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1996-09-26
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GoldWaveÖ Manual
Copyright ⌐ 1993-1996 Chris S. Craig
September 1996
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. . . . . . . . . . . . . . . . . .5
Setup. . . . . . . . . . . . . . . . . . . . . . . . .6
Graph type. . . . . . . . . . . . . . . . . . . .6
Controls. . . . . . . . . . . . . . . . . . . . .6
Recording Options . . . . . . . . . . . . . . . .6
User play button. . . . . . . . . . . . . . . . .7
Positioning . . . . . . . . . . . . . . . . . . .7
Buffer options. . . . . . . . . . . . . . . . . .7
Save. . . . . . . . . . . . . . . . . . . . . . .8
Output and Input buttons. . . . . . . . . . . . .8
Playing Sounds . . . . . . . . . . . . . . . . . . . .8
Pausing Playback . . . . . . . . . . . . . . . . . . .8
Stopping Playback. . . . . . . . . . . . . . . . . . .9
Rewinding and Fast Forwarding. . . . . . . . . . . . .9
Recording Sounds . . . . . . . . . . . . . . . . . . .9
Volume and Balance Scroll Bar. . . . . . . . . . . . .9
Speed Scroll Bar . . . . . . . . . . . . . . . . . . 10
Editing Overview. . . . . . . . . . . . . . . . . . . . . 10
Selecting Part of a Sound. . . . . . . . . . . . . . 10
Direct Editing with the Mouse. . . . . . . . . . . . 11
Combining Audio Layers (Mixing). . . . . . . . . . . 11
Storage Overview. . . . . . . . . . . . . . . . . . . . . 12
Direct-to-Disk . . . . . . . . . . . . . . . . . . . 12
RAM. . . . . . . . . . . . . . . . . . . . . . . . . 12
Flash. . . . . . . . . . . . . . . . . . . . . . . . 12
Keyboard Overview . . . . . . . . . . . . . . . . . . . . 13
File Menu Commands. . . . . . . . . . . . . . . . . . . . 14
New. . . . . . . . . . . . . . . . . . . . . . . . . 14
Open and Supported File Types. . . . . . . . . . . . 14
Close. . . . . . . . . . . . . . . . . . . . . . . . 15
Save . . . . . . . . . . . . . . . . . . . . . . . . 16
Save as. . . . . . . . . . . . . . . . . . . . . . . 16
Exit . . . . . . . . . . . . . . . . . . . . . . . . 16
File History . . . . . . . . . . . . . . . . . . . . 16
Edit Menu Commands. . . . . . . . . . . . . . . . . . . . 17
Undo . . . . . . . . . . . . . . . . . . . . . . . . 17
Cut. . . . . . . . . . . . . . . . . . . . . . . . . 17
Copy . . . . . . . . . . . . . . . . . . . . . . . . 17
Paste new. . . . . . . . . . . . . . . . . . . . . . 18
Paste and Paste at . . . . . . . . . . . . . . . . . 18
Mix. . . . . . . . . . . . . . . . . . . . . . . . . 18
Delete . . . . . . . . . . . . . . . . . . . . . . . 19
Trim . . . . . . . . . . . . . . . . . . . . . . . . 19
Insert silence . . . . . . . . . . . . . . . . . . . 19
Select view. . . . . . . . . . . . . . . . . . . . . 20
Channel. . . . . . . . . . . . . . . . . . . . . . . 20
Deflash. . . . . . . . . . . . . . . . . . . . . . . 20
Effects Menu Commands . . . . . . . . . . . . . . . . . . 20
Special Controls for Effects . . . . . . . . . . . . 21
Presets . . . . . . . . . . . . . . . . . . . . 21
Shape Controls. . . . . . . . . . . . . . . . . 21
Distortion . . . . . . . . . . . . . . . . . . . . . 22
Doppler. . . . . . . . . . . . . . . . . . . . . . . 22
Echo . . . . . . . . . . . . . . . . . . . . . . . . 22
Exchange channels. . . . . . . . . . . . . . . . . . 23
Filter . . . . . . . . . . . . . . . . . . . . . . . 23
Noise gate. . . . . . . . . . . . . . . . . . . 23
Low/Highpass. . . . . . . . . . . . . . . . . . 23
Bandpass/stop . . . . . . . . . . . . . . . . . 24
Parametric EQ . . . . . . . . . . . . . . . . . 25
User defined. . . . . . . . . . . . . . . . . . 25
Flange . . . . . . . . . . . . . . . . . . . . . . . 26
Interpolate. . . . . . . . . . . . . . . . . . . . . 27
Invert . . . . . . . . . . . . . . . . . . . . . . . 27
Mechanize. . . . . . . . . . . . . . . . . . . . . . 27
