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OS/2 Help File
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1994-08-21
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86KB
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1,732 lines
ΓòÉΓòÉΓòÉ 1. Introduction ΓòÉΓòÉΓòÉ
PMsndX 1.0
by
William S. Hiles
copyright WiSHware Inc.
First off, what is PMsndX? PMsndX is the acronym that I created to mean
Presentation Manager sound eXchange. PMsndX was written specifically for OS/2
to provide an editor for sound samples of many different formats. The editor
goes beyond just a cut and paste tool like the Digital Audio applet provided
with OS/2 by providing a rich set of tools for manipulating samples in memory.
PMsndX utilizes a large set of features of OS/2 and if present, the MMPM/2
interface is used to allow playback of any of the supported formats from
memory.
Using dialog boxes, PMsndX provides an intuitive user interface for utilizing
the clipboard, MMPM/2 playback, and algorithms for adding special effects to
samples. Everything is integrated together to make it easy to manage the
process of extracting or building samples in many different formats.
Wow, you are still reading! Well, now for some information on the user
interface. There is nothing more frustrating than trying to use a program with
a difficult or complex user interface. Twelve years ago I started programming
a TI99/4A in assembly language and from the start I have put more effort into a
clean user interface than anything. It wasn't till I ran across JOEVIEW that I
realized that OS/2 had one of the most capable environments that I had seen.
Presentation Manager programming has got to be one of the easiest environments
to use and is a breeze compared to Microsoft Windows or the X environment.
In any case, I spent more time on the user interface of this program than I
ever thought possible. It is designed around a single coordinating window
populated by bitmaps. Each bitmap has some sort of image that changes when the
button is pushed. To make sure that the literate people out there (or the icon
impaired) understand the buttons, I put a bit of text on them to describe the
function.
Now, I have used programs on a lot of platforms and I have my favorites along
with those that annoy me too. My pet peeves are the applications like Procomm
for Windows which just assumes that you want the darn thing to fill up your
screen. Or something like Microsoft Word which has so many menus and submenus
that it is hard to remember where a function is. So, taking this into account,
I designed the interface such that the main functions of the program are
accessible from the main panel. Pressing the button for the function will then
bring up a dialog box which asks the user for the necessary information.
Pushing the button again will remove the dialog box. I prefer this interface
because it provides a single point of control. Well, you just need to play
with it for a bit to get an understanding of what I am talking about here.
ΓòÉΓòÉΓòÉ 2. Conventions ΓòÉΓòÉΓòÉ
Throughout the documentation provided with PMsndX a number of terms are used
which may be common to Presentation Manager programs but uncommon to
conversational English. There are also terms which are specific to PMsndX
which may be new to a user of this program. The intent of this section is not
to recreate the OS/2 documentation; rather, it is intended to identify some
basic terms necessary to understand the language used in this documentation.
Presentation Manager:
The Presentation Manager is the Graphical User Interface (GUI) for most OS/2
systems. There are other GUIs available for OS/2 but this is the most
common and the one that comes with OS/2 out of the box. In general most
people refer to the Presentation Manager by the acronym PM.
SYSTEM MENU:
Every PM program for OS/2 generally provides a SYSTEM MENU through an icon
in the upper left corner of the window interface to the user. By default,
the system menu will contain the basic functions necessary to control the
window for on the OS/2 PM desktop.
TITLE BAR:
In order for a window to be moved about the desktop with the mouse, a window
must have a titlebar. This is the thick bar at the top of the window. The
titlebar provides another function in that it allows the program to display
relevant messages to the user.
MINIMIZE BUTTON:
A PM program may provide various control buttons for a window in the top
right corner of a window. One of these buttons is the MINIMIZE button. When
the user selects this button, the window will be removed from the desktop
and replaced by a small icon somewhere on the screen. In most cases, the
icon is placed at the bottom of the screen. To restore the window the user
can double click on the icon or can use a mouse button to bring up a menu
and select Restore.
MAIN CONTROL PANEL:
The main control panel for PMsndX is the window that is initially displayed
when the program is executed. This window is the main point of control for
the program and provides access to all of the above mentioned controls as
well as access to all of the functions of the program.
ACCELERATOR KEYS:
The buttons on the main control panel and many of the controls in the
associated tools provide accelerator keys. These are marked on the displays
by an underline. To access the particular item without using the mouse,
hold down the ALT key and press the underlined key. As an example, to
activate the OPEN button on the main control panel, hold down the ALT key
and press the letter o.
ΓòÉΓòÉΓòÉ 3. Mouse Pointer ΓòÉΓòÉΓòÉ
The mouse pointer is used as an indication of the state of the program. When
the program is processing, the mouse pointer will be changed to a small dial
with 10 markers on the dial. The percentage of work completed is then
indicated by the hand of the dial. When the dial reaches the vertical
position, the work has been completed.
There is one exception to this operation. When the echo effect is used, the
dial for the pointer will rotate more than once. This is because the results of
the echo effect change the length of the data depending on the markers and
volumes such that the resulting length is unpredictable.
PMsndX uses multiple threads to accomplish many of its tasks. As a result,
when a file is loaded the clock may turn more than once because each thread
will run as the resources that it is waiting on complete. An example of this
is opening a file when the playback box is open. In this case, as soon as the
file is completely loaded, the playback task will immediately start copying it
to the buffer for the playlist and the clock will turn around a second time.
ΓòÉΓòÉΓòÉ 4. System Menu ΓòÉΓòÉΓòÉ
As with any OS/2 program written for the Presentation Manager, PMsndX has an
icon in the top left corner of the control window. Pressing this icon will
bring up a menu of system operations.
The menu items provided in the system menu are:
Restore Restore the windows after being minimized
Move Move the control window
Minimize Minimize all of the windows of PMsndX to an icon
Close Close the all windows and exit
About Display information about the author and version and
registration
Welcome Display information about what is new to this version
Help Bring up the help system
Reset Size Reset the size of the main control panel to the default
ΓòÉΓòÉΓòÉ 4.1. Restore ΓòÉΓòÉΓòÉ
During the use of PMsndX, the user may select to Minimize the windows to an
icon on the desktop. To restore the window from the icon the user may either
double click on the icon or may press a mouse button while the pointer is over
the icon to bring up the system menu and select the restore item.
ΓòÉΓòÉΓòÉ 4.2. Move ΓòÉΓòÉΓòÉ
PMsndX provides the standard controls for moving the windows around on the
desktop. It is generally easiest to use the mouse to select the titlebar of
the window and drag the window to the new location. If the user uses the
system menu to move the window, the mouse will be centered in the control
window and any movement of the mouse will move the window until a mouse button
is pressed.
ΓòÉΓòÉΓòÉ 4.3. Minimize ΓòÉΓòÉΓòÉ
All of the windows of PMsndX can be minimized quickly by either selecting the
minimize button on the upper right corner of the control panel or by using the
Minimize menu item of the system menu. Either action performs the same
function.
ΓòÉΓòÉΓòÉ 4.4. Close ΓòÉΓòÉΓòÉ
To exit PMsndX the user can select the Close menu item from the system menu.
This is the default selection of the menu which enables the user to double
click on the PMsndX icon in the top left corner of the control panel to exit
the program. The user may also use the Exit button on the control panel to
perform the same function.
ΓòÉΓòÉΓòÉ 4.5. About ΓòÉΓòÉΓòÉ
To find out the current version and other information about PMsndX the About
menu item can be selected from the system menu. This display also shows the
current registration status of the program and the registration can be updated
by pressing the REGISTER button.
PMsndX is just one of the programs written by the Author for Intel based
machines. All programs developed under the WiSHware Inc. name have been
developed solely by the author (duhh, the Author is the sole member of the
company) and are copyrighted by US Copyright laws.
ΓòÉΓòÉΓòÉ 4.6. Welcome ΓòÉΓòÉΓòÉ
The HISTORY.TXT file contains a very complete list of all the changes between
each of the versions. When viewed as a whole, it also summarizes the total
functionality of PMsndX. Each version has specific changes which are
highlighted in the Welcome display. This display also shows the current
registration status of the program and the registration can be updated by
pressing the REGISTER button.
ΓòÉΓòÉΓòÉ 4.7. Help ΓòÉΓòÉΓòÉ
Selecting this option from the system menu performs the same function as
pressing the Help button on the main control panel. This brings up the online
help system for PMsndX.
ΓòÉΓòÉΓòÉ 4.8. Reset Size ΓòÉΓòÉΓòÉ
The default button size for the display is 64x64. At any time, the user may
select to reset the size of the main control panel so that it returns to the
defaults. The main control panel may be resized, using the border of the
window.
ΓòÉΓòÉΓòÉ 5. Resizing the main panel ΓòÉΓòÉΓòÉ
In accordance with the recommended Common User Access (CUA) guidelines, the
main control panel may be resized using the border of the window. The
horizontal and vertical proportions of the buttons is always fixed such that
the overall window proportions will display the buttons properly. When the
width of the main panel is changed, the height is automatically adjusted to
maintain the proper shape of the buttons.
