
Invert reflects the selection about the time axis. The selection
is essentially turned upside-down. This produces no noticeable
effect in mono sounds and has a slight effect in stereo sounds.
Inverting a single channel of a stereo sound produces an "in" or
"out" effect.
Mechanize
Mechanize adds a robotic or mechanical characteristic to sounds.
The percentage of quality can be entered after selecting this
command. Low values produce an untuned radio effect. Higher
values give a rough distorted effect.
To mechanize part of a sound:
1) Move the start and finish markers to the part of the
sound you want to mechanize.
2) Choose Mechanize from the Effects menu.
3) Enter the quality percentage, then choose OK.
Offset
Offset adjusts or removes a dc offset in the selection by
shifting it up or down (see figure 7) so that the wave is
centered on the horizontal axis. When this command is selected,
it first scans the selection for any existing offset. An offset
to cancel the existing offset is then displayed in a dialog where
it may be changed. A positive value shifts the graph up and a
negative value shifts it down.
To adjust the offset of part of a sound:
1) Move the start and finish markers to the part of the
sound you want to adjust.
2) Choose Offset from the Effects menu.
3) Enter the offset, then choose OK.
* You should check the offset from time to time after processing
effects. Otherwise, the offset may increase with each effect,
resulting in distortion.
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Pan
Pan presents the Shape Controls where panning can be specified.
The graph is divided into green and red regions, representing the
left and right channels respectively. The line, initially
located between the regions, represents the center for panning.
By bending and/or moving the line, you can dynamically alter the
selection's left/right balance or pan to and from each channel.
Figures 8 to 10 show several examples of panning shapes.
Reverse
This command reverses the selection so that it plays backward.
Now you have an easy way to listen to all those "satanic verses".
Silence
Silence erases the selection. The sound in the selection is
muted (set to zero volume).
Volume
The Volume pop-up menu contains several volume related commands.
Volumes are usually specified by a percentage of the sound's
original amplitude. Unlike the volume scroll bar in the Device
Controls window, which changes the audio device output volume,
these commands alter the sound's data to change the volume.
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Change
Change modifies the selection so that it sounds louder or
quieter. The percentage of volume can be entered after
selecting this command. Values less than 100 make the sound
quieter and values greater than 100 make it louder. Enter
50 to halve the volume and 200 to double the volume. A
value of 100 is normal volume and has no effect.
To change the volume of part of a sound:
1) Move the start and finish markers to the part of
the sound you want to change.
2) Choose Change from the Effects | Volume pop-up
menu.
3) Enter the volume percentage, then choose OK.
Fade in
Fade in gradually increases the volume throughout the
selection. The initial volume percentage can be entered
after choosing this command. A value of 25 starts with one
quarter volume and fades in to full volume. A value of 0
starts at silence and fades in to full volume.
To fade in part of a sound:
1) Move the start and finish markers to the part of
the sound you want to fade in.
2) Choose Fade in from the Effects | Volume pop-up
menu.
3) Enter the initial volume percentage, then choose
OK.
Fade out
Fade out gradually decreases the volume throughout the
selection. The percentage of fade can be entered after
choosing this command. The fade percentage is the amount
that the volume should decrease. A value of 100 fades to
complete silence. A value of 50 fades to half the original
volume.
To fade out part of a sound:
1) Move the start and finish markers to the part of
the sound you want to fade out.
2) Choose Fade out from the Effects | Volume pop-up
menu.
3) Enter the fade percentage, then choose OK.
Maximize (Normalize)
Maximize searches the selection for the maximum percent that
the volume can be increased without producing distortion or
clipping errors. The volume is then applied to the
selection. This is often referred to as a "normalize"
process. If the percentage is above 5000% or equal to 100%,
no changes will be made.
To maximize the volume of part of a sound:
1) Move the start and finish markers to the part of
the sound you want to normalize.
2) Choose Maximize from the Effects | Volume pop-up
menu.
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Shape
Shape presents the Shape Controls where the volume envelope
of the selection can be defined. The shape line is
initially horizontal at 100. By bending/moving the line,
you can dynamically change the volume over the selection.
Several preset shapes are included, demonstrating fade in
and fade out.
Playback rate
This command changes the playback rate of the entire sound. The
sound will play faster (or slower) and its pitch will be higher
(or lower). Essentially, this just changes the first number in
the status bar. Values of 11025, 22050, and 44100 are
recommended.
To change the playback rate of the entire sound:
1) Choose Playback rate from the Effects menu.
2) Enter the new rate, then choose OK.
* The playback rate of the audio device can be controlled using
the speed scroll bar in the Device Controls window.
Resample
Resample changes the sampling rate of the entire sound. Unlike
Playback rate, this command re-calculates and interpolates all
the data so that the pitch and playback time are not affected.