Offset . . . . . . . . . . . . . . . . . . . . . . . 27
Pan. . . . . . . . . . . . . . . . . . . . . . . . . 28
Reverse. . . . . . . . . . . . . . . . . . . . . . . 28
Silence. . . . . . . . . . . . . . . . . . . . . . . 28
Volume . . . . . . . . . . . . . . . . . . . . . . . 28
Change. . . . . . . . . . . . . . . . . . . . . 28
Fade in . . . . . . . . . . . . . . . . . . . . 29
Fade out. . . . . . . . . . . . . . . . . . . . 29
Maximize (Normalize). . . . . . . . . . . . . . 29
Shape . . . . . . . . . . . . . . . . . . . . . 29
Playback rate. . . . . . . . . . . . . . . . . . . . 30
Resample . . . . . . . . . . . . . . . . . . . . . . 30
Transpose. . . . . . . . . . . . . . . . . . . . . . 30
View Menu Commands. . . . . . . . . . . . . . . . . . . . 31
All. . . . . . . . . . . . . . . . . . . . . . . . . 31
Selection. . . . . . . . . . . . . . . . . . . . . . 31
User . . . . . . . . . . . . . . . . . . . . . . . . 32
Other. . . . . . . . . . . . . . . . . . . . . . . . 32
Zoom 10:1 and 5:1. . . . . . . . . . . . . . . . . . 32
Zoom 1:1 . . . . . . . . . . . . . . . . . . . . . . 32
Zoom 1:10, 1:100, 1:1000 . . . . . . . . . . . . . . 32
Start and Finish . . . . . . . . . . . . . . . . . . 32
Tools Menu Commands . . . . . . . . . . . . . . . . . . . 33
Cue Points . . . . . . . . . . . . . . . . . . . . . 33
Expression evaluator . . . . . . . . . . . . . . . . 34
CD player. . . . . . . . . . . . . . . . . . . . . . 34
Volume controls. . . . . . . . . . . . . . . . . . . 34
Device Controls. . . . . . . . . . . . . . . . . . . 34
Options Menu Commands . . . . . . . . . . . . . . . . . . 35
Colours. . . . . . . . . . . . . . . . . . . . . . . 35
File . . . . . . . . . . . . . . . . . . . . . . . . 35
Sound files . . . . . . . . . . . . . . . . . . 35
Temporary . . . . . . . . . . . . . . . . . . . 35
Undo. . . . . . . . . . . . . . . . . . . . . . 35
Flash open. . . . . . . . . . . . . . . . . . . 35
Temporary storage . . . . . . . . . . . . . . . 36
Clipboard . . . . . . . . . . . . . . . . . . . 36
Window . . . . . . . . . . . . . . . . . . . . . . . 36
Main window size. . . . . . . . . . . . . . . . 36
Sound window size . . . . . . . . . . . . . . . 36
User zoom . . . . . . . . . . . . . . . . . . . 36
Window Menu Commands. . . . . . . . . . . . . . . . . . . 36
Help Menu Commands. . . . . . . . . . . . . . . . . . . . 37
4 General Information . . . . . . . . . . . . . . . . . . . . 39
Warranty, Trademarks, and Copyrights. . . . . . . . . . . 39
Support and Updates . . . . . . . . . . . . . . . . . . . 40
Appendix A: An Introduction to Digital Audio . . . . . . . . . 41
Digital Audio Attributes. . . . . . . . . . . . . . . . . 41
Problems with Recording . . . . . . . . . . . . . . . . . 43
Frequency Spectrums . . . . . . . . . . . . . . . . . . . 44
Appendix B: Expression Evaluator . . . . . . . . . . . . . . . 45
Overview. . . . . . . . . . . . . . . . . . . . . . . . . 45
Evaluation Range, Variables, and Constants. . . . . . . . 46
Using Time in an Expression. . . . . . . . . . . . . 46
Using the Sample Index in an Expression. . . . . . . 47
User Variable f. . . . . . . . . . . . . . . . . . . 48
Conversion Between Variables . . . . . . . . . . . . 48
Group name and Expression name. . . . . . . . . . . . . . 48
Valid Operators and Functions . . . . . . . . . . . . . . 50
Signal Generation . . . . . . . . . . . . . . . . . . . . 51
Filters . . . . . . . . . . . . . . . . . . . . . . . . . 52
Appendix C: Troubleshooting and Q&A. . . . . . . . . . . . . . 53
Troubleshooting . . . . . . . . . . . . . . . . . . . . . 53
Common Questions and Answers. . . . . . . . . . . . . . . 55
----------------------------------------------------------------------------
1 Introduction
GoldWaveÖ is a comprehensive digital audio editor that allows you to play,
record, edit, and convert audio on your computer.
