Devices audiohd(7D)
NAME
audiohd - HD audio controller generic codec audio core
support..
DESCRIPTION
The audiohd driver provides support for the generic codec
chips which are compatible with the Intel High-Definition
Audio Controller 1.0 specification.
API
This interface is described in the mixer(7I) and audio(7I)
manual pages.
Driver Versions
Applications that open /dev/audio may use the AUDIOGETDEV
ioctl(2) to determine which audio device is being used. The
audiohd driver returns the string SUNW,audiohd in the name
field of the audiodevice structure. The version field con-
tains a letter "a" and the config field contains the string
onboard1.
Platform Ver. Out H. Phone Spkr. In Mic. CD
x86/64 w/MCP HD audio a Y Y Y Y Y Y
Key to the above table: Ver. = Version. Out = Line Out. H.
Phone = Head Phone. Spkr = Internal Speaker. In = Line In.
Mic. = Microphone. CD = CD=ROM.
The audiohd device provides support for the internal
speaker, headphone, line out, line in, microphone and repli-
cated front panel audio parts. The play.modports and
record.modports fields of the audioinfo structure (see
audio(7I)) indicate which ports may be manipulated.
Audio Mixer Mode
This driver supports the mixer mode only. (Compat mode is
not supported).
Audio Data Formats
The audiohd device supports 16-bit linear encodings in
stereo. With the mixer enabled, a continuous range of sample
rates from 5510 to 48000 Hz is supported. With the mixer
disabled, only sample rate 48000 Hz is supported.
Sample Granularity
Because the audiohd device follows the Intel HD Audio
specification, buffers of audio data are supplied by streams
SunOS 5.11 Last change: 12 Sep 2008 1
Devices audiohd(7D)
and the reported input and output sample counts vary at any
given time from the actual sample count by no more than the
size of the buffers the audiohd driver is transferring. As a
rule, programs should not rely on the absolute accuracy of
the play.samples and record.samples fields of the audioinfo
structure.
Interrupt Rate
The driver determines how often play and record interrupts
should take place. For playing audio, this determines how
often and how much audio is requested from the audio mixer.
The impact of interrupts on recording is minimal. However,
if a very small read buffer size is set, the record inter-
rupt rate should be increased to prevent the buffer from
overflowing. You can use the /kernel/drv/audiohd.conf file
to tune the play and record interrupt rates.
Audio Status Change Notification
As described in the audio(7I) and mixer(7I) man pages, it is
possible to request asynchronous notification of changes in
the state of an audio device.
ERORS
audiohd errors are described in the audio(7I) man page.
FILES
/dev/audio Symbolic link to the system's
primary audio device. (Not
necessarily an audiohd audio
device).
/dev/audioctl Control device for the primary
audio device.
/dev/sound/0 Represents the first audio dev-
ice on the system. (Not neces-
sarily an audiohd audio device).
/dev/sound/0ctl Audio control for /dev/sound/0.
/usr/share/audio/samples Audio sample files.
/kernel/drv/audiohd.conf audiohd driver configuration
file.
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Devices audiohd(7D)
ATRIBUTES
See attributes(5) for a descriptions of the following attri-
butes:
ATRIBUTE TYPE ATRIBUTE VALUE
Architecture PC-based system
Availability SUNWaudd, SUNWauda
Stability level Evolving
SEE ALSO
mixerctl(1), sdtaudiocontrol(1), ioctl(2), attributes(5),
audio(7I), mixer(7I), streamio(7I)
Intel High-Definition Audio Specification 1.0. - Intel
Corporation
ALC880 Specification - Realtek Inc.
http:/www.sun.com/io
DIAGNOSTICS
In addition to being logged, the following messages may
appear on the system console:
initstate() play interrupt rate set too low
The play interrupt rate in audiohd.conf is set too low.
It has been reset to the rate specified in the message.
Updateaudiohd.conf to a higher play interrupt rate.
initstate() play interrupt rate set too high
The play interrupt rate set in audio810.conf is set too
high. It has been reset to the rate specified in the
message. Updateaudiohd.conf to a lower play interrupt
rate.
initstate() record interrupt rate set too low
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Devices audiohd(7D)
The record interrupt rate inaudiohd.conf is set too low.
It has been reset to the rate specified in the message.
Update audio810.conf to a higher record interrupt rate.
initstate() record interrupt rate set too high
The record interrupt rate in audiohd.conf is set too
high. It has been reset to the rate specified in the
message. Updateaudiohd.conf to a lower record interrupt
rate.
SunOS 5.11 Last change: 12 Sep 2008 4
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