You are prompted to enter a new rate. Values of 11025, 22050,
and 44100 are recommended.
To change the sampling rate of the entire sound:
1) Choose Resample from the Effects menu.
2) Enter the new rate, then choose OK.
* If you have a sound recorded at 44100Hz and do not need CD
quality, you can save large amounts of disk space by resampling
the sound to 22050Hz or 11025Hz. This reduces the size by 2:1
or 4:1. Before down-sampling (converting 22050Hz to 11025Hz,
for example), the data should be lowpass filtered to prevent
aliasing. See Effects | Filter.
Transpose
Transpose changes the sampling rate of the entire sound so that
it plays back at a different pitch. This is useful for
converting instrument samples from one note to another.
Transpose combines the Resample and Playback rate effects. You
are prompted to select the original pitch and the new pitch from
notes provided in drop-down lists. By specifying "C" as the
original pitch and "C2" as26 the new pitch, you can shift the
pitch up one octave. Fine tune lets you make a slight pitch
adjustment.
View Menu Commands
This section assumes that you are familiar with the terms
introduced in the Windows Overview and Editing Overview sections.
View commands allow you to get more (or less) detail about the
actual shape of the sound. They are similar to Paintbrush's
zoom commands. When you zoom in (or magnify) the sound, you see
a smaller section, but with greater detail. When zoom out, you
see the entire sound, but with less detail. The Overview box
near the bottom of each Sound window gives you some information
about what section of the sound is currently shown in the view
(see figure 2).
When zoomed in to a part of the sound, a scroll bar will appear
at the bottom of the Sound window so you can move to different
parts of the sound while still keeping the same level of
magnification. The current level of magnification is displayed
in the Main window's status bar next to the word "Zoom".
Almost all View commands use the start marker's position as the
starting location for magnification, so you should move the start
marker to the position of interest first.
* If a file is flash opened, only the first second of sound is
initially display in the view. Otherwise, the entire sound is
displayed.
All
The entire sound is graphed in the view. By using View | All and
then Edit | Select view, you can quickly select the entire file.
Selection
The selection is magnified, increasing the detail of the graph
(see figure 11). You can zoom in many times by changing the
selection and magnifying it again until a single sample is shown
in the view.
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User
A User button is provided in the controls bar so that you can
quickly zoom to your favourite level. The sound is magnified to
the level of detail specified under the Options | Window dialog.
The level can be set to any value you find convenient.
Other
This magnifies the graph to any level you specify. The level is
given as 1:X, where X is the number you enter at the prompt. A
value of 10 gives a 1:10 level as described below. A value of
0.10 is equivalent to a 10:1 zoom level. If the given level is
not possible, the closest valid level is used.
Zoom 10:1 and 5:1
When the number to the left of the colon is greater than one, a
very small section of sound is magnified at a high level of
detail. At these levels, individual samples are easily visible
and direct sample editing with the mouse is possible.
Zoom 1:1
At a level of 1:1, each audio sample is represented as a single
pixel on the screen. This reveals a true representation of the
shape of the sound.
Zoom 1:10 and 1:100
When the number to right of the colon is greater than one, a
larger section of sound is displayed, but with less detail.
Levels beyond 1:10 show only an approximation of the shape of the
sound with minimum detail.
Start and Finish
These commands scroll the view to either the start or finish
marker's position. The marker will be in the center of the view
provided its position and the level of magnification permit it to
be centered. These commands are especially useful when you need
to move a marker to a precise position.
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Tools Menu Commands
Cue Points
Cue points allow you to mark and describe specific positions
within sounds. They have numerous uses. When recording speech,
for example, you can use them to hold information about the
speaker or a translation of what the speaker said. For music,
you can store lyrics for each verse. If you design instrument
samples, cue points can hold looping points. Some multimedia
applications use them to play or loop specific sections of a
sound.
Cue points can be set at the start or finish marker's position.
You can also move the start or finish marker back to a cue point.
Currently, cue points are fixed and do not change position when a
sound is modified. This should be considered when certain
commands, such as delete, are used. Any cues inside the deleted
selection will not be deleted and the cues outside the selection
will not be adjusted to account for the new positions.
! Cue points are saved only in Wave files.
To set a cue point at the start marker's position:
1) Move the start marker to the position where you want to
create a cue point.
2) Choose Cue points from the Tools menu.
3) Choose the Start marker radio button.
4) Enter a name and description for the cue point.
5) Choose the Add button.
6) Choose OK.
To delete a cue point:
1) Choose Cue points from the Tools menu.
2) Select the cue point from the list.
3) Choose the Delete button.
4) Choose OK.
To change a cue point:
1) Move the start marker to the position where you want to
move the cue point.
2) Choose Cue points from the Tools menu.
3) Select the cue point from the list.