Features
o 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.
o 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.
o A multiple document interface (MDI) allows many files to be
opened at one time, making file-to-file editing easy.
o 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 sampling rates, bit resolution, or number of channels,
intelligent editing simplifies the process.
o Huge files can be edited using hard disk editing. Small files
can be edited quickly using RAM based editing.
o 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).
o Many audio effects, such as Reverse, Echo, Pan, Flange, and
Distortion allow you to enhance, distort, or alter sounds in various
ways.
o 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.
o 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.
------------------------------------ 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.
Familiarity with the Windows 95 interface is recommend before reading this
manual.
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.
* A pointing hand emphasizes paragraphs containing helpful information and
techniques.
! An exclamation mark emphasizes warnings and other important
information.
------------------------------------ 2 ------------------------------------
2 Getting Started
System Requirements
The minimum system requirements for GoldWave are:
o 66MHz 486 or Pentium PC or compatible
o Microsoft« Windows« 95 or Windows NT 4.0
o 8 Megabytes of RAM (16MB recommended)
o 2 Megabytes of hard disk space
o Mouse
o Sound card with a 32-bit Windows software driver
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 95 sound driver using the "Add New Hardware" item under
Start | Settings | Control Panel. The driver and installation instructions
should be included with your sound card. The current settings for your
sound card are listed under Device Manager, which can be found by right
clicking the mouse pointer over the "My Computer" icon and selecting
Properties.
To add a GoldWave icon to your desktop, right click the mouse pointer on an
unused area of your desktop to display the pop up menu and select New |
Shortcut. Choose Browse, find and double click on goldwave.exe, then click
on Next. Type in "GoldWave" for the name of the shortcut, then click
Finish. To run GoldWave, either double click on the new GoldWave icon or
use the Start | Run command.
GoldWave allows you to choose which devices to use for input and output.
Choose the setup button on GoldWave's 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. The Input button presents a similar list, where you
can choose what device to use for recording.
------------------------------------ 3 ------------------------------------
The readme.txt file contains 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). Create a new folder called "GoldWave" (see Window 95 help
for more information about folders) and unzip the GoldWave zip file into
it.
Installation From the Deluxe Diskette
To install GoldWave from the deluxe diskette, simply copy all the files
from the diskette into a new GoldWave folder. To quickly copy all the
files using Windows Explorer, select the floppy disk drive from the list of
folders, choose Edit | Select All, then use the mouse to drag-and-drop the
list to the new folder on your hard disk.
------------------------------------ 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. It groups together and
manages all the Sound windows. The control bar buttons provide quick
access to many of the frequently used commands. The upper bar holds File,
Edit, and View commands, while the lower bar contains Effects and Tools
commands. 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 Sound window, including the sampling rate, length,
selected region, channels, and general file format information. By
clicking the mouse pointer over any status item that shows time, the unit
or format for that status item can be changed. If you click the mouse
pointer over the length item, for example, you will be presented with a
menu showing length in terms of storage size, time, and samples.
Sound windows 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" rectangle representing the entire sound 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 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.
Device Controls Overview
The Device Controls window 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. 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.
------------------------------------ 5 ------------------------------------
* 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 in the following
paragraphs.
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. Spectrum shows the sound as a
frequency spectrum. Spectrum bar displays a frequency bar graph
commonly found on stereo systems. 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 order of increasing magnitude, they are black,
purple, blue, cyan, green, yellow, red, and white.
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.
The Windowed check box enables or disables the use of a Hamming window
during FFT/spectrum processing. With windowing enabled, pure tones
such as sine waves generate a much cleaner spectrum. The Frames/s
box sets the number of times per second that the oscilloscopes are
updated. Values can range from 10 to 60 frames per second. If your
computer is not fast enough to redraw the oscilloscopes, GoldWave
automatically drops frames to reduce computer load.