Note: Note. To resize the window, either the corners or the vertical sides of
the window must be used. The horizontal sides of the window have no
effect when used alone.
ΓòÉΓòÉΓòÉ 6. Buttons ΓòÉΓòÉΓòÉ
The main control panel provides the user with access to all tools and functions
trough a set of buttons. Each button contains an icon and a single word which
describes the function of the button. The buttons have been designed as toggle
type push buttons. To select a particular button, the mouse must be positioned
over the button and the first mouse button pressed. This will depress the
button and activate a dialog for the desired function. The dialogs present
information to the user about the desired operation and request input from the
user to complete the operation.
The control panel is the main point of control for both activating and
deactivating a particular function. The dialog boxes can be removed from the
screen by positioning the mouse over a depressed button and pressing the first
mouse button. The dialog box will be removed and the button will return to the
non-depressed position. It is important to note that when a dialog box is
removed through this means, any information in the dialog is ignored and the
function is canceled. For each dialog box, the user must enter all of the
information required and then select the appropriate action on the push buttons
at the bottom of the dialog box. The Open and Save Dialog boxes may also be
removed once the file operation has been completed. This is the default
operation but may be changed so that the dialogs are not automatically
dismissed by deselecting the "AUTO Dismiss" box in the lower right corner of
the dialog window.
Now for the buttons. There are six buttons on the main control panel. These
are listed below with a brief explanation of their function.
Opens and reads a new sample file
Saves the current sample to a file
Plays the current sample to an audio device
Edit using the Clipboard
Displays options to save between sessions
Displays a notebook of tools
Displays general help about PMsndX
Exit PMsndX
ΓòÉΓòÉΓòÉ 6.1. Open ΓòÉΓòÉΓòÉ
The dialog box for opening a file and reading the sample into memory is
accessed from the OPEN button on the main control panel. When reading in a
file, PMsndX will attempt to open the file as the type indicated by the
extension on the filename. However, in the event that the file cannot be
loaded by the extension, PMsndX will automatically try to determine the type of
the file as it reads it. If the sample header does not match any of the known
header types, PMsndX will refuse to load the file.
When loading a file, the user may select to force PMsndX to load a file in a
specific format. This is required to load headerless formats (i.e. the formats
marked as RAW). To override the file format, select one of the buttons in the
Format box.
Note: If a Format override is specified, the file must still match the given
format if it contains a header. PMsndX will automatically recognize the
header format and load it using the correct format.
Once a file has been selected, either double click on the file name or press
the Load button. During the time that the file is being loaded, the user may
press the Abort button to stop the loading process. All data which may have
previously been loaded will be discarded.
The File Type pulldown box works in combination with the File EA pulldown box.
To select all files of a particular type based on the name of the file (e.g.
*.wav, *.au, *.iff, etc.) first select the name extension from the File Type
pulldown list, and then select <All Files> from the File EA pulldown list.
By default, the OPEN dialog box is automatically dismissed when the file has
been loaded. If an error occurs during the loading process, the dialog will
not automatically dismiss itself. To disable this feature (i.e. force the
dialog box to remain visible even after a file has been loaded) deselect the
AUTO Dismiss checkbox in the lower right corner of the window.
ΓòÉΓòÉΓòÉ 6.2. Save ΓòÉΓòÉΓòÉ
The dialog box for saving a file to disk is accessed from the SAVE button on
the main control panel. When saving a file, the extension of the file will
automatically determine the type of output to write for the file (e.g. if the
extension entered by the user is .wav, then the file will be saved in WAVE
format.) or the user may override the file type by selecting one of the buttons
for the type of file.
When saving a file, the extension of the file normally determines the format to
save the file in. The primary use of this feature will be to promote the use
of standard file name extensions for the various sample types. However, the
user may specify that the information is stored in a particular format
regardless of the file extension. In the event that no extension is specified
for the file, the PMsndX will automatically save the file under the specified
name under the format currently selected in the FORMAT field. The available
formats for file operations are listed below. If the file type of Undefined is
selected, then the extension of the file will be used to determine the file
type.
APPLE (.aif) Apple 8/16 bit unsigned multi-channel samples
SUN (.au) Sun/DEC/NeXT 8 or 16 bit single channel signed data samples or 8
bit ULaw samples.
MAC (.hcm) Apple Macintosh 8 bit single channel samples
RAW (.ub) Raw 8 bit single channel unsigned samples without header
information.
RAW (.sb) Raw 8 bit single channel signed samples without header
information.
RAW (.uw) Raw 16 bit single channel unsigned samples without header
information.
RAW (.sw) Raw 16 bit single channel signed samples without header
information.
RAW (.ul) Raw 16 bit U-Law single channel samples
IRACAM (.sf) Software produced 16 bit signed samples.
PC (.voc) Creative Voice file format, 8 bit single channel unsigned
samples
SAMP (.smp) Turtle beach samplevision files.
PC (.wav) Windows or OS/2 8 bit unsigned/16 bit signed multi-channel data
samples
The Save Directory checkbox allows the user to save the current save path
between sessions without having to open the Settings dialog box. when this box
is selected, if the OK button is selected, the specified directory path will be
saved when the program has is terminated. If the SAVE DIRECTORY is deselected
before the program is terminated, the path will not be saved. All file paths
are remembered during each session and the SAVE DIRECTORY box allows the user
to store this path between sessions.
Note: The file path is not saved until the program has been terminated.
By default, the SAVE dialog box is automatically dismissed when the file has
been loaded. If an error occurs during the loading process, the dialog will
not automatically dismiss itself. To disable this feature (i.e. force the
dialog box to remain visible even after a file has been loaded) deselect the
AUTO Dismiss checkbox in the lower right corner of the window.
ΓòÉΓòÉΓòÉ 6.3. Playback ΓòÉΓòÉΓòÉ
So, you are interested in playing some samples from my little program? Good.
The ability to play a sample is not intended to provide the full capabilities
of the digital audio player. It is intended to allow samples to be played
without having to save them to disk. Additionally, this feature allows the
user to play a file of any format currently supported by PMsndX. The sample
rates are limited to those supported by the audio device and if a sample is
loaded with an odd sample rate which is not supported, it must be converted to
a useable sample rate before it can be played.
Note: Whenever a sample is loaded and the PLAYBACK dialog is open, PMsndX will
attempt to load the audio buffers with the sound data. If the sample
cannot be played (the number of channels or the sampling rate is not
supported by the audio adapter) a warning is displayed. PMsndX will not
attempt to play a file that the audio adapter does not support.
If you don't have MMPM/2 installed with your OS/2, don't worry. PMsndX has
been written to provide as much of its capabilities as it can with or without
MMPM/2 installed. None of the tools, nor the editor require MMPM/2 to perform.
However, the playback button will be marked out if MMPM/2 is not installed
because there will be no means to play the sounds.
When the playback button is pressed, a dialog box is opened which contains a
set of standard controls for playing sounds. A checkbox is provided to allow
the samples to automatically repeat when the end of the playback is reached.
The controls for the playback player are basically the same as those used on
the digital audio player provided with the MMPM/2 package for OS/2.
Starts or continues playback.
Starts recording.
Stops playback.
Pauses playback.
Note: Recording has not been implemented at this time.
The Playback dialog provides a checkbox to allow a sample to be looped such
that it will continuously repeat. When this checkbox is selected, the repeat
function is enabled. Playback can be stopped by deselecting the repeat checkbox
(in which case, the sample will complete playback befor stopping) or by
pressing the button.
The Playback dialog also has the capability of playing a selected range and/or
a selected channel. If the edit dialog is active, the range and channels for
manipulation may be used to select the part of a sample to be played. When the
Use Channel Selection box is selected, the selected channel will be played.
This allows the user to extract and play individual channels. Similarly, when
the Use Range Selection box is selected, the specified range in the editor will
be played.
Note: If the edit dialog window is not open, the full sample (including all
channels) is automatically used.
ΓòÉΓòÉΓòÉ 6.4. Edit ΓòÉΓòÉΓòÉ
The editor is designed to be compatible with the format of data pasted to the
clipboard using the OS/2 Digital Audio Application to allow bi-directional use
of the clipboard between the two applications. To describe the use of the
editor each of the categories of controls will be described. Most are very
obvious, but some (particularly the operation buttons) have rules of
operation).
The editor is the central point of control for selecting the range and channels
for all operations. As a result, when an operation is being performed (as
indicated by the mouse pointer displayed as a clock face) if the range is
changed or the channel to manipulate is changed, a warning beep will be
produced; however, the display will indicate that the selection has been made.
For the editor, the change will be made, but the rest of the tools and playback
will not be updated until another selection is made causing changes to the
channels or range. Additionally, attempts to perform operations (i.e. Cut,
Paste, Copy, Remove, and Zero) will result in a audible warning and the
function will not be performed.