4) Choose the Start marker radio button.
5) Change the name and description, if necessary.
6) Choose the Revise button.29
7) Choose OK.
* If you do not want to change the cue point's position, you
should move the start marker to the cue point first by using
the Set button.
To move the start marker to a cue point:
1) Choose Cue points from the Tools menu.
2) Select the cue point from the list.
3) Choose the Start marker radio button.
4) Choose the Set button.
5) Choose OK.
Expression evaluator
The Expression Evaluator is a versatile tool for manipulating and
generating audio data. For a detailed explanation, please see
Appendix B.
CD Player
The CD Player provides access to your CD-ROM device for playing
audio CDS. Before using the CD Player, you should carefully
follow the CD-ROM installation instructions and make sure that
all the necessary CD-ROM drivers have been installed (in DOS and
Windows).
The buttons from left to right are play( ), pause( ), stop( ),
track up, track down, and eject( ). The track can be changed by
using the track up/down buttons or by using the scroll bar. The
status gauge shows how much of the current track has been played.
You can jump to any point in the track by clicking the mouse
inside the gauge.
If a CD contains both computer data and audio, attempting to play
the data track generates an error message.
Device Controls
The Device Controls window is discussed in the Device Controls
Overview section.
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Options Menu Commands
Colours
Use this command to change the colour scheme of Sound windows.
File
The File Options dialog lets you setup directories and file
storage options. This sections assumes you are familiar with the
terms introduced in the Storage Overview section.
Sound files
This specifies the directory where you keep your sound
files. The File | Open command will automatically list
files in this directory whenever you start GoldWave. If you
prefer to use Program Manager's Properties feature to
specify a working directory, enter a period, ".", for this
directory.
Temporary
This specifies the directory to use when creating temporary
files. This directory should be located on a large disk
with plenty of free space. Using a compressed drive is not
recommended. It will slow processing and give poor results
when recording if hard disk storage is enabled. Changing
this directory does not affect opened files already in
temporary storage.
Undo
Undo specifies the directory to use for storing undo data.
In most cases, it should be the same as the temporary
directory. Changing the undo directory does not affect the
current session of GoldWave since the undo file will have
been created already. Undo can be enable or disabled by
checking or unchecking the check box.
Flash open
The Flash open radio buttons let you control the flash
feature. If you usually edit small files or have a slow
system, set this to Never. If you always play files and
rarely modify them, choose Always. If you have a fast
system and often modify files, choose Limit and specify the
minimum size (in units of 1000 samples) for a file to be
flash. Any file larger than this will be flashed.
Temporary storage
This specifies where files should be stored for processing.
RAM storage is very fast, but limits the size of files.
Hard disk is slower, but allow huge files to be processed.
Changing 31this options does not affect files currently
opened.
Window
Use the Window Options dialog to configure the positions of the
Main window and Sound windows and specify the zoom value for View
| User.
Main window size
This controls the Main window's position and size when
GoldWave is started. Normal gives control to Windows.
Maximize makes the Main window occupy the entire screen.
Save position saves the Main window's position and size when
GoldWave is closed so that it will appear in the same
location next time.
Main window size
This controls the position and size of Sound windows.
Normal gives control to Windows. Maximize makes a Sound
window occupy the entire Main window. Auto-tile resizes all
Sound windows whenever a new sound is opened or closed so
that every one will be visible.
User zoom
This is where you specify the level of zoom for View | User
and the User button. Values between 0.01 to 1000 are valid.
Window Menu Commands
These commands organize Sound windows. Tile arranges Sound
windows side-by-side so that they are all fully visible.
Cascade layers Sound windows on top of each other so that their
title bars are visible. Arrange icons arranges minimized Sound
window icons in rows on the bottom of the Main window. Close all
closes all Sound windows. You will be asked to save any sounds
that have been modified. The bottom of the menu holds a list of
all Sound windows currently opened.
Help Menu Commands
Contents starts Window's online help utility and gives a list of
contents for GoldWave help. Using help provides instructions for
using Window's Help utility. About displays version and
registration information. The amount of available memory is
shown under the GoldWave icon.
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4 General Information
Warranty, Trademarks, and Copyrights
GoldWave ("the package") includes the following software and
documentation:
GOLDWAVE.EXE GoldWave application file
GOLDWAVE.HLP GoldWave help
EXPRESS.EQX Evaluator expressions
GWPRESET.INI Effects presets and shapes
ORDER.TXT Order form
README.TXT Important notes/information
WHATSNEW.TXT A list of new features
BWCC.DLL Borland's Windows control library
The package is provided as is, without warranty of any kind. The
author shall not be liable for damages of any kind. Use of this
software indicates you agree to this.
The package and this documentation are copyright ⌐ 1993-1995 by
Chris S. Craig. All rights reserved.