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 plays the sound backwards three times
faster than regular playback speed. By entering small numbers (such
as 0.1) the rewind and fast forward buttons play very slowly. This is
useful for finding pops or clicks, since the oscilloscopes move slowly
through the data as well.
------------------------------------ 6 ------------------------------------
Recording Options
This group configures how recording should be performed. Monitor
input connects the input to the oscilloscopes and LED meters so you
can adjust input levels before recording. Loop keeps recording over
and over until the stop button is pressed. This is useful for
capturing quotes from a TV show or Freudian slips in a speech. By
loop recording a 1 minute sound, you will always have the last minute
of audio stored for editing. Countdown timer delays recording for the
number of seconds specified in the Time box. This gives you some time
to get ready after you start recording or lets you automatically
record something at a later time. The Level activated feature pauses
recording until the input is loud enough to record. The Threshold
specifies how loud a sound should be before recording begins.
Normally, this value should be small (less than 0.2). The Duration
specifies how long to record after the input becomes quiet again.
Note that entering a zero value causes recording to continue to the
end, nonstop. Level activated recording is quite useful for
synchronizing recording. For example, you can enable level activated
recording, press the record button, then start up the CD player and
play an audio CD (make sure you selected CD input for recording).
GoldWave automatically starts recording when CD playback begins.
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. With Unselected enabled, 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 played and looped.
Finally the end of the sound, outside the selection, is played. This
is useful for musical accompaniment or looped instrument samples.
Loop, which applies to all of the above options, specifies the number
of times playback should be repeated. A zero value loops forever.
Positioning
This group lists several methods for determining the device's current
position during playback and recording. 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. If you notice any synchronization problems, select a
different method.
Buffer options
The Triple buffering check box enables triple buffering (checked) or
double buffering (unchecked) for playback and recording. Buffering
acts as an moderator 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 Record and Playback boxes control the size of the buffers, in
seconds, to use for recording and playback. Three recording buffers
and three playback buffers are created. Increasing the buffer
------------------------------------ 7 ------------------------------------
size may reduce the number of gaps 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 slight delay before
playback.
Save
If Setup is checked, all the values in the Device Controls Setup
dialog will be saved. If Window position is checked, the position and
size of the Device Controls window will be saved.
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 only. The
user play button can play or loop the entire sound or certain parts of it.
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.
------------------------------------ 8 ------------------------------------
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. Note that recording is stopped using
a different button.
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 as 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 (purple) that
appears in place of the record button. The behaviour of the record button
can be configured using the Device Controls setup 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. Changing 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 it left to decrease
the volume. The current volume is shown numerically to the left of the
scroll bar. A value of 100 is full volume.
------------------------------------ 9 ------------------------------------
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.
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. 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).
o To move the start marker, click the left mouse button on the
graph at the point where you want to move it.
o 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:
o You cannot place the finish marker before the start marker. The
same is true for setting the start marker after the finish marker.
o 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.
o Individual channels of a stereo sound can be selected using the
Edit | Channel command.
------------------------------------ 10 ------------------------------------
o 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.
o 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. The
Options | File command has additional clipboard settings.
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). If the sound was flash
opened, you will need to use the Edit | Deflash command to prepare the
sound for editing.
1) Zoom in 2:1 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.
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 to finish the changes.
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 vocals.
2) Choose Copy from the Edit menu.
3) Open the sound containing the music.
4) Choose Mix from the Edit menu.
5) 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.
------------------------------------ 11 ------------------------------------
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 is 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 one second of the sound is
initially 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. In most cases, GoldWave will
automatically deflash the file for you.
A flashed file requires no extra 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.
------------------------------------ 12 ------------------------------------
Keyboard Overview
Table 1 summarizes keystrokes for GoldWave.
Table 1: Keystrokes
Keystroke Action
Ctrl+O Open a sound.
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+N Pastes clipboard into a new Sound window.
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.
Ctrl+M or 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 view to the end of the
sound.
Ctrl+Left, Ctrl+Right Move the start marker left or right.
Ctrl+Shift+Left
Ctrl+Shift+Right Move the finish marker left or right.
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).
Ctrl+F9, Ctrl+F8 Start and stop recording 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).
F1 Starts help.
Ctrl+F4 Close the Sound window.
Alt+F6 Switch between Main window and Device Controls
window.
Ctrl+F6 Switch between Sound windows.
------------------------------------ 13 ------------------------------------
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. For Web and Java applications, you should
specify 16-bits, mono, with a sampling rate of 8012Hz. For CD quality, use
16-bits, stereo, with a sampling rate of 44100Hz.