As with the other tools, operations which take a significant amount of time to
accomplish will provide an indicator for the percentage of the task completed.
Operations which copy data to the clipboard or delete data from memory utilize
the DMA memory transfers and are fast enough that the indicator is not used.
Operations which copy data from the clipboard use the indicator because the
operation is much more complicated.
Note: The editor has been written without the use of the MMPM/2 libraries.
Although MMPM/2 has all the functions necessary to perform the clipboard
operations, they can only be used if MMPM/2 is installed. Since this
program has been written to do its core work on any OS/2 system (with or
without MMPM/2), everything is done manually. This provided a bit more
control over the PASTE operation and it is still very quick.
The editor has been written to provide a robust method of manipulating parts
(or all) of a sample. The functions are broken down into groups (marked by a
box around the group).
Channel Displayed:
The edit dialog box allows the user to view a single channel at a time through
the graphical display. The channel to be displayed is selected using radio
buttons which are enabled based on the number of channels in the current sample
in memory.
Area:
When using the Copy, Cut, Zero, and Remove operations, the user selects the
area of the sample to be affected by either selecting the entire sample or
selecting a part of the sample. When the radio button for the "Entire Sample"
is selected, the start and end will be set to the beginning and end of the
sample respectively. To select a part, the user may either select the Select
Part radio button or use the left or right buttons to select the start and end
respectively for the interval of the operation.
Selection:
The user may specify a specific time for the begin or end of the interval for
the desired operation by typing the time directly. The editor will
automatically adjust the time down to the nearest actual sample. To activate
the Selection entry fields, select the Select Part radio button in the Area
field.
Manipulate:
This is probably the one field to draw the most confusion. This group of
buttons allows the user to specify which channel to operate on. By default the
editor will operate on all channels of a sample. However, the user may select
a specific channel for the operation by pressing the "Selected Chan" radio
button and then selecting the channel for the operation. Once the operation is
performed, the Manipulate group will default back to All Channels.
The editor is integrated into the PMsndX such that the Tools and the Playback
dialogs utilize the information from the editor. Each tool indicates that it
uses the range or channels selected in the editor through a checkbox in the
lower left corner of the tool. The Playback dialog provides checkboxes to
enable or disable the usage of the channel and range selection.
Each of the groups provides the user with a means to select the parameters of
the various operations. Each operation has a set of rules defining how they
behave under the various conditions. These are defined in the following text.
Rules for cut:
1. If the channel to operate on is "ALL", the copy all of the data over the
specified interval and shift all data over to the left.
2. If the channel to operate on is specified, then copy the data over the
specified interval for that single channel to the clipboard, and shift the data
after the interval over to the left while clearing the end of the data for the
specified channel.
Rules for paste:
The PASTE button is used the paste the contents of the clipboard into memory.
If the SHIFT key is pressed the text on the PASTE button will change to MERGE.
When the MERGE button is pushed, the editor will merge the data from the
clipboard with the data in memory. When the merge function is used the rules
for PASTE apply except that the data is averaged equally instead of being
inserted.
The paste operation varies depending on the number of channels in the current
sample and the number of samples in the data on the clipboard. After the paste
operation, the start marker will be set at the beginning of the sample pasted
from the clipboard and the end marker will be set to the end of the new data.
1. If there is no current data, then just copy the clipboard directly to
memory.
2. If the number of pasted channels is the same as the current data, then past
the data in based on the selected channel for manipulation.
Note: When merging, the data is averaged based on the selected channel for
manipulation. Any excess difference between the length of the two will
be left unafffected.
3. If the number of pasted channels is 1, then just copy the data to the
channel(s) selected for manipulation and insert blank space for the
corresponding channels which are not being manipulated. If the number of
channels for manipulation is "ALL" then duplicate the data for the single
channel across all channels of the current data.
Note: If the number of merged channels is 1, then average the data from the
clipboard to the channel(s) selected for manipulation. If the length of
the samples does not match the data will be averaged for the common
length of the two and excess will not be modified.
4. If the number of pasted/merged channels is less than the current number of
channels (but greater than 1), then
a) if the channels selected for manipulation is set to "ALL" then copy the
channels from the clipboard directly into the current sample and zero out the
non-existent channels.
Note: When merging, average the data from the clipboard directly into the
current sample and leave the non-existent channels unaffected.
b) copy the first channel from the pasted sample into the selected channel for
manipulation.
Note: When merging, average the first channel from the clipboard with the
selected channel for manipulation.
5. If the pasted/merged sample has more channels than the current sample, then
a) if the channels selected for manipulation is set to "ALL" then create the
new channels in the existing data and set all non-existent channels in the
existing data to zero.
Note: When merging, average the existing channels and copy the clipboard data
directly to the channels that did not exist in memory.
b) copy the first channel from the pasted sample into the selected channel for
manipulation.
Note: When merging, the first channel is merged into the selected channel for manipulation.
6. If all of this fails, then just warn the user and give up.
Rules for Copy Operation:
1. If the channel to operate on is ALL, copy all of the data over the
specified interval to the to the clipboard.
2. If the channel to operate on is specified, then copy that single channel to
the clipboard.
Rules for Zero operation:
Set the data over the specified interval to 0 for the channels specified.
Rules for Remove operation:
1. If the channel to operate on is "ALL", then remove the data over the
interval specified and shift all data to the left.
2. if the channel to operate on is specified, then remove the data for that
channel over the interval and shift the end of that channel to the left while
zeroing out the end of the channel.
Rules for Clear operation:
This operation clears all data from the clipboard. It has no effect on data
currently in memory.
UNDO:
PMsndX utilizes a lot of memory to ensure that the current data in memory is
not lost if an operation fails. Normally the original data is deleted from
memory once an operation is completed to reduce the long term memory
requirements of the program. However, If the Enable UNDO checkbox is selected
from the settings display, PMsndX will store a single buffer for performing one
level of UNDO.
After any operation from the toolbox, any of the manipulations from the editor,
or after loading a new file, if the UNDO option is enabled, the current data
will be stored in a buffer. Pressing the UNDO button from the editor will swap
the current memory with the buffer. Pressing UNDO again will swap them back.
With this setup, the UNDO functions as a redo button.
Note: The UNDO capability is only available in the registered version of
PMsndX.
ΓòÉΓòÉΓòÉ 6.5. Settings ΓòÉΓòÉΓòÉ
PMsndX can store a number of settings that users commonly set in a file called
pmsndx.ini. This file is always located wherever the executable program is
found.
From the SETTINGS dialog box the user may select to save the current window
positions, open file path, save file path, maximum memory and enable MMPM/2
Support requirements of the program.
The window positions and file paths are maintained as long as PMsndX is
running. When PMsndX is terminated, it will not save the current positions and
paths for file operations unless the boxes are checked in the SETTINGS dialog
box. Selecting these buttons has no effect on remembering the current window
positions during a single session; rather, they only affect saving the
information between sessions.
Note: The information in the SETTINGS dialog box is only saved when the
program is terminated. If the SAVE CURRENT items are deselected, then
the information will not be saved between sessions.
Window Positions During a session, the user can move any of the dialog boxes
around on the screen. If the WINDOW POSITIONS box is checked, these window
positions will be saved when the program is terminated. If this button is
deselected before the program is terminated, the next session will revert to
the previous window positions saved by the program. By default, if no window
position has been saved for a particular window, the window will be opened in
the lower left corner of the desktop.
File Open Path The file path for loading samples into memory may be saved
between sessions by selecting the FILE OPEN PATH button. If this button is
selected, the last file open path will be saved when PMsndX is terminated. If
this button is deselected before the program is terminated, the next session
will revert to the path from the previous session. If no information is saved
for the program at any time, the current path will become the default path for
open operations.
Note: This box may be selected from either the SETTINGS dialog box or from the
OPEN DIRECTORY button on the OPEN dialog box.
File Save Path The file path for saving samples to a file may be saved between
sessions by selecting the FILE SAVE PATH button. If this button is selected,
the last file save path will be saved when PMsndX is terminated. If this
button is deselected before the program is terminated, the next session will
revert to the path from the previous session. If no information has not been
saved between sessions, the current path will become the default path for save
operations.
Note: This box may be selected from either the SETTINGS dialog box or from the
SAVE DIRECTORY button on the OPEN dialog box.
Maximum Sample Memory PMsndX takes advantage of OS/2's advanced memory
management facilities. When the program is started, it only takes up the
memory required for the executable to load. PMsndX then reserves the amount of
memory specified by the SETTINGS box from OS/2 but does not commit this memory.
This means that the program has requested that OS/2 allocate the necessary
resources to manage the amount of memory specified. Until the memory is
actually committed it is not taken from the system's memory pool. When a sound
sample is loaded into memory, PMsndX then requests that OS/2 commit the
necessary memory before it loads the sample. When a new sample is loaded, the
previous memory is decommitted and the procedure is repeated.