Borland is a registered trademark of Borland International
Incorporated.
GoldWave is a trademark of Chris S. Craig.
IBM is a registered trademark of International Business machines.
Matlab is a trademark of The Math Works Incorporated.
Microsoft is a registered trademark of Microsoft Corporation.
Sound Blaster is a trademark of Creative Labs Incorporated.
Windows is a registered trademark of Microsoft Corporation.
All other trademarks/registered names acknowledged.
Support and Updates
The GoldWave World Wide Web home page:
http://www.cs.mun.ca/~chris3/goldwave
contains the latest information and updates for GoldWave.
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If you encounter any problems, please check the following
information:
Appendix C: Troubleshooting and Q&A
The GoldWave home page under "Frequently Asked
Questions and Troubleshooting"
If a problem still cannot be resolved, please send a detailed
description to the address below.
Questions, comments, and suggestions are welcome. You can send
e-mail to:
chris3@cs.mun.ca
and regular mail to:
Chris Craig
P.O. Box 51
St. John's, NF
CANADA A1C 5H5
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Appendix A: An Introduction to Digital Audio
Digital Audio Attributes
Digital audio is composed of thousands of pieces of data, called
samples. Each sample holds the loudness, or amplitude, of a
sound at a given instant in time. This is similar to computer
graphics where each point of light (pixel) has a certain
brightness and location. All these points combine to make a
picture. In digital audio, all the samples combine to make a
sound. There are several attributes that determine the quality
and quantity of digital sound. They are the sampling rate, the
number of bits, and the number of channels.
The Sampling rate is the number of times, per second, that a
sample is recorded. It is measured in Hertz (seconds-1, Hz). A
high sampling rate will yield a high quality of digital sound in
the same manner that high graphics resolution will show better
picture quality. Compact disks, for example, use a sampling rate
of 44100Hz, whereas telephone systems use a rate of only 8000Hz.
The rate to use depends upon the type of sound and the amount of
memory and disk space you have available on you system. Higher
rates consume larger quantities of storage. In the above
example, the compact disk requires over 5 times the amount of
storage as the telephone system for the same digital sound.
Certain types of sounds can be recorded at lower rates without
loss of quality. Some standard rates are listed in Table A.1 at
the end of this section.
The number of bits determines how accurately the amplitude of a
sample is recorded. The two most common are 8-bit and 16-bit
formats. In an 8-bit sample, there are 256 different levels of
amplitude. 16-bit samples have 65,536 levels. To compare the
difference, let's say that you are a teacher grading tests and
you can use one of two marking schemes (figure 12). In scheme
#1, the mark is out of 10. In scheme #2, the mark is out of
1000. All marks must be rounded off (no decimals allowed). If
a student gets two thirds of the questions right, then in scheme
#1, the grade will be 7 out of 10. In scheme #2, the grade will
be 667 out of 1000. Obviously, scheme #2 is much more accurate.
In digital sound, low levels of accuracy can cause noise due to
quantization errors, as discussed in the next section.
The number of channels also affects the quality and quantity of
digital sound. Single channel sound, referred to as a monaural
(or mono) sound, contains information for only one speaker and is
similar to AM radio. Two channel sound, or stereo sound,
contains data for two speakers, much like FM stereo. Stereo
sounds can add depth, but they require twice as much storage as
mono sounds.
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Table A.1: Sound attributes
Attributes Quality and Sound type. Storage / second,
Storage / minute
11025Hz, 8-bit, mono Fair quality. Good for speech and low
pitch sounds. 11025 bytes, 662,000 bytes
11025Hz, 8-bit, stereo Fair quality stereo. 22050 bytes,
1,323,000 bytes
11025Hz, 16-bit, mono Less noise. 22050 bytes, 1,323,000 bytes
11025Hz, 16-bit, stereo Stereo, less noise. 44100 bytes,
2,646,000 bytes
22050Hz, 8-bit, mono Good quality. Good for music and
relatively complex sounds. 22050 bytes,
1,323,000 bytes
22050Hz, 8-bit, stereo Good quality stereo. 44100 bytes,
2,646,000 bytes
22050Hz, 16-bit, mono Very good quality. Less noise. 44100
bytes, 2,646,000 bytes
22050Hz, 16-bit, stereo Very good quality stereo. Less noise.
88200 bytes, 5,292,000 bytes
44100Hz, 8-bit, mono High quality. Good for all sounds.
44100 bytes, 2,646,000 bytes
44100Hz, 8-bit, stereo High quality stereo. 88200 bytes,
5,292,000 bytes
44100Hz, 16-bit, mono Excellent quality. Less noise. 88200
bytes, 5,292,000 bytes
44100Hz, 16-bit, stereo Excellent quality stereo (CD quality).