Open and Supported File Types
The Open command presents a list of files in your sound folder. The sound
folder 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 details about the sound are displayed in the status bar.
------------------------------------ 14 ------------------------------------
GoldWave supports all the sound types listed in Table 2.
Table 2: Supported File Types
Extension Comments
.au Sun or NeXT files. Supports 8 & 16-bit linear and u-law
encoded files. The header block is preserved.
.aif
.afc Apple / Macintosh sound files. The blocks NAME, COPY, ANNO,
AUTH, and CHAN are all preserved. Compressed files are not
supported. Markers are not supported.
.dwd DiamondWare sound files. Supports 8 & 16 bit PCM attributes.
.iff Amiga 8SVX files. The blocks NAME, COPY, ANNO, AUTH, and
CHAN are all preserved.
.mat Matlab files. 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, u-law, or A-law format.
.sds MIDI sample dump standard format. Loop points are not
supported.
.smp Sample Vision 16-bit PCM sound files. Markers/Loops are not
supported.
.snd Raw or NeXT files. NeXT files are automatically detected.
Raw files present the Raw File Format dialog for attributes.
.wav This includes RIFF WAVE 8 & 16-bit PCM mono or stereo, A-law
encoded, u-law encoded, and Microsoft ACM 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. Supports: 8-bit mono/stereo, 16-bit
mono/stereo, u-law encoded mono/stereo. ADPCM compressed
files are not supported since the compression algorithm must
be licensed from Creative Labs.
.vox Dialogic ADPCM encoded raw files. The Raw File Format
dialog is presented where you can specify the VOX format.
GoldWave presents the Raw File Format dialog if the file is corrupted,
unrecognized, or contains data without header information (often referred
to as 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.
Close
Use Close to close the current sound. If it has been modified, you will be
asked to save changes.
------------------------------------ 15 ------------------------------------
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 or 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 as type list box and select attributes from the
Attributes list box. Since each file type supports different attributes,
always select the type before selecting attributes. Java and Web sounds,
for example, should be saved using the "Sun (*.au)" type and the "Java/Web"
attribute.
! Note that just typing in a different extension for the filename does
not convert the sound to the type associated with the extension. The
extension must be selected from the type list box.
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.
------------------------------------ 16 ------------------------------------
Edit Menu Commands
These commands allow you to remove, insert, copy, and move sections of
sound. For an introduction to the concepts and terms discussed in this
section, refer to 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 folder
specified by the Options | File command.
Since the undo feature copies large amounts of data, you will notice a
delay before each modification. It can be disabled using the Options |
File command and unchecking the Undo box.
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).
* If you want to remove a section of sound and not put it in the
clipboard, you should use the Delete command since it is quicker.
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.
------------------------------------ 17 ------------------------------------
Paste new
Creates a new Sound window containing the sound copied into the clipboard.
The new sound will have the attributes and length of the clipboard sound.
This command is useful when you need to save part of a sound to a new file.
To paste part of a sound into a new sound:
1) Move the start marker 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.
3) Choose Paste new from the Edit menu or click on the PNew button.
Paste and Paste at
After copying a sound into the clipboard, you can use these commands to
insert it into another sound. Paste inserts the clipboard at the start
marker's position. Paste at inserts the clipboard 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.
------------------------------------ 18 ------------------------------------
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.
Trim
Trim permanently removes everything outside the selection. The selection
is not affected. Use this command to keep a section of sound and discard
everything else. 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 silence 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 Silen button.
------------------------------------ 19 ------------------------------------
Select view
Use Select view to select all of the sound currently shown in the Sound
window's graph. 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,
Playback rate, Pan, Exchange channels, and Doppler, the channel setting has
no effect and both the left and right channels will be modified.
Deflash
Usually a flashed file will be deflashed automatically. If you are trying
to play a compressed file on a slow system or to 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
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. For an
introduction to some of the terms discussed in this section, refer to the
Editing Overview section.
------------------------------------ 20 ------------------------------------
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.
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.
------------------------------------ 21 ------------------------------------
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.
Doppler
The Doppler effect is defined as a change in frequency of a wave caused by
motion. It is often heard during auto racing when a fast car passes in
front of you. The pitch of the engine appears to drop 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.
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.
------------------------------------ 22 ------------------------------------
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 preferred.
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.
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.