Although this minimizes the actual amount of physical memory required by
PMsndX, it still provides the potential to cause OS/2 to have to commit more
memory than is available on the system. To avoid this problem, PMsndX provides
the user with the ability to limit the amount of memory which can be committed
by OS/2. The user may either specify that the program automatically determine
the maximum or that it set the maximum at a specific value.
Memory is primarily used to hold samples for operations; however, whenever the
sound is manipulated in such a way that either the output has a different
number of samples or the operation requires the samples to remain in tact
during the entire operation, additional memory is used to hold the new data.
Once the operation has been completed, the memory is freed. When setting the
maximum memory, the user must take into account the size of the data in memory
as well as the size of the results of any operations. With the exception of
Sampling Rate changes, the maximum memory requirements will not exceed twice
the size of a sample. When changing rate, the size is dependent on the new
sampling rate. If the new rate is higher than the current rate, the memory
requirements will increase. If the new rate is lower than the original rate,
the memory requirements will shrink.
If the user selects the AUTO mode for memory (the default), PMsndX will limit
the memory usage to 32 megabytes. This is generally more memory than most
systems have but allows for a very large sample file to be loaded.
If the user chooses to limit the memory to a specific value, the AUTO checkbox
can be turned off and a value may be entered. Since the minimum OS/2 memory
block size is 4096 (4k) bytes, the user may specify the number of 4k pages for
the limit. The user may either use the up and down arrows to increment or
decrement the amount of memory or may place the cursor in the window and type
the specific value.
Enable MMPM/2 Support
PMsndX supports playing samples from memory directly to the MMPM/2 digital
audio device of OS/2. This allows samples to be played without having to save
the sample to disk in the native .WAV format. The settings dialog box provides
controls for disabling or enabling MMPM/2 support and for controlling the
actions taken when a file is loaded (e.g. Play sample on load, convert to a
standard rate when loaded, and exit after play from the command line).
Additionally, the digital audio device may be specified.
If the MMPM/2 capabilities of the program are not needed or if MMPM/2 support
is not installed on a particular system, the MMPM/2 may be disabled from the
settings dialog box. By disabling the MMPM/2 support, the button on the main
control panel for playback is disabled. By default the program will enable
MMPM/2 support. If MMPM/2 is available but disabled and the playback button is
selected, a message is displayed to the user to indicate that the setting
should be turned on from the settings box.
The controls for MMPM/2 and the ability to play the "playlist" using MMPM/2
utilize the files SW.DLL and MDM.DLL. These are part of the standard MMPM/2
distribution and must be present in the DLL path for the MMPM/2 portion of this
program to operate. The MMPM/2 support is not linked into the executable of
this program. Rather, it is only loaded when the user enables it. This allows
the program to run on machines which do not have MMPM/2 installed.
The MMPM/2 functionality of PMsndX has been implemented to share the audio
device with other programs on the system. However, if by disabling the MMPM/2
support, the audio device is freed up completely.
Play on Load
If the Play on Load box is selected, a sample is immediately played when it is
loaded into memory. To provide control during playback, the playback dialog
box is opened after the file has been loaded. When this feature is used in
conjunction with the exit after play feature, PMsndX provides the ability to
play any supported sample file format from the command line and have the
program exit when it is finished.
If this parameter is not specified, the sample will still be loaded from the
command line; however, it will not be played until the user accesses the
playback dialog.
Note: When a filename is specified on the command line, the control panel and
the dialog boxes are not opened. The intention of this operation is to
allow the program to play without being intrusive.
Exit after Play
The Exit after Play option provides the ability for PMsndX to exit after
playing the sample when the file is loaded from the command line. This is
primarily intended to provide a means to play any of the supported formats from
the command line.
Device
Obviously not every machine has the same digital audio device. PMsndX provides
a means to use a different audio device than the default digital audio
interface. By default the device name is Waveaudio01. Any Waveaudio device
may be selected by entering the device name in the Device entry field.
After the user has set all of the information in the SETTINGS dialog box, the
DO IT button must be used to save the changes. When this button is pressed, the
dialog box is dismissed and the settings are applied.
Note: If a sample is currently loaded into memory and the Maximum Sample
Memory is changed, the sample data will be flushed from memory. A
warning box will be displayed to indicate the result of this operation.
To dismiss the SETTINGS box without saving any changes, the CANCEL button can
be used. This has the same effect as pushing the SETTINGS button on the main
control panel when the SETTINGS box is displayed. All information entered by
the user is cleared and the SETTINGS remain unchanged.
ΓòÉΓòÉΓòÉ 6.6. Tools ΓòÉΓòÉΓòÉ
Using a notebook to display the TOOLS has some unique presentation advantages.
Primarily the notebook allows the effects to be displayed in a single dialog
window. Since each effect is mutually exclusive of any other tool this
approach displays the maximum information that the user can utilize at any
time. Another approach would have been to develop a dialog box for each tool.
This approach has the disadvantage that it would require a second control panel
to select the specific tools. This would violate the approach of providing a
single control panel for the user and would necessitate managing a number of
different windows which could potentially clutter the screen. The notebook is
a clean and aesthetically pleasing means for managing the tools.
The heart of manipulating the samples is accessed from the TOOLS notebook.
Some of the pages of the notebook provide information while others let the user
apply a particular effect on the current sound sample. The TOOLS notebook can
be dismissed by pressing the TOOLS button on the main control panel or by
pressing the DISMISS button at the bottom of the Tools notebook. The tabs on
the notebook provide access to the Info, Type, Average, Duplicate, Band Pass,
Low Pass, Rate, Speed, Echo, Invert, Reverse, Vibro, Volume, Fade, and Balance
functions for manipulating the samples.
The notebook may be navigated by either selecting the tab on the right of the
book for the desired function or by using the small Plus and Minus buttons at
the bottom of the notebook. Using the Plus and Minus buttons will move through
the notebook a single page at a time. The information for each function are
divided into the following categories.
To select the tabs using the keyboard, the focus for the notebook must be set
for the notebook container (by clicking the mouse outside of one of the tools
or by pressing the ALT key and the UP arrow). Selecting any character that is
underlined will bring that page to the top of the display.
The notebook can be displayed regardless of the presence of sample data in
memory. When no sample is present, the pages of the notebook will be
invalidated but can still be viewed.
ΓòÉΓòÉΓòÉ 6.6.1. Info ΓòÉΓòÉΓòÉ
The Info page displays all of the relevant information about the samples
currently in memory. This includes the following categories:
Load Format One of the formats which the program can save or open
Data Type The default extension for this file format.
Data Style SIGNED, UNSIGNED, ULAW, or ALAW
Channels Number of channels in the sample
Sampling Rate The number of samples taken each second
Data Size BYTE (8 bits), WORD (16 bits), LONG (32 bits)
Samples The number of samples that make the file
Comments Some sample files may contain comments. Any comments found are
displayed in this window
Byte Order The natural order of the bytes in each sample. This field can
display either Big Endian or Little Endian
ΓòÉΓòÉΓòÉ 6.6.2. Type ΓòÉΓòÉΓòÉ
The type of the file is determined by the header written to the beginning of
the file. See Save for information how the file type is determined when a file
is saved to disk. Additionally, the user may use the this tool to change the
Load Format (displayed in the Info page of the tools notebook). When the file
is saved, the default file format will automatically be set to whatever has
been chosen on this page of the notebook. Changing the file name extension or
selecting a file format in the SAVE dialog will override this setting.
Each file format utilizes different headers for the actual data. By selecting
one of the standard formats on this page the Info page will show the user how
the samples will be saved. The fields that are most likely to change are the
Load Format, Data Type, Data Style, and Data Size.
ΓòÉΓòÉΓòÉ 6.6.3. Average ΓòÉΓòÉΓòÉ
A sample with an even number of channels may be averaged to produce a sample
with half the initial number of channels. For example, a sample with four
channels can be averaged to produce a sample with two channels and a sample
with two samples can be averaged to produce a sample with one channel.
Channels may be averaged in three ways. The simplest is to take the left or
right channel data as the final data. A more complex method is to average the
samples of the left and right to produce a center sample. The results of these
operations are significantly different and can result in very different output
samples.
When a sample contains four channels, it is composed of four sound sources at
45 degrees in each quadrant. This corresponds to the Front Left, Front Right,
Rear Left, or Rear Right. To average these into two channels the user can
select to use any of the four channels or to average based on the left or
right. To select or average any combination of the channels into either of the
output channels, check the box for the channels from the source sample. To aid
in this, two radio buttons have been provided which enable or disable the
selection of check boxes in the second channel depending on the number of
output channels selected.
ΓòÉΓòÉΓòÉ 6.6.4. Dupe ΓòÉΓòÉΓòÉ
Channels can be duplicated such that a single channel sample can be made to
have two channels which are identical or two channels can be duplicated to form
four channels.
