GoldWave™ 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 GoldWave™ 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 ------------------------------------ 46 ------------------------------------ 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) ------------------------------------ 47 ------------------------------------ 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 ------------------------------------ 48 ------------------------------------ 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. ------------------------------------ 49 ------------------------------------ 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. ------------------------------------ 50 ------------------------------------ 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) ------------------------------------ 51 ------------------------------------ Filters One of the easiest ways to create digital filters is to use Matlab™ (The Student Edition of Matlab, by The Math Works Inc., published by Prentice-Hall, ISBN 0-13-855974-0). It has many built-in commands that generate filter coefficients. The coefficients can then used in the Expression Evaluator 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 (¼ 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). ------------------------------------ 52 ------------------------------------ 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. ------------------------------------ 53 ------------------------------------ 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. ------------------------------------ 54 ------------------------------------ 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). ------------------------------------ 55 ------------------------------------