Low/Highpass
Lowpass filters block high pitched frequencies (treble), but allow low
pitched frequencies (bass) to pass. They can be used to reduce high
end hiss noise or remove unwanted sounds above the given cutoff
frequency. If you were to apply a lowpass filter with a cutoff
frequency of 1000Hz on speech, it would make it sound mumbled and
deep. Lowpass filters can also be used to eliminate aliasing when
used before downsampling.
------------------------------------ 23 ------------------------------------
Highpass filters block low pitch frequencies, but allow high
pitched frequencies to pass. They can remove deep rumbling noise or
remove unwanted sounds below the given cutoff frequency. If you were
to apply a highpass filter with a cutoff frequency of 1000Hz on
speech, it would make it sound thin and hollow.
Cutoff frequency
The Initial box specifies the constant cutoff frequency for
static filtering. If the Dynamic option is selected (see below),
then a final cutoff frequency can be given in the Final box.
Filter options
Select Lowpass if you want to keep only the frequencies below the
cutoff frequency. Select Highpass if you want to keep only the
frequencies above the cutoff frequency.
If you want the cutoff frequency to remain constant throughout
the selection during processing, select the Static option. If
you want the cutoff frequency to change from the initial value to
the final value, select the Dynamic option. Note that dynamic
filtering will take more processing time.
The Steepness value specifies how sharply the filter cuts off
frequencies outside the cutoff frequency. A higher steepness
makes the filter sharper, but it also increases processing time.
In technical terms, the steepness specifies the number of second
order cascade filters used.
Examples
To make speech gradually become more hollow and thin:
1) Enter 60 in the Initial box.
2) Choose Dynamic.
3) Enter 1000 in the Final box.
4) Choose Highpass.
5) Choose OK.
Filtering before downsampling from 44100Hz to 22050Hz:
1) Enter 11025 in the Initial box.
2) Choose Lowpass.
3) Choose Static.
4) Enter 20 in the Steepness box.
5) Choose OK.
Bandpass/stop
Bandpass filters block all frequencies outside the specified range,
keeping only frequencies within the range.
------------------------------------ 24 ------------------------------------
Bandstop filters block all frequencies within the specified
range, keeping all other frequencies outside the range.
Frequency range
The From and To boxes specify the frequency range of the filter.
If the Dynamic option is selected, then a final frequency range
can be given in the other From and To boxes.
Filter options
Select Bandpass if you want to keep only the frequencies within
the range. Select Bandstop if you want to keep only the
frequencies outside the range.
The remaining options are explained above under Low/Highpass
filters.
Parametric EQ
A parametric equalizer is a flexible tool for reducing or enhancing
ranges of frequencies. GoldWave presents an easy to use interface
where all the parameters for up to 30 band can be configured quickly.
The Presets contain some commonly used settings.
Graph window
The graph shows frequency on the x-axis in hertz and the gain on
the y-axis in decibels. Each enabled band is displayed in the
graph as a diamond shaped box located at its center frequency and
gain. The width of the box shows the bandwidth. The currently
selected band is shown in blue and its exact settings are shown
by the scroll bars.
Controls
A band can be configured by selecting its number from the Select
band box and adjusting the scroll bars. A quicker way is to
drag-and-drop the band to a new location on the graph. Note that
because of the logarithmic frequency scale, the width of a
diamond changes as you move it left or right. The bandwidth,
however, remains constant.
Any unneeded can be disabled by unchecking the Enabled box.
Disabling unused bands improves processing speed.
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)
------------------------------------ 25 ------------------------------------
For speed, fixed point calculations are used. Coefficients can be
floating point values with magnitudes from 0.0001 to 200. 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 detailed knowledge of digital
filter theory, which is beyond the scope of this manual. A brief
introduction is provided in Appendix B.
Flange
A flanging effect is similar to an echo effect in that the original sound
can be mixed with a delayed copy of itself. Unlike an echo, where the
delay is constant, flanging varies the delay over a specified range or
depth. The speed, or frequency, at which the delay varies also can be
controlled. In GoldWave, the Flange effect presents a dialog where you can
set the depth, frequency, and fixed delay parameters and define how the
sound should be mixed. Several presets are included to demonstrate the
kinds of unusual audio effects that are possible with flanging.
The Input volume specifies the volume of the original sound to mix with the
final sound. A value of 0 means the original sound will not be mixed with
the final sound. If this value is set to 100 and all other volumes are 0,
no change will be made to the sound. The Mix volume specifies the volume
of the flanged (delayed) sound to mix with the final sound. Usually, this
value should be in the range of 50 to 100. Feedback specifies the level of
feedback to mix with the final sound. This makes the effect sound more
pronounced. Set this value to 0 if you do not want any feedback. Invert
check boxes determine whether a sound is added or subtracted when mixed.