Large storage requirements. 176400
bytes, 10,584,000 bytes
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Problems with Recording
There are five potential problems when recording sound:
aliasing, clipping, quantization, internal noise, and system
configuration.
Aliasing occurs when the sampling process does not get enough
data to correctly determine the shape of the sound wave. The
recorded sound will have missing tones (figure 13, top) or new
tones that never existed in the original sound (figure 13,
bottom). These problem can be eliminated by using higher
sampling rates or by using anti-aliasing filters.
Higher sampling rates increase the number of sampling points.
To see how this works, try adding a few points between each
sampling point in the figure and redraw the graph. The recorded
sound will more closely resemble the input.
Anti-aliasing filters remove all tones that cannot be sampled
correctly. They prevent high pitched tones from being aliased
to low pitch. Many sound cards include anti-aliasing filters in
hardware.
Clipping errors occur when the sampled amplitude is outside the
range of valid values. If, for example, the range is -1.0 to
1.0, and a value of 1.2 is sampled, then the value must be
clipped to 1.0 (see figure 14). This generates distortion. To
eliminate clipping, adjust the input volume before recording.
By using the Device Controls' monitor feature, you can analyse
the input to determine a suitable volume. The volume is low
enough when the red LEDs remain off.
Quantization errors occur when the sample is rounded to the
nearest level of amplitude. This can be explained by using the
"marking schemes" example in the previous section. The number
two thirds (2/3) is represented by 7/10 in scheme #1. This gives
a quantization error of:
| 7/10 - 2/3 | = 1/30
Similarly, in scheme #2, the quantization error is:
| 667/1000 - 2/3 | = 1/3000
Clearly, scheme #2 has the smallest error. Therefore, using 16
bits instead of 8 bits is a good way to reduce quantization
errors.
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The other two recording problems deal with computer hardware. To
minimize internal noise, make sure your audio card is installed
as far away from your graphics/monitor adaptor card as possible.
If you use a microphone, keep it away from your monitor and
computer fan. Remember to use shielded cables.
System configuration can also affect audio quality. Recording to
a compressed drive (DriveSpace) is not recommend. Compression
ratios on audio are generally poor and the CPU overhead can cause
gaps during recording. When recording 16-bit, 44100 Hz, you
should resize the Device Controls windows to hide the
oscilloscopes. This also reduces CPU overhead.
Periodic defects can often be heard when playing pure tones (sine
waves). With most audio hardware, these defects occur during DMA
updates and are unavoidable.
Frequency Spectrums
GoldWave features built-in frequency spectrum analysers in the
Device Controls window. Essentially, they allow you to see what
frequencies (or pitches) are present in a sound. A rainbow is an
example of a frequency spectrum of visible light. The sun's
light is broken down into a set of fundamental colours.
GoldWave's spectrum analysers do the same thing for sound.
GoldWave generates the spectrum by using a radix-2 fast Fourier
transform (FFT). FFTs require intensive computations, making
them somewhat unsuitable for real-time applications. To speed up
these computations, GoldWave makes extensive use of 32-bit 386
assembly language instructions. For accuracy, 64-bit temporary
results are used.
GoldWave optionally applies a windowing function to the data
before performing the FFT (see Setup in the Device Controls
Overview section). This reduces errors that occur when dividing
data into small chunks. The Hamming window, as defined below, is
used.
To make the spectrum more realistic to human hearing, magnitudes
are scaled logarithmically. This means that if one frequency
"sounds" twice as loud as another, it will be graphed with twice
the height (or the corresponding colour for the spectrogram).
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During playback with a spectrum oscilloscope, the following
operations are performed each time the oscilloscope is updated:
1) The current position is obtained.
2) The position is drawn on the Sound window's graph.
3) The sample data is windowed.
4) The FFT is performed.
5) The logs of the magnitudes are calculated.
6) The result is converted to screen coordinates or
colours.
7) The graph is drawn.
All this requires a significant amount of CPU time. Under some
circumstances, this may prevent dialogs from being displayed.
If you notice that a dialog is taking an unusually long time to
appear, press the pause or stop button to free up some CPU time
or hide the oscilloscopes by resizing the Device Controls window.
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Appendix B: Expression Evaluator
Overview
The Expression Evaluator is a versatile tool for manipulating and
generating audio data. After you select Expression evaluator from
the Tools menu, you are presented with a dialog that is similar
in appearance to a calculator.
The Destination is the Sound window where results of the
evaluation will be stored. The drop-down list contains all Sound
windows in the form "X - NAME", where X is the wave identifier
number of the Sound window and NAME is the filename of the sound.
For example, a Sound window with the title "HELLO.SND" could
appear as "1 - HELLO.SND" in the list. By default, the
destination is set to the current Sound window. You can change
the destination, if more than one Sound window is opened, by
using the up and down keys or by selecting it with the mouse from
the drop-down list.
