SunOS man pages : sbpro (7)
Devices sbpro(7D)
NAME
sbpro - Sound Blaster Pro, Sound Blaster 16, and Sound Blas-
ter AWE32 audio device driver
SYNOPSIS
sbpro:sound,sbpro
sbpro:sound,sbproctl
DESCRIPTION
The Creative Labs Sound Blaster family of audio cards
comprises DMA-capable
ISA bus plug-in cards that provide 8 and 16 bit mono and
stereo digitized sound recording and playback over a wide
range of sampling rates. Each card includes a digital sound
processor and mixing capability. Some of the cards also sup-
port more advanced audio features such as FM synthesis,
advanced signal processing, advanced wave effects, and MIDI
capability; however, the sbpro driver does not currently
support those advanced features. The features and interfaces
supported by the Solaris sbpro driver are described here and
in audio(7I).
Some Sound Blaster cards support optional non-audio capabil-
ities such as SCSI interfaces and CD-ROM interfaces. These
interfaces are not supported by the sbpro driver.
The sbpro driver also supports certain "Sound Blaster compa-
tible" audio devices, including some based on the ESS688
audio chip.
In addition, the driver supports some devices based on the
Analog Devices AD1847 and AD1848, and Crystal Semiconductor
CS4231 chips. Any CS4231-based devices supported by this
driver are programmed in AD1848 compatibility mode. There
is no special support in this driver for the more advanced
CS4231 features. This family of devices will be referred
to as the "AD184x family."
For a list of supported hardware implementations known to
work with this driver, consult the latest version of the
Solaris IA Device Configuration Guide or the Solaris IA
Driver Update Guide (available online on the World Wide Web
and other locations). The guide will contain more specific
information about the settings for each type of card or
motherboard.
APPLICATION PROGRAMMING INTERFACE
The Sound Blaster device is treated as an exclusive
resource: only one process may open the device at a time.
Since the Sound Blaster hardware does not support simul-
taneous sound input and output, the sbpro driver does not
allow the simultaneous access of the device by two
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Devices sbpro(7D)
processes, even if one tries to open it read-only and the
other write-only.
The sbpro driver will return "SUNW,sbpro" or "SUNW,sb16" in
the name field of the audio_device structure. The version
field will contain the version number of the card's
DSP chip, and the config field will be set to "SBPRO" or
"SB16". The AWE32 is currently identified as an SB16. In
all the discussion below, the Sound Blaster AWE32 behaves
the same as the Sound Blaster 16.
Audio Data Formats
The Sound Blaster Pro handles 8-bit samples. In mono mode,
audio data may be sampled at rates from 4,000 to 44,100 sam-
ples per second. In stereo mode, samples may be handled at
the rates of 11,025 and 22,050 samples per second. The SB-
16 can sample 8-bit or 16-bit mono or stereo data in the
range of 5,000 to 44,100 Hz. Devices in the AD184x family
can handle sample rates up to 48,000 Hz.
The Sound Blaster Pro hardware handles 8-bit linear samples
in excess-128 format. The Sound Blaster 16 handles that
format as well as 16-bit linear samples in two's complement
format. The sbpro driver will generate and accept data in
these formats if AUDIO_ENCODING_LINEAR is selected in the
encoding field of the audio information structure. 16 bit
precision is not available on the Sound Blaster Pro. The
sbpro driver will also accept and generate mu-law format
data (as in the Greek letter mu) if the encoding field is
set to AUDIO_ENCODING_ULAW. In this case, driver software
performs the translation between linear and mu-law formats.
mu-law encoding is designed to provide an improved signal-
to-noise ratio at low amplitude levels. To achieve best
results when using mu-law encoding, the audio record volume
should be set so that typical amplitude levels lie within
approximately three-fourths of the full dynamic range. Dev-
ices in the AD184x family support both mu-law and A-law in
hardware, and the driver allows either of those encodings to
be selected.
Audio Ports
The Sound Blaster hardware does not support multiple output
devices, so the play.port field of the audio information
structure only supports AUDIO_HEADPHONE. Output volume is
controlled by software. There is a volume control
thumbwheel on the back of the card which should be turned
all the way up to maximum; otherwise no sound may be audi-
ble.
The record.port field of the audio information structure
allows selection of which audio source is used for record-
ing, and may be set to one of AUDIO_MICROPHONE,
SunOS 5.8 Last change: 1 Jan 1997 2
Devices sbpro(7D)
AUDIO_LINE_IN, or AUDIO_CD. These select input from the
microphone jack, line-level input jack, or internal CD
input, respectively. The microphone input is treated as a
mono source by the hardware, although the microphone jack is
a stereo jack. If your microphone has a mono plug, you
should convert it to a stereo plug using an appropriate
adapter. Line and CD are stereo sources. When recording
in mono mode, both stereo channels are mixed before record-
ing.
FILES
/dev/audio
linked to s/dev/sound/0
/dev/audioctl
linked to /dev/sound/0ctl
/dev/sound/0
first audio device in the system
/dev/sound/0ctl
audio control for first audio device
/usr/demo/SOUND
audio demonstration programs
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Architecture | IA |
|_____________________________|_____________________________|
SEE ALSO
audioconvert(1), ioctl(2), attributes(5), audio(7I),
streamio(7I)
Solaris IA Device Configuration Guide
Solaris IA Driver Update Guide
Creative Labs, Inc. Sound Blaster Pro User Reference Manual
BUGS
The current driver implementation does not support the A-law
encoding mode for Sound Blaster and compatible devices.
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Devices sbpro(7D)
The conversion of mu-law to 8-bit linear format for Sound
Blaster and compatible devices can cause a loss of preci-
sion, resulting in poor sound quality in cases where the
original recording level was well below normal. If this
occurs while using the Sound Blaster 16 card, audioconvert(1)
can be used to convert the original mu-law data to
16-bit linear format before play. This will preserve all
the precision from the original mu-law sample.
SunOS 5.8 Last change: 1 Jan 1997 4
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