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1994-09-23
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120 lines
_____ ______ ______ _____ ______
/ _ \ | __ \ | __ \ / _ \ | __ \
| / \__| | | \ | | | \ | | / \__| | | | |
| \___ | |__/ | | | | | | \___ | |__| |
\___ \ | __ < | | | | \___ \ | ___/
__ \ | | | \ | | | | | __ \ | | |
| \_/ | | |__/ | | |__/ | | \ / | | |
\_____/ |______/ |______/ \_____/ |____|
Version 1.03 (9/23/94)
Written by Ethan Brodsky
Copyright 1994 by Ethan Brodsky. All rights reserved.
This library is distributed AS IS. The author specifically disclaims
any responsibility for any loss of profit or any consequential,
incidental, or other damages. SBDSP is freeware and is distributed
with full Turbo Pascal source code. You are free to incorporate parts
of the code into your own programs as long as you give credit to Ethan
Brodsky. This source code may only be distributed in it's original
form, including this documentation file.
------------------------------------------------------------------------
You may have used my SBVox and SBVoice units. They played VOC files
on a Sound Blaster using Creative Labs' CT-VOICE driver. Since they
used the CT-VOICE driver, they wouldn't work on other sound cards. The
driver needed to be included with the program, either in a separate file
or linked into the executable.
SBDSP performs the same functions as the SBVox unit without using
the CT-VOICE driver. It has only been tested on a SB16 and PAS16, but
it should work on all Sound Blaster compatible sound cards. By using
DMA transfers, it plays sound without using the CPU, saving processor
cycles for your program.
I have many improvements planned, including 16-bit sound, stereo
effects, and mixing, along with new library for FM music. But I NEED
FEEDBACK! If you use my code, tell me about it! If you make any
modifications, send them to me! If you have any suggestions for
improvements, tell me about them! If you want me to write a C version,
or a version to play WAV files, tell me!
You don't need to pay me for using this unit. All you have to do
is put my name in the credits for your product. I'd appreciate it if
you'd send me a message telling me how you used SBDSP. (If you used
it in a game, tell me where I can get it) And finally, if you ever
have a sound programming job, think of me.
You can find out most of the things you need to know in order to
use this library by looking at the PlayVOC example program, but I'll
go over it again. The first thing you need to do is to reset the DSP,
initialize SBDSP's internal variables, and install the interrupt
handler. In order to do this, you need to know the sound cards base
address, IRQ number, and 8-bit DMA channel. If this is being used
on a Sound Blaster, this information can be obtained from the BLASTER
environment variable. I don't know whether other cards use this. You
can use the EnvironmentSet function to find out if the environment
variable is set. If it is, you can call the function InitSBFromEnv.
Otherwise, you'll have to find out the settings some other way and pass
them to the InitSB function.
Use the LoadVOCFile function to allocate a sound buffer. Make sure
that you save the value returned from this function. It is the size of
the allocated buffer. It will be needed when you deallocate the buffer.
The memory needed for Sound will be allocated inside this function. You
do NOT need to allocate it beforehand.
Before you can play any sounds, you have to turn on the speaker
output. Do this by calling TurnSpeakerOn. Make sure you turn it off
at the end of the program. If you want to install a marker handler,
make sure you do it now by calling SetMarkerProc. A marker handler
will be called each time a marker block is reached. Before you install
your marker handler, save the old one using GetMarkerProc. If the value
returned is not nil, then another marker procedure has been installed.
Call it each time your marker procedure is called. This is a good
practice to get into when setting up a handler such as this. It will
make it possible to install more than one marker procedure.
To play a sound, pass a pointer to the sound buffer to PlaySound.
Any sound output in progress will be stopped. To find out if the sound
is finished, check the SoundPlaying variable. The VOC file format has
a provision for repeating sounds. The sound can be set to repeat for
a number of times (Or forever) You can break out of the loop by calling
BreakLoop. The current iteration will finish and it will continue to
the next block. When the program is completely finished playing sound,
call the ShutDownSB procedure. This will stop any sound output in
progress and remove the interrupt handler. You should deallocate all
sound buffers by using FreeBuffer. The pointer to the buffer should be
typecasted as a pointer. Make sure that you pass the buffer size that
was returned by LoadVOCFile so that the right amount of memory is
deallocated.
This library will not allow you to play 16 bit or stereo VOC files.
It will not work in protected mode since it uses DMA transfers. If you
have any other questions, feel free to ask. If you would like me to
make any modifications or a customized version of this unit to use in
your program, contact me and we can work out some arrangements.
There are several ways to contact me:
E-Mail: ericbrodsky@psl.wisc.edu (Preferred)
Phone: (608) 238-4830
Mail:
Ethan Brodsky
4010 Cherokee Dr.
Madison, WI 53711
Bug fixes and other announcements will be posted in:
comp.lang.pascal
comp.sys.ibm.pc.soundcard
comp.sys.ibm.pc.soundcard.tech
rec.games.programmer
Revision history:
1.00 - First release
1.01 - Fixed bug that caused problems with sound cards with an IRQ
settings 8-15.
1.02 - Fixed bug that caused problems initializing sound card from
the BLASTER environment variable. Improved documentation.
1.03 - Fixed a bug that caused problems initializing sound card from
the environment. The GetSettings function has an uninitialized
return value.