A Source is a Sound window containing existing audio data that
will be used in the expression. By selecting a source from this
list, the function waveX( will be placed in the expression. X is
the wave identifer number as mentioned in the preceding
paragraph. To double the volume of "1 - HELLO.SND", for example,
you would select it as both the destination and a source and
complete the expression wave1(n)*2.
A large Expression box is located in the middle of the dialog.
This is where an expression is entered. A list of valid
operations and functions is given in a following section.
To enter an expression, you can:
1) Type it in using the keyboard.
2) Click on the "calculator" buttons with the mouse.
or
3) Use the Group name and Expression name boxes to select
a previously saved expression.
The evaluator uses three special variables, which may be
initialized in the Variables box. These variables are discussed
later.
After you have specified the destination, expression, and initial
values, choose the Start button (or just press the "Enter" key)
to begin evaluation. If you entered an expression incorrectly, a
message will be displayed by the word Status. The Status area
also gives the progress during evaluation. 41 Since the
evaluation process takes time, you can stop it at any time with
the Cancel button. Pressing the Cancel button a second time
will close the Expression Evaluator dialog.
* You can copy, cut and paste expression in the Expression box
using the usual keystrokes (Copy = Ctrl+C, Cut = Ctrl+X, Paste
= Ctrl+V). You can also copy and paste expression from the
online help.
* To speed up evaluation, make sure that you are using RAM
storage (see Options | File). A co-processor can dramatically
increase the speed of the evaluation, since the evaluator uses
floating point calculations.
Evaluation Range, Variables, and Constants
Knowledge of the structure of digital audio is essential to
understand how the evaluator works. To illustrate this
structure, let's assume we have the following sound:
Title bar: HELLO.SND
Total length: 2.0 seconds
Sampling rate: 8000Hz
Start marker: 0.5 seconds
Finish marker: 1.2 seconds
Digital audio is stored as a series of amplitudes, which are
often referred to as samples (see figure 15). The evaluator
interprets each sample as a value between -1 and 1, inclusive.
If the result of an evaluation is outside this range, it will be
clipped. Only samples between the start and finish markers are
considered valid; all other values are assumed to be zero. The
number of samples selected is defined as N.
Each sample has a relative index number, n, and a time, t,
associated with it. Since the time of each sample depends on the
sampling rate, it is usually written in terms of the unit of time
between each sample, T. You many have noticed that the time is
related to the index number by the equation t=nT. Figure 15
shows how all these variables relate to the structure of the
sound.
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Using Time in an Expression
Let's assume we have entered the expression sin(t). Since
expressions are evaluated over the selection range, the initial
value for t is automatically set to start markers position of
0.5. By choosing the Start button, the expression will be
evaluated from t = 0.5 to t = 1.2 in steps of 1/8000 of a second.
This means that the expression is calculated for each sample in
the selection, changing each sample as follows:
Sample4000 sin(0.500000)
Sample4001 sin(0.500125)
Sample4002 sin(0.500250)
...
Sample9600 sin(1.200000)
Using the Sample Index in an Expression
The sample index is useful for modifying an existing sound. If
we want to double the amplitude of HELLO.SND, for example, we
need to multiple each sample by two and store it back into the
sound. In this case, HELLO.SND will be both the destination and
the source. To set it as the destination, we simply select it
from the Destination list. To use it as a source, we need to
determine its wave identifier number. These numbers are provided
in the Source list. Assuming it is listed as "3 - HELLO.SND", we
now know that its wave identifier number is 3. This number is
necessary for the evaluator's wave function, which has the
following syntax:
waveX(n) where: X = wave identifer number
n = sample index number
* In the evaluator, the index number, n, is relative to the
starting index. This means that the starting index is added to
the index number (i.e. n+Start). For the example in figure 15, a
relative index of n=0 has an absolute index of 4000. The Start
sample always has a relative index of 0.
The final expression is wave3(n)*2. By choosing Start, this
expression will be evaluated from n=0 to n=5600 (=N) in steps of
1. This produces the following changes (remember than n is
relative):
Sample4000 Sample4000 * 2
Sample4001 Sample4001 * 2
Sample4002 Sample4001 * 2
...
Sample9600 Sample9600 * 2
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Note that N and n are always integers. The evaluator rounds
indices to the nearest integer, so the expression wave3(.7)
would be calculated as wave3(1).