When copying two channels to 4, PMsndX allows the user to specify which of the
input channels will be placed on the output channels. In this way, a single
channel of a dual channel sample can be copied to any of the four output
channels.
ΓòÉΓòÉΓòÉ 6.6.5. Band Pass ΓòÉΓòÉΓòÉ
This tool provides the ability to apply a band-pass filter to a sample. The
frequency response for the filter is designed to drop logarithmically around a
center frequency. The slope of the drop at the desired start (Wp) and end (Ws)
of the filter varies with the distance between the Wp and Ws. This width is
used to determine the slope of the dropoff at the edges of the filter. The
frequencies at Wp and Ws will be approximately half of their original
amplitudes and all frequencies outside of the Center - Wp and the Center + Ws
will be eliminated. The bandpass filter can be mode oriented to pitched
signals (i.e. voice, singing, or instrumental music) or can be modified by
adding noise to the filter so that un-pitched signals can be effectively
processed.
Note: To aid the user in locating the maximum effective center frequency, a
light blue vertical bar is placed at half the sampling rate for the
data.
The transformation for the Bandpass filter was taken from a a program called
MUSIC56K (as documented in the MUSIC56K source code) and implemented in C++ for
this program.
Operation of the bandpass filter tool is probably one of the most complex
interfaces in the toolbox. It is based on a simple principle. The entire
display of the filter represents the frequency response of the filter and is
operated like a slider. However, since the Start frequency and the Stop
frequency are independent, the sliding bar is divided into identical controls
for each filter edge. Before getting into the operation of the controls the
display needs to be explained to establish the terms that will be used.
As mentioned, the display is designed to illustrate the frequency response of
the bandpass filter (independent of any added noise). The center of the Start
(Wp) and End (Ws) of the filter are marked by vertical BLUE bars. The Center
(Wc) of the filter is marked by a vertical RED bar. These three markers
provide the means for the user to modify the filter. The region to the left of
the RED center frequency is always the start of the filter. The user may click
the mouse to the left of Wp to decrease Wp by 1000 Hz. Clicking between Wp and
Wc increases Wp by 1000 Hz. Likewise, clicking between Wc and Ws decreases Ws
by 1000 Hz and clicking to the right of Ws increases Ws by 1000 Hz. The user
may also click the mouse near Ws or Wp to drag the respective ends of the
filter quickly.
To provide fine control of the filter, Right and Left arrows are provided for
both Wp and Ws. Clicking on either the right or left arrow will increase the
indicated filter edge by 1 Hz. To increase or decrease the filter edges by 10
Hz, the user may select the plus or minus corresponding to the filter edges.
The left set of controls affects Wp and the right set of controls affects Ws.
As the mouse is used to adjust Wp and Ws, the exact frequencies for Wp, Ws, Wc,
and the filter Width are updated in the text input fields. The user can use
the mouse to select one of the input fields and modify it directly. To accept
a value in the entry field and recalculated the dependent frequencies select
another window or click on another item which moves the focus from the
notebook. The rules for the fields are as follows:
1. If the Center frequency is modified, new values for Wp and Ws are
immediately calculated using the current Width. If Wp or Ws are outside of
the possible ranges, then Wp or Ws are set to the limit of the acceptable
range and the Width and Center are recalculated.
2. If the Width of the filter is modified, new values for Wp and Ws are
immediately calculated using the current Center frequency. If Wp or Ws are
then outside of the acceptable ranges, Wp or Ws is then set to its limit
and the Center and Width are recalculated.
3. If Wp is changed, the Width and Center are automatically recalculated to
reflect the new start of the filter.
4. If Ws is changed, the Width and Center are automatically recalculated to
reflect the new end of the filter.
The bandpass filter has been selected because of the desirable effect on
typical sounds that will be processed by PMsndX such as voice or music.
However, if other types of noise are to be filtered, noise can be added to the
filter which results in a sharper peak of the filter. To add this noise,
select the checkbox for "Add filter noise". Selecting the checkbox again will
disable the filter noise.
Note: The display of the frequency response for the filter does not reflect
added noise.
ΓòÉΓòÉΓòÉ 6.6.6. Low Pass ΓòÉΓòÉΓòÉ
A Low Pass filter can be applied to a sample to eliminate high frequencies.
Filtering is accomplished in the digital domain through the use of a very
simple second order digital Fourier transform. Future implementation may have
a more complex Fourier transform; however, the chosen function is desirable
because it provides a smooth dropoff without significant ringing. The
performance of the filter is determined by the cutoff frequency and the rate of
drop. If the dropoff is made too quickly, the filter will exhibit a ringing
effect at the begin and end of the dropoff. If the dropoff is performed too
slowly, the filter will suppress more frequencies toward the end of the desired
range. The more orders of the filter (more stages), the better the frequency
response; however, more orders increase the time for filtering significantly. A
two order filter works adequately.
When performing the digital convolution of the sample with the step function a
Gain factor is used to normalize the output data. This acts as a Volume
control for the sample to prevent losses due to numerical overflow. Values for
the gain range from 0 to 1 in increments of 0.01. A slider bar is used to set
the gain of the low pass filter. When the low pass filter is first brought up,
the Gain will default to a value of 0.8. If this is changed, it will remain at
the new setting until the session is terminated.
The Frequency response of the low pass filter is determined by a the
centerpoint of the dropoff at the end of the step function. When performing a
digital filter, it is not possible to prevent the gradual drop at the end of
the step function due to the convolution of the samples used in the
transformation. This is true for analog components also. The centerpoint of
the dropoff can be set in three ways. The user may enter the specific frequency
in the text entry box in the lower right corner or may use the filter display
like a sliding bar. As is typical of a sliding bar, the mouse may be used to
capture the cutoff frequency by pressing the mouse button while the mouse is
near the cutoff frequency. By holding the button down, the user may drag the
frequency to the desired range. Additionally, the user may click to the right
or the left of the frequency cutoff to increase or decrease the frequency by
1000 Hz. The right and left arrows in the corners of the display may be used to
increase or decrease the frequency by 1 Hz. The plus and minus buttons in the
corners of the display may be used to increase or decrease the frequency by 10
Hz. The frequency response curve illustrates the dropoff that occurs at the end
of the step function.
ΓòÉΓòÉΓòÉ 6.6.7. Rate ΓòÉΓòÉΓòÉ
Once a sample has been loaded into memory, the current rate information is
displayed on the RATE page of the notebook. The user can change the rate of the
sample using this page of the tools notebook.
Note: Changing the sampling rate may degrade the quality of the sound.
The user may select from a set of standard sampling rates for common computer
formats or may specify a specific rate. OS/2 and Windows use standard rates
which are multiples of 11025 Hz. Sun, DEC, and NeXT computers commonly use a
sampling rate of 8000 Hz. Standard rates of 8000, 11025, 22050, and 44100 Hz
have been provided for the user to select.
If the user wishes to use a sampling rate which is not one of these, the button
for Non-Standard should be pressed. This will activate the slider bar and user
input windows to allow the user to specify the rate. The slider bar can be
used to quickly change the rate in the input window or the user may select the
input window and type in the desired rate.
ΓòÉΓòÉΓòÉ 6.6.8. Speed ΓòÉΓòÉΓòÉ
This function will change the playback speed of a sample. This is the same
thing as setting a phonograph to a different speed such that the sound is
played too fast or too slow. The controls for this effect simply specify the
new playback speed. Once a new speed is selected, the sample is resampled to
interpolate the new playback points. As a result, a sample is still played at
the same rate, but the data is modified to play at the new rate. This allows
the sample to be stored in a file which is of a standard rate.
The user may select any of the standard rates including 8000 Hz, 11025 Hz,
22050 Hz, and 44100 Hz. Additionally, the user may specify the playback speed
to be either double (x2) or half (x1/2) or may specify a specify playback speed
by selecting the User button. If a speed other than the current speed is
specified, the DOIT button will be activated which will allow the user to
perform the change.
ΓòÉΓòÉΓòÉ 6.6.9. Echo ΓòÉΓòÉΓòÉ
The echo effect will modify a sample to provide attenuation at specific points
in a sample. The operator must specify the points where the echo effects are
to start and an attenuation or Volume for the echo. The attenuation determines
the length of time that it takes for the echo to die away. If the Attenuation
specified for all of the echo points is greater than 1, then the echo will
"melt" rather than fading away and consequently may take a long time to
complete. If an attenuation is set to 0 or less, the Echo point is ignored.
The echo effect presents an interesting challenge to the user interface. How
do you provide the user with an intuitive method to set the echo locations and
the strength of the echo from a dialog box? Well, look at the ECHO notebook
page and follow along in the explanation of the operation. This notebook page
includes a graphical display of the current sample, a text entry field for
editing (e.g. adding or deleting) time marks, and a volume control for setting
the strength of the echo.