Inverted sounds are subtracted.
Depth specifies the maximum delay in milliseconds. A value of 40 will
allow the delay to vary from 0 to 40 milliseconds. Frequency specifies how
fast to vary the delay. A value of 2 will vary the delay over its
------------------------------------ 26 ------------------------------------
depth twice a second. For a value of 0.2, the full delay depth is reached
every five seconds. The Fixed delay is added to the depth to change the
minimum delay. If the depth is 40 and the fixed delay is 10, the delay
will vary from 10 to 50 milliseconds.
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 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.
------------------------------------ 27 ------------------------------------
* You should check the offset from time to time after processing effects.
Otherwise, the offset may increase with each effect, resulting in
distortion.
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.
Reverse
This command reverses the selection so that it plays backward. Now you
have an easy way to listen to all those "satanic verses". You can play a
sound backwards by using the rewind button on the Device Controls window as
well.
Silence
The Silence command 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.
* To convert gain (in dB) to a percentage, you would use the formula:
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.
------------------------------------ 28 ------------------------------------
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.
------------------------------------ 29 ------------------------------------
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" as the new pitch, you can shift the pitch
up one octave. Fine tune lets you make a slight pitch adjustment.
------------------------------------ 30 ------------------------------------
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 see a more detailed graph of part of the sound.
They are similar to zoom commands in the Windows Paint accessory. 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.
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.
* Note that if a file is flash opened, only one 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. You can
zoom in many times by changing the selection and magnifying it again until
only a single sample is shown in the view.
------------------------------------ 31 ------------------------------------
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 in the box. 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, 1:100, 1:1000
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 view will be centered over the marker's position 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. For example, you can zoom in 1:1 and move the start
marker to an exact position and then use View | Finish to set the finish
marker's position.
------------------------------------ 32 ------------------------------------
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.
7) Choose OK.
------------------------------------ 33 ------------------------------------
* 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
If you installed the CD player bundled with Windows 95, you can use this
command to start it. Note that the command will not be enabled if the CD
player is not installed. For information about using or installing the CD
player, please refer to Windows 95 help.
Volume controls
This command will starts the Volume Control accessory, if it is installed
on your system. If this accessory is not installed, the command is
disabled. The accessory initially shows volumes for output devices. To
show input volumes, use Options | Properties on the menu, choose the
Recording radio button, and make sure that the inputs you want to use are
checked in the bottom list. After choosing OK, recording inputs can be
selected and adjusted. For information about using or installing Volume
Controls, please refer to Windows 95 help.
Device Controls
The Device Controls window is discussed in the Device Controls Overview
section.
------------------------------------ 34 ------------------------------------
Options Menu Commands
Colours
Use this command to change the colour scheme of Sound windows. The
Preview box shows the Sound's current colour scheme. The Colour Settings
group allow you to make changes. To set the colour of a particular item,
select the item from the drop-down list or click on the item in the Preview
box. Once the item is selected, you can change its colour by clicking on
one of the colour boxes.
File
The File Options dialog lets you setup folders and file storage options.
This sections assumes you are familiar with the terms introduced in the
Storage Overview section.
Sound files
This specifies the folder where you keep your sound files. The File |
Open command automatically lists files in this folder whenever you
start GoldWave. If you prefer to use the Windows 95 Properties
feature to specify a working folder, enter a period, ".", for this
folder.
Temporary
This specifies the folder to use when creating temporary files. This
folder 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 folder does not affect opened files already in temporary
storage.
Undo
Undo specifies the folder to use for storing undo data. In most
cases, it should be the same as the temporary folder. Changing the
undo folder 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.
------------------------------------ 35 ------------------------------------
Temporary storage
This specifies where files should be stored for processing. RAM
storage is usually very fast, but limits the size of files. Hard disk
is slower, but allow huge files to be processed. Changing this
options does not affect files already opened.
Clipboard
Due to size limitations in the standard Windows clipboard, copying
large sounds can cause some problems. If you encounter any unusual
behaviour or you frequently work with large files (20 megabytes or
more), choose GoldWave to use GoldWave's special clipboard. If you
edit small files and need to copy and paste between different
applications, choose Windows to use the standard clipboard. Technical
note: Normally GoldWave automatically uses an appropriate clipboard,
but recent developments have shown unreliability in the standard
clipboard, making this manual option necessary.