You can use the sample index number and the wave function to mix
two or more wave together. If you have several sounds opened,
you can obtain the wave identifier number for each sound from the
Source list. If the sounds you wanted to mix were identified as
2 and 3, you would enter the expression:
wave2(n) + wave3(n)
You must be careful when indexing signals with different sampling
rates. Assume wave1 is a voice recorded at 11025Hz and wave2 is
music recorded at 22050Hz. If you want to mix these two signals,
with wave1 as the destination, then the expression
wave1(n) + wave2(n*2)
must be used (ideally, wave2 would have to be low-pass filtered
first). Whereas, if wave2 is the destination, the expression
should be
wave1(n/2) + wave2(n)
A variable N has several uses, such as reversing a sample.
Assume wave2 is a new sound that has the same sampling rate and
length of wave1. By setting the destination to wave2 and using
the expression
wave1(N-n)
wave2 will be the reverse of wave1.
User Variable f
The user variable, f, can be set to any value you choose. In
many cases, this value is used as a frequency, hence the letter
"f". For example, if you entered the expression
sin(2*pi*f*t)
you can then generate any sine wave by specifying a frequency in
the f box. This value does not change during evaluation, but
stays at the value you assign to it.
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Conversion Between Variables
The following equations convert between time and sample index
number. The start parameter is the position of the start marker
(in seconds).
Group name and Expression name
The Group name and Expression name boxes allow you to organize
and store expressions in the express.eqx file located in your
Windows directory. Similar expressions can be stored together
in groups. The Group name box lists all of these groups, while
the Expression name box lists all the expressions in a group.
To retrieve an expression:
1) Select the group from the Group name list.
2) Select the expression from the Expression name list.
To add an expression:
1) Enter the expression.
2) Type in the group name or select a group from the Group
name list.
3) Type in an expression name.
4) Choose the Add button.
To delete an expression:
1) Select the group from the Group name list.
2) Select the expression from the Expression name list.
3) Choose the Delete button.
When a group becomes empty, it will be deleted automatically.
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Valid Operators and Functions
The following table summarizes the operators and functions
included in the evaluator.
Table B.1: Evaluator Operators and Functions
Label Operation, function
(, ) Parenthesis
+, *, -, / Add, multiply, subtract (negate), and divide
% Modulus operator (remainder)
^ To the power of, yx
pi Constant (3.14159...)
cos Cosine
sin Sine
tan Tangent
acos Arccosine
asin Arcsine
atan Arctangent
cosh Hyperbolic cosine
sinh Hyperbolic sine
tanh Hyperbolic tangent
sqrt Square root
abs Absolute value
log, ln Log base 10, natural logarithm
exp Exponential base e
step Unit step (0 for t < 0, 1 for t >= 0)
int Integer value
rand(n) Random number between 0 and n
wavex(n) Sound amplitude at n. x specifies the Sound
window as given in the Source list. If no x is
specified, the destination Sound window data is
used.
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Signal Generation
Several signal generation expressions are listed below. Words
given in italics represent numeric values that you must enter.
To try one of the following expression, perform the following
steps:
1) Choose New from the File menu.
2) Choose OK.
3) Choose Expression evaluator from the Tools menu.
4) Type in the expression as given in the example. For
example:
sin(2*pi*261.7*t)
5) Choose Start.
6) Wait for the "Finished" message.
7) Play the sound.
Table B.2: Expressions
Type
General Expression
Examples
Sine wave
sin(2*pi*frequency*t)
Middle C:
sin(2*pi*261.7*t)
Telephone dial tone for "5":
(sin(2*pi*773*t) + sin(2*pi*1336*t)) / 2
Saw (triangle) wave
1 - 2*abs(1 - 2*frequency*t%2)
200Hz tone:
1 - 2*abs(1 - 2*200*t%2)
White noise
1 - rand(2*amplitude)
Full volume white noise:
1 - rand(2)
Square wave
int(2*t*frequency)%2*2-1
400Hz tone:
int(2*t*400)%2*2-1
Sweep
sin(2*pi*t^rate)
Slow sweep up to 20kHz:
sin( 2*pi*160*(t%5)^3 )
Exponential decay
(1 - minimum)*exp(-t) + minimum
50% decay of a 500 Hz sine wave:
(0.5*exp(-t) + 0.5) * sin(2*pi*500*t)
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Filters
One of the easiest ways to create digital filters is to use
Matlab (The Student Edition of Matlab, by The Math Works Inc.,
published by Prentice-Hall, ISBN 0-13-855974-0). It has many
built-in commands that generate filter coefficients. The
coefficients can then used in the expression evaluator.
Example of a Low-Pass Filter
In preparation for down-sampling, you can use Matlab to generate
the coefficients of a 4th order Butterworth low pass filter that
will remove noise above half the Nyquist frequency (1/2 the
sampling rate). Enter:
[b,a] = butter(4, 0.5)
The result should be similar to:
b = 0.0940 0.3759 0.5639 0.3759 0.0940
a = 1.0000 0.0000 0.4680 0.0000 0.0177
To implement this filter in the evaluator, let's assume that the
sound to be filtered is in the Sound window titled SOUND.SND.