The ECHO notebook is centered around the graph at the top of the page. This
display is the primary point of control. However, to allow for a bit more
direct control, the user may use the entry fields to add and delete echo points
too. To explain it all, I will start with the graphical display first and then
lead to the secondary controls.
Once a sample has been loaded into memory, the graphical display will become
active. The display is controlled through two slider bars for the position in
the sample and for the magnification. The sample is normalized so that the
largest sample value will hit the limit of the display. This makes the display
volume independent but gives maximum clarity of the actual waveform in memory.
Markers may be added or moved to set the echo points in the waveform. To aid
the operator in locating the desired echo point, the display contains a status
bar for the starting timemark for the sample in the window, the current
timemark under the mouse, and the magnification factor.
To move to the right or left in the display, the horizontal slider bar may be
used. Pressing the end arrows moves the display one displayed sample to the
left or right. When the slider bar is pressed, the display will move one half
screen to the right or left. The user may move the display to a region quickly
by selecting the slider button and dragging it to the appropriate position.
The display is immediately updated to display the current position.
The display area at the bottom of the graph provides a timemark indicator for
the first sample appearing at the left of the graph. This provides a reference
for moving through the data. The time marker is displayed in the form of
m:ss.ssss where m is the number of minutes into the sample and ss.ssss is the
number of seconds into the sample.
Even the smallest sample contains more data than can fit on the graphical
display. For this reason the vertical slider to the right of the graphical
display is used to adjust the viewing magnification of the samples. The
maximum magnification of the samples is determined by the length of the sample
and is calculated by dividing the total sample length by the largest number of
data points which may be scrolled through on the display. The display is
limited to the maximum size of an signed 16 bit value due to the limitations of
the signals for the horizontal slider bar. This results in a maximum of 32767
data points which can be displayed and scrolled through.
Initially, the magnification is set for the maximum displayable. To decrease
the magnification ( i.e. zoom out) on the sample, move the slider down the bar.
The arrows on the ends of the bar can be used to increase or decrease the
magnification in increments of 1. Selecting between the button and the arrows
doubles or halves the magnification. If the button is selected, the
magnification can be set immediately to a value. Markers are displayed for the
nearest point in the zoom. However, markers can only be set on exact multiples
of the zoom. Therefore, when trying to move a marker, if it is set at a
different magnification, it may not be possible to move the marker without
returning to that zoom. Essentially, the marker is displayed but cannot be
selected because that exact sample point is not visible. I considered making
the mouse select the nearest marker, but this is a point of confusion if many
markers are displayed at the same location for a specific magnification.
The current magnification is displayed in the status area of the display in the
form of "x1/nnnnn" where "nnnnn" is replaced by the current magnification
number (i.e. number of points represented by a single point on the display).
If the display says that the zoom is x1/2, then the magnification of the
display is halved. If this sounds confusing, then just play with the notebook
page for a bit to get a feel for the operation of the zoom.
Before going on, another area of the display needs to be described. The center
number on the status area of the display indicates the timemark for the current
(or last) mouse position. Whenever the mouse is moved into the display area,
this number will be updated to indicate the time offset for that particular
point. This takes into account the magnification.
Now for the fun part. To add an echo point to the sample, move the mouse to
the place where you desire the echo. The status display will provide a
reference for the timemark. When the proper position has been selected, click
the mouse and a blue marker will be placed. If the mouse is released, the
marker will be set at that location in the sample. If the mouse is not
released, the marker may be dragged across the display. This marker may be
moved later if necessary by other means too.
Note: If at any time the mouse pointer is moved outside of the display before
the mouse button is released, the marker will not be set and the blue
mark will be erased from the display.
A echo marker may be moved by positioning the mouse pointer over the marker
and pressing the mouse button. If the marker is on a multiple of the zoom
level, it will be selected and will follow the mouse as long as the button is
pressed. When the button is released, the marker will be placed at that
position.
A marker may be moved to another time delay by entering the desired delay
directly through the Time Mark entry field.
Note: If the mouse is moved off the display area, the marker will be restored
to its original position.
For each marker displayed, the timemark is stored in a Combo Box. This box is
like an entry field in that the user can edit the time directly; however, it
also has a drop down box that can scroll vertically through all of the
different markers. This type of box provides a great deal of flexibility for
the user.
To add a marker at a specific time, position the cursor in the Timemark box and
edit the time index. The format is the same as that used to display the time
marks in the main display. Enter the number of minutes followed by the
seconds. The granularity of the seconds is on the order of 1/10000 of a
second. For example, entering 6:54.4253 would accept a time mark at 6 minutes,
54.4253 seconds. If a value is entered with is beyond the maximum sample of
the file or less than 0, then the data is ignored.
Once the desired time mark has been entered, the user may press the Add button
to place the marker in the current database. All timemarks added to the
display use the volume specified for the last timemark, or 0 if no volume has
been set yet.
When the listbox is pulled down for the timemarks, each of the timemarks that
have been entered are displayed in a vertically and horizontally scrollable
window. Up to 32 markers may be placed in the file and any markers which are
unused are displayed with the word "EMPTY". The markers are placed in the
database in the order that they are entered unless a free slot is open (from
being deleted). The user may select any of the time marks using the combo box.
If the selected timemark is not empty, the display will be updated to display
the selected timemark in the center of the graph. In the event that the
timemark is too close to the end or beginning of the sample to display in the
center of the graph, the timemark will be displayed without being centered.
Once a timemark has been selected, the Del button may be pressed to delete the
marker from the database. The entry field is not cleared in order to allow the
user to directly edit the timemark which was deleted and add it later.
The volume for each timemark may be set by specifying a value in the volume
entry field. This is a simple entry field in which the user can type or delete
numbers. Since the volume (attenuation) for each timemark may range from 0 to
infinity, the only method for entering the volume is through the keyboard.
Sorry, no sliders here. As each character is typed, it is stored. The user
does not have to press enter or any key to accept the value.
I have not found a big use for numbers greater than 1, but I could not find any
reason to limit the user to a specific range of numbers. Anyone who has
experience with this effect and knows of a reason for a limitation should
contact the author and I will be happy to set up something to make entry of the
Volume easier.
Note: The most common mistake for the echo effect is in forgetting to enter a
value in the Volume field. Remember that you must provide an
attenuation for the echo in the Volume entry field to make the echo
point valid.
ΓòÉΓòÉΓòÉ 6.6.10. Invert ΓòÉΓòÉΓòÉ
A sample is composed of numbers which are digital snapshots of an analog wave
at regular intervals. These numbers can take on positive and negative values
which push or release the cone of a speaker to produce sound. The range and
channels for this function are selected through the editor.
Any series of samples may be inverted such that all positive values become
negative and all negative values become positive. To the human ear, there is
no difference in the sound produced; however, mathematically, the new wave is
very different. An inverted wave may be added to a normal wave to
mathematically subtract one from another. When this function is combined with
the MERGE function of the editor, samples can be added together to eliminate
common frequencies.
ΓòÉΓòÉΓòÉ 6.6.11. Reverse ΓòÉΓòÉΓòÉ
This effect allows the user to reverse a section (or all) of a sample. The
range and channels for this function are selected through the editor.
ΓòÉΓòÉΓòÉ 6.6.12. Vibro ΓòÉΓòÉΓòÉ
This function performs the "world-famous" Fender Vibro-Champ sound effect to a
sound sample by using a sine wave as the amplitude of the volume at each
sample. This tool requires that the user set the Speed and the Depth of the
sine wave.
The speed setting gives the frequency of the sine wave in Hertz. The range of
values for the slider are from 1 to 30 in increments of 1 Hertz. A value of 0
would be useless for a frequency and is not allowed.
The depth setting gives the amount by which the volume will be cut into by the
sine wave. The range of values for the slider are from 0.0 to 1.0 in
increments of 0.01. The initial value of the slider is 0.5.
ΓòÉΓòÉΓòÉ 6.6.13. Volume ΓòÉΓòÉΓòÉ
Most anyone who has received a sound sample from different sources has had the
problem that the recorded volume is inconsistent between different samples.
After all, there is no standard recording level for the different machines or
different software.
To allow the user to adjust the volume of a sample, PMsndX provides a tool
which can either adjust the volume by multiplying every sample by a fixed
amount or by multiplying the samples by a value based on the limit of the data
that can held in memory.
By specifying a maximum value for the sound sample, all sound samples can be
set to have a similar maximum. The obvious use for this function is to allow a
library of sounds to be set at the same volume. The value used for the maximum
volume is based on a percentage of the maximum data that can be held in a
single sample. As an example, a value of 100% for the volume represents a
value of 127 for a signed byte sample.
When the button for the Maximum is selected, the slider bar directly beneath
the button is activated. Initially, this will be set to the current volume in
terms of the percentage of the maximum value for the sample. The volume may be
adjusted by setting the slider to a value between 0 and 100 percent of the
maximum.