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.
Sound 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. Smaller values
show more detail. Larger values show more of the sound.
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.
------------------------------------ 36 ------------------------------------
Arrange icons arranges minimized Sound window 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 Help 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.
------------------------------------ 37 ------------------------------------
------------------------------------ 38 ------------------------------------
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.DOC Order form
README.TXT Important notes/information
WHATSNEW.TXT A list of new features
BWCC32.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 ⌐ 1993-1996 by Chris S.
Craig. All rights reserved.
Borland is a registered trademark of Borland International Incorporated.
GoldWave is a trademark of Chris S. Craig.
Matlab is a trademark of The Math Works Incorporated.
Windows and Microsoft are registered trademarks of Microsoft Corporation.
Sound Blaster is a trademark of Creative Labs Incorporated.
All other trademarks/registered names acknowledged.
------------------------------------ 39 ------------------------------------
Support and Updates
The latest information and updates can be found on the GoldWave World Wide
Web home page:
http://www.cs.mun.ca/~chris3/goldwave
If you encounter any problems, please check the following information:
o Appendix C: Troubleshooting and Q&A
o 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
------------------------------------ 40 ------------------------------------
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 (1/seconds, 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. 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.
------------------------------------ 41 ------------------------------------
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
------------------------------------ 42 ------------------------------------
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 or new tones that never existed in the original sound.
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. 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.
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.
------------------------------------ 43 ------------------------------------
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.
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).
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 or stop
controls from working. If you notice such behaviour, you should reduce the
frames/s value under Device Controls Setup or resize the Device Controls
window to so that the oscilloscopes are hidden.
------------------------------------ 44 ------------------------------------
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. In most cases, expressions will be some
function of n or t, just as in regular math, where y is usually a function
of x (i.e. y = f(x)). In the expression evaluator, we can have destination
= f(t), where f(t) is any expression you enter.
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. Since the evaluation process takes time, you can
------------------------------------ 45 ------------------------------------
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. By creating a new mono sound with a low sampling
rate (11025Hz), you can experiment with expressions quicker. You
can then create a sound with a higher sampling rate for the final
evaluation.
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. 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.
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 marker's 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
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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 multiply 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). 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
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)
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Care must be taken 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.
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 folder.
Similar expressions can be stored together in groups. The Group
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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.
Note that you can play the file during evaluation.
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 MatlabÖ (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 or the user defined filter command.
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 (╝ 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: Troubleshooting 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. CD
quality sound requires 10MB per minute and 30MB per minute when
editing.
Cannot play sounds
- GoldWave or audio device/driver is incorrectly installed. Make sure
an audio driver is installed in the Device Manager or use the Control
Panel "Add New Hardware" option to install a driver.
- Check that the Windows Sound Recorder accessory 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 or oscilloscopes do not work
- The audio driver is synchronous. This means that Windows (and
GoldWave) loses control until the sound has finished playing.
- Your system may not be fast enough to draw the oscilloscopes. Try
reducing the frames/s rate in Device Controls Setup or resize the
Device Controls window so that the oscilloscopes are hidden.
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. A Pentium system is recommended.
- If the system freezes after copying a large file, choose "GoldWave" as
the clipboard under Options | File.
- You may have encountered a problem. If you can duplicate the problem,
contact the author for more information.
After a crash, there is less free space on the hard disk
- Delete files in the temporary storage folder specified under
Options | File. These files usually have name like gw0.$$$.
Oscilloscopes / LEDs are out of synch
- Try using a different positioning method in Device Controls Setup.
- 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 close and reopen your sounds for this setting to apply.
- Your system does not have a co-processor.
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Problem
Cause/Solution
Editing seems to be getting slower and disk activity is increasing
- Files on your hard disk are becoming fragmented. Use the Windows
Disk Defragmenter system tool.
Distortion in recording
- You need to lower the input/recording volumes. On some sound cards,
adjusting the volume for your speakers/headphones does not alter
recording volume. See Tools | Volume control for information
about selecting and controlling recording volume.
- Check that all connections are correct and firm (do not connect a
"line-out" to "mic-in", for example).
Gaps in recording/playback or dialogs slow to 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, a new version is being planned. If you have any suggestions, please
pass them along.
Have you written any other software?
A multitrack editor is currently under development.
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.
How do I record from the CD player?
You need to select the CD-ROM as the input to your sound card. This is
accomplished by using the Volume Control accessory (see Tools | Volume
control).
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