1) Use File | New to create a new Sound window with the
same sampling rate as SOUND.SND.
2) Make sure the length of the new sound is as long (or
longer) than the original. If it is not, use Edit |
Insert space to increase its length.
3) Use Tools | Expression evaluator to open the expression
evaluator dialog.
4) Set the destination to the new sound.
5) Enter the following expression (assuming SOUND.SND has
a wave identifier of 1):
wave1(n)*0.0940 + wave1(n-1)*0.3759 + wave1(n-2)*0.5639
+ wave1(n-3)*0.3759 + wave1(n-4)*0.0940
- wave2(n-2)*0.4860 - wave2(n-4)*0.0177
6) Choose Start (You might want to get a coffee while you
wait).
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Appendix C: Trouble Shooting and Q&A
Troubleshooting
Problem
Cause/Solution
Cannot open large files
* Make sure that hard disk storage is enabled in Options |
File. Make sure that you have plenty of free RAM and hard
disk space.
Cannot play sounds
* GoldWave or audio device/driver is incorrectly installed.
Make sure a WAVE driver is installed in the Control Panel's
Drivers applet.
* Check that Window's Sound Recorder can play sounds. If it
doesn't, the driver is not installed correctly.
* Make sure that your audio device is selected by using the
Output button in Device Controls Setup.
Cannot record sounds
* See above.
* Make sure your audio device/driver can record sounds.
* Sound may be in use by the output device; click on the stop
button.
Cannot use the stop or pause button
Oscilloscopes do not work
* The audio driver is synchronous. This means that Windows
(and GoldWave) loses control until the sound has finished
playing.
System freezes or crashes or a General Protection fault occurs
* Make sure that you have a 386 or better system. GoldWave
will not run on a 286 system.
* You may have encountered a problem. If you can duplicate
the problem, contact the author for more information.
Oscilloscopes / LEDs are out of synch
* Try using a different positioning method in the Device
Controls Setup dialog.
* Many audio drivers return inaccurate "current" positions.
Make sure you have the most up-to-date device driver.
Periodic popping or clicking while playing a pure sine wave
* Most audio devices/drivers make periodic pop/clicks between
DMA transfers and/or memory boundaries. It is most
noticeable when playing pure sine waves.
* Pops and clicks can occur at the beginning or ending of a
sound if the first or last sample is not 0 (silence).
Fading in/out a small selection can sometimes fix this.
Expression Evaluator slow
* Make sure that RAM storage is selected in Options | File.
Remember to reopen your sounds for the setting to apply.
* Your system does not have a co-processor.
Gaps in recording or dialogs do not appear
* Your system may be too slow to display the oscilloscopes.
Resize the Device Controls window so that the oscilloscopes
are hidden.
Sound won't play for more than a few seconds.
* Make sure your driver is configured to play for more than
few seconds. The PC-Speaker driver, for example, will play
for only 4 seconds unless you configure it to play longer.
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Common Questions and Answers
Can I edit individual samples with the mouse?
Yes, see Editing Overview, Direct Editing with the Mouse.
How can I improve recording quality?
Do not use disk compression (DriveSpace). Resize the Device
Controls window to hide the oscilloscopes. Increase the Record
buffer value in the Device Controls Setup. See Appendix A,
Problems with Recording section for more information.
Will there be any new versions?
Yes, version 3.20 is being planned. It will be a 32-bit Windows
95 application. If you have any suggestions, please pass them
along.
Have you written any other software?
Not yet, but I have several ideas.
Are there any plans to make a multilingual version?
The effort and resources needed to develop a multilingual version
is far too much for one person to handle. However, a French
version of GoldWave v2.12 is available from SYBEX France.
Can I play MOD files with GoldWave?
No, but you can extract the instrument samples. After you select
the file with File | Open, the Raw File Format dialog is
displayed. Set the attributes to 8-bit, mono, signed, 16000Hz,
no swap. By using the start/finish markers, you can extract the
individual instruments. Warning: do not save the MOD file within
GoldWave. GoldWave does not update the MOD header.
Can I convert sound files to MIDI?
No. MIDI files do not contain digital audio. They contain notes
and timing information for instruments. In other words, they
contain instructions for playing the music, but not the music
itself.
How are you?
Fine, thanks.
Why don't VOC files saved by GoldWave work with my Sound Blaster
software?
GoldWave uses version 1.20 of the VOC file format. You can save
your files in the old format (version 1.0) by using the File |
Save as command. GoldWave will use the old format if the file is
an 8-bit, mono file with a sampling rate less than 23000Hz. You
may have to use the Effects | Resample command to reduce the
sampling rate. You can convert the file by selecting
"VOC (*.voc)" and "8-bit mono unsigned" from the type and
attributes lists.
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