Since the value is based on a percentage of the maximum value of the data that
can be stored in a sample, clipping is not possible.
When the button for the Fixed value is selected, the slider bar directly
beneath the button is activated as well as the checkbox for clipping. The
fixed bar provides the means to multiply all sound samples by a fixed value
between 0 and 2 in increments of 0.1. A value of 1 makes no change. Any value
greater than 1 increases the volume and any value less than 1 decreases the
volume. A value of 2 doubles the volume of the sample.
When using fixed sampling it is possible to exceed the maximum data that may be
stored for a sample. The Allow Clipping checkbox may be selected to allow the
data to be clipped. If the checkbox is not set and if the fixed multiple will
result in clipping, then the multiple will be set to the maximum value that
will not result in clipping. If the clipping box is set, data may exceed the
maximum that may be stored for the sample which will result in noise.
ΓòÉΓòÉΓòÉ 6.6.14. Fade ΓòÉΓòÉΓòÉ
This effect allows the user to either fade in or fade out the volume of a
sample. Fading the data in a sample is produced by increasing or decreasing
the volume of the sample over a period. To fade a sample in is to slowly
increase the volume of the sample from 0 to the normal volume of the sample
over a block of time. To fade the sound out is just the opposite in which the
volume of the sample is slowly reduced over a period.
The FADE tool provides three methods for fading which provide a robust means
for controlling the volume of the data over the specified range of operation.
These are Linear, Slow Geometric, and Fast Geometric.
ΓòÉΓòÉΓòÉ 6.6.15. Balance ΓòÉΓòÉΓòÉ
When a sample has more than one channel, the volume of the individual channels
can be varied. The balance of the channels can be achieved either
instantaneously or over a period of time. These are the same basic functions
as used in the FADE and SWAP effects and are Linear, Slow Geometric, and Fast
Geometric, and Step.
The volume of a sample may vary by either starting at the specified percentage
of the current volume for each channel and progressively approaching full
volume. This is similar to fading in a sample and is achieved by selecting the
"IN" button. The opposite effect is achieved when the volume starts at the
current volume and progressively decreases to a percentage of the current
volume.
When balancing a sample, the user must specify a percentage for each channel.
When fading in, this is the percentage that the volume will start at for each
respective channel. When fading out, this is the final percentage of the
original volume. The display at the top of this dialog varies depending on the
number of channels in the current sample.
ΓòÉΓòÉΓòÉ 6.7. Help ΓòÉΓòÉΓòÉ
PMsndX is equipped with extensive on line help that can be accessed by pressing
the HELP button from the main control panel. When this button is selected a
window will appear which will display the table of contents for the system.
Links to other text is displayed in a blue-green color and can be selected to
jump to that description in the text. When the control panel buttons appear in
a tabular form, the buttons are active links in the help like the blue-green
colored text. Pressing these buttons will jump to the respective text.
ΓòÉΓòÉΓòÉ 6.8. Exit ΓòÉΓòÉΓòÉ
When the EXIT button is pressed, the program terminates. If the Settings box
or the SAVE DIRECTORY from the Open or Save dialog boxes have been set to save
information, the data will be saved to the initialization file before the
program exits. Before exiting, PMsndX requests verification that the user
wants to exit to prevent accidentally exiting. All windows of PMsndX including
any dialog boxes are removed from the screen when the program terminates.
If the data in the memory buffers has been modified, PMsndX will warn the user
that there are modified buffers and ask for verification that the user really
wants to exit.
ΓòÉΓòÉΓòÉ 7. Technical Issues ΓòÉΓòÉΓòÉ
Memory Usage: I have worked with means for storing and converting from one
format to another efficiently. Initially I tried to store things in a data
structure which was a union of all of the types of data that are used by the
computers. However, converting from one format to another was difficult and
each effect had to be able to understand the initial and final format. This
became unwieldy considering that there can be either signed or unsigned samples
of sizes byte or word. As new effects were added, it became unmanageable. At
a sacrifice to memory efficiency, I have changed it to store all data as a
signed SHORT (2 byte) sample. The effects then operate generically on the
samples and the only time that the type of data is important is when reading or
writing the samples. The savings in complexity justified the memory
requirements. As a result, if a sample is 1k of bytes (.wav format), then in
memory it will take up 2k. Currently the program will only read and write 8
and 16 bit samples. Since I don't know of any sound cards that can sample at
greater bit sizes, this is the limit. In the future, this approach to memory
usage can be easily extended to 32 bits without rewriting every part of the
program. In fact, to change the storage sizes, two definitions have to be
changed and then the proper input/output routines written. Simple? I think so.
Additional known faults:
1. The button for Record has no function at this time. This functionality
will be added later.
2. There is no drag and drop capability yet.
ΓòÉΓòÉΓòÉ 8. About the Author ΓòÉΓòÉΓòÉ
My name is William Scott Hiles but I usually go by the name Scott. I have a
masters degree in signal processing and satellite communications.
Unfortunately, my occupation utilizes very little of my formal education and
takes more advantage of my less formally learned talents. I work as an
electrical engineer for the Navy in the area of LAN and WAN research. My job is
centered around promoting open systems in networking within the Navy and I am a
Navy expert on fiber optic networking. I have worked with the ANSI X3
committees for the past 5 years and currently (1993-1994) am the chairman of
the FDDI Repeater specification. Enough of that dribble...the point is that I
don't use my education in my job.
Which leads me into the purpose of this program. I am an electrical engineer,
and my heart lies in hardware design and programming. Well, with this program
I can at least satisfy my need to create software. So, this program came about
because I was playing with sampling and recreating sound with my Sound Blaster
16 when I had the need to convert from the .wav format to the Sun .au format.
After finding a little program that would convert Sun audio files to the PC
format I found that it had problems with the new version of .WAV files. So, I
set out to write something that worked with the latest versions. Well, from
there it was not difficult to add other formats, and then I started playing
with manipulations and so forth. Over about 9 months of very time consuming
work, I came up with the present program called PMsndX.
My resources are modest. I am 29 (1993) and have programmed everything from a
PC to a 486 for the past 10 years. I dumped my 286 in February of 1993 and got
me a nice 486. I decked the thing out and got OS/2. I had been playing with
OS/2 since 1.3 on machines that I did not own, but this was the first time I
had it at home to play with as I pleased. Programming under OS/2 provided a
unique challenge with unlimited creative abilities. The company called
WiSHware which is listed in the About box was formed as a shareware/freeware
incorporated name for anything I write. I have a significant library of
programs for DOS and even a couple for Windows. PMsndX is the second program
for OS/2 that I have written. The first one was not well received as it did
not provide a significant function to the community. Big deal. I use it at
home and I don't care.
So that is my history and my qualification. I am a bit surprised that you read
this far. Congratulations. By the way, did you wonder why I chose a little
blue motorcycle for the icon? Very simply put, the modern day sportsbike
represents the art of functional integration while still maintaining the
quality and sound of much more expensive motorcycles.
I can easily be reached by my current email address
(whiles@relay.nswc.navy.mil) or through US mail at:
Scott Hiles
4421 Savannah St.
King George, VA 22485
ΓòÉΓòÉΓòÉ 9. Shareware ΓòÉΓòÉΓòÉ
During the development stages of PMsndX (i.e. until version 1.0 is available)
PMsndX is free to all for distribution. After version 1.0 is finished, the
program will then be distributed as shareware. Anyone who does not want to
register later versions will still be able to use all of the releases before
1.0.
Licensing and registration fees apply to the user interface and style of the
program but do not apply to the algorithms used to create the effects. These
algorithms are public domain and may be copied and distributed freely.
I have put a lot of effort into making this program robust and very pleasing.
It has taken me more than nine months and 24,000 lines of code to get this
program to where it is now, and I would hope that if you like the program and
use it, you will appreciate it enough to send me a little cash to help fund
future work. I don't expect much.
Asking for money is a sticky thing. The big problem is to give people a
program so that they can play with to see what it can do and yet hold back
enough to get people to want to register the program. I put a lot of thought
into this and have considered the many ways that authors achieve their goals.
My solution was to disable the ability to read or write any formats other than
the PC .WAV and the Sun .AU types, and disable the UNDO capibility.
Additionally, the multi-channel capability of the program is disabled and the
clipboard will not copy or cut anything less than the entire sample in memory.
ΓòÉΓòÉΓòÉ 10. Registration ΓòÉΓòÉΓòÉ
I have three options which I can offer which seem to follow with common
SHAREWARE practice. I have looked in stores for something that provides
anything similar and found that a commercial product for Windows with half the
functions cost considerably more. A registration form is provided and the
following are the options for registration.
1. $15.00 will get you a password that will enable all of the functions of the
current version.
2. $30.00 will get you a password that will enable all of the functions for
all versions up to the next major release. If you chose to register using
option 1 first and then want to upgrade, I will give you a $10 credit and you
can get option 2 for $20.00.
3. $50.00 will get you a password that will enable all of the functions for
all future versions. If you have chosen to register using option 2 first, I
will give you a $20 credit and you can get the lifetime registration for
$30.00. If you have registered with option 1 first, then I will give you $10
credit and you can get the lifetime registration for $40.00.
Note: Please note. These prices cover just the registration. Shipping
charges for the disks through the Postal service are extra. If you
order the program through the mail, add $3.00 to cover the media and
shipping costs.
The section describing the Author provides my email and US postal mail
addresses.
Now, what do you get when you register. Well, you obviously get a password
that will enable all functions of the program. The functions that are disabled
for unregistered users are:
Formats Only .AU and .WAV formats can be loaded and saved
Editor The Cut and Paste operations of the editor only work for the full
sample (i.e. will not work for ranges)
Undo The UNDO function is disabled
In addition to that, I can provide limited technical support through regular
phone service, email, or the US Postal service. A number of people have
contacted me to ask for special programs (e.g. programs that will just play any
format without the overhead of the editor or a program that will just convert
between formats). These will be fairly easy to create using the existing
objects of PMsndX. If you are registered for PMsndX, these programs will
automatically recognize the registration and work on your system.
If and when you register, you will receive a password through whatever means
that you prefer. If you choose the postal service, you will receive it via
disk along with the latest copy of the program (remember to include an
additional $3.00 to cover the shipping and media). If you choose to receive
your registration through email, you will receive an email message that can be
imported using the FILE button of the registration dialog. Registrations will
be sent after your form of payment has cleared.
Although not currently provided, credit cards will eventually be accepted if
the program makes enough profit to afford the service. Please allow at least
two weeks to receive your registration.
Since PMsndX is provided as ShareWare, there is no provision for refunds. In
the event that you are dissatisified with the operation of PMsndX due to an
error in loading or saving a format, contact me and I will fix the program if
you can provide me with a copy of the file that is causing the problem.
ΓòÉΓòÉΓòÉ 11. Entering Registration Info ΓòÉΓòÉΓòÉ
Once you receive your registration you have a couple of options for entering it
into the program. First, pull up either the Welcome or About dialog box from
the system menu of PMsndX. Press the REGISTER button to bring up the
registration dialog box.
You may enter the data directly into the entry fields or you may have the
program scan a data file for your registration information. When entering data,
enter it exactly as it is shown in the file or text for your registration. The
Name field must not have any additional spaces and it must be entered in exact
case. The password is 16 characters long and will never contain any space
characters. It is case sensitive so be careful to get the case right.
Passwords never contain the upper case letter O or the upper case letter I to
avoid confusion with similar looking numbers.
When PMsndX scans a file for the password information, it looks for the
following keys:
PMsndX Name:
Through version:
PMsndX Password:
These lines can be anywhere in a file so there is no need to remove a mail
header or extra information. PMsndX will search the file for the specific text
that it is looking for and extract it.
The registration information is stored in the file called os2.ini. This allows
a copy of PMsndX to be run from a network and each machine can have it's own
registration. This also allows the pmsndx.ini file to be copied form one
machine to another without violating the licensing agreement. Four items are
stored in the os2.ini and total about 100 bytes. Any .ini editor can be used
to remove this information if the user wishes to delete PMsndX from the system.
Note: The information in the os2.ini file is only written when the program is
registered. This avoids adding stuff to the os2.ini file unless the
user has chosen that the program is worth keeping.
ΓòÉΓòÉΓòÉ 12. Tradeoffs ΓòÉΓòÉΓòÉ
When PMsndX is operating on a sample for the clipboard, playback, or the tools,
it stores the entire sample in memory. This has the advantage that the program
can double buffer the sample for faster operation; but, it has the disadvantage
that it can take up a tremendous amount of memory to hold large samples.
PMsndX provides the user with a simple interface at the expense of resources on
the host computer.
ΓòÉΓòÉΓòÉ 13. Copyright ΓòÉΓòÉΓòÉ
The author makes NO WARRANTY or representation, either expressed or implied,
with respect to PMsndX, its quality, accuracy, merchantability, or fitness for
a particular purpose. This software is provided "AS IS" and you, its user,
assume the entire risk as to its quality and accuracy.
This software is copyright (C) 1994, William S. Hiles. All rights Reserved
except as specified below.
Permission is hereby granted to use, copy, and distribute this software (or
portions thereof) for any purpose, without fee, subject to these conditions:
(1) The seven files, pmsndx.exe, pmsndx.hlp, readme.txt, history.txt,
license.txt, order.txt and file_id.diz must always be included during
distribution. Any alterations to the files must be clearly documented. No
changes may be made to the About screen or any of the copyright information.
(2) Permission for use of this software is granted only if the user accepts
full responsibility for any undesirable consequences. The author accepts NO
LIABILITY for damages of any kind.
(3) Permission is not granted for the use of the author's name or company name
in advertising or publicity relating to this software or products derived from
it.
(4) Users are granted permission to collect fees for the distribution of
PMsndX, (such as BBS's that have a membership fee or a downloading charge, or
FTP sites that sell cdrom versions of their archives) but users are
specifically prohibited from selling PMsndX as a product or bundling PMsndX
with other products that are then sold.
(5) Unless otherwise negotiated in writing with the Author, registration
passwords for PMsndX may not be distributed in part or in whole. Registrations
are provided to individuals (or for site licensing as negotiated at time of
registration) and may not be distributed or transferred.
ΓòÉΓòÉΓòÉ 14. Acknowledgements ΓòÉΓòÉΓòÉ
Of course, IBM deserves a great deal of recognition for providing an operating
system that is robust and stable and affordable enough for the general user.
Many thanks to IBM for a fine job on creating OS/2.
A special thanks is required for Linden deCarmo for his help in understanding
the MMPM/2 portion of OS/2.
Many thanks to the fine group of people who made suggestions for corrections
and improvements in this program. This team of very patient individuals from
around the world comprised the Beta Test team. Each and every one of them
contributed in some way to the development of PMsndX. Their names are listed
below (in alphabetical order).
David Charlap
Christopher W. Curtis
Linden deCarmo
Terrance L. Eck
Scott E. Garfinkle
Jesse Gearhart
Nicole Greiber
Christopher Hemmer
Rick Huebner
Mark R. Johnson
Dov Nelkin
Lara Olofsson
Steve Patrick
Rupa Schomaker
Kamal Shakker
Brett Sherron-Ferrell
Jimmy Shaw
Kent Williams
And of course, that special person and the kids who took the many hours of
clicking away at the keyboard in stride. They stuck by me throughout this
entire thing, read all the documentation, tested the user interface, and
actually began to understand how sound really works.
Sounds like a Grammy award, huh.
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
JoeView is an excellent program written by Joe Burkley. If you ever need to
view a graphics image of virtually any format, this is the program for you!!!
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
The only exception to the operation of the control panel buttons is the HELP
button. Since the HELP is spread across all dialogs within the program, the
help system is independent of the source of its invocation. For this reason
the HELP button is not animated.
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
The .WAV format is actually defined as a RIFF file. The header and data are
very robust and there are extensions for proprietary keywords and formats.
PMsndX only supports the standard PCM format and will not load proprietary
formats. You will receive a STYLE error if it contains an unsupported format.
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
The bits in a word are stored such that the leftmost bit is stored first in the
first byte and the rightmost bit is stored last in the last byte. If a word is
composed of 16 bits, the word would be written to a file starting with bit 16
and ending in bit 0.
The number 0x1234 (0001 0010 0011 0100) is actually stored as 0001 0010 0011
0100.
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
The bits in a word are stored such that the leftmost bit is stored first in the
last byte and the rightmost bit is stored last in the first byte. If a word is
composed of 16 bits, the word would be written to a file starting with bit 7
and ending in bit 8.
The number 0x1234 (0001 0010 0011 0100) is actually stored as 0011 0100 0001
0010.
ΓòÉΓòÉΓòÉ <hidden> ΓòÉΓòÉΓòÉ
There are four methods of transitioning channels in a sample. These methods are
used in various tools to provide a smooth transition from one end of a range to
another. The four types of transitions are listed in the following text.
The first method is linear. In this case, the increase or decrease in the
volume is constant over time. This can be defined by the mathematical
equation:
volume(t) = volume(t) * t/interval
A second method for adjusting the volume is to use a geometric expression so
that the sample transitions slowly in the beginning of the range and then
changes quickly toward the end of the range. To transition a sample out slowly
over time a form of the function:
volume(t) = volume(t) * (1 - (t/interval))¤
The third method is exactly the reverse of the slow transition in which the
transition moves very quickly in the beginning of the range and then slowly
reaches the end of the range. The equation for this is as follows:
volume(t) = volume(t) * (t/interval)¤
Finally a fourth method is to have the samples make an immediate transition or
a step. In this case, the transition is made immediately at the beginning of
the range.